1. Appendicular Skeleton

2. Appendicular Skeleton
The appendicular skeleton is composed of the 126 bones of the limbs as well as the pectoral and pelvic girdles which attach the limbs to the axial skeleton.

3. Pectoral Girdle
The pectoral or shoulder girdle consists of two bones: the clavicle and the scapula.

4. Clavicle
The clavicle or collar bone is a slender double curved bone.

5. Clavicle
The clavicle attaches medially to the sternum and laterally to the scapula.

6. Function of Clavicle
The function of the clavicle is to act as a brace to hold the arm away from the thorax and prevent shoulder dislocation.
When the clavicle is broken, the whole shoulder region caves in medially.

7. Scapula
The scapulae or shoulder blades are triangular and are commonly called “wings”.
Each scapula has a flattened body and two important processes:
The acromion process which is the enlarged end of the spine of the scapula and connects with the clavicle laterally at the acromioclavicular joint
The coracoid process which points over the top of the shoulder and anchors some of the muscles of the arm.
Two other important features:
Suprascapular notch which serves as a nerve passageway
Glenoid cavity, a shallow socket that receives the head of the arm bone

8. Scapulae

9. Functions of the Shoulder Girdle
The shoulder girdle is very light and allows the upper limb exceptionally free movement due to three factors:
Each shoulder girdle attaches to the axial skeleton at only one point: sternoclavicular joint
Loose attachment allows the scapula to slide back and forth against the thorax as muscles act.
Glenoid cavity is shallow and shoulder joint is poorly reinforced by ligaments
Drawback to free movement is that the shoulder is very easily dislocated.

10. Bones of the Upper Limbs
Thirty separate bones form the skeleton of each upper limb.
The parts of the upper limb are the: arm, forearm and hand.

11. Arm The arm is formed by a single bone, the humerus.
The humerus is a typical long bone.
The rounded head at the humerus’s proximal end fits into the glenoid cavity of the scapula.

12. Structure of the Humerus
Opposite the head, are two bony projections: the greater and lesser tubercles where muscles attach.
At the midpoint of the shaft is the deltoid tuberosity where the deltoid muscle attaches.
The radial groove runs down the posterior side of the shaft and contains the radial nerve.

13. Distal End of Humerus
At the distal end of the humerus, is the trochlea and the capitulum that articulate with the bones of the forearm.
The coronoid fossa, olecranon fossa and medial and lateral epicondyles correspond with the process of the ulna to form the elbow joint.

14. Forearm Two bones, the radius and the ulna form the forearm.
The radius is the lateral bone and the ulna is the medial bone.
The radius and ulna articulate both proximally and distally at the radioulnar joints.
The bones are connected along their length by the interosseous membrane.

15. Radius
The head of the radius forms the elbow joint with the capitulum of the humorous.
Below the head of the radius is the radial tuberosity where the tendon of the biceps muscle attaches.

16. Ulna The ulna is the medial bone in the forearm.
On its proximal end are the coronoid process and the olecranon process which grip the humerus in a joint.

17. Hand
The hand consists of the carpals, the metacarpals and the phalanges.

18. Carpal Bones
The eight carpal bones are arranged into two rows of four bones.
They form the part of the hand called the carpus or wrist.
The carpals are bound together by ligaments that restrict their movement.

19. Metacarpals and Phalanges
The metacarpals make up the palm of the hand.
They are number 1-5 starting at the thumb side.
The phalanges are the bones of the fingers.
Each hand has 14 phalanges, three in each finger and two in the thumb.

20. Bones of the Pelvic Girdle
The pelvic girdle is formed by two coxal bones, commonly called hip bones.
The bones of the pelvic girdle are large, heavy and attached securely to the axial skeleton.
The sockets that receive the thigh bones are deep and heavily reinforced with ligaments.
The main function of the pelvic girdle is to bear the weight of the upper body.
Bones of the Pelvic Girdle

21. Hip Bones
Each hip bone is formed from the fusion of three bones: the ilium, ischium and pubis.
The ilium, which connects posteriorly with the sacrum, is a large, flaring bone that forms most of the hip bone.
The ischium or “sit down bone” forms the most inferior part of the coxal bone and receives the body weight when you are sitting.
The pubic bone is the most anterior part of the coxal bone.
The ilium, ischium and pubis fuse at the acetabulum ( the socket of the thigh bone)

22. The Bony Pelvis
The coxal bones, the sacrum and the coccyx form the bony pelvis.
The function of the pelvis is to protect the reproductive organs, the bladder, and a portion of the large intestine.

23. Pelvic Regions
The bony pelvis is divided into two regions: the false pelvis and the true pelvis.
The false pelvis is superior to the true pelvis and is medial to the flaring portions of the ilia.
The true pelvis is surrounded by bone and lies inferior to the flaring parts of the ilia.
The dimensions of this cavity are important for childbirth because it must be able to allow the child’s head to pass through during birth.

24. Differences Between the Male and Female Pelvis
Female inlet is larger and more circular.
Female pelvis is shallower and bones are lighter and thinner.
Female ilia flare more laterally.
Female sacrum is shorter and less curved.
Female outlet is larger.
Female pubic arch is more rounded because of greater pubic angle.

25. Bones of the Lower Limbs
The lower limbs carry the total weight of the body and therefore are much stronger and thicker than the bones of the upper limbs.
The bones of the lower limbs include: the femur, tibia, fibula, tarsal bones, the metatarsals, and the phalanges.

26. Femur
The femur is the only bone in the thigh and is the heaviest and strongest bone in the body.
It’s proximal end has a ball-like head, a neck and four locations for muscles attachment including the gluteal tuberosity.
It articulates with the acetabulum of the hip bone and is a common site of bone fracture in old age.

27. Structure of Femur
The femur slants medially as it joins with the leg bones bringing the knees in line with the body’s center of gravity.
Distally on the femur, the lateral and medial condyles articulate with the tibia.
Anteriorly on the distal end of the femur is the smooth patellar surface which forms a joint with the patella.

28. Leg
Connected along their length by an interosseous membrane, the tibia and fibula are the two bones that form the leg.
The thin, sticklike fibula lies alongside the tibia and joints with it both proximally and distally.
The fibula does not help form the knee joint, but does form the outer part of the ankle.

29. Tibia The tibia or shinbone is larger and more medial than the fibula.
At it’s proximal end, it articulates with the femur to form the knee joint.
At it’s distal end, it forms the inner bulge of the ankle.
The anterior surface of the tibia is unprotected by muscle and forms a sharp ridge called the anterior border.

30. Foot The foot is composed of tarsals, metatarsals, and phalanges.
The foot has two important functions:
Support the body’s weight
Serve as a lever to propel the body forward when walking or running

31. Bones of the Foot
The tarsus is composed of the seven tarsal bones and forms the posterior half of the foot.
Body weight is mostly carried by the two largest tarsal bones: the calcaneus (heel bone) and the talus (ankle).
Five metatarsal bones form the sole of the foot and 14 phalanges form the toes.

32. Arches of the Foot
The bones of the foot are arranged to form three strong arches: two longitudinal (medial and lateral), and one transverse.
Ligaments bind the foot bones together and tendons of the foot muscles hold the bones in an arched position while allowing give.