Skeletal System 3

1. Skeletal System 3 Honors Anatomy to copy edition

2. The Appendicular Skeleton

3. The Pectoral Girdle(Shoulder) 2 pectoral girdles attach bones of upper limbs to axial skeleton each: 1 clavicle 1 scapula

4. Clavicle S-shaped, (medial ½ convex anteriorly, lateral ½ concave anteriorly) slender bone lies horizontally across anterior thorax superior to 1st rib

5. Clavicle medial end = sternal end is rounded & articulates with the manubrium @ sternoclavicular joint

6. Clavicle lateral end = acromial end is flat articulates with acromion of the scapula to form acromialclavicular joint

7. Clavicle last bone to stop growing 1 of most frequently fx’d bones (2 curves) usually from fall on outstretched arm or see compression fx in auto accidents from shoulder strap which can cause damage to median n. (between clavicle & 2nd rib)

8. Scapula aka shoulder blade, angel bone large, triangular, flat bone in superior part of posterior thorax between levels of 2nd & 7th ribs spine: prominent ridge that runs diagonally across posterior surface

9. Scapula lateral edge: acromion a flattened expanded process, easily felt as hi pt of shoulder (tailors use it as landmark to measure length of arm) glenoid cavity: inferior to acromion, smooth, shallow depression that accepts head of humerus in shoulder joint

10. Upper Limb 6 parts: Humerus Ulna Radius Carpals Metacarpals Phalanges Joints: Shoulder Elbow Wrist Hand

11. Humerus • longest & largest bone of upper limb • articulates proximally with scapula & distally with ulna & radius • head: rounded proximal end • articulates with glenoid cavity of scapula to form glenohumeral joint

12. Humerus distal end: capitulum: rounded knob on lateral aspect that articulates with head of radius trochlea: medial to capitulum, spool-shaped, articulates with ulna

13. Ulna medial aspect of forearm longer than radius proximal end: olecranon (prominence in elbow) distal end: head, styloid process (posterior)

14. Radius lateral aspect of forearm proximal end: head of radius: articulates with capitulum distal end: styloid process (palpable proximal to thumb)

15. Ulna & Radius connect @ 3 places interosseous membrane proximal end distal end

16. Carpals proximal to the hand, distal to radius & ulna 8 small bones joined by ligaments articulations w/each other called intercarpal joints

17. Metacarpals

18. Phalanges 14 bones of the digits (each hand) #’d I to V beginning with thumb thumb is the pollex has only 2 phalanges, other digits have 3 joints between phalanges called interphalangeal joints

19. Pelvic Girdle 2 hip bones (oscoxa) which unite anteriorly at pubic symphysisand posteriorly with the sacrum @ sacroiliac joint

20. Pelvic Girdle Functions: provides sturdy support for vertebral column connects lower limb to axial skeleton

21. Newborn Pelvis • 3 bones on each side: • Ilium • superior • Pubis • anterior & inferior • Ischium • posterior & inferior

22. Ilium largest of the 3 hip bones distinguishing features: Iliac Crest along superior surface Sacroiliac Joint (SI Joint) between sacrum and ilium

23. Ischium ramus of ischium fuses with pubis distinguishing features: IschialTuberosity what you feel when someone sits on your lap

24. Pubis • Acetabulum • formed by ilium, ischium, & pubis • is the “socket” half of the hip joint • Pubic Symphysis • joint between the 2 hip bones

25. True Pelvis/ False Pelvis Pelvic Brim: line that distinguishes between true & false palvis

26. Male Pelvis • generally male bone heavier & stronger & have larger surface marker (because larger muscles attach) • Pelvis: • deeper false pelvis, smaller, narrower • pelvic brim heart-shaped • acetabulum larger, faces posterior • obturator foramen round

27. Female Pelvis • generally bones lighter & thinner • Pelvis: • false pelvis shallow, widers • pelvic brim larger, more oval • acetabulum smaller & faces anterior • obturator foramen oval

28. Lower Limb 30 bones in each: 1 femur 1 patella 1 tibia 1 fibula 7 tarsals 5 metatarsals 14 phalanges

29. Femur • longest, heaviest, & strongest bone in the body • proximally articulates with the acetabulum to form hip joint • Head of the Femur: “ball” part of joint • small, central depression: fovea capitis • Greater Trochanter • prominence felt & seen @ side of hip

30. Patella (kneecap) small, triangular, sesamoid bone develops in tendon of quadriceps femoris muscle Parts: Base: broad, superior end Apex: pointed, inferior end

31. Tibia “shin bone” larger, medial, weight-bearing bone of lower leg proximally articulates with femur & fibula distally articulates with fibula & tarsals

32. Tibia medial malleolus forms prominence that is palpable & visible on medial ankle

33. Fibula parallel & lateral to the tibia & considerably smaller head of fibula on proximal end lateral malleolus at distal end

34. Tarsals 7 bones: 1 calcaneous: heel bone, largest of the tarsals

35. Metatarsals 5 bones between tarsals & phalanges #’d I to V from medial  lateral

36. Arches of the Foot 2 arches in foot: allows the foot to support weight of body by distributing weight over the soft & hard tissues provide leverage while walking fully developed by age 12 - 13

37. Arches of the Foot 2 longitudinal arches (medial & lateral 1 transverse arch

38. Development of the Skeletal System • all skeletal tissue arises from mesoderm • 1st bone: skull in 4th wk • U/S ~ 24 – 25 wks:

39. Medical Terminology • Clubfoot: • inherited deformity in which baby is born with foot twisted inferiorly & medially • 1/1000 births • tx: casts or wraps, surgery may be indicated

40. Medical Terminology 2. Genuvalgum: • knees abnormally close together with increased space between ankles • aka “knock-knee”