Trapezium Bone Area, Definition & Anatomy | Body Maps Your message has been sent. OK We're sorry, an error occurred. We are unable to collect your feedback at this time. However, your feedback is important to us. Please try again later. Close Trapezium There are eight carpal bones in the human wrist. They are arranged in two rows. They are located between the metacarpals and the ends of the radius and ulna bones. The trapezium rests in the row closest to the metacarpals. The scaphoid is located directly behind it, and the trapezoid is located to its side. The trapezium has three contact surfaces. These surfaces provide articulation points with other bones. The superior surface faces an upward and medial direction. It articulates with the scaphoid. The inferior surface is oval in shape. It articulates with the first metacarpal bone. The medial surface has a concave upper facet, which articulates with the trapezoid bone. The trapezium also provides an origination point for the oppenens pollicis and abductor pollicis, which help move the thumb.

Most of the muscular tissues attach to the trapezium's palmar surface. However, many ligaments also attach to its lateral surface, which is broad and rough. The dorsal surface of the trapezium is smooth. It does not serve as many functions as its counterparts. Trapezoid Bone Structure Anatomy, Function & Definition | Body Maps Your message has been sent. OK We're sorry, an error occurred. We are unable to collect your feedback at this time. However, your feedback is important to us. Please try again later. Close Trapezoid The structure of the trapezoid bone forms a firm, stationary joint with the second metacarpal base. The trapezoid is shaped like a wedge. The side of the bone that is closest to the back of the hand, referred to as dorsal, is broader than the palm-side of the bone, described as palmar. It is the least frequently injured carpal bone. The structure of the trapezoid places it in a sheltered position. The trapezoid is two times wider dorsally than it is palmarly. It has been shown that the trapezoid lacks internal anastamoses, but has several sources of blood supply.

Axial force, while applied to the second metacarpal base, can cause the trapezoid bone structure to become injured or even to fracture. People with trapezoid fractures tend to describe pain at the base of the second metacarpal. This may lead to wrist swelling and decreased range of motion. Standard treatment is not yet available as trapezoid fractures are a rare occurrence. However, sometimes a doctor will recommend the removal of a small fragment of trapezoid. In other cases, fractures of the trapezoid can involve open reduction and internal fixation. Trapezium - definition of trapezium by The Free Dictionary Trapezium - definition of trapezium by The Free Dictionary n. pl. tra·pe·zi·ums or tra·pe·zi·a (-zē-ə) 1. Mathematics a. A quadrilateral having no parallel sides. b. Chiefly British A trapezoid. 2. Anatomy A bone in the wrist at the base of the thumb.

[Originally, a quadrilateral with two parallel sides (later confused with trapezoid , originally, a quadrilateral having no parallel sides), from Modern Latin trapezium, a quadrilateral with two parallel sides, from Late Greek trapezion, from Greek, diminutive of trapeza, table : tra-, four; see kwetwer- in the Appendix of Indo-European roots + peza, foot; see ped- in the Appendix of Indo-European roots.] trapezium (trəˈpiːzɪəm) n, pl -ziums or -zia (-zɪə) 1. (Mathematics) chiefly Brit a quadrilateral having two parallel sides of unequal length. Usual US and Canadian name: trapezoid 2. (Mathematics) chiefly US and Canadian a quadrilateral having neither pair of sides parallel 3. (Anatomy) a small bone of the wrist near the base of the thumb [C16: via Late Latin from Greek trapezion, from trapeza table] traˈpezial adj n., pl. -zi•ums, -zi•a (-zi ə) 1. a.

(in Euclidean geometry) any rectilinear quadrilateral plane figure not a parallelogram. b. a quadrilateral plane figure of which no two sides are parallel. c. Brit. trapezoid (def. 1a). 2. the mammalian wrist bone that articulates with the metacarpal of the first digit or thumb. [1545–55; < New Latin < Greek trapézion kind of quadrilateral, literally, small table, diminutive of trápeza table, shortening of *tetrapeza=tetra- four + -peza foot, akin to poús; see tetra -, foot ] tra•pe′zi•al, adj. tra·pe·zi·um A four-sided figure having no parallel sides. ThesaurusAntonymsRelated WordsSynonymsLegend: 1. trapezium - a quadrilateral with no parallel sides U.S.A. , United States , United States of America , US , USA , America , the States , U.S.

- North American republic containing 50 states - 48 conterminous states in North America plus Alaska in northwest North America and the Hawaiian Islands in the Pacific Ocean; achieved independence in 1776 quadrangle , quadrilateral , tetragon - a four-sided polygon parallelogram - a quadrilateral whose opposite sides are both parallel and equal in length 2. Trapezium - a multiple star in the constellation of Orion multiple star - a system of three or more stars associated by gravity 3. trapezium - the wrist bone on the thumb side of the hand that articulates with the 1st and 2nd metacarpals Types of Joints Home > Skeletal System > Bones of the Leg and Foot > Types of Joints Types of Joints A need for strength makes the bones rigid, but if the skeleton consisted of only one solid bone, movement would be impossible. Nature has solved this problem by dividing the skeleton into many bones and creating joints where the bones intersect. Joints, also known as articulations, are strong connections that join the bones, teeth, and cartilage of the body to one another.

Each joint is specialized in its shape and structural components to control the range of motion between the parts that it connects.... Move up/down/left/right: Click compass arrows Rotate image: Click and drag in any direction, anywhere in the frame Identify objects: Click on them in the image 2D Interactive 3D Rotate & Zoom Change Anatomical System Full Types of Joints Description [Continued from above] . . . Joints may be classified functionally based upon how much movement they allow. A joint that permits no movement is known as a synarthrosis. The sutures of the skull and the gomphoses that connect the teeth to the skull are examples of synarthroses. An amphiarthrosis allows a slight amount of movement at the joint. Examples of amphiarthroses include the intervertebral disks of the spine and the pubic symphysis of the hips. The third functional class of joints is the freely movable diarthrosis joints. Diarthroses have the highest range of motion of any joint and include the elbow, knee, shoulder, and wrist. Joints may also be classified structurally based upon what kind of material is present in the joint.

Fibrous joints are made of tough collagen fibers and include the sutures of the skull and the syndesmosis joint that holds the ulna and radius of the forearm together. Cartilaginous joints are made of a band of cartilage that binds bones together. Some examples of cartilaginous joints include joints between the ribs and costal cartilage, and the intervertebral disks of the spine. The most common type of joint, the synovial joint, features a fluid-filled space between smooth cartilage pads at the end of articulating bones. Surrounding the joint is a capsule of tough dense irregular connective tissue lined with synovial membrane. The outer layer of capsule may extend into thick, strong bands called ligaments that reinforce the joint and prevent undesired movements and dislocations. Synovial membrane lining the capsule produces the oily synovial fluid that lubricates the joint and reduces friction and wear. There are many different classes of synovial joints in the body, including gliding, hinge, saddle, and ball and socket joints. Gliding joints, such as the ones between the carpals of the wrist, are found where bones meet as flat surfaces and allow for the bones to glide past one another in any direction.

