Bergdahl- Chapter 20

Question 1

describe the ducts of the endocrine system

Answer 1

no ducts ! they secrete substances directly into extracellular spaces around the gland

Question 2

what is a half-life ?

Answer 2

time required to reduce a hormone’s blood concentration by a half, and gives an indication on how long its effect persists

Question 3

how are steroid hormones different from amine and peptide hormones ?

Answer 3

they’re not soluble in blood plasma

Question 4

what are 4 ways that a hormone can specifically target a cell ?

Answer 4

1) modify rate of intracellular protein synthesis by stimulating nuclear DNA
2) change rate of enzyme activity
3) alter plasma membrane transport with a second-messenger system
4) induce secretion

Question 5

what is the first step in initiating hormone action ?

Answer 5

hormone-receptor binding

Question 6

what are the three things that a target cell’s activation by a hormone depends on ?

Answer 6

1) hormone concentration in blood
2) number of target cell receptors for hormone
3) sensitivity or strength of union between hormone and receptor

Question 7

what are 3 ways that a hormone can increase enzyme activity ?

Answer 7

1) stimulate its production
2) combine with it to alter its shape and ability to act, increasing or decreasing its catalytic effectiveness
3) activating inactive enzyme forms, therefore increasing total amount of active enzyme

Question 8

what are 4 factors that determine plasma concentration of a hormone ?

Answer 8

1) quantity synthesized in host gland
2) rate of catabolism or secretion in blood
3) quantity of transport proteins present
4) plasma volume changes

Question 9

what does “secreted amount” mean ?

Answer 9

the plasma concentration of a hormone
the sum of hormone synthesis and release by host gland, in addition to uptake by tissues and removal by liver and kidneys

Question 10

can changes in plasma volume alter hormone concentration ?

Answer 10

yeah, independent of the host organ’s secretion rate

Question 11

what is hormonal stimulation ?

Answer 11

hormones influencing secretion of other hormones (eg ACTH)

Question 12

what is humoral stimulation ?

Answer 12

changing levels of ions and nutrients stimulate hormone release (ADH, insulin)

Question 13

what is neural stimulation ?

Answer 13

neural activity affects hormonal release (catecholamines)

Question 14

what does a mean concentration of a hormone at a given time indicate ?

Answer 14

not much. the half-life and the pattern of release is much more significant

Question 15

what controls the 6 releasing factors (hypothalamic hormones) ?

Answer 15

neural input to the hypothalamus from anxiety, stress, physical activity

Question 16

what is growth hormone’s main mission ?

Answer 16

to promote cell division and cellular proliferation throughout the body

Question 17

in adults, what are the 3 ways that GH promotes protein synthesis ?

Answer 17

1) increase aa transport through membrane
2) stimulate RNA formation
3) activate ribosomes that increase protein synthesis

Question 18

what energy sources does GH promote or inhibit?

Answer 18

less protein and carbs, more fat utilization

Question 19

how does training affect GH?

Answer 19

extends GH’s action on target tissues

Question 20

what mediates GH’s effects ?

Answer 20

Insulin-like Growth Factors

Question 21

what is thyrotropin’s main role ?

Answer 21

thyrotropin = thyroid-stimulating hormone

controls hormone secretion by thyroid gland

Question 22

what is adenocorticotropic hormone’s main use ?

Answer 22

acts directly to enhance fatty acid mobilization and stimulate protein catabolism and increase gluconeogenesis

Question 23

what are the two hormones that mediate ACTH release ?

Answer 23

vasopressin and corticotropin-releasing hormone

Question 24

what is prolactin’s main role ?

Answer 24

initiates and supports milk secretion from mammary glands

Question 25

how do prolactin levels change in exercise ?

Answer 25

increase at high intensities and return to baseline within 45 min during recovery

Question 26

how is prolactin involved in training adaptations ?

Answer 26

exercise-induced release may inhibit ovarian function and contribute to menstrual cycle alterations

Question 27

what is the main role of gonadotropic hormones ? what are they called ?

Answer 27

stimulate male and female sex organs to grow and secrete hormones at faster rate follicle-stimulating hormone and luteinizing hormone

Question 28

what are the two posterior pituitary hormones ?

Answer 28

ADH and oxytocin

Question 29

what is the main role of ADH

Answer 29

anti-diuretic duh

Question 30

what happens to ADH during physical activity ?

Answer 30

stimulus for secretion in order to help conserve body fluids

Question 31

what does T4 do ?

Answer 31

raises metabolism of all cells except brain, spleen, sex, and thyroid gland

Question 32

what does T3 do ?

Answer 32

facilitates neural reflex activity

Question 33

how do thyroid hormones influence BP ?

Answer 33

by provoking an increase in adrenergic receptors in blood vessels

Question 34

what are 4 effects of hyperthyroidism ?

Answer 34

1) increased VO2 and metabolic heat production at rest 2) increased protein catabolism 3) heightened reflex ability- irritability, insomnia 4) rapid HR

Question 35

what are 4 effects of hypothyroidism ?

