4. Appendicular skeleton.pdf

Duration: 120 min College of Medicine Grades: 1 Lect. no. 3 Appendicular skeleton  The primary function is movement It includes bones of the upper and lower limbs Girdles attach the limbs to the axial skeleton Skeleton of the upper limb 1. Shoulder girdle: Clavicle, Scapula. 2....

Duration: 120 min College of Medicine Grades: 1 Lect. no. 3 Appendicular skeleton  The primary function is movement It includes bones of the upper and lower limbs Girdles attach the limbs to the axial skeleton Skeleton of the upper limb 1. Shoulder girdle: Clavicle, Scapula. 2. Arm: Humerus. 3. Forearm: Radius and Ulna. 4. Bone of the hand: Carpal, Metacarpal and Phalanges. The Pectoral Girdle Consists of: 2 clavicles 2 scapulae The Pectoral Girdle Provides attachment for many muscles that move the upper limb Girdle is very light and upper limbs are mobile Only clavicle articulates with the axial skeleton Socket of the shoulder joint (glenoid cavity) is shallow Good for flexibility – bad for stability Clavicles Provide attachment for muscles Hold the scapulae and arms laterally Transmit compression forces from the upper limbs to the axial skeleton  Clavicle (Collar bone) ▪ Two ends Lateral end join the scapulae (Acromial end). Medial end articulates with the manubrium and first rib (sternal end). ▪ Shaft Lateral one third and, Medial two third, Surfaces of the scapula A. Costal surface B. Dorsal surface divided by spine A into: i. Supra-spinatus fossa and, Acromion ii. Infra-spinatus fossa. i spine ii Greater scapular natch Angles of the scapula A ▪It has three angles B A. Superior angle B. Lateral angle (Glenoid cavity) C C. Inferior angle. Humerus ▪Is the largest bone in the upper limb. ▪Articulation superiorly with the scapula and inferiorly with the radius and ulna. ▪It has upper and lower ends and shaft. Humerus Upper extremity Shaft Distal extremity The proximal end zor la grng nachet wa dlnya nem balam to bxwena ▪The Proximal end of the humerus has: 1. Head 2. The greater tubercle 3. The lesser tubercle 4. Anatomical neck 5. Surgical neck 6. Intertubercular (bicipital) groove. Surgical neck of humerus ▪ Is the narrowest part just distal to the tubercles. Fracture of surgical neck ▪Fracture of the surgical head of the humerus may cause injure of the axillary nerve and rupture of a branch from axillary artery called profundus brachial artery. Distal end of the humerus ▪Is flatted and has: Two condyle trochlea(med) and capitulum(lat). Two epicondyle medial and lateral. Three fossa radial, coronoid fossa and olecranoon fossa. zor la grng nachet wa dlnya nem balam to bxwena The (a) anterior and (b) posterior view of the humerus. Forearm ▪The bones of the forearm are radius and ulna. ▪Proximal ends articulate with the humerus ▪Distal ends articulate with carpals Forearm Radius and ulna articulate with each other At the proximal and distal radioulnar joints The interosseous membrane Interconnects radius and ulna In anatomical position The radius is lateral and the ulna is medial The radius ▪The radius is the lateral bone of forearm. ▪Its shorter of the two forearm. ▪It has upper and lower ends and the shaft. The upper end of the radius ▪Superior surface of the head of the radius articulates with the capitulum ▪Medially – the head of the radius articulates with the radial notch of the ulna ▪Contributes heavily to the wrist joint ▪Distal radius articulates with carpal bones ▪When radius moves, the hand moves with it Ulna Main bone responsible for forming the elbow joint with the humerus Hinge joint allows forearm to bend on arm Distal end is separated from carpals by fibrocartilage Plays little to no role in hand movement The ulna ▪The ulna is the medial bone of forearm. ▪It has upper and lower and shaft  The ulna ▪The proximal end has: 1. Olecranon and coracoid processes. 2. Trochlear and radial notches. 