Hinge joints, such as the elbow and knee, limit movement in only one direction so that the angle between bones can increase or decrease at the joint. The limited motion at hinge joints provides for more strength and reinforcement from the bones, muscles, and ligaments that make up the joint. Saddle joints, such as the one between the first metacarpal and trapezium bone, permit 360 degree motion by allowing the bones to pivot along two axes. The shoulder and hip joints form the only ball and socket joints in the body. These joints have the freest range of motion of any joint in the body – they are the only joints that can move in a full circle and rotate around their axis. However, the drawback to the ball and socket joint is that its free range of motion makes it more susceptible to dislocation than less mobile joints. Prepared by Tim Taylor, Anatomy and Physiology Instructor Carpal bones | Wrist bones Carpal bones | Wrist bones Carpal bones Introduction: Bones of the wrist are called carpal bones. They are small bones, 8 in number that make synovial joints with each other and thus add to the mobility of human hand.

The carpal bones are arranged in two rows: First (Proximal) Row: The first or proximal row is made of: (from radial to ulnar side) Scaphoid The second or distal row is made of: (from radial to ulnar side) Trapezium Carpal bones of Proximal row: Scaphoid: The scaphoid is the largest and the most lateral bone of the first row. Lunate: Named because of its deeply excavated form, the lunate lies between the scaphoid on the lateral side and the triquetral on the medial side. Triquetral (Cuneiform): This bone may be recognized by the small oval or circular facet for the pisiform on its anterior surface. The bone is placed obliquely, so that its surfaces cannot be accurately described as distal, proximal, etc. It is attached to Lunate on the lateral side and pisiform of the antero-medial side. Pisiform: About the size and shape of a large pea, the pisiform bone rests on the anterior surface of the triquetral, with which it articulates by an oval or circular facet on its dorsal aspect.

Carpal Bones of Distal row: Trapezium: The trapezium is the most lateral bone of the distal row of the carpus. It may be readily recognized by the oval saddle-shaped facet on its distal surface for articulation with the metacarpal bone of the thumb. Trapezoid Bone: With the exception of the pisiform, the Trapezoid is the smallest of the carpal bones. Its rough anterior surface is small and pentagonal in outline. Capitate: This is the largest of the carpal bones. Its anterior surface is rough and rounded. The proximal portion of the bone forms the head, and is furnished with convex articular facets which fit into the hollows on the medial surface of the scaphoid and distal surface of the lunate. Hamate: The hamate can be readily distinguished by the hook-like process (hamulus) which projects from the distal and medial aspect of its anterior surface. The Carpus as a whole: When the carpal bones are articulated together they form a bony mass, the dorsal surface of which is convex from side to side. Anteriorly they present a grooved appearance, concave from side to side.

This arrangement is further emphasized by the forward projection, on the medial side, of the pisiform and hamate, while laterally the tuberosity of the scaphoid and the ridge of the trapezius help to deepen the furrow by their elevation. To these four points the transverse carpal ligament is attached, which stretches across from side to side, and thus converts the furrow into a canal. Ossification of Carpal bones: At birth the carpus is entirely cartilaginous. Different bones of the carpus take different length of time to ossify. The following data shows the time taken by each bone to ossify. Capitate = 11 to 12 months Hamate = 12 to 14 months Triquetral = 3 years Lunate = 5 to 6 years Traprzium = 6 years Trapezoid = 6 to 7 years Pisiform = 10 to 12 years Share this page: Your Bones Your Bones Tus huesos Think back to last Halloween for a minute. Wherever you looked, there were vampires, ghosts, or bony skeletons grinning back at you.

Vampires and ghosts don't really exist, but skeletons sure do! Every single person has a skeleton made up of many bones. These bones give your body structure, let you move in many ways, protect your internal organs, and more. It's time to look at all your bones — the adult human body has 206 of them! What Are Bones Made Of? If you've ever seen a real skeleton or fossil in a museum, you might think that all bones are dead. Although bones in museums are dry, hard, or crumbly, the bones in your body are different. The bones that make up your skeleton are all very much alive, growing and changing all the time like other parts of your body. Almost every bone in your body is made of the same materials: The outer surface of bone is called the periosteum (say: pare-ee-OSS-tee-um). It's a thin, dense membrane that contains nerves and blood vessels that nourish the bone. The next layer is made up of compact bone. This part is smooth and very hard. It's the part you see when you look at a skeleton.

Within the compact bone are many layers of cancellous (say: KAN-sell-us) bone, which looks a bit like a sponge. Cancellous bone is not quite as hard as compact bone, but it is still very strong. In many bones, the cancellous bone protects the innermost part of the bone, the bone marrow (say: MAIR-oh). Bone marrow is sort of like a thick jelly, and its job is to make blood cells. continue How Bones Grow When you were a baby, you had tiny hands, tiny feet, and tiny everything! Slowly, as you grew older, everything became a bit bigger, including your bones. A baby's body has about 300 bones at birth. These eventually fuse (grow together) to form the 206 bones that adults have. Some of a baby's bones are made entirely of a special material called cartilage (say: KAR-tel-ij). Other bones in a baby are partly made of cartilage. This cartilage is soft and flexible. During childhood, as you are growing, the cartilage grows and is slowly replaced by bone, with help from calcium. By the time you are about 25, this process will be complete.

After this happens, there can be no more growth — the bones are as big as they will ever be. All of these bones make up a skeleton that is both very strong and very light. Your Spine Your spine is one part of the skeleton that's easy to check out: Reach around to the center of your back and you'll feel its bumps under your fingers. The spine lets you twist and bend, and it holds your body upright. It also protects the spinal cord, a large bundle of nerves that sends information from your brain to the rest of your body. The spine is special because it isn't made of one or even two bones: It's made of 26 bones in all! These bones are called vertebrae (say: VER-tuh-bray) and each one is shaped like a ring. There are different types of vertebrae in the spine and each does a different kind of job: The first seven vertebrae at the top are called the cervical (say: SIR-vih-kul) vertebrae. These bones are in the back of your neck, just below your brain, and they support your head and neck.

Your head is pretty heavy, so it's lucky to have help from the cervical vertebrae! Below the cervical vertebrae are the thoracic (say: thuh-RAS-ik) vertebrae, and there are 12 in all. These guys anchor your ribs in place. Below the thoracic vertebrae are five lumbar (say: LUM-bar) vertebrae. Beneath the lumbar vertebrae is the sacrum (say: SAY-krum), which is made up of five vertebrae that are fused together to form one single bone. Finally, all the way at the bottom of the spine is the coccyx (say: COK-siks), which is one bone made of four fused vertebrae. The bottom sections of the spine are important when it comes to bearing weight and giving you a good center of gravity. So when you pick up a heavy backpack, the lumbar vertebrae, sacrum, and coccyx give you the power. When you dance, skip, and even walk, these parts help keep you balanced. In between each vertebra (the name for just one of the vertebrae) are small disks made of cartilage.

These disks keep the vertebrae from rubbing against one another, and they also act as your spine's natural shock absorbers. When you jump in the air, or twist while slamming a dunk, the disks give your vertebrae the cushioning they need. previous continue Your Ribs Your heart, lungs, and liver are all very important, and luckily you've got ribs to keep them safe. Ribs act like a cage of bones around your chest. It's easy to feel the bottom of this cage by running your fingers along the sides and front of your body, a few inches below your heart . If you breathe in deeply, you can easily feel your ribs right in the front of your body, too. Some thin kids can even see a few of their ribs right through their skin. Your ribs come in pairs, and the left and right sides of each pair are exactly the same. Most people have 12 pairs of ribs, but some people are born with one or more extra ribs, and some people might have one pair less. All 12 pairs of ribs attach in the back to the spine, where they are held in place by the thoracic vertebrae.

