Appendicular Skeleton

Composed of 126 bones of the limbs and the pectoral and pelvic girdles which attach the limbs to the axial skeleton.

Consist of two bones: clavicle and scapula

Consist of two bones: clavicle and scapula

• or collorbone
• slender,doubly curved bone
• attaches to the manubrium of the sternum at its medial or sternal end and attaches to the scapula latterally where it helps to form the shoulder joint
• the clavicle acts as a brace to hold the arm away from the top of the thorax and helps prevent shoulder dislocation
• when clavicle is broken the whole shoulder regoin caves in medially which shows how important its bracing function is

• or shoulder blades
• are trianglular and are commonly called"wings" because they flare when we move our arms posteriorly
• has a flattened body with two important processes: Acromion and coraciod
• three borders: superior, medial, lateral
• three angles: superior, inferior, lateral

• which is the enlargedend of the spine of the scapula
• connects with the clavicle latterally at the at the acromioclavicular joint

• beaklike
• pionts over the op of the shoulder and anchors some of the muscles of the arm

• medial to the coraciod process
• which serves as a nerve passageway

a shallow socket that recieves the head of the arm bone is in the lateral angle

• Each shoulder girdle ataches to the axial skeleton at only one piont
• the loose attachment of the scapula allows it to slideback and forth against the thorax as muscles act
• the gleniod cavity is shallow, and the shoulder joint is poorly reinforced by ligaments

Thirty separate bones form the skeletal framework of each upper limb

• the arm is formed by a single bone
• typicl long bone
• at its proximal endis a rounded head the fits into the shallow gleniod cavity of the scapula

• opposite of the head are two bony projections
• sites of muscle attachment

• in the midpiont of the shaft
• roughened area
• large, flashy deltoid muscle of the shoulder attaches

• runs obliquely down the posterior aspect of the shaft
• this groove marks the course of the radial nerve, an important nerve of the upper limb

at the distal end of the humerous is the medial trochlea whcih looks somewhat like a spool

 at the distal end is also the lateral ball like capitulium

above the trochlea anteriorly is a depresion called coronoid fossa

on the posterior surface is the olecranon fossa

These two depressions which are flanked by medial and lteral epicondyles allow the corresponding processes of the ulna to move freely when the elbow is bent and extended

in anatomical position the radius is on the thumbside of the forearm

Both proximally and distally the radius and ulna articulate small radioulnar joints

the two bones are connected along the entire length by flexible interosseous membrane

just below the head is the radial tuberosity where the tendon of the biceps muscle attaches

when the upper limb is in the annatomical position the ulna is the medial bone

on its proximal end are the anterior coroniod process and

posterior olecranon process

processes are separated by the trochlear notch

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• aranged in two irregular rows of four bones each form part of the carpus or wrist
• carpals are bound together by ligaments that restrict movements between them

palm of hand consist of metacarpals

are bones of the fingers

• Formed by two coxal bones
• large and heavy
• attached securly to the axial skeleton
• sockets which receive high thigh bones are deep and heavily rienforced by ligaments that attach the limbs firmly to the girdle
• bearing wieght is the most important function
• all weight of the upperbody rests on pelvis
• also organs are protected by pelvis
• each hip bone is formed by the fusion of three bones: the ilium, ischium, and pubis.

hip bones

• connects posterioly with the sacrum at the sacroiliac joint
• large, flaring bone  thatforms most of the hipbone

connects posterioly with the sacrum at the sacroiliac joint

the upper edge of the alae is called the iliac crest

the iliac crest ends anteriorly in the anterior superior spine

and posteriorly in the posterior superior spine

• "sit down" bone
• form most of the inferior part of the coxal bone

roughened area thatrecieves body wieght  when you are sitting

superior to the tuberosity is another important anatomical landmark particulary in pregnant women because it narrows the outlet of the pelvis through which the baby must pass during birth process

allows blood vessels and the large sciatic nerve to pass from the pelvisposteriorly into the though

is the most anterior part of the coxal bone

fusion of the rami of the pubic bone anteriorly and the ischium posteriorly forms a bar of bone enclosing the obturator faramen an opening which allows blood vessels and nerves to pass into the anteirior part of the thigh.

pubic bones of hip fuse anteriorly to form a cartilaginous joint

• ilium ischium and pubis fuse at the deep socket called the acetabulum
• meaning vineger cup
• this socket recieve the head of the thigh bone

• false pelvis is superior
• medial to the flaring parts of the iliia

• true pelvis is inferior
• surrounded by bone
• lies inferior to the flaring parts of the ilia and the pelvic brim

inferior opening of the pelvis

superior opening of the pelvis

• Female inlet is larger and more circular
• Female pelvis as a whole is shallower, and the bones are lighter and thinner
• The female ilia flare more laterally
• The female pubic arch is more rounded because of the angle of the pubic arch is greater
• The female sacrum is shorter and less curved
• The female ischial spines are shorter and farther apart;thus the outlet is larger

Carry are entire body weight

heavyest and strongest bone in the body

Its proximal end has a ball like head, a neck and greater and lesser trochanters

separates greater and lesser trochanters anteriorly

separates greatr and leser trochanter posteriorly

serves as a sight for muscle attachment

separate the medial and lateral condyles that articulate the tibia

Connected along there lenght by interosseous membrane

• Shinbone
• larger and more medial

roughened area on the anterior tibial surface

forms inner bulge of ankle

• sharp ridge
• unprotected by muscles

• lies along side the tibia 
• forms joints with it both proximally and distally
• thin and stick like
• fibula has no part in forming the knee joint

forms the outer part of the ankle

Forming the posterior half of the foot composed of seven tarsal bones

• seven
• body wieght is carried by two largest: calcaneus and talus

heelbone

lies between the tibia and the calcaneus

• Five
• form the sole

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