vania-janet/multiturn-rag-retrieval-data huggingface dataset:
Dense connective tissue
Dense connective tissue , also called dense fibrous tissue , is a type of connective tissue with fibers as its main matrix element . The fibers are mainly composed of type I collagen . Crowded between the collagen fibers are rows of fibroblasts , fiber - forming cells , that generate the fibers . Dense connective tissue forms strong , rope - like structures such as tendons and ligaments . Tendons attach skeletal muscles to bones ; ligaments connect bones to bones at joints . Ligaments are more stretchy and contain more elastic fibers than tendons . Dense connective tissue also make up the lower layers of the skin ( dermis ) , where it is arranged in sheets .
Stem cell
Stem cell Transmission electron micrograph of an adult stem cell displaying typical ultrastructural characteristics . Details Identifiers Latin Cellula praecursoria MeSH D013234 TH H1. 00.01. 0.00028 , H2. 00.01. 0.00001 FMA 63368 Anatomical terminology ( edit on Wikidata )
Human musculoskeletal system
The human musculoskeletal system ( also known as the locomotor system , and previously the activity system ) is an organ system that gives humans the ability to move using their muscular and skeletal systems . The musculoskeletal system provides form , support , stability , and movement to the body .
Spinal cord
The spinal cord ends at the level of vertebrae L1 -- L2 , while the subarachnoid space -- the compartment that contains cerebrospinal fluid -- extends down to the lower border of S2 . Lumbar punctures in adults are usually performed between L3 -- L5 ( cauda equina level ) in order to avoid damage to the spinal cord . In the fetus , the spinal cord extends the full length of the spine and regresses as the body grows .
Ground tissue
Unlike the collenchyma , mature sclerenchyma is composed of dead cells with extremely thick cell walls ( secondary walls ) that make up to 90 % of the whole cell volume . The term sclerenchyma is derived from the Greek σκληρός ( sklērós ) , meaning `` hard . '' It is the hard , thick walls that make sclerenchyma cells important strengthening and supporting elements in plant parts that have ceased elongation . The difference between fibers and sclereids is not always clear : transitions do exist , sometimes even within the same plant .
Thymus
Thymus of a fetus On chest X-ray , the thymus appears as a radiodense ( brighter in this image ) mass by the upper lobe of the child 's right ( left in image ) lung .
Nasal cavity
This section needs expansion . You can help by adding to it . ( February 2011 )
T cell
This process does not remove thymocytes that may cause autoimmunity . The potentially autoimmune cells are removed by the process of negative selection , which occurs in the thymic medulla ( discussed below ) .
Tooth decay
Unlike enamel , the dentin reacts to the progression of dental caries . After tooth formation , the ameloblasts , which produce enamel , are destroyed once enamel formation is complete and thus can not later regenerate enamel after its destruction . On the other hand , dentin is produced continuously throughout life by odontoblasts , which reside at the border between the pulp and dentin . Since odontoblasts are present , a stimulus , such as caries , can trigger a biologic response . These defense mechanisms include the formation of sclerotic and tertiary dentin .
Femur
One of the earliest known vertebrates to have a femur is the eusthenopteron , a prehistoric lobe - finned fish from the Late Devonian period .
Ground tissue
Collenchyma tissue is composed of elongated cells with irregularly thickened walls . They provide structural support , particularly in growing shoots and leaves . Collenchyma tissue makes up things such as the resilient strands in stalks of celery . Collenchyma cells are usually living , and have only a thick primary cell wall made up of cellulose and pectin . Cell wall thickness is strongly affected by mechanical stress upon the plant . The walls of collenchyma in shaken plants ( to mimic the effects of wind etc . ) , may be 40 -- 100 % thicker than those not shaken .
Spinal cord
The white matter is located outside of the grey matter and consists almost totally of myelinated motor and sensory axons . `` Columns '' of white matter carry information either up or down the spinal cord .
Heart
The heart functions as a pump in the circulatory system to provide a continuous flow of blood throughout the body . This circulation consists of the systemic circulation to and from the body and the pulmonary circulation to and from the lungs . Blood in the pulmonary circulation exchanges carbon dioxide for oxygen in the lungs through the process of respiration . The systemic circulation then transports oxygen to the body and returns carbon dioxide and relatively deoxygenated blood to the heart for transfer to the lungs .
