Ass. Prof. Faculty of Medicine Essentials of Human Anatomy The Skeletal System 3 Appendicular Skeleton Dr Fadel Naim Ass. Prof. Faculty of Medicine IUG 1

The Appendicular Skeleton Pectoral girdle Attaches the upper limbs to the trunk Pelvic girdle Attaches the lower limbs to the trunk Upper and lower limbs differ in function Share the same structural plan

Articulated Pectoral Girdle

Appendicular Skeleton Upper extremity Consists of the bones of the shoulder girdle, upper arm, lower arm, wrist, and hand Shoulder girdle Made up of scapula and clavicle Clavicle forms only bony joint with trunk, the sternoclavicular joint At its distal end, clavicle articulates with the acromion process of the scapula

Pectoral Girdle shoulder girdle clavicles scapulae supports upper limbs

Clavicles articulate with manubrium articulate with scapulae (acromion process)

Scapulae spine supraspinous fossa infraspinous fossa acromion process coracoid process glenoid cavity

The Upper Limb 30 bones form each upper limb Grouped into bones of the Arm Forearm Hand

Upper Limb Humerus Radius Ulna Carpals Metacarpals Phalanges

Humerus The long bone of the upper arm Articulates proximally with the glenoid fossa of the scapula and distally with the radius and ulna

Humerus head greater tubercle lesser tubercle anatomical neck surgical neck deltoid tuberosity capitulum trochlea coronoid fossa olecranon fossa

Radius Long bone found on thumb side of forearm Articulates proximally with capitulum of humerus and radial notch of ulna articulates distally with scaphoid and lunate carpals and with head of ulna

Radius lateral forearm bone head radial tuberosity styloid process

Ulna Long bone found on little finger side of forearm Articulates proximally with humerus and radius and distally with a fibrocartilaginous disk

Ulna medial forearm bone trochlear notch olecranon process coronoid process styloid process

Wrist and Hand Carpals (16) Metacarpals (10) Phalanges (28) trapezium trapezoid capitate scaphoid pisiform triquetrum hamate lunate Metacarpals (10) Phalanges (28) proximal phalanx middle phalanx distal phalanx

Appendicular Skeleton Lower extremity Consists of the bones of Hip Thigh lower leg Ankle Foot

Pelvis The adult pelvis is composed of four bones: the sacrum, the coccyx, and the right and left ossa coxae. Protects and supports the viscera in the inferior part of the ventral body cavity. Pelvic girdle refers to the left and right ossa coxae only.

Os Coxae Commonly referred to as the “hip bone” or innominate bone. Each is formed from three separate bones: the ilium the ischium the pubis Each articulates posteriorly with the sacrum at the sacroiliac joint.

Pelvic Girdle Coxae (2) supports trunk of body protects viscera

Coxae hip bones acetabulum ilium ischium pubis obturator foramen iliac crest iliac spines greater sciatic notch ischium ischial spines lesser sciatic notch ischial tuberosity pubis obturator foramen symphysis pubis pubic arch

Greater and Lesser Pelvis sacrum and coccyx posteriorly lower ilium, ischium, and pubis bones laterally and anteriorly Greater Pelvis lumbar vertebrae posteriorly iliac bones laterally abdominal wall anteriorly

Male and Female Pelvis Female iliac bones more flared broader hips pubic arch angle greater more distance between ischial spines and ischial tuberosities sacral curvature shorter and flatter lighter bones

Lower Limb Femur Patella Tibia Fibula Tarsals Metatarsals Phalanges

Femur longest bone of body head fovea capitis neck greater trochanter lesser trochanter linea aspera condyles epicondyles

Patella kneecap anterior surface of knee flat sesamoid bone located in a tendon

Tibia shin bone medial to fibula condyles tibial tuberosity anterior crest medial malleolus

Fibula lateral to tibia long, slender head lateral malleolus does not bear any body weight

Ankle and Foot Tarsals (14) Metatarsals (10) Phalanges (28) calcaneus talus navicular cuboid lateral cuneiform intermediate cuneiform medial cuneiform Metatarsals (10) Phalanges (28) proximal middle distal

Ankle and Foot

Arches of the Foot The sole of the foot does not rest flat on the ground. Helps it support the weight of the body. Ensures that the blood vessels and nerves on the sole of the foot are not pinched when standing.

Arches of the Foot Medial longitudinal arch extends from the heel to the big toe. Lateral longitudinal arch is not as high as the medial longitudinal arch. Transverse arch runs perpendicular to the longitudinal arches.

Hallux valgus A lateral deviation of the great toe at the metatarsophalangeal joint Its incidence is greater in women than in men Associated with badly fitting shoes. Often accompanied by the presence of a short first metatarsal bone. Once the deformity is established, it is progressively worsened by the pull of the flexor hallucis longus and extensor hallucis longus muscles.

Hallux rigidus Osteoarthritic changes in the metatarsophalangeal joint, which then becomes stiff and painful

Pes planus (flat foot) A condition in which the medial longitudinal arch is depressed or collapsed. As a result, the forefoot is displaced laterally The head of the talus is no longer supported The causes of flat foot are both congenital and acquired.

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