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KIN 207 > Chapter 5 > Flashcards

Chapter 5 Flashcards

1
Q

Development of the skeletal system is not ____ and reflects the influence of both _____ and _____ factors.

A
  • static
  • genetic
  • external
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2
Q

Embryonic skeleton =

A

cartilage model of bones

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3
Q

Ossification centres:

A

sites gradually appear in the cartilage model where bone is deposited

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4
Q

2 types of ossification centres:

A
  • primary ossification centres

- secondary ossification centres

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5
Q

Primary OC appear where?

A

mid portion of shaft of long bones

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6
Q

Primary OC forms…

A
  • from centre outward

- forms bone shafts

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7
Q

Primary OC starts when?

A

at fetus age of 2 months

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8
Q

In primary OC, bone cells are formed. What does this mean?

A

cartilage model bones of fetal skeleton begin ossifying

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9
Q

Secondary OC is for ______ bone growth.

A

postnatal

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10
Q

Secondary OC is aka…

A

epiphyseal plate

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11
Q

Where are secondary OC located? What does this mean?

A
  • areas near the end of long bones where new bone cells are formed and deposited
  • bones grow in length
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12
Q

Active secondary OC are indicated by what on a x ray?

A
  • a line

- an area not opaque

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13
Q

This line seen on a x ray is actually…

A
  • layer of cartilage cells

- aka pressure epiphysis

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14
Q

Epiphyseal plate has many _____ layers where cartilage cells ____, _____, _____, and _____ to leave new bone in place.

A
  • cellular
  • form
  • grow
  • align
  • erode
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15
Q

Bone is laid down at epiphyseal plates to…

A

increase the length of the bone

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16
Q

Increasing length of bone depends on…

A
  • adequate blood supply

- any injury that disturbs blood supply threatens the bone’s normal growth in length

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17
Q

Unlike long bones, small round bones (ex. ones in _____ and _____) ossify from…

A
  • wrist and ankle

- the centre outward

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18
Q

When does growth at ossification centres cease?

A

at different times in different bones

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19
Q

How does bone become fixed?

A

cartilage zone eventually disappears and the shaft (diaphysis) of the bone fuses with the epiphysis

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20
Q

Almost all epiphyseal plates are closed by age ___.

A

18 or 19

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21
Q

Since girls mature faster than boys, ossification centres appear…

A

at younger chronological ages in girls than in boys

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22
Q

Since girls mature faster than boys, epiphyseal plates close…

A

at younger chronological ages in girls than in boys

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23
Q

Children at the same chronological age could vary in skeletal age by ___ years or more.

A

3

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24
Q

Appositional bone growth:

A
  • Addition of new layers on previously formed layers so that a bone grows in girth
  • Addition of new tissue layers under the periosteum (thick outer covering of the bone)
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25
Q

Traction epiphyses:

A

epiphyses at the sites where the muscles’ tendons attach to bones

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26
Q

Osgood-Schlatter disease:

A
  • Irritation of the traction epiphysis where patellar tendon attaches to the shin bone below the knee
  • Refrain from vigorous activities
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27
Q

Overuse injuries to traction epiphyses during the growth period can…

A

threaten the pain-free movement at a joint later in life

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28
Q

Give an example of overuse injury to traction epiphyses.

A
  • traction epiphysis near elbow

- forcefully pronating forearm in throwing

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29
Q

Because linear growth of the body is almost completely the result of _____ growth, measures of height reflect…

A
  • skeletal

- increase of bone length

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30
Q

In youth, new bone is ____ _____ than older bone is ______ = _____.

A
  • formed faster
  • resorbed
  • growth
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31
Q

In adulthood, bone formation begins to _____ and eventually cannot keep pace with ____ =

A
  • slow
  • resorption
  • loss of bone tissue
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32
Q

Loss of bone tissue starts in mid ____ averaging about ___% bone mass/year.

A
  • mid 20s

- 1%

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33
Q

Children have _____ amounts of ______ and _____ components in their bone tissue.

A
  • equal
  • inorganic
  • organic
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34
Q

Older adults have ___x more inorganic material = more _____ bones, subject to ______.

A
  • 7x
  • brittle
  • microfracture
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35
Q

What 3 factors play a role in bone loss with aging?

