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The Hand PowerPoint Presentation

The Hand

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The Hand

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  1. The Hand

  2. Terminology • Anterior = Palmar (Volar also used) • Posterior = Dorsal • Ulnar (Medial) = pinky finger side • Radial (Lateral) = thumb side

  3. The Hand Carpals Phalanges Metacarpals

  4. Joints of Wrist & Hand • Radiocarpal joints • Carpometacarpal joints • Metacarpophalangeal joints • Interphalangeal joints

  5. Terminology • 27 bones per hand • 3 parts of hand • Proximal end, Carpals – Wrist • Hand proper, Metacarpals – Palm • Distal region, Phalanges – Fingers

  6. Terminology • Anatomical position is PALM FORWARD • Humans retain ancestral (primitive) configuration of 5 sets of digits

  7. Terminology • Wrist • 8 Carpals (carpus) form the wrist • 5 rays (I-V)—refer to metacarpals & phalanges (digits) • 5 metacarpals (metacarpus) • 14 phalanges • 5 proximal • 4 intermediate • Ray 1 does not have an intermediate phalanx (i.e., the thumb or pollex) • 5 distal

  8. Terminology • Sesamoid bones (develop w/i tendons) • Usually found on palmar aspect of head for MC1

  9. Ossification of Hand • Carpals • Single center of ossification • Metacarpals • 2 centers • Primary = shaft • Secondary = head • Except MC1 (secondary is at base) • Phalanges • 2 centers • Primary = shaft & distal end • Secondary = Base

  10. The Carpus (Wrist) • 8 bones in 2 rows • very tightly bound by ligaments • Proximal Row (lateral – medial) • Scaphoid, lunate, triquetral, pisiform • First 2 articulate with the radius • Distal Row (lateral – medial) • Trapezium, trapezoid, capitate, hamate

  11. The Carpus (Wrist) C H T T P T S L Palmar

  12. Carpals—Scaphoid (Navicular of Hand) Hold like rubber ducky (or Donald Duck in profile) and the beak points to the side that it is from

  13. Carpals—Lunate Place facet for the scaphoid on flat table with crescent moon facing you; the facet for the triquetral will “lean” to the side that it is from

  14. Carpals—Triquetral (triquetrum) Place facet for the hamate (largest facet) on flat table with the facet for the pisiform and lunate facing you; the facet for the pisiform will be on the side that the bone is from

  15. Carpals—Pisiform

  16. Carpals—Trapezium (Greater Multangular) Hold saddle facet superior with the trapezial ridge and groove facing you; the bone will “point” to the side that it is from

  17. Carpals—Trapezoid (Lesser Multangular) Think of the traqpezoid as a boot for your foot. Visualize where the toes would go, the arch of your foot and the “zipper” on the lateral side. The side of your foot that the boot would “fit on is the side that it is from.

  18. Carpals—Capitate Think of the capitate as Elvis’ head in profile. The facet for the hamate is his hair and the nonarticular palmar surface is his face. His hair is on the side that the bone is from.

  19. Carpals—Hamate The hamate has a hook (hamulus). With the hook curved towards you and the facet for the capitate facing you, the hook will be positioned on the side that it is from.

  20. Metacarpals

  21. Metacarpals • 5 bones numbered I-V, beginning laterally with the thumb • Round head, square-shaped base • Body (shaft) is slightly concave on the palmar side • Head is rounded for articulation with surface of proximal phalanges • Base has complex facets for multiple articulations with each other & with carpals

  22. Metacarpal I • MC1- 1st metacarpal • short thick body, base articulates with trapezium only (single facet) • Saddle shaped sellar joint • Allows MCI to rotate 90° medially (for opposition of the thumb and fingers).

  23. Metacarpal I L M Lateral facet = 0 Medial facet = 1 (very slight) Left Bone Depicted

  24. Sesamoids • Small oval ossicles (extra bones) usually found where tendons traverse a joint between (2) bones • Most commonly on palmar surface (MC1 head)

  25. Metacarpals II-V • Metacarpal II – usually longest, has wide & deeply cleft base • Metacarpal III – styloid process that projects proximally from the base • Metacarpal IV – Smaller than II and III, has a rectangular base • Metacarpal V – small, slight medial facet or tubercle

  26. Metacarpal II Medial facet = 2 Lateral facet = 1 Left Bone Depicted

  27. Metacarpal III Medial facet = 2 Lateral facet = 2 In anatomical position, styloid on side that the bone is from Left Bone Depicted

  28. Metacarpal IV Medial facet = 1 Lateral facet = 2 Left Bone Depicted

  29. Metacarpal V • Base of fifth metacarpal saddle shaped & articulates with hamate

  30. Metacarpal V Medial facet = 0 Lateral facet = 1 Left Bone Depicted

  31. Phalanges • 5 “rays” in 3 rows • Proximal • I-V • Intermediate • II-V • Distal • I-V

  32. Proximal Phalanges • Body relatively long and smooth • Proximal end (base) concave • Distal end (head) convex

  33. Phalanges—Proximal

  34. Intermediate Phalanges • Body relatively long and smooth • Shorter than proximal • Proximal end (base) concave • Double-faceted • Distal end (head) convex • Ray I (thumb/pollex) lacks intermediate phalanx

  35. Phalanges—Intermediate

  36. Distal Phalanges • Body short & flares out toward distal end • Base double-faceted • Distal (terminal)–diminutive flattened head, lacks distal articular facets • non-articular pad (distal phalangeal tuberosity)

  37. Phalanges—Distal

  38. The Foot

  39. The Foot

  40. Terminology • Plantar – sole of the foot • Dorsal – top of the foot • Proximal – toward the tibia • Distal – toward the toe

  41. Feet • Foot bones are very similar to the hands, but slightly modified for: weight bearing, bipedal locomotion, shock absorbing and propulsion • 26 bones in each foot

  42. Feet • 3 regions • Tarsals (Tarsus) – 7 bones, proximal portion of foot • Metatarsals (Metatarsus)– 5 bones, body of foot • Phalanges (toes)– 14 bones

  43. Orientation of Tarsals & Metatarsals Right side depicted

  44. Tarsals • Proximal row (2 bones) • Talus • Calcaneus • Intermediate row (1 bone) • Navicular • Distal row (4 bones) • Cuboid • Lateral cuneiform • Intermediate cuneiform • Medial cuneiform Right side depicted

  45. Talus • Proximal row • Talus (astragalus in animals) • Articulates with distal tibia and fibula, calcaneus, and navicular. • Lacks muscle attachments Left side depicted

  46. Talus Left side depicted

  47. Talus Place on table with trochlea up and head away from you; it looks like a turtle! The foot is sticking out from the “shell” on the side that it is from.

  48. Calcaneus (Heel) • Proximal row • Calcaneus – largest tarsal • Articulates with talus and cuboid. Left side depicted

  49. Calcaneus (Heel)