1. The Appendicular Skeleton Resident Orientation Course 2012 By Dr. Totakhil

2. THE SKELETAL SYSTEM The Appendicular Skeleton 2 pairs of limbs and 2 girdles – Pectoral (shoulder) girdle attaches upper limbs – Pelvic (hip) girdle secures lower limbs 3-Segmented limbs Upper = armLower = Leg ArmThigh ForearmLeg HandFoot

3. Pectoral Girdle (Shoulder Girdle) Clavicle – anterior: collar bone – Sternal end attaches to the manubrium medially – Acromial end articulates with the scapula laterally Scapula – posterior: shoulder blade

5. Scapula Glenoid cavity articulates with the humerus Acromium articulates with clavicle Coracoid process projects anteriorly

6. Scapulae: triangular, paired, does not connect in back (adds thoracic flexibility)

7. Upper Extremity Arm or Brachium = upper arm – Between shoulder and elbow (humerus) Forearm or Antebrachium – Radius & ulna Hand includes: – Wrist (carpus) – Palm (metacarpus) – Fingers (phalanges)

9. Arm Humerus is the only bone – Head of humerus fits into glenoid cavity of scapula – Distal & medially, trochlea articulates with the ulna – Distal & laterally capitulum articulates with the radius – Medial & lateral epicondyles

11. Muscles of the Shoulder Girdle

12. Anterior Compartment Flexors

13. Posterior Compartment Flexors

14. Forearm Consists of 2 bones the radius and ulna These bones articulate with each other proximally and distally An interosseous membrane is between these 2 bones

15. Radius Long bone situated on the lateral side of the forearm Together with the ulna, it provides attachment for the forearm muscles It consists of an articular head above, which articulates with the humerus and ulna to form the elbow joint Consists of an articular surface below, which articulates with the carpal bones to form the wrist Its lower end rotates around the ulna, whose position is fixed, to supinate and pronate the forearm and hand

16. Ulna Long bone situated on the medial side of the forearm. Together with the radius, they provide attachment for the forearm muscles Consists of a large trochlear surface above, which articulates with the humerus to form the elbow joint Consists of a small head below, which articulates with the radius to form the radioulnar joint

17. Radius is thinner proximally, like a spool of thread, and wide distally; ulna is slightly longer and looks like a monkey wrench (supposedly!)

18. Anatomic Position In the anatomical position: – Radius is lateral (thumb side); with pronation the palm faces posteriorly and the bones cross Prone: body lying face down – You can remember prone if you think about how you would fall forward onto your face if you passed out Supine: body lying face up

19. Proximal and Distal Joints of the Forearm

20. Muscles of the Forearm

22. Hand Wrist: consists of 8 carpal bones – Articulate above with the radius at the radiocarpal joint – Articulate with each other at the intercarpal joints – Articulate below with the metatarsals at the carpometacarpal joints

23. Hand Hand: consists of 5 metacarpals bones – The 1st metacarpal lies laterally, providing a base for the thumb – The 5th metacarpal lies medially, forming a base for the little finger – Proximally they articulate with the carpal bones at the carpometacarpal joints – Distally they articulate with the proximal phalanges at the metacarpophalangeal joints

24. Hand Fingers (or digits) consist of miniature long bones called phalanges: – Thumb has 2 bones: proximal and distal – The other fingers have 3 bones: proximal, middle, distal

27. Pelvic Girdle Strongly attached to axial skeleton (sacrum) More stable than pectoral (shoulder) girdle Less freedom of movement Made up of the paired hip bones – “Bony pelvis” is basin-like structure: hip bones plus the axial sacrum and coccyx

28. Male PelvisFemale Pelvis HeavierLighter and thinner Heart shaped pelvic inlet Round or oval shaped pelvic inlet Prominent muscle and ligament attachments Less prominent muscle and ligament attachments Sub-pubic angle is less than 90 degrees Sub-pubic angle is greater than 90 degrees Longer narrower pelvic cavityShorter wider pelvic cavity Differences Between Male and Female Pelvis

29. Hip bone (Os Coxae): 3 separate bones in childhood which fuse

30. Ilium Iliac crest Anterior superior iliac spine Greater sciatic notch Forms part of “acetabulum” (hip socket) which receives ball-shaped head of femur

31. Ischium Body Ramus Ischial spine Ischial tuberosity Part of hip socket

32. Pubis Joins medially in pubic symphysis Forms “obturator foramen” (large hole) with ischium Part of hip socket

33. Lower Limb Thigh: femur Leg (Lower Leg) – Tibia – Fibula Foot

35. Thigh Femur: Longest bone in the body – It consists of a head above, which articulates with the hip bone to form the hip joint – Has two large condyles below, which articulate with the tibia and patella to form the knee joint

36. Patella The patella, the largest sesamoid bone in the body It is embedded in the tendon of quadriceps femoris, and is located anterior to the knee-joint Its outline is somewhat in the shape of an inverted triangle It is separated from the femur by the suprapatellar bursa

39. Leg Tibia – The larger and medial of the two bones of the leg – It consists of two expanded extremities joined by a shaft Fibula – Lateral and more slender of the two bones of the leg

43. Foot Tarsus: 7 tarsal bones – Talus: articulates with tibia and fibula anteriorly and calcaneus posteriorly – Calcaneus: heel bone – Other bones: Cuboid, navicular, and 3 cunieforms (medial, intermediate and lateral) 5 metatarsals 14 phalanges – Great toe is called the hallux

45. Muscles of the Foot

46. Any Questions??

47. References www. rci.rutgers.edu