Human musculoskeletal system
Ligaments may also restrict some actions : movements such as hyper extension and hyper flexion are restricted by ligaments to an extent . Also ligaments prevent certain directional movement . Bursae
Connective tissue
All connective tissue consists of three main components : fibers ( elastic and collagenous fibers ) , ground substance and cells . Not all authorities include blood or lymph as connective tissue because they lack the fiber component . All are immersed in the body water .
Spinal cord
In cross-section , the peripheral region of the cord contains neuronal white matter tracts containing sensory and motor axons . Internal to this peripheral region is the grey matter , which contains the nerve cell bodies arranged in the three grey columns that give the region its butterfly - shape . This central region surrounds the central canal , which is an extension of the fourth ventricle and contains cerebrospinal fluid .
Connective tissue
The cells of connective tissue include fibroblasts , adipocytes , macrophages , mast cells and leucocytes .
Nervous system
All bilaterian animals at an early stage of development form a gastrula , which is polarized , with one end called the animal pole and the other the vegetal pole . The gastrula has the shape of a disk with three layers of cells , an inner layer called the endoderm , which gives rise to the lining of most internal organs , a middle layer called the mesoderm , which gives rise to the bones and muscles , and an outer layer called the ectoderm , which gives rise to the skin and nervous system .
White blood cell
Histiocytes Dendritic cells ( Although these will often migrate to local lymph nodes upon ingesting antigens ) Mast cells Microglia
Femur
About the junction of the upper one - third and lower two - thirds on the intertrochanteric crest is the quadrate tubercle located . The size of the tubercle varies and it is not always located on the intertrochanteric crest and that also adjacent areas can be part of the quadrate tubercel , such as the posterior surface of the greater trochanter or the neck of the femur . In a small anatomical study it was shown that the epiphysial line passes directly through the quadrate tubercle .
Thymus
People with an enlarged thymus , particularly children , were treated with intense radiation in the years before 1950 . There is an elevated incidence of thyroid cancer and leukemia in treated individuals . Cervical
Middle ear
In reptiles , birds , and early fossil tetrapods , there is a single auditory ossicle , the columella ( that is homologous with the stapes , or `` stirrup '' of mammals ) . This is connected indirectly with the eardrum via a mostly cartilaginous extracolumella and medially to the inner - ear spaces via a widened footplate in the fenestra ovalis . The columella is an evolutionary derivative of the bone known as the hyomandibula in fish ancestors , a bone that supported the skull and braincase .
Skeletal muscle
Skeletal muscle is one of three major muscle types , the others being cardiac muscle and smooth muscle . It is a form of striated muscle tissue which is under the ' voluntary ' control of the somatic nervous system . Most skeletal muscles are attached to bones by bundles of collagen fibers known as tendons .
Pleurisy
Magnetic resonance imaging ( MRI ) , also called nuclear magnetic resonance ( NMR ) scanning , uses powerful magnets to show pleural effusions and tumors . Arterial
Heart
The pericardium is the sack that surrounds the heart . The tough outer surface of the pericardium is called the fibrous membrane . This is lined by a double inner membrane called the serous membrane that produces pericardial fluid to lubricate the surface of the heart . The part of the serous membrane attached to the fibrous membrane is called the parietal pericardium , while the part of the serous membrane attached to the heart is known as the visceral pericardium . The pericardium is present in order to lubricate its movement against other structures within the chest , to keep the heart 's position stabilised within the chest , and to protect the heart from infection .
Stem cell
When a stem cell self - renews it divides and does not disrupt the undifferentiated state . This self - renewal demands control of cell cycle as well as upkeep of multipotency or pluripotency , which all depends on the stem cell .
Femur
A femoral fracture that involves the femoral head , femoral neck or the shaft of the femur immediately below the lesser trochanter may be classified as a hip fracture , especially when associated with osteoporosis . Femur fractures can be managed in a pre-hospital setting with the use of a traction splint .