A
  • changes in certain hormone levels
  • dietary deficiencies
  • decreased exercise
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36
Q

Why do post menopausal women tend to have bone loss?

A
  • decreased level of estrogen = loss of bone mass
  • estrogen stimulates osteoblastic (bone-forming) activity
  • estrogen lowers bone resorption
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37
Q

How do dietary deficiencies play a role in bone loss?

A
  • prolonged deficiency of calcium in diet
  • calcium lowers bone resorption
  • shortage of vitamins and minerals
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38
Q

How does decreased exercise play a role in bone loss?

A
  • Exercise has effect on maintenance of bone by increasing bone formation
  • When someone engages in -PA, the mechanical forces applied to the bones help maintain bone thickness and density
  • Significant increases in bone mass are even seen when older adults initiate exercise programs
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39
Q

Many older adults suffer from ______.

A

osteoporosis

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40
Q

Osteoporosis:

A
  • major bone mineral disorder
  • bone mineral density significantly below the average for young adults
  • loss of bone strength
  • bone becomes abnormally porous
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41
Q

What does it mean when bone becomes abnormally porous with osteoporosis?

A

enlargement of canals or formation of spaces in the bone

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42
Q

Osteoporosis increases risk of _______, especially at the _____.

A
  • fractures

- hip

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43
Q

Osteoporosis also adds difficulty to _____ _____.

A

fracture repair

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44
Q

Osteoporosis can lead to _______ of the ______ in the spine.

A
  • microfractures

- vertebrae

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45
Q

With osteoporosis, vertebrae may eventually ______, which means…

A
  • collapse
  • rib cage collapses forward
  • lower edge resting on the pelvis
  • posture becomes stooped
  • standing height notably reduced
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46
Q

What is the key to reducing the effects of osteoporosis?

A
  • early detection and treatment

- increased awareness

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47
Q

Example of implementing strategies to minimize loss of bone tissue in adulthood:

A

women can maintain adequate calcium intake during adulthood so that they enter menopause with the highest bone mineral density possible

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48
Q

Muscular system changes over lifespan under the influence of _____ and _____ factors.

A
  • genetic

- extrinsic

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49
Q

Muscle fibres (cells) grow during prenatal life by what 2 ways?

A
  • hyperplasia

- hypertrophy

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50
Q

At birth, muscle mass accounts for ____ % of body weight.

A

23-25%

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51
Q

_____ continues for a short time after birth, but soon muscle growth occurs predominantly by _____.

A
  • hyperplasia

- hypertrophy

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52
Q

______ pattern of growth in weight reflects the growth of the muscle tissue.

A

sigmoid

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53
Q

Muscle cells grow in both _____ and _____.

A
  • diameter

- length

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54
Q

Amount of increase in muscle diameter is related to …

A

the intensity of muscle activity during growth

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55
Q

Muscles must ______ ____ _______ as the skeleton grows.

A

increase in length

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56
Q

Lengthening of muscles is accomplished through:

A
  • the addition of sacromeres (contractile units of muscle cells) at the muscle-tendon junction
  • lengthening of sarcomeres
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57
Q

Sex differences in muscle mass during childhood:

A
  • minimal

- muscle mass constitutes a slightly greater proportion of body weight in boys

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58
Q

Sex differences in muscle mass during and after adolescence:

A
  • muscle mass increases rapidly in boys up to about age 17
  • girls add muscle mass only until age 13
  • especially prominent in upper body musculature
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59
Q

Muscle mass ultimately accounts for ___% of men’s body weight.

A

54%

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60
Q

Muscle mass ultimately accounts for ___% of women’s body weight.

A

45%

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61
Q

Why are sex differences in muscle mass so dramatic in adolescence?

A

related to hormonal influences

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62
Q

Twitch:

A

Brief period of contraction of a muscle fibre (cell) followed by relaxation

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63
Q

2 main types of fibres in human muscles:

A
  • slow twitch

- fast twitch

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64
Q

Slow twitch:

A
  • type I
  • suited for endurance activities
  • slower contraction-relaxation cycle
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65
Q

Fast twitch:

A
  • types IIa, IIx, and IIb

- suited to intense short duration activities

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66
Q

At birth, approximately ____% of muscle fibres have yet to differentiate into slow or fast twitch fibres.

A

15%

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67
Q

At birth, ____% of type II fibres cannot be clearly categorized.

