Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

EPHE 441 > Hormonal Responses to Exercise > Flashcards

Hormonal Responses to Exercise Flashcards

1
Q

How do the two systems in the neuroendocrine response function?

A

Nerves use NT (synaptic signals) to relay from nerve-nerve or nerve-tissue. Endocrine system releases hormones (endocrine signals) into blood to circulate tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the classes of hormones?

A

Amino acid derivatives, proteins, peptides, and steroids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the plasma hormone concentration dependent on?

A

1) The hormone secretion rate from the endocrine gland
2) The rate of hormonal metabolism or excretion
3) Transport protein quantity (for lipid based hormones)
4) Changes in plasma volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What influences when the pancreas releases insulin into the blood?

A

1) Concentration changes in: plasma glucose, epinephrine, amino acids
2) Increased sympathetic (norepi) and sympathetic (ACh) activity
3) Incretins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What causes insulin secretion to increase?

A

Concentration changes in: plasma glucose, epinephrine, amino acids
Incretins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What causes insulin secretion to decrease?

A

Increased sympathetic (norepi) and sympathetic (ACh) activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are incretins?

A

Hormones secreted by a group of endocrine cells in the digestive tract when food is being digested

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What hormones are bound to transport proteins?

A

Steroids and thyroxine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What do capacity and affinity refer to?

A

Capacity is the maximal quantity of a hormone than can be bound to a protein and affinity is the tendency of the transport protein to bind to the hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What mechanisms can hormones use to modify cellular activity?

A

1) Altering activity of DNA in the nucleus to imitate or suppress the synthesis of a specific protein
2) Activation of special proteins in the cells by “second messengers”
3) Alteration of membrane transport mechanisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How do hormones alter the activity of DNA in the nucleus to imitate or suppress the synthesis of a specific protein?

A

1) Hormone passes through plasma membrane
2) Inside target cell the hormone binds to a receptor protein in the cytoplasm or nucleus
3) Hormone-receptor complex binds to hormone response element on DNA, regulating gene transcription
4) Protein synthesis
5) Change in protein synthesis is cellular respone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is a second messenger?

A

A G Protein: G proteins are the link between the hormone-receptor on the surface and the subsequent events within the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What occurs if a G protein activates adenylate cyclase?

A

1) Cyclic AMP is formed from ATP.
2) Cyclic AMP activates protein kinase A which activates response proteins
3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What inactivates cyclic AMP?

A

Phosphodiesterase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the mechanism of activating adenylate cyclase used for?

A

Breaking down glycogen to glucose or breaking down triglycerides to FFA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the two lobes of the pituitary gland?

A

Anterior (adenohypophysis) and posterior (neurohypophysis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What affects the release of hormones from the anterior pituitary?

A

Controlled by releasing hormones which originate in the hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What affects the release of hormones from the posterior pituitary?

A

Receives hormones from special neurons originating in the hypothalamus. Travels down axon to blood vessels in posterior hypothalamus where they are released into general circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the anterior pituitary hormones?

A

Adrenocorticotrophic hormone (ACTH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), melanocyte-stimulating hormone (MSH), thyroid-stimulating hormone (TSH), growth hormone (GH), and prolactin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why is prolactin different from the other anterior pituitary hormones?

A

It directly influences an action (production of breast milk) while the others trigger the release of other hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does the thyroid stimulating hormone (TSH) do?

A

Controls the rate of thyroid hormone secretion and formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does adrenocorticotropic hormone (ACTH) do?

A

Stimulates production and secretion of cortisol in the adrenal cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does luteinizing hormone (LH) do?

A

Stimulates testosterone (testes) and estrogen (ovaries)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does growth hormone (GH) do?

A

Stimulates release of insulin like growth factors from liver and other tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How does insulin like growth factor influence muscle hypertrophy?

A

Its produced in muscle due to muscle contraction acts locally via autocrine and paracrine mechanisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the factors responsible for the stimulation and the inhibition of growth hormone?