The first seven pairs of ribs attach in the front to the sternum (say: STUR-num), a strong bone in the center of your chest that holds those ribs in place. The remaining sets of ribs don't attach to the sternum directly. The next three pairs are held on with cartilage to the ribs above them. The very last two sets of ribs are called floating ribs because they aren't connected to the sternum or the ribs above them. But don't worry, these ribs can't ever float away. Like the rest of the ribs, they are securely attached to the spine in the back. Your Skull Your skull protects the most important part of all, the brain. You can feel your skull by pushing on your head, especially in the back a few inches above your neck. The skull is actually made up of different bones. Some of these bones protect your brain, whereas others make up the structure of your face. If you touch beneath your eyes, you can feel the ridge of the bone that forms the hole where your eye sits. And although you can't see it, the smallest bone in your whole body is in your head, too.

The stirrup bone behind your eardrum is only .1 to .13 inches (2.5 to 3.3 millimeters) long! Want to know something else? Your lower jawbone is the only bone in your head you can move. It opens and closes to let you talk and chew food. Your skull is pretty cool, but it's changed since you were a baby. All babies are born with spaces between the bones in their skulls. This allows the bones to move, close up, and even overlap as the baby goes through the birth canal. As the baby grows, the space between the bones slowly closes up and disappears, and special joints called sutures (say: SOO-churs) connect the bones. previous continue Your Hands As you sit and type at the keyboard, while you swing on a swing, even when you pick up your lunch, you're using the bones in your fingers, hand, wrist, and arm. Each arm is attached to a shoulder blade or scapula (say: SKA-pyuh-luh), a large triangular bone on the upper back corner of each side of the ribcage.

The arm is made up of three bones: the humerus (say: HYOO-muh-rus), which is above your elbow, and the radius (say: RAY-dee-us) and ulna (say: UL-nuh), which are below the elbow. Each of these bones is wider at the ends and skinnier in the middle, to help give it strength where it meets another bone. At the end of the radius and ulna are eight smaller bones that make up your wrist. Although these bones are small, they can really move! Twist your wrist around or wave and you'll see how the wrist can move. The center part of your hand is made up of five separate bones. Each finger on your hand has three bones, except for your thumb, which has two. So between your wrists, hands, and all your fingers, you've got a grand total of 54 bones — all ready to help you grasp things, write your name, pick up the phone, or throw a softball! Your Legs Sure, your arm, wrist, hand, and finger bones are great for picking up the phone, but how are you supposed to run to answer it? Well, with the bones of the legs and feet!

Your legs are attached to a circular group of bones called your pelvis. The pelvis is a bowl-shaped structure that supports the spine. It is made up of the two large hip bones in front, and behind are the sacrum and the coccyx. The pelvis acts as a tough ring of protection around parts of the digestive system, parts of the urinary system, and parts of the reproductive system. Your leg bones are very large and strong to help support the weight of your body. The bone that goes from your pelvis to your knee is called the femur (say: FEE-mur), and it's the longest bone in your body. At the knee, there's a triangular-shaped bone called the patella (say: puh-TEL-luh), or kneecap, that protects the knee joint. Below the knee are two other leg bones: the tibia (say: TIH-bee-uh) and the fibula (say: FIH-byuh-luh). Just like the three bones in the arm, the three bones in the leg are wider at the ends than in the middle to give them strength.

The ankle is a bit different from the wrist; it is where the lower leg bones connect to a large bone in the foot called the talus (say: TAL-iss). Next to the talus are six other bones. But the main part of the foot is similar to the hand, with five bones. Each toe has three tiny bones, except for your big toe, which has just two. This brings the bone total in both feet and ankles to 52! Most people don't use their toes and feet for grabbing stuff or writing, but they do use them for two very important things: standing and walking. Without all the bones of the foot working together, it would be impossible to balance properly. The bones in the feet are arranged so the foot is almost flat and a bit wide, to help you stay upright. So the next time you're walking, be sure to look down and thank those toes! Your Joints The place where two bones meet is called a joint. Some joints move and others don't. Fixed joints are fixed in place and don't move at all. Your skull has some of these joints (called sutures, remember?), which close up the bones of the skull in a young person's head.

One of these joints is called the parieto-temporal (say: par-EYE-ih-toh TEM-puh-rul) suture — it's the one that runs along the side of the skull. Moving joints are the ones that let you ride your bike, eat cereal, and play a video game — the ones that allow you to twist, bend, and move different parts of your body. Some moving joints, like the ones in your spine, move only a little. Other joints move a lot. One of the main types of moving joints is called a hinge joint. Your elbows and knees each have hinge joints, which let you bend and then straighten your arms and legs. These joints are like the hinges on a door. Just as most doors can only open one way, you can only bend your arms and legs in one direction. You also have many smaller hinge joints in your fingers and toes. Another important type of moving joint is the ball and socket joint. You can find these joints at your shoulders and hips. They are made up of the round end of one bone fitting into a small cup-like area of another bone. Ball and socket joints allow for lots of movement in every direction.

Make sure you've got lots of room, and try swinging your arms all over the place. Have you ever seen someone put oil on a hinge to make it work easier or stop squeaking? Well, your joints come with their own special fluid called synovial fluid (say: SIH-no-vee-ul) that helps them move freely. Bones are held together at the joints by ligaments (say: LIH-guh-mints), which are like very strong rubber bands. Taking Care of Bones Your bones help you out every day so make sure you take care of them. Here are some tips: Protect those skull bones (and your brain inside!) by wearing a helmet for bike riding and other sports. When you use a skateboard, in-line skates, or a scooter, be sure to add wrist supports and elbow and knee pads. Your bones in these places will thank you if you have a fall! If you play sports like football, soccer, lacrosse, or ice hockey, always wear all the right equipment. And never play on a trampoline. Many kids end up with broken bones from jumping on them. Broken bones can eventually heal, but it takes a long time and isn't much fun while you wait.

Strengthen your skeleton by drinking milk and eating other dairy products (like low-fat cheese or frozen yogurt). They all contain calcium, which helps bones harden and become strong. Be active! Another way to strengthen your bones is through exercise like running, jumping, dancing, and playing sports. Take these steps to be good to your bones, and they will treat you right! Bone | definition of bone by Medical dictionary Bone | definition of bone by Medical dictionary Related to bone: Bone Cancer bone [bōn] 1. the hard, rigid form of connective tissue constituting most of the skeleton of vertebrates, composed chiefly of calcium salts. 2. any distinct piece of the skeleton of the body. See anatomic Table of Bones in the Appendices for regional and alphabetical listings of bones, and see color plates 1 and 2. Called also os . adj., adj bo´ny. There are 206 separate bones in the human body. Collectively they form the skeletal system , a structure bound together by ligaments at the joints and set in motion by the muscles, which are secured to the bones by means of tendons.

Bones, ligaments, muscles, and tendons are the tissues of the body responsible for supporting and moving the body. Some bones have a chiefly protective function. An example is the skull, which encloses the brain, the back of the eyeball, and the inner ear. Some, such as the pelvis, are mainly supporting structures. Other bones, such as the jaw and the bones of the fingers, are concerned chiefly with movement. The bone marrow in the center manufactures blood cells. The bones themselves act as a storehouse of calcium , which must be maintained at a certain level in the blood for the body's normal chemical functioning. Structure and Composition. Bone is not uniform in structure but is composed of several layers of different materials. The outermost layer, the periosteum, is a thin, tough membrane of fibrous tissue. It gives support to the tendons that secure the muscle to the bone and also serves as a protective sheath. This membrane encloses all bones completely except at the joints where there is a layer of cartilage. Beneath the periosteum lie the dense, hard layers of bone tissue called compact bone. Its composition is fibrous rather than solid and it gives bone its resiliency.

