Block 1.4 Appendicular Skeleton PDF

Appendicular Skeleton Outline I. Pectoral girdles a. Clavicle Muscles attached to the clavicle: b. Scapula II. Upper extremity Trapezius a. Humerus...

Appendicular Skeleton Outline I. Pectoral girdles a. Clavicle Muscles attached to the clavicle: b. Scapula II. Upper extremity Trapezius a. Humerus Sternocleidomastoid b. Ulna Pectoralis Major c. Radius Subclavius Deltoid d. Carpals III. Pelvic girdle a. Ilium b. Ischium Scapula c. Pubis Flat, triangular IV. Lower extremity Level of 2nd to 7th thoracic rib a. Femur b. Tibia c. Fibula d. Patella e. Tarsals f. Metatarsals g. Phalanges h. Arches APPENDICULAR SKELETON Composed of 126 bones Pectoral girdles – clavicle, scapula Arm & forearm – humerus, ulna, radius Hands – carpal, metacarpal, phalanges Pelvis Thigh & leg – femur, tibia, patella, fibula Feet – tarsal, metatarsal, phalanges PECTORAL GIRDLE Clavicle Doubly curved bone that connects the arm to the body Medially – attached to manubrium Laterally – attached to acromion process of scapula Left clavicle:  Humerus Scapula Origin of biceps brachii Articulates with scapula at shoulder and (Shoulder blade) muscle: radius/ulna at the elbow joint. Glenoid Coracoid Process Spine Supraglenoid Acromion tubercle Important parts of Humerus Acromioclavicular Head - articulates glenoid cavity of the Joint scapula Inferior and Anatomical neck - below the head Superior Angles Surgical neck - prone to fractures (weakest region) Greater and lesser tuberosity - separated by the occipital groove Deltoid tuberosity - elevation at the lateral aspect of the shaft Spiral groove - tuberosity which accommodates the radial nerve Intertubercular Sulcus ○ Biceps tendon Coronoid Fossa Olecranon Fossa Trochlea Medial and Lateral Epicondyles UPPER EXTREMITY Called as the arm or Upper limb Upper Arm = Brachium Forearm = Antebrachium Humerus, Radius and Ulna Carpus (wrist) Hand (manus) Ulna Medial bone of forearm Important parts of Ulna Olecranon process - proximal end Trochlear notch - articulates with trochlea of humerus Styloid process - projection at the medial aspect of the head Coronoid Process Interosseous Membrane - a fibrous tissue with an oblique orientation from the radius to the ulna. It maintains the interosseous space between the radius and ulna through forearm rotation and actively transfers Radius forces from the radius to the ulna. "Funny bone” Lateral bone of forearm Radius and Ulna: Pronation & Supination Located on the lateral aspect (thumb side) Ulna and radius articulate with the humerus of the forearm at the elbow joint. Proximal end of the radius has a disc This articulation occurs in 2 places shaped head that articulates with the ○ The head of radius articulate with capitulum of the humerus and the radial capitulum of the humerus notch of the ulna ○ Trochlear notch of the ulna Inferior to the head is the constricted neck articulates with the trochlea of the A roughened area inferior to the neck on the humerus medial side, called the radial tuberosity, is a point attachment for the tendons of the biceps brachii muscle The shaft of the radius is widens distally to form a styloid process on the lateral side Important parts of Radius Head - proximal end Neck - point of attachment for the tendons of the biceps brachii muscle Shaft - widens distally to form a styloid process on the lateral side Bicipital tuberosity Insertion of biceps brachii Radial Tuberosity Radial Styloid Process Carpals LOWER EXTREMITY From lateral to medial Pelvis Scaphoid: most commonly fractured Transition between trunk and lower limbs Lunate: most commonly dislocated carpal Composed of 4 bones - 2 hip bones, bone sacrum, соссух Symphysis pubis - 2 hip bones; articulate anteriorly Carpus = Wrist Sacroiliac joints - Four proximal Four distal posterior articulation