A

Stimulating: Growth hormone releasing hormone
Inhibition: hypothalamic somatostatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What input can cause the hypothalamus to increase growth hormone production?

A

Exercise, stress, low plasma glucose concentration, and sleep

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How does growth hormone influence plasma glucose concentrations?

A

1) opposes the action of insulin to reduce the use of plasma glucose
2) Increases the synthesis of new glucose in the liver from amino acids, glycerol, and lactate
3) increases mobilization of fatty acids from adipose tissue to increase the use of fat as a fuel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Why does growth hormone increase during exercise?

A

To mobilize FFA from adipose tissue and aid in maintenance of blood glucose levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are the posterior pituitary hormones?

A

Oxytocin and antidiuretic hormone (ADH)

31
Q

What does antidiuretic hormone do?

A

Reduces water loss

32
Q

What stimuli cause an increase of ADH?

A

1) High plasma osmolality than can be the result of excessive sweating without fluid replacement
2) Low plasma volume either due to loss of blood or inadequate fluid replacement

33
Q

What causes the release of thyroxine from the thyroid gland?

A

Thyroid stimulating hormone

34
Q

What does thyroxine do?

A

Maintains metabolic rate. Part of a self-regulating system that controls release of TSH-releasing hormone and TSH.

35
Q

Where are epi and norepi released from?

A

The adrenal gland (adrenal medulla)

36
Q

What is the adrenal glands main hormone?

A

epi (80%)

37
Q

What systems, organs, tissues, etc. does epi affect?

A

Cardiovascular and respiratory, GI tract, liver, other endocrine glands, muscles, adipose tissue

38
Q

What hormones does the adrenal cortex secrete?

A

Mineralocorticoids (aldosterone), glucocorticoids (cortisol), and sex steroids (androgens and estrogen)

39
Q

What is the function of aldosterone?

A

regulates Na+ reabsorption and K+ secretion in kidney. Directly involved in Na+/h2o balance, and therefore plasma volume and blood pressure.

40
Q

How is a negative feedback loop used in terms of aldosterone secretion?

A

Increase in K+ triggers an increase in aldosterone secretion, which stimulates kidneys to transport more K+

41
Q

How is aldosterone secretion regulated by the renin-angiotensin system?

A

A decrease in plasma volume, BP, or increased symp activity stimulates kidneys to produce renin. Renin converts angiotensinogen in plasma to angiotensin I and eventually angiotensin II by angiotensin converting enzyme in lungs (ACE). Angiotensin II stimulates aldosterone release which increases Na+ reabsorption

42
Q

How do renin and aldosterone levels adjust with exercise?

A

Light=little to no change
Light with heat= increase in both renin and aldosterone secretion
50%VO2 max= parallel increase in aldosterone, renin, and angiotensin II.

43
Q

What physiological mechanisms is cortisol responsible for?

A

1) Promotes the breakdown of tissue protein (INH synthesis) to form amino acids which the liver uses to form new glucose
2) stimulates metabolism of FFA from adipose tissue
3) Stimulates liver enzymes involved in metabolic pathways leading to glucose production
4) Blocks entry of glucose into tissues forcing tissues to use FFA as fuel

44
Q

What is general adaptation syndrome?

A

The increase in ACTH and cortisol in response to a wide variety of stressful environments

45
Q

What are the three stages of general adaptation syndrome?

A

1) Alarm reaction, involves cortisol secretion
2) Stage of resistance, where repairs are made
3) Stage of exhaustion, where repairs are not adequate and sickness or death results

46
Q

What hormones are produces by the pancreas?

A

Insulin, glucagon, somatostatin

47
Q

What does insulin do?

A

Stimulates tissues to uptake nutrients such as amino acids and glucose and store them as glycogen, proteins, and fats. facilitates diffusion of glucose across cell membranes

48
Q

What happens when there is a lack of insulin?