Thymus
Autoimmune diseases are caused by a hyperactive immune system that instead of attacking pathogens reacts against the host organism ( self ) causing disease . One of the primary functions of the thymus is to prevent autoimmunity through the process of central tolerance , immunologic tolerance to self antigens . APECED
Mitochondrion
The number of mitochondria in a cell can vary widely by organism , tissue , and cell type . For instance , red blood cells have no mitochondria , whereas liver cells can have more than 2000 . The organelle is composed of compartments that carry out specialized functions . These compartments or regions include the outer membrane , the intermembrane space , the inner membrane , and the cristae and matrix .
Bone age
The most commonly used method is based on a single x-ray of the left hand , fingers , and wrist . A hand is easily x-rayed with minimal radiation and shows many bones in a single view . The bones in the x-ray are compared to the bones of a standard atlas , usually `` Greulich and Pyle '' .
Epiphyseal plate
Epiphyseal plate Radiogram of distal tibia ( left ) and fibula ( right ) showing two epiphyseal plates . Light micrograph of epiphyseal plate showing the hypertrophic zone with its typical chondrocytes , matrix and three zones : maturation ( top ) , degenerative ( middle ) and provisional calcification ( bottom ) . Details Identifiers Latin lamina epiphysialis TA A02. 0.00. 020 FMA 75427 Anatomical terminology ( edit on Wikidata ) This
Skeletal muscle
Other pathways also influence adult muscle character . For example , physical force inside a muscle fiber may release the transcription factor serum response factor ( SRF ) from the structural protein titin , leading to altered muscle growth .
Stem cell
During embryonic development these inner cell mass cells continuously divide and become more specialized . For example , a portion of the ectoderm in the dorsal part of the embryo specializes as ' neurectoderm ' , which will become the future central nervous system . Later in development , neurulation causes the neurectoderm to form the neural tube . At the neural tube stage , the anterior portion undergoes encephalization to generate or ' pattern ' the basic form of the brain . At this stage of development , the principal cell type of the CNS is considered a neural stem cell . These neural stem cells are pluripotent , as they can generate a large diversity of many different neuron types , each with unique gene expression , morphological , and functional characteristics . The process of generating neurons from stem cells is called neurogenesis . One prominent example of a neural stem cell is the radial glial cell , so named because it has a distinctive bipolar morphology with highly elongated processes spanning the thickness of the neural tube wall , and because historically it shared some glial characteristics , most notably the expression of glial fibrillary acidic protein ( GFAP ) . The radial glial cell is the primary neural stem cell of the developing vertebrate CNS , and its cell body resides in the ventricular zone , adjacent to the developing ventricular system . Neural stem cells are committed to the neuronal lineages ( neurons , astrocytes , and oligodendrocytes ) , and thus their potency is restricted .
Neuron
The body contains a variety of stem cell types that have the capacity to differentiate into neurons . A report in Nature suggested that researchers had found a way to transform human skin cells into working nerve cells using a process called transdifferentiation in which `` cells are forced to adopt new identities '' .
Skeletal muscle
Bipennate arrangements are essentially `` V '' s of fibers stacked on top of each other , such as in the rectus femoris .
Femur
The lower extremity of the femur ( or distal extremity ) is larger than the upper extremity . It is somewhat cuboid in form , but its transverse diameter is greater than its antero - posterior ( front to back ) . It consists of two oblong eminences known as the condyles .
Bird feet and legs
The legs are attached to a very strong , lightweight assembly consisting of the pelvic girdle extensively fused with the uniform spinal bone called the synsacrum , which is specific to birds . The synsacrum is built from the lumbar fused with the sacral , some of the first sections of the caudal , and sometimes the last one or two sections of the thoracic vertebrae , depending on species ( birds have altogether between 10 and 22 vertebrae ) . Except for those of ostriches and rheas , pubic bones do not connect to each other , easing egg - laying .
Ear
After implantation , around the second to third week the developing embryo consists of three layers : endoderm , mesoderm and ectoderm . The first part of the ear to develop is the inner ear , which begins to form from the ectoderm around the 22nd day of the embryo 's development . Specifically , the inner ear derives from two thickenings called otic placodes on either side of the head . Each otic placode recedes below the ectoderm , forms an otic pit and then an otic vesicle . This entire mass will eventually become surrounded by mesenchyme to form the bony labyrinth .