Scaphoid Trapezium Lunate Trapezoid Triquetrum Capitate Pisiform Hamate Hand = manus Five metacarpal bones (1-5) 5 fingers - labelled 1-5 Thumb = Pollex (Digit 1) ○ 2 phalangeal bones Fingers = phalanges = Digits 2-5 ○ 3 phalangeal bones ○ Proxima, middle, distal Important parts of Pelvis a. Hip Bone Innominate bone, pelvic bone or coxal bone Two hip bones join at the pubic symphysis and together with the sacrum and coccyx (the pelvic part of the spine) b. Acetabulum Concave surface of the pelvis Where the head of femur meets the pelvis forming the hip joint c. Iliac Fossa Large smooth concave surface on the internal surface of the ilium  Gives origin to the iliacus muscle d. Arcuate Line of Ilium Smooth rounded border on the internal surface of the ilium Forms part of the border of the pelvic inlet e. Iliac spine Bony projections (ASIS,AIIS) ○ ASIS: Anterior superior iliac spine ○ AIIS: Anterior inferior iliac spine Attachments for muscles and ligaments g. Greater Pelvis McBurney point - used as a guide to locate the False pelvis position of the appendix for surgery Superior pelvic portion Supports the lower abdominal viscera (e.g. intestines) h. Lesser Pelvis True pelvis Inferior portion of the pelvis Within which resides the pelvic cavity and pelvic viscera (e.g. especially in females their reproductive organs) i. Pelvic Inlet Marks the boundary between greater and lesser pelvis Boundaries: ○ Posterior: The sacral promontory (the superior portion of the sacrum). ○ Lateral: The arcuate line on the inner surface of the ilium, and the pectineal line on the superior ramus ○ Anterior: The pubic symphysis f. Ischium Forms the lower and back part of the hip bone Below the ilium and behind the pubis Forms 1/3 of the acetabulum Male pelvis: Narrow Female: Wider and broader pelvis (to accommodate giving birth) Femur Tibia Articulates with the acetabulum above to Larger than fibula form the hip joint Triangular shaft Articulates with the patella and tibia to form Medially located the knee joint “Shin bone” Longest and largest bone Important parts of Femur Proximal - head, neck,greater/lesser trochanter Head Fovea capitis - ligament head attachment, obturator artery passes here Distal - lateral/medial condyles separated by intercondylar notch Articulate with pelvis Neck ("fracture pelvis") Greater and Lesser Trochanters Shaft Lateral and medial condyles and epicondyles Intercondylar fossa Patellar Surface Fibula Laterally located No part in knee articulation but inferiorly forms the lateral malleolus of the ankle joint No part in transmission of body weight but serves as attachment for muscles Patella  Largest sesamoid bone Triangular Apex lies inferiorly Metatarsals Tarsal Intermediate region of food Only the talus articulates with tibia and 5 metatarsal bones (numbered 1-5) fibula at the ankle joint Parts of Metatarsal The foot Proximal base Metatarsals (1-5) Intermediate shaft Phalanges (3 per toe except big toe) Distal head Longitudinal Arches ○ Medial and lateral Phalanges Transverse Arch Resembles those in hand both number and arrangement Important parts of Tarsal Toes are numbered 1-5, beginning with Calcaneum - posterior part (longest & great toe, from medial to lateral strongest) Parts of Phalanges Talus Proximal base Navicular - anterior Intermediate shaft Cuboid Distal head Cuneiform bones (3) ○ except for a great big toe (hallux) ○ 3rd: Lateral that only contains the proximal & ○ 2nd: Intermediate distal phalanges ○ 1st: Medial Arches Enables to support the weight of the body Ideal distribution of body weight Fully developed by 12 to 13 yo Parts of Arches Lateral longitudinal arch Medial longitudinal arch Anterior longitudinal arch ○ found between medial & lateral aspect of the foot ○ formed by navicular, 3 cuneiforms & the bases of the 5 metatarsals