Encased within these layers is the tissue that makes up most of the volume of bone, called cancellous or spongy bone because it contains little hollows like those of a sponge. The innermost portion of the bone is a hollow cavity containing marrow. Blood vessels course through every layer of bone, carrying nutritive elements, oxygen, and other products. Bone tissue also contains a large number of nerves. The basic chemical in bone, which gives bone its hardness and strength, is calcium phosphate. Development. Cartilage forms the major part of bone in the very young; this accounts for the great flexibility and resiliency of the infant skeleton. Gradually, calcium phosphate collects in the cartilage, and it becomes harder and more brittle. Some of the cartilage cells break loose, so that channels develop in the bone shaft. Blood vessels enter the channels, bearing with them small cells of connective tissue, some of which become osteoblasts, cells that form true bone. The osteoblasts enter the hardened cartilage, forming layers of hard, firm bone. Other cells, called osteoclasts, work to tear down old or excess bone structure, allowing the osteoblasts to rebuild with new bone.

This renewal continues throughout life, although it slows down with age. Cartilage formation and the subsequent replacement of cartilage by hard material is the mechanism by which bones grow in size. During the period of bone growth, cartilage grows over the hardened portion of bone. In time, this layer of cartilage hardens as calcium phosphate is added, and a fresh layer grows over it, and it too hardens. The process continues until the body reaches full growth. Long bones grow in length because of special cross-sectional layers of cartilage located near the flared ends of the bone. These harden and new cartilage is produced by the same process as previously described. Bone Disorders. fracture , a break in the bone, is the most common injury to the bone; it may be closed, with no break in the skin, or open, with penetration of the skin and exposure of portions of the broken bone. osteoporosis is excessive brittleness and porosity of bone in the aged.

osteomyelitis is a bone infection similar to a boil on the skin, but much more serious because blood supply to bone is less exquisite than that to other body organs and bone metabolizes more slowly, so that the infection can destroy the bone and invade other body tissues. osteomalacia is the term used for rickets when it occurs in adults. In these diseases there is softening of the bones, due to inadequate concentration of calcium or phosphorus in the body. The usual cause is deficiency of vitamin D, which is required for utilization of calcium and phosphorus by the body. In osteitis fibrosa cystica , bone is replaced by fibrous tissue because of abnormal calcium metabolism. The condition usually is due to overactivity of the parathyroid glands. osteoma refers to abnormal new growth, either benign or malignant, of the tissue of the bones. Although it is not common, it may occur in any of the bones of the body, and at any age. alveolar bone the thin layer of bone making up the bony processes of the maxilla and mandible, surrounding and containing the teeth; it is pierced by many small blood vessels, lymphatic vessels, and nerves. bundle bone lamina dura .

cancellated bone (cancellous bone) bone composed of thin intersecting lamellae, usually found internal to compact bone. cartilage bone bone developing within cartilage, ossification taking place within a cartilage model, as opposed to membranous bone. cheek bone zygomatic bone. collar bone clavicle . compact bone bone substance that is dense and hard. cortical bone the compact bone of the shaft of a bone that surrounds the marrow cavity. cranial b's the bones that constitute the cranium , including the occipital, sphenoid, temporal, parietal, frontal, ethmoid, lacrimal, and nasal bones, the inferior nasal concha, and the vomer. Some authorities also include the maxilla, zygomatic bone, and palatine bone. See anatomic Table of Bones in the Appendices. ethmoid bone the sievelike bone that forms a roof for the nasal fossae and part of the floor of the anterior cranial fossa. See anatomic Table of Bones in the Appendices.

facial b's the bones that form the skeleton of the face, including the hyoid, palatine, and zygomatic bones, the mandible, and the maxilla. Some authorities include the lacrimal bones, nasal bones, inferior nasal concha, and vomer and exclude the hyoid bone. See anatomic Table of Bones in the Appendices. flat bone one whose thickness is slight, sometimes consisting of only a thin layer of compact bone, or of two layers with intervening cancellous bone and marrow; usually curved rather than flat. frontal bone the bone at the anterior part of the skull. See anatomic Table of Bones in the Appendices. heel bone calcaneus . hip bone the ilium, ischium, and pubis as a unit. See anatomic Table of Bones in the Appendices. hyoid bone a horseshoe-shaped bone at the base of the tongue. See anatomic Table of Bones in the Appendices. Called also lingual bone . incisive bone the portion of the maxilla bearing the incisors; developmentally, it is the premaxilla, which in humans later fuses with the maxilla, but in most other vertebrates persists as a separate bone.

innominate bone hip bone . jaw bone either the mandible (lower jaw) or the maxilla (upper jaw). See anatomic Table of Bones in the Appendices. mastoid bone mastoid part of temporal bone . membrane bone (membranous bone) bone that develops within a connective tissue membrane, in contrast to cartilage bone. occipital bone the bone constituting the back and part of the base of the skull. See anatomic Table of Bones in the Appendices. parietal bone one of two bones forming the sides and roof of the cranium. See anatomic Table of Bones in the Appendices. pterygoid bone pterygoid process . rider's bone localized ossification sometimes seen on the inner aspect of the lower end of the tendon of the adductor muscle of the thigh in horseback riders. squamous bone squamous part of temporal bone . sutural bone any of the variable and irregularly shaped bones in the sutures between the bones of the skull. Called also wormian bone . temporal bone one of two bones forming part of the lateral and inferior surfaces of the skull and containing the organs of hearing . See anatomic Table of Bones in the Appendices.

wormian bone sutural bone . zygomatic bone the quadrilateral bone that forms a cheek. See anatomic Table of Bones in the Appendices. bone (bōn), [TA] A hard connective tissue consisting of cells embedded in a matrix of mineralized ground substance and collagen fibers. The fibers are impregnated with inorganic components, including crystals of calcium phosphate, such that using X-ray defraction, they are seen to be organized in a hydroxyapatite pattern (calcium phosphate is 85% by weight) as well as calcium carbonate (10%), and magnesium; by weight, bone is composed of 65-75% inorganic and 25-35% organic material; a portion of osseous tissue of definite shape and size, forming a part of the animal skeleton; in humans there are approximately 200 distinct bones in the skeleton, not including the auditory ossicles of the tympanic cavity or the sesamoid bones other than the two patellae. A bone is enveloped by a fibrous membrane, periosteum, that covers the bone's entire surface except for the articular cartilage.