A

15%

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68
Q

During the first postnatal year, the number of ______ fibres decreases.

A

undifferentiated

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69
Q

Heart = _____ tissue

A

muscle

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70
Q

The heart grows by _____ and _____.

A
  • hyperplasia

- hypertrophy

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71
Q

____ ventricle is larger than the _____ ventricle at birth.

A
  • right

- left

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72
Q

Left ventricle catches up after birth by…

A

growing more rapidly than the right

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73
Q

The heart generally follows the _____ pattern of whole-body growth.

A

sigmoid

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74
Q

One study found that left ventricular mass was _____ in overweight and obese children at ____ years.

A
  • already greater

- 2

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75
Q

Myth of early 20th century with regards to heart:

A
  • Large blood vessels around the heart develop more slowly than the heart itself
  • Implied that children who engaged in vigorous activity might be at risk
  • Later shown that this myth was the result of a misinterpretation of measurements taken in the late 1800s
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76
Q

How does body comp begin changing in young adulthood?

A

proportion of lean body weight decreases, most often as a result of fat weight increasing

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77
Q

Only ___% of skeletal muscle mass is lost on average between the mid 20s and age 50.

A

10

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78
Q

How do changes in diet and PA affect shift in body composition?

A
  • poor diet = increased fat weight

- lack of PA = decreased muscle weight

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79
Q

After age ____, individuals begin to lose muscle mass at a greater rate.

A

50

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80
Q

On average, an additional ___% of muscle mass is lost by age 80.

A

30

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81
Q

At very old age, sedentary individuals with poor nutrition can lose as much as ___% of muscle mass they possessed in early adulthood.

A

50%

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82
Q

With old age, both ____ and ____ of muscle fibres appear to decrease.

A
  • number

- diameter (size)

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83
Q

Loss in numbers of muscle fibres is small before 50s (___%), and ____% after.

A
  • 5%

- 35%

84
Q

Muscle fibres do not seem to decrease in size until the ____s..

A

70s

85
Q

With old age, the heart’s ability to …. declines.

A

adapt to an increased workload

86
Q

The heart decreasing in adaptability as we get old may relate to:

A
  • degeneration of the heart muscle
  • Decrease in elasticity
  • Changes in the fibres of the heart valves
  • Major blood vessels lose elasticity
87
Q

Most changes in the heart muscles of individuals are related to changes in ____ and resulting _____ rather than …

A
  • lifestyle
  • pathology
  • aging of the cardiac muscle fibres
88
Q

____ and ____ mass are related to one another throughout the lifespan.

A
  • bone

- muscle

89
Q

Use of the _____ stimulates the ____ to respond with increased ____ formation.

A
  • muscle
  • bone
  • bone
90
Q

Decline in bone and muscle mass is a ______ in the movement of older adults.

A

constraint

91
Q

Any loss of muscle strength accompanying decreases in muscle mass with aging can lead to…

A

decrease in PA that is important to CV health

92
Q

Adipose tissue plays a vital role in:

A
  • energy storage
  • insulation
  • protection
93
Q

Amount of adipose tissue ____ in early life.

A

increases

94
Q

Adipose tissue first appears in the fetus at ____ months.

A

3.5

95
Q

Adipose tissue increases rapidly during the last ___ prenatal months.

A

2

96
Q

Adipose tissue accounts for only ___ kg of body weight at birth.

A

0.5

97
Q

Rapid increase of fat in the firs ___ months after birth.

A

6

98
Q

Highest peak weight velocity occurs in the ___ month.

A

first

99
Q

Greater than average peak weight velocities =

A

increased risk of overweight and obesity

100
Q

After 6 months, fat mass increases gradually until age ____ in both boys and girls.

A

8

101
Q

____ tend to have slightly more fat mass at age 2.

A

Girls

102
Q

In boys, what happens to adipose tissue throughout adolescence?

A

continues to increase gradually

103
Q

In girls, what happens to adipose tissue throughout adolescence?

A
  • experience a more dramatic increases

- adult women have more fat weight than adult men

104
Q

Fat weight during growth increases by both ____ and ____.

A
  • hyperplasia

- hypertrophy

105
Q

After ___ years of age, it is more likely to maintain their relative fatness.

A

7-8 years

106
Q

In childhood, ____ fat increases faster than _____ fat.

