lecture 30

Question 1

3 mechanical functions of our bones

Answer 1

structural framework
stable foundation for posture and movement
protection of important organs

Question 2

4 non mechanical functions of the bones

Answer 2

reservoir for mineral deposition, blood regulation pf calcium and phosphorus.
supports heamatopiesis
defends against acidosis
absorbs/captures potentially toxic materials (lead, things we might accidently take in from food)

Question 3

whoose skeleton accounts for the mots weight of their body?

Answer 3

Young adults - weight is a force and mass is multiplied by gravity.

Question 4

prenatal changes to bone systems

Answer 4

week 5 = formation of bones begin

Question 5

when is peak heigh velocity?

Answer 5

~12.5 yrs (males) ~13,5 yrs (females)

Question 6

when does epiphydeal plates close?

Answer 6

~25 years

Question 7

when is max bone mass ?

Answer 7

~30 years

Question 8

when is our rapid bone growth

Answer 8

1-4 years, puberty.

Question 9

elderly - osteopenia

Answer 9

components of bone fail to develop, loss of bone mineral density = weaker bones.

Question 10

osteomalacia

Answer 10

elderly - related to calcium and phosphate deficiencies

Question 11

osteoporosis

Answer 11

decreased formation of new bone = brittle bones.

Question 12

when do myotubes form?

Answer 12

5 weeks prenatal.

Question 13

how much of body mass is muscles at birth?

Answer 13

25%

Question 14

when are your first muscle fibres?

Answer 14

around 20 weeks. first ones that have the components of muscle such as actin and myosin.

Question 15

what percent of fibres are type 1 at birth?

Answer 15

28-41%

Question 16

infancy and adolesence changes ot the muscular system.

Answer 16

development proceeds from head to muscles.
differentiation of muscles fibres continues after birth.
adult-like distribution of fibres

Question 17

when do muslces mature

Answer 17

in childhood. doesnt mean they can behave like adult muscles though.

Question 18

what does muscle relaxation mean in regards to the muscular change of it and when does it happen?

Answer 18

around 10 years.
soeed reaches adult levels, this is likely lead to improved contraction speed.

Question 19

when do males have a sig increase in body mass muscle

Answer 19

5-17 years 41-53%

Question 20

how does the muscle change in adults

Answer 20

almost linear. researches postilate that accross the lifespan muscles undergo fast-slow-fast phenotype changes, largely influenced by nervous innovation.

Question 21

stats of sacropenia for elderly women and men in 70s

Answer 21

19% men and 34% women

Question 22

stats of sacropenia for elderly women and men in 80s

Answer 22

55% men and 52% women

Question 23

motor unit remodelling before and after

Answer 23

B 1MU/50 fibres
A 1 MU/ 75-100 fibres

Question 24

what does motor unit remodelling look like

Answer 24

reorganising, including increasing number of slow motor units.

Question 25

what is better retained concentric or eccentric in old age

Answer 25

eccentric strength.

Question 26

what is fibre type differentation ?

Answer 26

how you have been able yo differntiate muscle fibres, through sport or just in your life.

Question 27

when do the majority of lower limb musculoskeletal injuries occur in pre-elite soccer players?

Answer 27

from a stuyd it was found that post peak height velocity.

Question 28

crictical periods represent times ...

Answer 28

when neurons compete for synaptic sites.

Question 29

experience-expectant plasticity

Answer 29

given typically experience in daily activities we expect the brain will rewire its self accordingly

Question 30

experince dependent plasticity

Answer 30

ability to reorganise its structure and function in response to sensory injury, learning , and environment experiences.

Question 31

apoptosis

Answer 31

programmed cell death

Question 32

axon pruning

Answer 32

trimminf of extraneous axon connections, occurs without damadge to cells. peaks around puberty

Question 33

PNS response to injury

Answer 33

PNS able to regenerate = given ideal conditions around 30mm a month.

Question 34

CNS response to injury

Answer 34

regeneration does not occur.

Question 35

initial formation of the CNS

Answer 35

3 weeks prenatal

Question 36

when do motor nerve fibres appear

Answer 36

4 weeks prenatal

Question 37

when do synapse formation and myelination begin begin?

Answer 37

6-7 weeks prenatal.

Question 38

myelination of motor then sensory nuerons

Answer 38

16,20 weeks prenatal.

Question 39

when is the brain double its weight

Answer 39

6 months

Question 40

when are the critical periods for brain growth

Answer 40

3-10 months and 15-24 months

Question 41

crictical periods in childhood and adolescence

Answer 41

6-10 yrs, 10-12 yrs and around 18 yrs.