Skeleton

Question 1

Function of the skeleton

Answer 1

• support
• muscle attachment surface
• protection of delicate organs

Question 2

what type of tissue is bone

Answer 2

• mineralised connective tissue

*contains collagen and calcium
*calcium hydroxyapatite crystals give hardness

Question 3

difference between cartilage and bone

Answer 3

bones are hard, inelastic and tough
cartilage is soft, elastic and flexible

Question 4

What are the cells of bone

Answer 4

1. osteoblasts = bone forming cells
2. osteocytes = bone cells
3. osteoclasts = break down + resorb bone

Question 5

steps of endochondral ossification (long bones)

Answer 5

1. cartilage model
2. Bone formations - osteoblasts produce bone and ossify the cartilage, blood vessels enter
3. marrow cavity forms - primary ossification occurs
4. growth plates develop - bone formed in growth plates = secondary ossification
5. mature bone and bone marrow

Question 6

define endochondral ossification

Answer 6

bone formation in which cartilage models are gradually replaced by bone forming *mineralisation

Question 7

Explain intramembranous bone formation

Answer 7

• bones forming directly within fibrous tissues
• e.g. dermal bones (skull and pelvis) - usually smooth

Question 8

what are the 3 skeletal systems

Answer 8

1. Axial
2. appendicular
3. heterotorphic

Question 9

what’s included in axial skeleton

Answer 9

• skull and head bones
• vertebral column
• sternum and ribs

Question 10

explain the groups of the vertebral collumn

Answer 10

1. Cervical - neck, enable movement of head (7)
2. thoracic - chest, attachments for ribs, support head (12)
3. lumbar - connect to postural muscles/back - have larger spikes for muscle attachment (5)
4. sacral - pelvic (5)
5. candal - tail (variable)

Question 11

what are the first two vertebrae called and their purposes

Answer 11

1st - Atlas = allow pivoting (nodding up and down), ring shaped/ gaps for spinal chord
2nd - Axis = allows head movement side to side

Question 12

Explain what is included in the apppendicular system

Answer 12

limbs and gurdles

Question 13

Basic structure of limbs (draw and label)

Answer 13

Front:
- humerus (larger)
- Radius (smaller) and Ulna
- carpals (wrist area), then metacarpals (first bone in finger), then phalanges (final finger)

Back:
-femur (large)
- patella (knee)
- Tibia (larger of the two), and fibula (skinny)
- tarsals (feet)
- metatarsals (back of toe)
- phalanges (toe)

Question 14

what are girdles?

Answer 14

bones that support the attachment of limbs to axial skeleton

Question 15

What’s included in the heterotorpic skeleton

Answer 15

• random bones e.g. penis bone

Question 16

Different types of bones

Answer 16

1. long bones - femur
2. short bones - carpals
3. flat bones - scapulla
4. sesamoid - patella
5. irregular - vertebrae

Question 17

how does each type of bone form

Answer 17

long bones - endochondral ossification
short bones - EO
flat = intramembranous
sesamoid - within a tendon (ossification of tendon)
irregular - both or complicated

Question 18

explain the shape of each type of bone

Answer 18

long - epiphysis (weird end shape), metaphysis (other end) and diaphysis (long thin middle)
short - single centre of ossification, cube/rectangular shape
flat - thin and flat in most areas
sesamoid - rounded, ball shaped (usually at joints)
irregular - weird shapes e.g vertebrae

Question 19

what is a joint

Answer 19

where two or more bones are attached to enable movement

Question 20

3 classifications of joints

Answer 20

tissue composition
degree of flexibility
movement permitted

Question 21

what are the three catergories of joint flexibility

Answer 21

fibrous joint = immobile
cartilagenous = limited
synovial = freely mobile (have ligaments and tendons)

Question 22

what are ligaments

Answer 22

fibrous connective tissue joining bone to bone

Question 23

what are tendons

Answer 23

cord of strong flexible tissue connecting bone to muscle

Question 24

compare and contrast EO and Intramembranous

Answer 24

bones formed - EO: long bones, I: flat bones

EO: catrilage model, I: no cartilage formation, direct formation of osteoblasts

Both involve mineralisation of osteoblasts into bone

speed- EO: slower, I: faster

Question 25

differences between endo and exo skeleton

Answer 25

endo = internal, bone, grows over time with the organism
exo = external, rigid chitin, molting

Question 26

what is a suture

Answer 26

rigid joint between two or more hard elements of an organism, with or without significant overlap of the elements.