Lecture 30

Question 1

what are the mechanical functions of bones

Answer 1

structural framework

stable foundation for posture and movement

protection of important organs

Question 2

what are the non mechanical functions of bones

Answer 2

reservoir for mineral deposition, blood regulation of calcium and phosphorus

supports haematopoiesis

defends against acidosis

absorbs / captures potentially toxic minerals

Question 3

when does bone formation begin

Answer 3

prenatal = 5 weeks

Question 4

what changes to bone occur in infancy + childhood + adolescence

Answer 4

mechanical stimulation of epiphyseal plates affects long bone growth

Question 5

when does rapid bone growth occur and what is important that needs to happen

Answer 5

1-4 years, puberty

important that forces are applied against the bones

Question 6

when does peak height velocity occur

Answer 6

~12.5 (males)

~13.5 (females)

Question 7

what age do epiphyseal plates close

Answer 7

~25 years

Question 8

what age is maximal bone mass

Answer 8

~30 years

Question 9

what is osteopenia

Answer 9

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

Question 10

what is osteomalacia

Answer 10

related to calcium and phosphate deficiencies

Question 11

what is osteoporosis

Answer 11

decreased bone formation of new bone = brittle bones

Question 12

what happens to the walls and width of bones as we age

Answer 12

walls become thinner and bones become a bit wider

Question 13

what happens to the muscular system at ~5 weeks prenatal

Answer 13

myotubes formed

Question 14

when are the first muscle fibres formed

Answer 14

~20 weeks

Question 15

at birth what % of body mass is muscle

Answer 15

~25%

Question 16

when do muscles mature but what does this mean

Answer 16

muscles mature in childhood, but this doesn’t mean they can behave physiologically like adult muscles can

Question 17

at 10 years old muscle relaxation occurs, what does this mean

Answer 17

speed reaches adult levels, likely to improve contraction speed

Question 18

what is sarcopenia

Answer 18

loss of muscle mass

Question 19

in their 70s, what is the prevalence of men and women with sarcopenia

Answer 19

19% men and 34% women

Question 20

in their 80s, what is the prevalence of men and women with sarcopenia

Answer 20

55% men and 52% women

Question 21

inside muscles, what changes in the elderly

Answer 21

change in muscle protein synthesis

change in contractile proteins

Question 22

at 16 the average male is stronger than what

Answer 22

stronger than a very strong female

Question 23

at the age of 30 what % muscle mass is lost per decade

Answer 23

5%

Question 24

what type of strength is maintained better in old age

Answer 24

eccentric strength is maintained better than concentric strength

Question 25

what is the saying of endurance as we age

Answer 25

use it or lose it

Question 26

what are 3 adaptations to central and peripheral nervous systems with age

Answer 26

neural plasticity neuron cell death response to injury

Question 27

what is neuroplasticity

Answer 27

ability of nervous system in particular the cortico-cerebellar system to change

Question 28

what is experience dependent plasticity

Answer 28

ability to reorganise its structure and function to sensory input, learning and environmental experiences

Question 29

what is experience expectant plasticity

Answer 29

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

Question 30

why does neuron cell death occur

Answer 30

there is overproduction of neurons to ensure sufficient number to complete “wiring”, so some culled

Question 31

what is apoptosis

Answer 31

programmed cell death

Question 32

what is axon pruning

Answer 32

trimming of extraneous axon connections, occurs without damage to cells

Question 33

when does axon pruning peak

Answer 33

around puberty

Question 34

if there is an injury to the PNS can it regenerate

Answer 34

Yes

Question 35

if there is an injury to the CNS can it regenerate

Answer 35

no

Question 36

when is the inital formation of CNS - prenatal

Answer 36

~3 weeks

Question 37

when do motor nerve fibres occur- prenatal

Answer 37

~4 weeks

Question 38

when do synapse formations begin and myelination

Answer 38

~6-7 weeks

Question 39

at birth the brain is what fraction of their weight

Answer 39

1/4

Question 40

at 6 months the brain weight has what

Answer 40

doubled

Question 41

at 13 the brain is …

Answer 41

morphologically mature but not physically mature

Question 42

when is peak myelination

Answer 42

~50 years

Question 43

what are the reductions to the basal ganglia like with age

Answer 43

no significant reductions

Question 44

what does the vestibular sense provide

Answer 44

provides information about the bodies position relative to gravity

Question 45

most important sense

Answer 45

vision

Question 46

three forms of sensory intergration

Answer 46

intrasensory integration intersensory integration sensorimotor integration

Question 47

what is another word for proprioception

Answer 47

kinasethesis

Question 48

when does adult like depth perception occur

Answer 48

aged 12