Answer 35

1) reduced metabolic rate 2) decreased protein synthesis 3) depressed reflex- sluggishness 4) slow HR

Question 36

what does parathyroid hormone do ?

Answer 36

control blood calcium balance | decrease in calcium triggers PTH release

Question 37

what hormones come out of the adrenal cortex ?

Answer 37

mineralocorticoids, glucocorticoid, and androgens

Question 38

what does aldosterone do ?

Answer 38

a mineralocorticoid, regulates minerals like Na+ concentration, stimulates ion reabsorption

Question 39

what does cortisol do ?

Answer 39

a glucocorticoid, promotes breakdown of energy sources

Question 40

what are distinctly male and female hormones ?

Answer 40

none

Question 41

what are the two hormones from the pancreas and where are they secreted ?

Answer 41

alpha cells: glucagon | beta cells: insulin

Question 42

is pancreas endocrine or exocrine ?

Answer 42

both. islets are endocrine, acini are exocrine

Question 43

how is GLUT 1 different from GLUT 4 in glucose transport ?

Answer 43

GLUT 1 moves glucose based on concentration difference | GLUT4 requires insulin to undergo a conformational change and transport glucose

Question 44

what directly controls insulin secretion ?

Answer 44

blood glucose levels in pancreas

Question 45

why does no excessive insulin release occur with a concentrated glucose feeding during physical activity ?

Answer 45

less blood flow to the pancreas since it's not a crucial organ

Question 46

what does glucagon do ?

Answer 46

"insulin antagonist" | stimulates glycogenolysis and gluconeogenesis, and increases lipid use too.

Question 47

does exercise training enhance GH secretion and conserve glycogen reserve ?

Answer 47

not really

Question 48

how is blood GH different in trained individuals ?

Answer 48

endurance-trained people have less of a rise in blood GH levels because there is less exercise stress

Question 49

how are women's GH levels different from men's in exercise ?

Answer 49

they're the same | women's are higher at rest

Question 50

how does training affect ACTH release ? how does this change the metabolism ?

Answer 50

increases release | therefore increases fat catabolism and spares glycogen

Question 51

how do prolactin levels differ in trained individuals ?

Answer 51

at rest, they're lower in male runners than in sedentary nonrunners

Question 52

how does reproductive response vary with physical activity level ?

Answer 52

exercise depresses reproductive hormone response lower testosterone levels for example lower FSH and LH in women

Question 53

what is the difference in LH and FSH levels between trained and untrained men ?

Answer 53

there is none | there's only lower levels in trained women

Question 54

how does exercise impact aldosterone levels ?

Answer 54

it doesn't

Question 55

how does exercise impact cortisol levels ?

Answer 55

levels increase less in trained people

Question 56

when can adrenal gland enlargement occur ?

Answer 56

with repeated bouts of intense exercise training

Question 57

how does catecholamine activity differ in trained individuals ?

Answer 57

in general there is a reduction in HR and BP, so lower levels HOWEVER, relatively, there is a higher response that occurs following aerobic training

Question 58

if there is a greater catecholamine output at the same relative exercise intensity following training, what 3 factors could explain the greater SNS activation ?

Answer 58

1) greater demand for substrate use 2) increased overall cardiovascular response 3) larger muscle mass activation

Question 59

how does glucagon and insulin concentration vary with training status ?

Answer 59

with time, trained have less and requires less

Question 60

what are 3 ways that exercise can improve insulin action ?

Answer 60

1) translocation of GLUT 4 from endoplasmic reticulium to cell surface 2) increase in total quantity of GLUT 4 3) increase in glycogen synthase activity and therefore storage

Question 61

what tissue consumes the major amount of glucose transported in blood ?

Answer 61

skeletal muscle

Question 62

how does intense exercise improve long term glycemic control ?

Answer 62

a bout decreases plasma glucose for a long time the immediate effects increase the active muscles' insulin sensitivity, which causes long-term improvement in glycemic contol

Question 63

what are the two primary hormones that affect adaptations to resistance training ?

Answer 63

GH and testosterone

Question 64

what are 3 hormonal factors responsible for exercise induced changes in muscle size and function ?

Answer 64

1) changes in hepatic and extrahepatic hormone clearance rates 2) differential rates of hormone secretion 3) altered receptor site activation via neurohumoral control

Question 65

what are short term effects of moderate and maximal exercise on the immune system ?

Answer 65

MODERATE: boosts natural immune function up to several hours EXHAUSTIVE: severely depresses the body's first line of defense due to strenuous exertion

Question 66

what are long term effects of aerobic exercise on immune system ?

Answer 66

positively affects natural immune function during weight loss

Question 67

what 2 areas of improvement of immune system in long-term aerobic exercise ?

Answer 67

1) enhanced functional capacity of natural cytotoxic immune mechanisms 2) diminished age-related decrease in T-cell function

Question 68

how does resistance training long term affect immune system ?

Answer 68

doesn't affect natural cytotoxic immune mechanisms