Beneath the periosteum is a dense layer, compact bone, and beneath that a cancellous layer, spongy bone. The core of a long bone is filled with marrow. bone (bōn) 1. the hard, rigid form of connective tissue constituting most of the skeleton of vertebrates, composed chiefly of calcium salts. 2. any distinct piece of the skeleton of the body. cancellous bone see lamellar b. capitate bone the bone in the distal row of carpal bones lying between the trapezoid and hamate bones. carpal bones the eight bones of the wrist (carpus), including the capitate, hamate, lunate, pisiform, scaphoid, trapezoid, and triquetral bones and the trapezium. cartilage bone bone developing within cartilage, ossification taking place within a cartilage model. cheek bone zygomatic b. compact bone see lamellar b. cortical bone the compact bone of the shaft of a bone that surrounds the marrow cavity. cuboid bone a bone on the lateral side of the tarsus between the calcaneus and the fourth and fifth metatarsal bones.

cuneiform bone, intermediate the intermediate and smallest of the three wedge-shaped tarsal bones located medial to the cuboid and between the navicular and the first three metatarsal bones. cuneiform bone, lateral the most lateral of the three wedge-shaped tarsal bones located medial to the cuboid and between the navicular and the first three metatarsal bones. cuneiform bone, medial the medial and largest of the three wedge-shaped tarsal bones located medial to the cuboid and between the navicular and the first three metatarsal bones. ethmoid bone the cubical bone located between the orbits and consisting of the lamina cribrosa, the lamina perpendicularis, and the paired lateral masses. flat bone one whose thickness is slight, sometimes consisting of only a thin layer of compact bone, or of two layers with intervening cancellous bone and marrow; usually curved rather than flat. frontal bone a single bone that closes the anterior part of the cranial cavity and forms the skeleton of the forehead; it is developed from two halves, the line of separation (the frontal suture) sometimes persisting in adult life.

funny bone the region of the median condyle of the humerus where it is crossed by the ulnar nerve. hamate bone the medial bone in the distal row of carpal bones. heel bone calcaneus . hip bone the large bone in the hip, consisting of the ilium, the ischium, and the pubic bone. hyoid bone a horseshoe-shaped bone at the base of the tongue, just superior to the thyroid cartilage. incisive bone the portion of the maxilla bearing the incisors; developmentally, it is the premaxilla, which in humans later fuses with the maxilla, but in most other vertebrates persists as a separate bone. jaw bone the mandible or maxilla, especially the mandible. jugal bone zygomatic b. lacrimal bone a thin scalelike bone at the anterior part of the medial wall of the orbit, articulating with the frontal and ethmoid bones and the maxilla and inferior nasal concha. lamellar bone the normal type of adult bone, organized in layers (lamellae), which may be parallel (cancellous b.) or concentrically arranged (compact b.). lingual bone hyoid b.

long bone a bone that has a longitudinal axis of considerable length, consisting of a body or shaft (the diaphysis) and an expanded portion (the epiphysis) at each end that is usually articular; typically found in the limbs. lunate bone the bone in the proximal row of carpal bones lying between the scaphoid and triquetral bones. malar bone zygomatic b. mastoid bone mastoid part of temporal bone ; see under part. metacarpal bones the five cylindrical bones of the hand (metacarpals), which articulate proximally with the bones of the wrist and distally with the proximal phalanges of the fingers; numbered from that articulating with the phalanx of the thumb to that articulating with the phalanx of the little finger. metatarsal bones the five bones (metatarsals) extending from the ankle to the phalanges of the toes; numbered from the most medial articulating with the phalanx of the big toe to the most lateral articulating with the phalanx of the little toe. nasal bone either of the two small, oblong bones that together form the bridge of the nose.

navicular bone the oval-shaped tarsal bone found between the talus and the three cuneiform bones. occipital bone a single trapezoid-shaped bone at the posterior inferior part of the cranium, articulating with the two parietal and two temporal bones, the sphenoid bone, and the atlas; it contains a large opening, the foramen magnum. palatine bone the irregularly shaped bone forming the posterior part of the hard palate, the lateral wall of the nasal fossa between the medial pterygoid plate and the maxilla, and the posterior part of the floor of the orbit. parietal bone either of the two quadrilateral bones forming part of the superior and lateral surfaces of the skull, and joining each other in the midline at the sagittal suture. pelvic bone hip b. petrous bone petrous part of temporal bone ; see under part. pisiform bone the medial bone of the proximal row of carpal bones. pneumatic bone bone that contains air-filled spaces. premaxillary bone premaxilla . pterygoid bone see under process .

pubic bone the anterior inferior part of the hip bone on either side, articulating with its fellow in the anterior midline at the pubic symphysis; it is a separate bone in early life. rider's bone localized ossification of the inner aspect of the lower end of the tendon of the adductor muscle of the thigh; sometimes seen in horseback riders. semilunar bone lunate b. sesamoid bones numerous ovoid nodular bones, often small, usually found embedded within a tendon or joint capsule, principally in the hands and feet; two sesamoid bones, the fabella and patella, are associated with the knee. shin bone tibia . sphenoid bone a single irregular, wedge-shaped bone at the base of the skull, forming part of the floor of the anterior, middle, and posterior cranial fossae. squamous bone squamous part of temporal bone ; see under part. sutural bone variable and irregularly shaped bones in the sutures between the bones of the skull. tail bone coccyx .

tarsal bones the seven bones of the ankle ( tarsus ), including the calcaneus, the cuboid bone, the navicular bone, the talus, and the intermediate, lateral, and medial cuneiform bones. temporal bone either of the two irregular bones forming part of the lateral surfaces and base of the skull, and containing the organs of hearing. It is divided anatomically into four parts: the mastoid, petrous, squamous, and tympanic parts. thigh bone femur . trapezoid bone the bone in the distal row of carpal bones lying between the trapezium and the capitate bone. triquetral bone the bone in the proximal row of carpal bones lying between the lunate and pisiform bones. turbinate bone any of the nasal conchae. tympanic bone tympanic part of temporal bone ; see under part. unciform bone , uncinate bone hamate b. wormian bone sutural bone . zygomatic bone the quadrangular bone of the cheek, articulating with the frontal bone, the maxilla, the zygomatic process of the temporal bone, and the greater wing of the sphenoid bone. bone n. 1.

a. The dense, semirigid, porous, calcified connective tissue forming the major portion of the skeleton of most vertebrates. It consists of a dense organic matrix and an inorganic, mineral component. b. Any of numerous anatomically distinct structures making up the skeleton of a vertebrate animal. There are more than 200 different bones in the human body. c. A piece of bone. 2. bones 5. bones The fundamental plan or design, as of the plot of a book. 6. a. bones Flat clappers made of bone or wood originally used by the end man in a minstrel show. b. Bones(used with a sing. verb) The end man in a minstrel show. 7. Vulgar Slang The penis. v. boned, boning, bones 1. To remove the bones from: bone a fish. 2. To stiffen (a piece of clothing) with stays, as of whalebone. 3. Vulgar Slang To have sexual intercourse with. Used especially of a man. v.intr. Vulgar Slang To have sexual intercourse.

bone Etymology: AS, ban 1 the dense, hard, and somewhat flexible connective tissue constituting the framework of the human skeleton. It is composed of compact osseous tissue surrounding spongy cancellous tissue permeated by many blood vessels and nerves and enclosed in membranous periosteum. 2 any single element of the skeleton, such as a rib, the sternum, or the femur. Also called (Latin) os . See also connective tissue . Structure of a long bone bone Bone that is abnormally fragile, as in osteogenesis imperfecta. cancellous bone A spongy bone in which the matrix forms connecting bars and plates, partially enclosing many intercommunicating spaces filled with bone marrow. Synonym: spongy bone carpal bone One of the eight wrist bones, which are aligned in two rows. The proximal row contains (from the thumb to the little finger) the scaphoid, lunate, triquetral, and pisiform bones. The distal row contains (from thumb to little finger) the trapezium, trapezoid, capitate, and hamate bones. cartilage bone A bone formed by endochondral ossification developing from the primary centers of bone formation.