A
  • internal (fat around the viscera)

- subcutaneous fat (fat under the skin)

107
Q

Subcutaneous fat decreases until age ____, then increases until age ____.

A
  • 6-7

- 12-13

108
Q

Increase in subcutaneous fat ______ in girls, but boys typically _____ subcutaneous fat in midadolescence.

A
  • continues

- lose

109
Q

Increases in fat cell number are significant because…

A

adipose cells persist once they are formed, even with malnutrition

110
Q

2 periods are critical in the control of obesity:

A
  • first 6 postnatal months

- around puberty

111
Q

Both sexes tend to gain _____ weight during the adult years. This reflects changes in _____ and ______ _____.

A
  • nutrition

- activity level

112
Q

Total body weight begins to decline after age ____. This reflects _____ and ____ loss. _____ continues to increase.

A
  • 50
  • bone
  • muscle
  • body fat
113
Q

How does body fat redistribute with aging?

A
  • Subcutaneous fat on the limbs tends to decrease

- Internal fat in the abdomen tends to increase

114
Q

Abdominal obesity =

A

risk of CV disease

115
Q

How is overweight and obesity a constraint to movement at any age?

A
  • Movement is more effortful
  • Joint movement can be restricted
  • Social pressure related to body image and self-esteem can discourage participation in PA
116
Q

2 control systems:

A
  • nervous system

- endocrine system

117
Q

Hormones:

A
  • Chemical substances secreted into body fluids by a gland

- Have specific effects on the activities of target cells, tissues, or organs

118
Q

Endocrine system’s regulation of growth is a complex and delicate interaction of …

A
  • hormones
  • genes
  • nutrients
  • environmental factors
119
Q

Why must hormone levels be delicately balanced?

A

Excess or deficiency of hormones may disturb the normal process of growth and development

120
Q

4 hormones that we focus on:

A
  • GH
  • TH
  • Gonadal hormones
  • Insulin
121
Q

All 4 hormones promote growth in the same way:

A

stimulate protein anabolism (constructive metabolism) resulting in the retention of substances needed to build tissues

122
Q

GH influences growth during childhood and adolescence by…

A

stimulating protein anabolism so that new tissue can be built

123
Q

GH is under control of …

A

the CNS

124
Q

GH is secreted by ….

A

anterior pituitary

125
Q

GH is needed for _____ ____ after birth.

A

normal growth

126
Q

Deficiency or absence of GH results in…

A
  • growth abnormalities

- in some cases the cessation of linear growth

127
Q

TH secreted by…

A

thyroid gland

128
Q

2 types of TH influence _____ ____ growth after birth. 3rd type plays a role in _____ growth.

A
  • whole body

- skeletal

129
Q

_____ gland secretes ____ that regulates thyroid hormones.

A
  • pituitary

- TSH

130
Q

TSH is increased by….

A

a releasing factor found in the brain’s hypothalamus

131
Q

Gonadal hormones affect ____ and ____ maturation, particularly during ______, by stimulating development of the ____ _____ ______ and ____ ____.

A
  • growth
  • sexual
  • adolescence
  • secondary sex characteristics
  • sex organs
132
Q

Androgens (specifically _____ and _____) hasten fusion of the _____ ____ _____ in the bones.

A
  • testosterone
  • androgens
  • epiphyseal growth plates
133
Q

Testosterone secreted by…

A

testes

134
Q

Androgen secreted by…

A

cortex of adrenal glands

135
Q

Testosterone and androgens promote _____ maturation (_____) at the expense of _____ growth. This explains why early maturers tend to be _____ in stature than late maturers.

A
  • skeletal
  • fusion
  • linear
  • shorter
136
Q

Androgens play a role in the adolescent growth spurt of muscle mass by…

A

increasing nitrogen retention and protein synthesis

137
Q

Why is muscle mass more pronounced in young men than young women (hormones)?

A
  • men secrete both testosterone and adrenal androgens

- women produce only the adrenal androgens

138
Q

_____ and ____ ____ secrete estrogens.

A
  • ovaries

- adrenal cortex

139
Q

Women have increased _____ secretion during adolescence, as with _____, it speeds ____ closure.

A
  • estrogen
  • androgens
  • epiphyseal
140
Q

Estrogen promotes ____ accumulation (primarily in ____ and _____).

