Hello, this is Rob Swatsky from the York campus of Harrisburg area community college in York, Pennsylvania. And this is the first of a series of podcasts reviewing the bones and bony landmarks of the app andicular skeleton. And in this podcast we'll be exploring the bones of the hand, including the carpals, metacarpals, and philanges. There is a total of 27 bones in the hand, which are organized into three groups. The carpals or the wrist bones contain eight bones. The metacarpals which make up the palm contain five bones. The philanges which make up the digits or fingers, including the thumb, contain 14 bones. Let's begin with the carpals, which are the bones that make up the wrist or the carpus. These most proximal bones of the hand consist of eight pebble-like bones that are clustered together within two rows, with each row containing four bones each. One way that you can remember that the carpals are the bones of the wrist is the phrase carpenter's use their carpals. The carpals are arranged in two rows, the proximal row and the distal row. The carpals in the proximal row articulate with the ulna and the radius to form the wrist joint, while the carpals in the distal row are those nearest to the metacarpals. As you're learning to identify the carpal bones, remember that your thumb is on the lateral side of your hand, and your little finger is on the medial side of your hand. The carpals are named after their shapes, and will use this information along with a few other points about their position and other features to help remember their location. In the proximal row, starting from the lateral side, our first carpal is the scaphoid, which means ship-like. Our second carpal is the lunate, which means moon-shaped. Our third carpal is the tri-queetrum, which means three-cornerd, and our fourth and most medial carpal bone is the pisaform, which means p-shaped. The scaphoid is sort of curved like a ship's hull, and the lunate is round like the moon. The tri-queetrum is the third carpal bone in the proximal row, remember tri, for three, and the pisaform is a small round p-shaped bone. The carpals of the distal row begin with the most lateral trapezium. The trapezium is a four-sided figure where no two sides are parallel. Our second carpal is the trapezoid. The trapezoid is also a four-sided figure with two of the sides being parallel. Our third carpal is the capatate, which means head-shaped. And our fourth distal carpal, and most medial, is the hammate, which means hooked. The geometric shapes of the trapezium and trapezoid are pretty difficult to see. I would remember that the trapezium is under the thumb. Another way to remember the order is the last letter of trapezium, which is an m, as in Mary, and the trapezoid, which is a d, as in dog, m, d. You call the md if you happen to break your carpal bones. The capatate is the largest of the carpal bones, and you can see how its round head articulates with the lunate in the proximal row. You can tell the hammate by its unique hook-like process found only on the anterior side of the bone. The carpal tunnel is an interior space created by the piece of form and hammate, and the scaffoid and trapezium. This space allows passage of the flexor tendons of the fingers and thumb, as well as the median nerve. With repeated use, these tissues become inflamed, which reduces the size of this space, which leads to carpal tunnel syndrome. Just distal to the carpals are the five metacarpals, which are located in the intermediate area of the hand. Each metacarpal consists of three parts, the proximal base, the intermediate shaft, and the distal head. The base forms the carpal metacarpal joints with the carpal bones. The heads of the metacarpals form our knuckles, as well as form the metacarpal phalangeal joints with the proximal phalanges. The metacarpals are also numbered Roman numerals 1 through 5, beginning with the lateral thumb, number 1, and ending with the medial little finger number 5. The phalanges are the bones of the digits that make up the distal parts of the hand, and like the metacarpals, they're also numbered Roman numerals 1 through 5, beginning with the lateral thumb. And the individual bone of the phalanges is called a phalanges, and each phalanges consists of a proximal base, an intermediate shaft, and a distal head similar to the metacarpal bones. The thumb or polyx consists of two phalanges, a proximal and distal phalanges, where there are three phalanges in each of the other four digits. In each of the phalanges, we have articulation through the interfellangeal joints. Okay, that ends our review of the bones of the hand. I hope this podcast has been a helpful review for you. Thanks for watching. Bye!