Synonym: endochondral bone cavalry bone Clavicle. compact bone The hard, dense bone made of haversian systems that forms the surface layer of all bones and the shafts of long bones, in contrast to spongy bone that forms the bulk of the short, flat, and irregular bones and the ends of long bones. cotyloid bone A bone that forms a part of the medial portion of the acetabulum during fetal development. It subsequently fuses with the pubis. cranial bone A bone of the skull or brain case. cuboid bone The outer bone of the instep bones of the foot that articulates posteriorly with the calcaneus and anteriorly with the fourth and fifth metatarsals. cuneiform bone One of the bones of the internal, middle, and external tarsus. dermal bone Cartilage bone. ethmoid bone A complex thin-walled bone, roughly cuboidal in shape, located in the middle of the skull above the nasal cavities and below the anterior fossa of the cranial cavity.

Its flat upper surface is the cribriform plate, which forms much of the roof of the nasal cavities; its upper surface has a midline bony keel that projects up into the cranial cavity and on both sides of which are perforated valleys through which the olfactory nerves project up from the olfactory epithelium. In the midline under the cribriform plate is a mirror-image (to the crista galli) keel, the perpendicular plate, which projects down between the nasal cavities as part of the bony nasal septum. The right and left sides of the ethmoid bone are the ethmoidal labyrinths, composed of ethmoidal air cells; the inner surfaces of the labyrinths form the middle nasal conchae, while the lateral surfaces form the orbital plates, which are part of the mosaic of bones that form the inner walls of the orbits. frontal bone The forehead bone. funny bone A colloquial term for the groove along the inner back side of the elbow (behind and underneath the medial epicondyle of the humerus) in which the ulnar nerve runs.

Pressure on the groove compresses the ulnar nerve, producing a tingling discomfort on the inside of the forearm as well as the 4th and 5th fingers. greater multangular bone The first or outermost of the distal row of carpal bones. Synonym: trapezium hamate bone The most medial wrist (carpal) bone in the distal row. It has a hooked process on its palmar side. The hamate articulates with the 4th and 5th metacarpals. Synonym: hamatum ; os hamatum ; unciform bone heel bone Bone appearing as small pieces fitted together, characteristic of Paget's disease. nasal bone Either of the two small bones forming the bridge of the nose. occipital bone The bone that forms the lower, posterior skull; it articulates with the parietal and temporal bones anteriorly, and the atlas inferiorly. orbicular bone The rounded end of the long process of the incus, a middle ear ossicle. It probably represents a secondary ossification center in the long or lenticular process. palate bone Palatine bone.

palatine bone One of the bones forming the posterior part of the hard palate and lateral nasal wall between the interior pterygoid plate of the sphenoid bone and maxilla. Synonym: palate bone parietal bone One of two bones that together form the posterior roof and sides of the skull. pelvic bone Bone formed beneath the perichondrium. periosteal bone Bone formed by osteoblasts of the periosteum. ping pong bone A thin shell of osseous tissue covering a giant-cell sarcoma in a bone. pubic bone The lower anterior part of the innominate bone. It is a separate bone at birth; it begins to fuse with the ischium by age 8, and it is fully fused with the ischium and ilium by 16-18 years of age. Synonym: os pubis replacement bone Any bone that develops within cartilage. rider's bone Ossification of the distal end of the adductor muscles of the thigh, as may be seen in horseback riders. Synonym: cavalry bone sacral bone Sacrum. scaphoid bone The largest carpal bone in the first row of wristbones.

It is on the thumb side of the hand and articulates directly with the radius. bone, n 1. the material of the skeletons of the tissue composing bones. n 2. dense, hard, and slightly elastic connective tissue in which the fibers are impregnated with a form of calcium phosphate similar to hydroxyapatite. 3. the bones of the human skeleton. n 4. a single element of the skeleton such as a rib or femur. bone, alveolar n the specialized bone structure that contains the alveoli or sockets of the teeth and supports the teeth. bone, alveolar, architecture, n the structural pattern of the alveolar bone and its subjacent latticework of supporting bone. The alveolar bone is thin and compact adjacent to the periodontal ligament. The trabecular bone connects and reinforces the individual alveoli. The architecture of a bone is the result of functional stimuli to that bone; the stimuli vary according to type, intensity, and duration. bone, alveolar, metabolism, n the metabolic activity occurring within alveolar bone, which is generally slower than that occurring within metaphyseal bone but more rapid than that of diaphyseal bone.

bone apposition, n See bone deposition. bone augmentation, n a procedure used to build or enhance bone. It refers to either bone grafting or bone growing. Bone augmentation materials are classified as osseous, in which bone or bony substitutes are used to form new bone, or osseous conductive, in which these materials provide a platform for regeneration without taking part in actual bone formation. bone, basal, n the part of the mandible and maxilla from which the alveolar process develops. bone, bundle, n the bone forming the immediate bone attachment of the numerous bundles of collagen fibers of the periodontal ligament that have been incorporated into the bone. bone bur, n a drill designed to cut into bone. bone, cadaver, n bone that has been donated for medical purposes from one person to another; used especially in bone grafting procedures. See also allogenic and allografts . bone calcium content, n the amount of calcium stored in bone tissue. Plasma calcium is in constant exchange with the calcium of the extracellular fluid and bones. The parathyroid gland maintains the constancy of the calcium concentration in the plasma.

The bones serve as a reservoir of calcium and phosphate to provide for the other needs of the body and supply minerals for deposition in the skeleton. bone, cancellous (spongy bone, supporting bone, trabecular bone), n the bone that forms a trabecular network, surrounds marrow spaces that may contain either fatty or hematopoietic tissue, lies subjacent to the cortical bone, and makes up the main portion of a bone. bone, cancellous, atrophy of disuse n the wasting of bone tissue occurring with loss of function of a part (e.g., a tooth). The supporting bone assumes an osteoporotic nature, and the marrow remains fatty or hematopoietic. bone cells, n.pl the group includes osteoblasts, osteocytes, osteoclasts, and osteoprogenitor cells. bone changes, mechanical factors, n.pl the pressure and tension forces that play an important role in determining bone structure. Improperly controlled appliances can resorb bone faster than deposition can occur, causing mobile teeth and traumatic occlusion. Poor vascularity is a concomitant cause of undue pressure and tension and may inhibit repair and cause necrosis.

bone chips, n.pl the small pieces of cancellous bone generally used to fill in bony defects and precipitate recalcification. bone, compact, n the hard, dense bone composing the outer cortical layer and consisting of periosteal bone, endosteal bone, and haversian systems. bone conduction, n the most coronal portion of alveolar bone. bone cyst, n 1. a vascular cyst eccentrically placed within a bone. n 2. ostitis fibrosa cystica, a parathyroid disorder characterized by cyst formation and the replacement of bone tissue with fibrous connective tissue. bone defects, angular, n.pl the usually localized anomalies that occur in the crestal bone as the result of both periodontal inflammation and occlusive trauma. bone density, n the compactness of bone tissue. The demonstration of bone density by means of radiographs directly depends on the quantity of inorganic salts contained in the bone tissue. bone deposition, n the apposition or formation of new bone as a normal physiologic process. bone development, n B See bone, endochondral, formation; bone formation; and bone, intramembranous, formation.