A
  • fat
  • breasts
  • hips
141
Q

Insulin has a ____ role in growth.

A

indirect

142
Q

Insulin is produced in _____.

A

pancreas

143
Q

Insulin is vital to ______ metabolism, stimulating the transportation of ____ and _____ _____ through membranes.

A
  • carbohydrate
  • glucose
  • amino acids
144
Q

Presence of insulin is necessary for the full functioning of ____.

A

GH

145
Q

Deficiency of insulin can …

A
  • decrease protein synthesis

- detrimental at any time in life but especially at growth

146
Q

One theory about cause of aging:

A
  • Suggests that over time the nervous system, endocrine system, and immune system gradually fail to function
  • Gradual failure can occur at different rates in the 3 systems
  • Imbalances and reduced effectiveness within systems leave older individuals at increased risk of disease
147
Q

____ function tends to decline with aging, making ____ disorders more prevalent among older adults. Long term increase in _____ hormone levels can be related to…

A
  • thyroid
  • thyroid
  • thyroid
  • congestive heart failure
148
Q

Hypothyroidism is associated with ….

A

acceleration of aging systems

149
Q

_____ hormone levels decrease with age, and _____ ______ therapy can counteract this.

A
  • gonadal

- hormone replacement theory

150
Q

Hormone replacement theory:

A
  • Ex. prescribing androgen supplements has been successful in countering muscle wasting and osteoporosis
  • Need more info on the side effects
151
Q

Incidence of ____ ____ diabetes increases markedly with age. Why?

A
  • type 2

- possible that older adults do not utilize insulin as effectively as younger adults to promote glycogen storage

152
Q

Nervous system is the site of ____, _____ and _____.

A
  • thinking
  • analysis
  • memory
153
Q

Development of nervous system is important to…

A
  • social
  • cognitive
  • motor development
154
Q

Genes directs the development of the nervous system’s …

A

structures and its main circuits

155
Q

Extrinsic factors effect the development of the nervous system by…

A

fine tuning finer connections between nervous system cells

156
Q

What 3 events occur prenatally in nervous system development?

A
  • Formation of immature neurons
  • Differentiation into general type
  • Migration to a final position in the nervous system
157
Q

Neurons:

A

cells of nervous system that receive and transmit information

158
Q

By______, almost all the neurons that human brain will ever have are formed

A

third and fourth prenatal months

159
Q

_____ receives impulses from other neurons.

A

dendrites

160
Q

_____ transmits impulses to other neurons, glands, organs, or muscles.

A

axons

161
Q

New neurons travel to a final destination during the ____ period. Some form the…

A
  • prenatal

- brainstem, cerebellum, cerebral cortex

162
Q

Generally, neurons are in their final location by …

A

the 6th prenatal month

163
Q

Neurons _____, then grow an _____.

A
  • specialize

- axon

164
Q

Synapse:

A
  • Connection between 2 neurons
  • Made by the release of chemicals called neurotransmitters from an axon
  • These neurotransmitters cross a small gap between neurons, then permeate the cell wall at the dendrite, or cell body, of a receiving neuron to trigger an electrical impulse
165
Q

Because of overproduction of neurons, ____ compete for the chemical trails. Some _____ and their ____ die off.

A
  • axons
  • axons
  • neurons
166
Q

Neurons fire _____ ____ that strengthen some of the connections between neurons. This is somewhat _____ prenatally and gets more organized as they grow and receive input from the ______.

A
  • electrical impulses
  • random
  • environment
167
Q

Describe how natural pruning occurs of both neurons and their branches and connections.

A

Weak or incorrect connections are sacrificed to make the neural network more efficient

168
Q

What parts of nervous system development is susceptible to effects of environmental factors delivered via the fetal nourishment system?

A
  • migration of neurons

- branching of their processes

169
Q

Faulty migration of neurons =

A

some disorders (epilepsy, autism, dyslexia)

170
Q

Nicotine might affect…

A
  • migration, branching, pruning of neurons

- increased risk of mental retardation

171
Q

Alcohol affects….

A
  • improper neuron migration

- babies with FAS known to exhibit lower IQ

172
Q

At birth, the brain is about ___% of its adult weight.

A

25%

173
Q

Brain growth increases rapidly after birth and reaches 80% of adult weight by age __. How does this happen?

