lecture 3 - Structure of the skeleton

Question 1

functions of the skeleton

Answer 1

1. support - provides framework
2. movement - bones are leavers
3. protection - protects major organs
4. storage - minerals are stored
5. Red Blood cell formation - in marrow

Question 2

what are the two types of bones

Answer 2

1. compact

2. cancelous

Question 3

Compact bone

Answer 3

• strong
• good at transmitting force in one direction
• (within the femur a compact bone can be found in the shaft)

Question 4

cancelous bone

Answer 4

• light, spongy bone
• shock absorbing
• resists and channels forces that come from multiple directions
• fibers in different directions that help resist force

Question 5

bone classes x4

Answer 5

1. long bones
2. short bones
3. irregular bones
4. flat bones

Question 6

long bones

Answer 6

• longer than they are wide
• composed of wider epiphyses and a longer narrower diaphysis
• mostly limb bones

Question 7

short bones

Answer 7

• close to equal width and length
• weight bearings (from multiple directions)
• mostly cancelous
• (basically anything square or round)

Question 8

flat bones

Answer 8

• are flat bones (thin plates of compact bone) - some can be cancellous two!
• Function ONE - provides surface for muscle attachment eg scapular
• Function TWO provides protection for organs ect. eg skull and sternum

Question 9

irregular bones

Answer 9

• the bone doesnt seem to fit in any of the other t3 categories
• it is various shapes and functions (often have a big hole in it)
• not long, not round/square shaped, not just cancellous bone, not flat, often have a foramen / foramina

Question 10

axial skeleton

Answer 10

• protection of vital organs
• skull
• sternum
• ribs
• vertebral column
• sacrum
• coccyx

Question 11

Appendicular skeleton

Answer 11

most important for movement

- bones of the limbs

Question 12

axial skeleton - the skull

Answer 12

1. cranium (valt)
   
   • encloses the brain
   • muscle attachments
2. facial bones
   
   • protect and support sensory organs
   • these bones make up the face
   • small fragile
   • often irregularly shaped
3. joint at structures (immovable)

Question 13

Axial skeleton - the vertabral column

Answer 13

1. keeps the trunk upright
   
   • lots of muscle / ligament attachments
2. supports head
3. divisions
   
   • Cervical (7)
   • Thoracic (12)
   • Lumbar (5)
   • sacrum AND coccyx

Question 14

Axial skeleton - rib cage

Answer 14

• the rip cage protects the heart AND lungs
  
  • rips
  • sternum
• protecting the heart and lungs you need MOBILITY because lungs expand and deflate
  
  • thin structure to make movements

Question 15

Appendicular skeleton - limb structure

Answer 15

1. single proximal long bones
   
   • humerus / femur
2. two distal long bones
   
   • ulna and radius / tibia and fibular
3. hands and feet
4. different form / function in upper and lower limb

Question 16

appendicular skeleton - regions

Answer 16

1. arm
2. forearm
3. thigh
4. leg
5. single proximal long bone
   
   • humerus / femur
6. two distal long bones
   - ulna and radius / tibia and fibula
   - the ulna and radius are more mobile than the tibia and fibula
7. hands and feet

Question 17

why is the human skeleton this shape

Answer 17

• form related to function
• we walk on 2 limbs (bipedalism) VS other apes walk on 4 limps (quadrapedalism)
• human lower limb needs stability and movement

Question 18

hands free

Answer 18

• not involved in locomotion
• loss of stability
• adapted for precision

Question 19

humerus and femur

Answer 19

• humerus - shorter, lighter
• deeper articulation for prox. femur than prox. humerus
• stability vs movement

Question 20

mobile forearms and wrists VS stability of legs

Answer 20

Mobile forearms & wrists

• pronation and supination of radius and ulna
• shape of distal articulation for wrist mobility

Stability of legs

• no pronation and supination
• tibia very robust (weight - bearing)
• ankle joint = stable

Question 21

hand made up of

Answer 21

• carpals (8)
• metacarpals (5)
• Phalanges (3 per finger) - except your thumb (only two)

Question 22

foot made up of

Answer 22

• tarsals (7)
• metatarsals (5)
• phalanges (3)

Question 23

how do limbs attach to the axial skeleton

Answer 23

1. pectoral girdle
   
   • clavicle
   • scapula
2. pelvic girdle
   
   • hip bone we have 2 of them
   • sacrum (axial)
     - pelvic bones + sacrum = pelvis

Question 24

The pectoral girdle

Answer 24

• clavicle (stabilizing joint)

- scapula (free moving, muscle attachments)

Question 25

pelvic girdle

Answer 25

• hip bones (x2)
• sacrum (part of the axial skeleton)
• pelvic bones + sacrum = pelvis
• lots of weight bearing