Human musculoskeletal system
Musculoskeletal system Features of the human activity system from the 1911 Encyclopædia Britannica Identifiers MeSH D009141 FMA 7482 Anatomical terminology ( edit on Wikidata )
Bird feet and legs
The legs are attached to a strong assembly consisting of the pelvic girdle extensively fused with the uniform spinal bone ( also specific to birds ) called the synsacrum , built from some of the fused bones .
Nervous system
Glial cells ( named from the Greek for `` glue '' ) are non-neuronal cells that provide support and nutrition , maintain homeostasis , form myelin , and participate in signal transmission in the nervous system . In the human brain , it is estimated that the total number of glia roughly equals the number of neurons , although the proportions vary in different brain areas . Among the most important functions of glial cells are to support neurons and hold them in place ; to supply nutrients to neurons ; to insulate neurons electrically ; to destroy pathogens and remove dead neurons ; and to provide guidance cues directing the axons of neurons to their targets . A very important type of glial cell ( oligodendrocytes in the central nervous system , and Schwann cells in the peripheral nervous system ) generates layers of a fatty substance called myelin that wraps around axons and provides electrical insulation which allows them to transmit action potentials much more rapidly and efficiently . Recent findings indicate that glial cells , such as microglia and astrocytes , serve as important resident immune cells within the central nervous system .
Thymus
type : functional ( positive selection ) autoreactive ( negative selection ) location : cortex medulla In order to be positively - selected , thymocytes will have to interact with several cell surface molecules , MHC / HLA , to ensure reactivity and specificity . Positive selection eliminates ( by apoptosis ) weakly - binding cells and only takes strongly - or medium - binding cells . ( Binding refers to the ability of the T - cell receptors to bind to either MHC class I / II or peptide molecules . ) Negative selection is not 100 % complete . Some autoreactive T cells escape thymic censorship , and are released into the circulation . Additional mechanisms of tolerance active in the periphery exist to silence these cells such as anergy , deletion , and regulatory T cells . If these peripheral tolerance mechanisms also fail , autoimmunity may arise .
Nasal cavity
There is a rich blood supply to the nasal cavity . In some animals , such as dogs , the capillary beds flowing through the nasal cavity help cool the blood flow to the brain .
Cell wall
An extracellular matrix ( ECM ) is also present in metazoans . Its composition varies between cells , but collagens are the most abundant protein in the ECM .
Estrogen
Estrogen has anti-inflammatory properties and helps in mobilization of polymorphonuclear white blood cells or neutrophils .
Thymus
Galen was the first to note that the size of the organ changed over the duration of a person 's life .
Epiphyseal plate
A mnemonic for remembering the names of the epiphyseal plate growth zones is `` Real People Have Career Options , '' standing for : Resting zone , Proliferative zone , Hypertrophic cartilage zone , Calcified cartilage zone , Ossification zone . The growth plate is clinically relevant in that it is often the primary site for infection , metastasis , fractures and the effects of endocrine bone disorders . Masson
Myelin
Myelin is a fatty white substance that surrounds the axon of some nerve cells , forming an electrically insulating layer . It is essential for the proper functioning of the nervous system . It is an outgrowth of a type of glial cell .
Axial skeleton
Axial skeleton Diagram of the axial skeleton Details Identifiers Latin Skeleton axiale TA A02. 0.00. 009 FMA 71221 Anatomical terminology ( edit on Wikidata )
Human musculoskeletal system
Articular ( of or pertaining to the joints ) disorders are the most common . However , also among the diagnoses are : primary muscular diseases , neurologic ( related to the medical science that deals with the nervous system and disorders affecting it ) deficits , toxins , endocrine abnormalities , metabolic disorders , infectious diseases , blood and vascular disorders , and nutritional imbalances .