3. Ulnar tuberosity. The lower end of the ulna has: 1. Head. 2. Styloid process. Hand Includes the following bones Carpus – wrist Metacarpals – palm Phalanges – fingers Skeleton of the hand ▪include three parts: 1. the carpal bones, phalanges 2. the metacarpal bones, Metacarpal bones 3. and phalanges. Carpal bones Carpus Forms the true wrist – the proximal region of the hand Gliding movements occur between carpals Composed of eight marble-sized bones Metacarpus Five metacarpals radiate distally from the wrist Metacarpals form the palm Numbered 1–5, beginning with the pollex (thumb) Articulate proximally with the distal row of carpals Articulate distally with the proximal phalanges Phalanges ▪There are 14 phalanges in each hand. Distal phalanges ▪Each digits has three Middle phalanges phalanx : proximal, middle and distal. Proximal phalanges EXCEPT THE THUMB. Metacarpal bones ▪Each phalanx has base and distal head, and Carpal bones shaft(body). Bones of the Lower Limbs Femur (thigh) Tibia and fibula (leg) Tarsals (ankle) Metatarsals (foot) Phalanges (toes)  Bones of the pelvic girdle ▪They composed of: 1. Two hip bones, 2. Sacrum and, 3. Coccyx, 4. Hip bones unite anteriorly with each other at symphysis pubis 5. Articulates posteriorly with the sacrum  Pelvic Girdle Consists of paired hip bones (coxal bones) Hip bones unite anteriorly with each other Articulates posteriorly with the sacrum Bony Pelvis Formed by Hip bones, sacrum, and coccyx True and False Pelves Bony pelvis is divided into two regions False (greater) pelvis – bounded by alae of the iliac bones True (lesser) pelvis – inferior to pelvic brim Forms a bowl containing the pelvic organs Hip bone ▪Composed of A. Ilium, A B. Ischium and, C. Pubis, Acetabulum is a deep D hemispherical socket on C lateral pelvic surface B , Sex difference of the pelvis ▪ Pelvic inlet is oval in female and heart shape in male due to sacral promonotary in male ▪ The ischial spines don't project medially in to the pelvis in female as they do in male. ▪ The pubic angle is 80-90 in female while is 50-60 in male The Lower Limb Carries the entire weight of the erect body Bones of lower limb are thicker and stronger than those of upper limb Divided into three segments Thigh, leg, and foot Femur Is the largest and strongest bone of the body. It has upper and lower ends and the shaft Patella Triangular sesamoid bone Imbedded in the tendon that secures the quadriceps muscles Protects the knee anteriorly Leg Refers to the region of the lower limb between the knee and the ankle Composed of the tibia and fibula Tibia – more massive medial bone of the leg Receives weight of the body from the femur Fibula –lateral bone of the leg Interosseous membrane Connects the tibia and fibula Leg Tibia articulates with femur at superior end Forms the knee joint Tibia articulates with talus at the inferior end Forms the ankle joint Fibula does not contribute to the knee joint Stabilizes the ankle joint Fibula The fibula has upper and lower ends and the shaft. The upper end has: 1. Styloid process (apex), 2. Head, 3. Neck and, 4. Tibial notch. Bones of Foot ▪ The bones of the foot include the Phalanges tarsus, metatarsus, and phalanges. ▪ There are 7 tarsal bones, ▪ 5 metatarsal bones Metatarsal bones ▪ First metatarsal supports body weight ▪ 14 phalanges. ▪ Body weight is primarily borne by the Tarsal talus and calcaneus Arches of the Foot Foot has three important arches Medial and lateral longitudinal arch Transverse arch Arches are maintained by Interlocking shapes of tarsals Ligaments and tendons Disorders of the Appendicular Skeleton Bone fractures Hip dysplasia Head of the femur slips out of acetabulum Clubfoot Soles of the feet turn medially The Appendicular Skeleton Throughout Life Growth of the appendicular skeleton Increases height Changes body proportions At birth head and trunk are 1.5 times as long as lower limbs Lower limbs grow faster than the trunk Few changes occur in adult skeleton until middle age When skeleton loses mass Osteoporosis and limb fractures become more common