Skeletal System

1. Skeletal System

2. Fun Facts • 270 bones in an infant but several fuse together • 206 bones in human body • largest is femur, smallest ossicles http://www.youtube.com/watch?v=flIAxGsV1q0

3. 2 Divisions • axial– makes longitudinal axis of body  skull, spine, rib cage, sternum 2. appendicular-bones of limbs and girdles • also includes joints, ligaments (bone-bone connectors), cartilages

4. Function • Support - maintains structure of body - helps hold some organs in place • Protection - protects soft body organs (brain, heart, etc.) • Movement - tendons attach muscles to bones • Storage - fat stored in cavities of bones - bones store minerals (Calcium & Phosphorus) • Formation of Blood Cells AKA hematopoiesis

5. Types of Bone • Compact Bone- dense, looks smooth • Spongy Bone- has small needle-like pieces of bone and lots of open space

7. Spinal Column • spinal cord passes through center of vertebrae • Via vertebral foramen • made of 26 irregular bones connected by ligaments to allow flexibility of spine • When born there are 33 *think meal times to remember #’s 7am, 12 pm, 5 pm… we’ll get back to this http://www.youtube.com/watch?v=QWCKiyKuL8c start @ 46 sec

8. Spinal Column • Are pads between vertebrae intervertebral discs • As you age discs harden • drying of discs and weakening of the ligaments predisposes people to herniated discs

9. Spinal Column • Curvature in thoracic and sacral regions are present at birth (primary curvatures) • Curvature in cervical & lumbar regions develop after birth (secondary curvatures) • cervical curvature  allows baby to raise its head • lumbar curvature  allows walking

10. Abnormal Curvatures: Kyphosis

11. Abnormal Curvatures: Scoliosis

12. Abnormal Curvatures: Lordosis

15. Cervical Vertebrae • 7 cervical vertebrae • 1st called Atlas • No body, superior surface has depressions for the occipital condyles (bumps on the base of the skull)  can shake head yes • 2nd called Axis • Has a large process called (dens) on the superior surface  can shake head no

16. How to Know a Cervical Vertebrae When You See One… • C3-C7 • smallest, lightest vertebrae • short spinous process • foramina (holes) in transverse processes (through which arteries flow)

18. How to Know a Thoracic Vertebrae When You See One… • T1-T12 • larger than cervical • only vertebrae that articulate (fit) with ribs • heart-shaped body • 2 facets- 1 set for ribs and 2 set for neighboring vertebrae • long spinous process that hooks down

20. How to Know a Lumbar Vertebrae When You See One… • L1-L5 • large, block-shaped bodies • spinous process like a hatchet • sturdiest vertebrae

22. Remember these… They’re back!

23. Skull Bones

26. Rib Cage • Sternum • flat bone • formed by the fusion of 3 bones • manubrium (superior) • body (middle) • xiphoid process (inferior) • attached to first 7 ribs • bone marrow can be take from here since it’s superficial

27. Rib Cage • Ribs • 12 pairs, make walls of chest cavity • articulate w/ vertebrae and curve downward and toward the anterior body • 1st 7 pairs TRUE ribs - attach to sternum by cartilage • pairs 8-12 FALSE ribs – attach to sternum indirectly ( 3 pairs fuse with cartilage of other pair) OR lack sternal attachments • if no attachment to sternum FLOATING rib

29. Clavicle

30. Hand and Wrist Bones

31. Some LadiesTry Positions That They Can't Handle To remember the carpal bones :Scaphoid, Lunate, Triquetral, Pisiform, Trapezium, Trapezoid, Capitate, Hamate

32. Bone Shapes • Long bones- longer than they are wide, have a long shaft and heads at both ends • all limb bones are long bones EXCEPT the patella, wrist bones, & ankle bones • Short bones- cube-shaped • patella, wrist bones, & ankle bones • Flat bones- thin, flattened usually curved; 2 thin layers of compact bone & spongy bone between • most bones of skull, ribs, sternum • Irregular bones- bones that don’t fit into the other 3 categories • hip bones, vertebrae

33. Pelvis • Purposes: • bearing weight • protects bladder, reproductive organs, & some of the large intestines • Hip bone made of • ilium- forms most of hips, has wings that flare out, connects w/ the sacrum, • iliac crest where you put hands on hips • ischium- “sit down bone” takes weight when you sit • pubis- most anterior part of pelvis -> forward buldge • meets w/ ischium to make obturator foramen for muscles, nerves, and bl vessels to go to the anterior part of thigh • all meet at the acetabulum where femur inserts

34. Which is which?

35. Males vs. Female Differences • female pelvis is shallower & bones are lighter • iliac crest of a female flare more laterally  making opening larger and more circular • in females the pubic arch at bottom of pelvis is more rounded and larger than 90o • female acetabulum is more shallow  more flexible

36. Foot and Ankle Bones

37. New Tricks… • Clavicle- put rounded side towards palm, large curve out from body & flat end in opposite hand, using opposite hand feel for the bump facing towards you, if not there other side • Tibia- Tough guy… big guy, larger side facing up, large bump to the front, longest process towards the inside/medial side of the ankle  makes medial malleolus (can follow curve on shin) • Fibula- PUNY, feel the 2 necks, skinny neck on top, larger/flatter neck on bottom, largest inferior process must be POSTERIOR and on the lateral side of the ankle  makes lateral malleolus • Femur- ball and neck medially, large fossa to the back/towards your body, the direction the ball faces is the side • Patella- point down, hold like a controller with thumbs on smooth facets, broader side is the side that the patella is on • Pelvis- put knuckle of index finger in the sciatic notch, if you can wrap four fingers around and into the hip bone fossa ACETABULUM that’s the side