bone, effect of external radiation to, n damage to the bones of adults is most often seen after heavy and localized radiation treatment. bone, endochondral n a bone that is developed in relation to antecedent cartilages (e.g., long bones, mandible). See also bone, intramembranous. bone, endochondral, formation, n a replacement of previously formed embryonic cartilage with an adult bony structure. The actual replacement of cartilage by bone is only part of the process, however; much of the bone is laid down directly external to the embryonic cartilage. See also bone, membrane, formation. bone formation, n the deposition of an organic mucopolysaccharide matrix (osteoid) that is subsequently mineralized with calcium salts. See also bone apposition and bone deposition. bone graft, autogenous n See recipient site. bone groove, n an osteotomy into or near the crest of the alveolar ridge for placement of an endosteal blade type of implant. bone groove, canted, n an osteotomy sloped to avoid the mandibular canal or keep the implant infrastructure within the medullary confines.

bone, horizontal loss of, n a resorption of bone caused by periodontal inflammation in which the bone crest remains even with the cementoenamel junctions of two adjoining teeth. The condition may be localized or generalized. Horizontal bone loss. bone, internal reconstruction of, n the formation of bone on the tensional side of the periodontal ligament with concurrent resorption from the marrow space; contralaterally, resorption of alveolar bone with apposition from the endosteum in the marrow space. bone, interproximal, n the bone that forms the septa between the teeth; consists primarily of a spongy supporting bone covered by a layer of cortical bone. See also septum, interdental. bone, intramembranous, n a bone developed within a membrane but having no associated cartilage (e.g., parietal, frontal, bones of upper face). See also bone, endochondral.

bone, intramembranous, formation, n membrane bone forms directly from the mesenchyme, first as a thin, flattened, irregular bony plate or membrane in the dermis and gradually expanding at its margins and becoming thickened by the deposition of successive layers of additional bone on the inner and outer surfaces. See also bone, endochondral, formation. bone involvement, n changes in the alveolar and supporting bone occurring as a sequel to or accompanying inflammatory or dystrophic disease; usually of a resorptive nature. n the small, fragile, paired facial bone that helps form a part of the orbital wall and also a small part of the nasal cavity. The bone has four borders and two surfaces that articulate with four other facial bones. bone lamella, n bone having the appearance of layers of thin leaves or plates. This appearance is produced by lines representing periods of inactivity of bone formation. bone, malar (zygomatic bone), frontal process of, n a prominence on the zygomatic bone (cheekbone) that forms the anterior lateral orbital wall. n a prominence on the zygomatic bone (cheekbone) that forms part of the inferior rim of the orbit and a small part of the orbital wall.

n a prominence on the inferior aspect of the zygomatic bone (cheekbone) that articulates with the zygomatic process of temporal bone to form the zygomatic arch. bone, marble, n See osteopetrosis. bone marrow, n the soft vascular tissue that fills bone cavities and cancellous bone spaces and consists primarily of fat cells, hematopoietic cells, and osteogenetic reticular cells. bone marrow transplant, n the transplantation of bone marrow from healthy donors to stimulate production of formed blood cells. It is used in treatment of hematopoietic or lymphoreticular diseases such as aplastic anemia, leukemia, immune deficiency syndromes, and acute radiation syndrome. bone membranes, n.pl the membrane structures associated with the growth, development, and repair of bone. They include the periosteum, a connective tissue layer adjacent to bone surfaces; periodontal ligament, a modified periosteum associated with tooth structure; and endosteum, a thin layer of connective tissue lining the walls of the bone marrow spaces. bone, microscopic appearance of, n the composition of bone tissue as viewed under a microscope.

Microscopically, bone is composed of osteocytes embedded within lacunae in a calcified intercellular matrix. Extending from the lacunae are small canals called canaliculi, which communicate with canaliculi of adjacent lacunae. Through this system of canals, nutrient material reaches the osteocytes and provides avenues for the removal of waste products of metabolism. It is deposited in incremental layers (lamellae) around haversian canals, the lamellae toward the surface of the bone being more or less parallel to it. bone mineral content, chemistry of, n the hardness of bone results from its mineral content in the organic matrix. The minerals (commonly designated as bone salts) and the organic matrix make up the interstitial substance of bone. The bone salts consist essentially of hydroxyapatite (Ca10[PO4]6[OH2]), carbon dioxide, and water, with small amounts of other ions. bone morphogenetic protein (BMP), n See protein, bone morphogenetic (BMP). bone, normal level of, n the distance from the interdental bone crest to the cementoenamel junction in healthy teeth, usually 1 to 1.5 mm.

n the saucer-shaped cranial bone that forms the most posterior part of the skull; the spinal cord passes through the foramen magnum, an opening at its base. bone onlay, n See graft, onlay bone. bone, perichondrial n bone that is deposited in concentric layers around the long shaft of the bone in a manner similar to that of the growth of endochondral bone. bone, physical properties of, n a compact bone has the following physical characteristics: specific gravity, 1.92 to 1.99; tensile strength, 13,000 to 17,000 psi; compressive strength, 18,000 to 24,000 psi; compressive strength parallel to the long axis, 7150 psi; compressive strength at right angles to the long axis, 10,800 psi. These physical characteristics make bone particularly suitable for carrying out its functions of weight bearing, leverage, and protection of vulnerable viscera. bone rarefaction n a decreased density of bone such as a decrease in weight per unit of volume. bone recession, n See recession, bone.

bone, resorption and repair of, n an adaptive physiologic mechanism occurring as long as the individual retains the natural dentition. See also resorption of bone. bone, resting lines in, n.pl the regular lines created by alternating periods of bone formation and rest, giving a tierlike appearance to lamellar bone. bone, reversal lines in, n.pl the irregular lines containing concavities directed away from the bundle bone and serving as histologic indications that resorption has taken place up to that line from the marrow side. bone sequestrum, n See bone, cancellous. bone support, n the amount of alveolar and trabecular bone adjacent to a tooth that can provide attachment, investment, and support for the tooth. bone, supporting, bone, supporting, atrophy of disuse, n See bone, cancellous, atrophy of disuse. bone surgery, n See surgery, osseous. bone, thickened margin of, n the widening of the crest of the alveolus, primarily on the buccal and lingual aspects, varying from a thick ledge to a “beading” of the bone margin; results in a more or less bulbous contour of the gingival tissue overlying it.

bone, trabecular n See bone, cancellous. bone, vertical loss of, n a resorption of bone caused by periodontal inflammation and occlusal trauma in which the bone crest is below the cementoenamel junctions of two adjoining teeth. It can be localized (mainly) or generalized. bone, vertical plates of the palatine, n the thin, oblong-shaped bone with two surfaces and four borders. It helps to form the floor of the orbit, the outer wall of the nasal cavity, and several adjoining structures. bone volume (mass), age-affecting, n decreases that occur in human body bone mass after age 40. Diet and exercise may be contributing factors. bone wax, n See wax, bone. bone, woven, n a character and pattern of bone resulting from the interweaving of broad bands of bone. bone(s), cranial, n the eight bones that make up the skull and protect the brain and include the ethmoid, frontal, occipital, sphenoid, two parietal, and two temporal bones. bone(s), facial, n the 14 bones that include the mandible, maxilla, frontal bones, nasal bones, and zygoma.