Connective tissue
Connective tissue Section of epididymis . Connective tissue ( blue ) is seen supporting the epithelium ( purple ) Identifiers FMA 9640 Anatomical terminology ( edit on Wikidata )
Insulin
In mammals , insulin is synthesized in the pancreas within the beta cells . One million to three million pancreatic islets form the endocrine part of the pancreas , which is primarily an exocrine gland . The endocrine portion accounts for only 2 % of the total mass of the pancreas . Within the pancreatic islets , beta cells constitute 65 -- 80 % of all the cells .
Sleep
It has been shown that sleep deprivation affects the immune system . It is now possible to state that `` sleep loss impairs immune function and immune challenge alters sleep , '' and it has been suggested that sleep increases white blood cell counts . A 2014 study found that depriving mice of sleep increased cancer growth and dampened the immune system 's ability to control cancers .
Megaloblastic anemia
Megaloblastic anemia Peripheral blood smear showing hypersegmented neutrophils , characteristic of megaloblastic anemia . Classification and external resources Specialty Hematology ICD - 10 D51. 1 , D52. 0 , D53. 1 ICD - 9 - CM 281 DiseasesDB 29507 MedlinePlus 000567 eMedicine med / 1420 ped / 2575 MeSH D000749 ( edit on Wikidata )
Lead poisoning
Lead encephalopathy is a medical emergency and causes permanent brain damage in 70 -- 80 % of children affected by it , even those that receive the best treatment . The mortality rate for people who develop cerebral involvement is about 25 % , and of those who survive who had lead encephalopathy symptoms by the time chelation therapy was begun , about 40 % have permanent neurological problems such as cerebral palsy .
Lead poisoning
One of the main causes for the pathology of lead is that it interferes with the activity of an essential enzyme called delta - aminolevulinic acid dehydratase , or ALAD ( see image of the enzyme structure ) , which is important in the biosynthesis of heme , the cofactor found in hemoglobin . Lead also inhibits the enzyme ferrochelatase , another enzyme involved in the formation of heme . Ferrochelatase catalyzes the joining of protoporphyrin and Fe to form heme . Lead 's interference with heme synthesis results in production of zinc protoporphyrin and the development of anemia . Another effect of lead 's interference with heme synthesis is the buildup of heme precursors , such as aminolevulinic acid , which may be directly or indirectly harmful to neurons .
Lead poisoning
The classic signs and symptoms in children are loss of appetite , abdominal pain , vomiting , weight loss , constipation , anemia , kidney failure , irritability , lethargy , learning disabilities , and behavioral problems . Slow development of normal childhood behaviors , such as talking and use of words , and permanent intellectual disability are both commonly seen . Although less common , it is possible for fingernails to develop leukonychia striata if exposed to abnormally high lead concentrations .
Lead poisoning
Lead poisoning is a type of metal poisoning caused by lead in the body . The brain is the most sensitive . Symptoms may include abdominal pain , constipation , headaches , irritability , memory problems , inability to have children , and tingling in the hands and feet . It causes almost 10 % of intellectual disability of otherwise unknown cause and can result in behavioral problems . Some of the effects are permanent . In severe cases anemia , seizures , coma , or death may occur .
Lead poisoning
Symptoms may be different in adults and children ; the main symptoms in adults are headache , abdominal pain , memory loss , kidney failure , male reproductive problems , and weakness , pain , or tingling in the extremities .
Spinal cord
Spinal shock and neurogenic shock can occur from a spinal injury . Spinal shock is usually temporary , lasting only for 24 -- 48 hours , and is a temporary absence of sensory and motor functions . Neurogenic shock lasts for weeks and can lead to a loss of muscle tone due to disuse of the muscles below the injured site .
Smooth muscle tissue
`` Smooth muscle condition '' is a condition in which the body of a developing embryo does not create enough smooth muscle for the gastrointestinal system . This condition is fatal .
Anemia
In cases where oral iron has either proven ineffective , would be too slow ( for example , pre-operatively ) or where absorption is impeded ( for example in cases of inflammation ) , parenteral iron can be used . The body can absorb up to 6 mg iron daily from the gastrointestinal tract . In many cases the patient has a deficit of over 1,000 mg of iron which would require several months to replace . This can be given concurrently with erythropoietin to ensure sufficient iron for increased rates of erythropoiesis .