A
  • 4

- Increase in the size of neurons, further branching to form synapses, increase in glia and myelin

174
Q

Glia:

A

Cells of the nervous system that support and nourish the neurons

175
Q

Myelin:

A

Insulating sheath around the axons

176
Q

Rapid growth in early postnatal period continues to make neurological development…

A

very susceptible to extrinsic factors

177
Q

Cerebral cortex:

A

Wrinkled surface of the brain containing millions of neurons and regulating many human functions and behaviours

178
Q

____ is one of the most significant extrinsic factors influencing postnatal development of the nervous system. The brain restructures itself with _____.

A

learning

179
Q

From early weeks of life and continuing over the lifespan, neural connections and pathways that are ______ are strengthened, those that are not used are _____.

A
  • stimulated

- weakened

180
Q

_____ ____ and _____ brain structures are more advanced at birth than _____ brain structures.

A
  • spinal cord
  • lower
  • higher
181
Q

Lower brain centres involved in vital tasks:

A
  • respiration
  • food intake
  • relatively mature
  • mediate many reflexes and reactions
182
Q

____ movement responses dominate fetus and newborn movements.

A

fetus

183
Q

____ is involved in purposeful, goal-directed movement.

A

cortex

184
Q

First clear evidence of successful intentional movement (reaching) occurs at ____ ____ months. Researchers assumed this signalled the first functioning of the ____.

A
  • 4-5 postnatal months

- cortex

185
Q

Most recently used ____ scans and found activity in the ____ _____ at ___ age, increased activity at ____ , and adult levels at _____.

A
  • PET
  • frontal cortex
  • 5 days
  • 11 weeks
  • 7-8 months
186
Q

Development of myelin in the myelin contributes to….

A

speedy conduction nerve impulses

187
Q

Myelin cells are made mostly out of ____.

A

fat

188
Q

Myelin cells:

A
  • Wrap around the outgoing neuron cell process (axon)

- myelinated axons can fire nerve impulses at higher frequencies and speeds for longer periods than those not myelinated

189
Q

Myelination:

A

The process whereby the axons of the neural cells are insulated when insulating myelin sheaths formed by Schwann (glial) cells wrap themselves around the axon

190
Q

Spinal cord at birth:

A
  • relatively small and short
  • Central area contains tightly packed neuron cell bodies
  • Roots lie just outside the cord, contain axons of the cord’s neurons and nerve cell bodies (sensory roots)
191
Q

Marked increase in the myelination of the peripheral nerves occurs ____ weeks after birth

A

2-3

192
Q

Nerve tracts = major _____ _____.

A

neurological pathways

193
Q

2 major motor tracts:

A
  • extrapyramidal

- pyramidal

194
Q

Extrapyramidal motor tract:

A

Involved in delivering the commands for both the random and postural movements made by the infant in the first days after birth

195
Q

Pyramidal motor tract:

A
  • Myelinates after birth

- Functioning by 4-5 months and controls the muscles for finger movements

196
Q

2 directions in the cord:

A
  • cervical portion

- lower portions

197
Q

2 horns:

A
  • motor (ventral) horns

- sensory (dorsal) horns

198
Q

Direction of myelination tends to be away from the ____ in the motor tracts.

A

brain

199
Q

_____ pathways mature slightly faster than ____ pathways.

A
  • sensory

- motor

200
Q

Neurogenesis:

A

division and propagation of neurons

201
Q

Repercussions of age-related losses in the nervous system are wide spread:

A
  • Can effect movements in recreational activities, ADL

- Performance of cognitive tasks

202
Q

Neural network model:

A
  • Nervous system is seen as a neural network of links and nodes
  • To respond to a stimulus, a signal begins at the input end of the individual’s nervous system and travels through the network to the output end
203
Q

What happens to the neural network model with aging?

A
  • Links break at random
  • Signal must detour
  • Increased response time
204
Q

Broken links in the neural network model is the result of:

A
  • Loss of neurons, dendrite, synapses

- Decline in neurotransmitters

205
Q

How does exercise help neural development?

A
  • Reduced risk of stroke
  • Increased branching of dendrites
  • Maintenance of the neuron’s metabolism
  • Maintains level of blood flow to brain
  • Lessens loss of dendrites
  • Stimulates neurogenesis
  • Promotes new synaptic connections
  • Improved cognitive function in older adulthood

KIN 207 (27 decks)

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