Chapter 8 (4)

• The upper limb is divided into four regions containing a total of 30 bones per limb. (1) The Brachium (arm proper) which extends from shoulder to elbow. It contains only 1 bone—the humerus. (2)The Antebrachium (forearm) which extends from elbow to wrist and contains 2 bones—radius and ulna. (3)The Carpus (wrist) contains 8 small bones arranged in two rows. (4)The Manus (hand) has 19 bones in two groups; 5 metacarpals in the palm and 14 phalanges in the fingers.
• The Proximal end of the humerus is the point where the hemispherical head articulates with the glenoid cavity of the scapula. The humerus has an anatomical neck. It also has the greater and lesser tubercles and deltoid tuberosity. The Distal end of the humerus is the rounded capitulum that articulates with the head of the radius. The Trochlea articulates with the ulna. The distal end of the humerus has the lateral and medial epicondyles as well as lateral and medial supracondylar ridges. The olecranon fossa holds the olecranon process of the ulna. The olecranon is the elbow.
• The Radius bone has a disc-shaped head, which allows for easy rotation during pronation and supination. The superior surface of the head articulates with the capitulum on the humerus, while the side of the disc spins on the radial notch on the ulna. The bone also has a neck and radial tuberosity for the biceps muscle. The styloid process can be easily located near the thumb. Finally, the ulnar notch of the radius accommodates the head of the ulna. REMEBER radiUs is on the same side as the thUmb.

  
• The ulna is a bone in the forearm that connects the elbow to the wrist. It has several important features, including the trochlear notch which articulates with the trochlea of the humerus, the olecranon which is the bony point at the back of the elbow, and the radial notch which holds the head of the radius. The ulna also has a styloid process and an interosseous membrane, which is a ligament that attaches the radius to the ulna along the margin of each bone. REMEMBER the ulNa is on the same side as the piNky.
• The radius is thicker and bigger than the ulna.
• The Carpal Bones are eight bones that form the wrist. They allow the movements of flexion, extension, abduction, and adduction. There are two rows (four bones each); the Proximal row: scaphoid, lunate, triquetrum, and pisiform (a sesamoid developed by the age of 9 to 12 intendon of flexor carpi ulnaris muscle) and the Distal row: trapezium, trapezoid, capitate, and hamate.
• The Metacarpals are the bones of the palm. Metacarpal I is proximal to the base of the thumb. Metacarpal V proximal to the base of the little finger. The metacarpals are made up of the proximal base, body, and distal head. The phalanges are the bones of the fingers. The thumb or pollex has two phalanges; Proximal and distal phalanx. WHILE fingers have three phalanges; Proximal, middle, and distal phalanx.
• The pelvic girdle is a ring composed of three bones; Two hip (coxal) bones, also called ossa coxae or innominate bones, and One sacrum that is also part of the vertebral column. The pelvis is the pelvic girdle plus ligaments and muscles that line the pelvic cavity and form its floor.
• The sacroiliac joint joins coxal bone to vertebral column from the auricular surface of the ileum to the auricular surface of the sacrum. The pubic symphysis is the interpubic disc (of fibrocartilage) that joins pubic bones anteriorly.
• In the pelvic girdle there are the; Greater (false) pelvis that is between the flare of the hips. The lesser (true) pelvis that is narrower and below. The Pelvic brim that is a round margin that separates the two. The Pelvic inlet is an opening circumscribed by the brim that an infant’s head must pass during birth. And the Pelvic outlet which is the lower margin of the lesser pelvis.
• There are three distinct features of the hip bone; the Iliac crest: which is the superior crest of the hip. The Acetabulum: which is the hip socket. And the Obturator foramen: which is the large hole below the acetabulum. Each adult hip bone is formed by the fusion of three childhood bones: the ilium, the ischium, and the pubis.

  A) the socket where the femur goes into is the acetebulum

  B) the socket where the femur goes into is the acetebulum

  
• The pelvic girdle consists of three bones: the ilium, the ischium, and the pubis. The ilium is the largest bone in the hip and extends from the iliac crest to the center of the acetabulum. It has a greater sciatic notch and iliac fossa. The ischium is situated in the inferioposterior part of the hip and has a heavy body with a prominent spine, a lesser sciatic notch, an ischial tuberosity, and a ramus. The pubis is the most anterior portion of the hip bone and consists of a body, superior, and inferior ramus.
• The pelvic girdle in men is heavier and thicker than it is in women but in women the pelvic girdle is wider and shallower, and adapted to the needs of pregnancy and childbirth, with a larger pelvic inlet and outlet for passage of the infant’s head.
• The lower limb is made up of four regions, each containing 30 bones per limb. The femoral region, which is the thigh area, extends from the hip to the knee region. It contains the femur and patella. The crural region, which is the leg proper, extends from the knee to the ankle and contains the medial tibia and lateral fibula. The tarsal region, also known as the ankle, is the union of the crural region with the foot. The tarsal bones are considered a part of the foot. Lastly, the pedal region, which is the foot area, is composed of 7 tarsal bones, 5 metatarsals, and 14 phalanges in the toes.
• The Femur is the longest and strongest bone of the body. Its hemispherical head articulates with the acetabulum of the pelvis. The fovea capitis is the head of the femur used for attachment of a ligament. The femur has greater and lesser trochanters for muscle attachment and medial and lateral condyles and epicondyles are found distally.
• The patella is a triangular sesamoid bone that is embedded in the tendon of the knee. It is cartilaginous at birth but ossifies at age 3 to 6 years old. The base of the patella is the broad, superior portion, while the apex is the pointed, inferior portion.

  
• The tibia is a thick bone located in the medial part of the leg. It is the only bone in the crural region that bears weight. The bone features medial and lateral condyles, which are flat surfaces that articulate with the condyles of the femur. The tibial tuberosity is located at the top of the tibia and serves as an attachment point for the patellar ligament, which is a continuation of the quadriceps tendon. The medial malleolus is a bony knob located on the inside of the ankle. The tibia is THICKER AND BIGGER THAN THE FIBULA.
• The fibula is a slender, lateral strut that plays a role in stabilizing the ankle. It doesn't bear any body weight. The proximal end of the fibula is called the head, and its apex is the pointy part. On the distal end of the fibula, there is a bony knob on the lateral side of the ankle called the lateral malleolus. The interosseous membrane joins the fibula to the tibia. The fibula is SMALLER AND THINNER THAN THE TIBIA.