With the exception of the mandible, maxilla, and vomer bones, the bones of the face occur in pairs, thus accounting for facial symmetry. They provide the framework for the face, serve as entry points for the digestive and respiratory systems, and provide the attachments for the muscles controlling facial expression. bone(s), horizontal plates of palatine, n the bones that form the posterior part of the hard palate and consist of four borders and two surfaces. bone 1. the hard, rigid form of connective tissue constituting most of the skeleton of most vertebrates, composed chiefly of an organic component of collagenous matrix and cells and a mineral component of calcium phosphate and other salts. 2. any distinct piece of the skeleton of the body. For a named list of bones see Table 10. 3. describes conformation, substance, thickness and quality of bone structure in an animal, e.g. an animal with good bone. See also osseous . bone ash analysis of the degree of mineralization of bone is done by an ash analysis in which the bone is heated at 600°C until there is no further weight loss. bone atrophy see hemal arch.

chondroid bone has histological characteristics of both cartilage and bone; may develop in response to tensions from frequently changing directions. bone clamp strongly built, handheld, tong-like instrument with outcurving blades making a circle when closed for grasping a piece of bone shaft. The handles are ratcheted to give a firm grasp, and the faces of the blades have deep, crossways grooves. compact bone bone substance that is dense and noncancellous. cortical bone the compact bone of the shaft of a bone that surrounds the marrow cavity. bone cyst a discrete, grossly visible cavity, filled with fluid and often lined by a membrane. It may be located under cartilage (subchondral), be a single cavity (unicameral), filled with blood (aneurysmal) or contain epidermal cells (epidermoid). Aneurysmal bone cyst. By permission from Slatter D, Textbook of Small Animal Surgery, Saunders, 2002 decalcified bone a material for bone grafting. Prepared by treatment with hydrochloric acid, bone morphogenic protein is retained. bone density the degree of mineralization, usually demonstrable in radiographs.

bone discoloration continuous intake of tetracycline colors bone of growing animals yellow; inherited or acquired porphyria discolors bone red-brown. ectopic bone bone which develops in abnormal sites. Needs to be differentiated from ectopic ossification and ectopic mineralization. endochondral bone bone formed by the ossification of cartilage. The means of lengthening of long bones. See also enchondral ossification . entoglossal bone the bone in a bird's tongue. bone file, bone rasp see bone rasp . flat bone one whose thickness is slight, sometimes consisting of only a thin layer of compact bone, or of two layers with intervening cancellated bone and marrow; usually curved rather than flat. bone flour finely ground bone used as a mineral supplement in animal feed to supply additional calcium and phosphorus. Needs to be properly sterilized. bone fragility the ease with which bone fractures depends to a large extent on the density of its compact bone, that is its degree of mineralization, which in turn depends on a number of factors including age, nutritional adequacy, state of pregnancy and lactation and exposure to weight bearing. bone G1a protein mature bone in which the collagen fibers are in an orderly layered arrangement producing lamellae.

laminar bone the formation of bone by the periosteum in layers, sometimes more than one layer at a time, to supplement the diaphyseal expansion of the bone. Is marked in farm animals and large dogs, and serves to accommodate the skeleton to the very rapid growth of the musculature. lingual bone see hyoid bone. long bone one whose length usually exceeds its breadth and thickness and which usually bears epiphyses at each extremity during growth. Structure of typical long bone. By permission from Aspinall V, O'Reilly M, Introduction to Veterinary Anatomy and Physiology, Butterworth Heinemann, 2004 malar bone the posterior part of the petrous temporal bone; the mastoid process. bone matrix the intercellular component of bone. It includes collagen and amorphous ground substance consisting mostly of mucopolysaccharides (chondroitin sulfate). bone meal a product made from meatless bones which are crushed and sterilized. The bones are derived from boning plants and retail outlets. The bonemeal is used as stock feed, fertilizer and in a number of industries.

Care is needed in its preparation and in the selection of the bones because of the high risk of transmitting diseases including anthrax, salmonellosis, tuberculosis. A coarse grade of bone flour (see above). Prohibited from being used as a feed in many countries as part of programs to control or prevent bovine spongiform encephalopathy. membrane bone bone that develops within a connective tissue membrane. metaplastic bone bone formed by connective tissue by redifferentiation of mesenchymal cells. bone mineral principally calcium and phosphorus but includes also magnesium and, to a lesser extent, potassium and fluorine. Consisting mainly of hydrated calcium phosphate (apatite) and calcium carbonate. bone modeling the sum of the activities of the endosteum and periosteum of bone to produce bone forms. bone neoplasm includes fibroma, fibrosarcoma, chondroma, osteochondroma, chondrosarcoma, osteoma, osteosarcoma. pelvic bone hip bone. perilacunar bone low density bone around the lacunae of bone which contains much amorphous mineral. In this form the mineral is labile and therefore important in the maintenance of calcium homeostasis.

periosteal bone bone deposition by the periosteum in successive laminae; the bone formation in new bone and in a callus, beginning as fibrocellular tissue forming from the endosteum and periosteum, followed by calcification and bone formation. bone pinning sutural bones. woven bone primitive bone with coarse collagen bundles arranged in a disorderly fashion and replaced subsequently by lamellar bone. Patient discussion about bone Q. Is a bone tumor cancer? My son is 10 years old and his Doctor found a tumor on his bone in an x-ray he did to him. Is this cancer? A. A bone tumor doesn't necessarily mean cancer. It could be a benign tumor and not a cancer one. Your son's doctor may then obtain a biopsy sample of the tumor. This involves taking a small sample of the tumor that can be examined in the laboratory to determine what kind of tumor it is. The biopsy can be obtained either through a small needle (needle biopsy) or through a small incision (incisional biopsy). Q. is bone loss related to Arthritis? A. It depends on the kind of arthritis.

In some arthritic diseases there's local bone loss, and generalized bone loss (osteoporosis) may result from steroids used to treat arthritic diseases. You may read more here: Q. I have constant pain on my feet more on my bones than anything,do I have arthritis? I do already have plantar fascictis A. Chronic arthritis is a disease of the elderly and it isn't common to suffer from it in young age, however joint pain or bone pain can be caused by several other reasons, that might not be chronic, such as an infection, excessive physical activity or such. You should see a doctor to evaluate the pain and joint movement. He/ she might send you to do an x-ray to see if there's something they can see that is wrong with the joint or bone (dislocation or fracture). BBC Science & Nature - Human Body and Mind - Skeleton Layer Flexibility: Joints enable your body to move Ball and socket joints: Are the most mobile type of joint in your body Saddle joints: Enable you to grasp things Where bones meet Joints are the place where two bones meet. All of your bones, except for one (the hyoid bone in your neck), form a joint with another bone.

Joints hold your bones together and allow your rigid skeleton to move. Fixed joints Some of your joints, like those in your skull, are fixed and don't allow any movement. The bones in your skull are held together with fibrous connective tissue. Slightly movable joints Other joints, such as those between the vertebrae in your spine, which are connected to each other by pads of cartilage, can only move a small amount. Synovial joints Most of your joints are 'synovial joints'. They are movable joints containing a lubricating liquid called synovial fluid. Synovial joints are predominant in your limbs where mobility is important. Ligaments help provide their stability and muscles contract to produce movement. The most common synovial joints are listed below: Ball and socket joints, like your hip and shoulder joints, are the most mobile type of joint in the human body. They allow you to swing your arms and legs in many different directions. Ellipsoidal joints, such as the joint at the base of your index finger, allow bending and extending, rocking from side to side, but rotation is limited. Gliding joints occur between the surfaces of two flat bones that are held together by ligaments.

Some of the bones in your wrists and ankles move by gliding against each other. Hinge joints, like in your knee and elbow, enable movement similar to the opening and closing of a hinged door. The pivot joint in your neck allows you to turn your head from side to side. The only saddle joints in your body are in your thumbs. The bones in a saddle joint can rock back and forth and from side to side, but they have limited rotation.

Question: Where in the human body can you find the Trapezium bone ?
Answer: WRIST