A

Glucose accumulates in plasma. If glucose plasma volumes are too high they reabsorption mechanism in the kidneys becomes overwhelmed=diabetes mellitus

49
Q

What factors influence insulin secretion?

A

Plasma glucose concentration, plasma amino acid concentration, sympathetic and parasympathetic stimulation, and other hormones

50
Q

What does glucagon do?

A

Stimulates the mobilization of both glucose from liver and FFA from adipose tissue

51
Q

What stimulates glucagon secretion?

A

Low plasma glucose concentrations

52
Q

Where is testosterone produced and what controls its secretion?

A

Testes, interstitial cell stimulating hormone aka Luteinizing hormone

53
Q

What hormones make up estrogen?

A

Estradiol (main one), estrone, and estriol.

54
Q

What are the four mechanisms by which plasma glucose concentrations are protected?

A

1) Mobilization of existing glucose from liver glycogen stores
2) Mobilization of FFA from adipose tissue to increase the use of fat as a fuel, sparing plasma glucose
3) synthesize new glucose from amino acids a glycerol and lactate (gluconeogenesis)
4) Blocking of glucose entry into cells forcing cells to use FFA

55
Q

How is glycogenolysis initiated?

A

By second messengers which activate protein kinases in muscle cells. Plasma epinephrine when bound to beta-adrenergic receptors is a potent stimulator

56
Q

How is calmodulin associated with glycogen breakdown?

A

During muscle contraction, calcium floods the sarcomere. Some initiates contraction, some binds to calmodulin. The increased intracellular concentration of calcium acts as the initial event stimulating muscle glycogen breakdown

57
Q

What hormones act permissively and are slow-acting?

A

Thyroxine, cortisol, and growth hormone

58
Q

Why are T3 and T4 improtant?

A

For determining metabolic rate and allowing hormones to exert their full effect (permissive)

59
Q

How do T3 and T4 act permissively?

A

Influence the number or receptors or the affinity of the receptors. E.G. without T3, epi would have little effect on the mobilization of FFA

60
Q

What role do T3 and T4 play during exercise?

A

“Free” T3 increases during exercise, T3 and T4 are removed from plasma at greater rate than at rest. TSH secretion from ant.pit. is increased stimulating the secretion of T3 and T4

61
Q

How does growth hormone support the action of cortisol?

A

1) Decreases glucose uptake by tissue
2) Increases FFA mobilization
3) Enhances gluconeogenesis in liver

62
Q

In what cases to the effects of epi and norepi differ?

A

Epi is more responsive to changes in plasma glucose concentration. Low glucose stimulates hypothalamus to increase epi secretion, only moderate effects of norepi
When BP is challenged, e.g. with an increased heat load, the primary catecholamine is norepi

63
Q

How does endurance training effect plasma epi and norepi levels?

A

Decreases plasma volumes. Reduction of glucose metabolism also occurs with endurance training

64
Q

How does physical training affect the sympathetic nervous system?

A

Increases its capacity. catecholamine responses approximately 35% higher in trained individuals

65
Q

How does long-term exercise effects of insulin influence plasma glucagon levels?

A

They increase. This favors mobilization of FFA from adipose tissue and glucose from liver. Also increases gluconeogenesis

66
Q

Why do trained individuals exhibit improved counter-regulatory control of insulin and glucagon?

A

Endurance trained individuals have an increased glucagon sensitivity in their liver due to an increased glucagon receptor density, a decrease in glucose uptake by muscle, and an increase in the muscle use of fat as a fuel

67
Q

How does the nervous system modify the secretion of insulin and glucagon?

A

Under stable conditions, epi and norepi stimulate alpha-adrenergic regions on beta cells in pancrease to decrease insulin production. Stimulate beta-adrenergic cells on alpha cells when to increase glucagon production

68
Q

How does the glucose uptake rate increase by 7-20 percent during exercise if the insulin concentration is decreased?

A

Blood flow is increased to working muscle. Glucose delivery is a combination of muscle blood flow rate and blood glucose concentrations. Because muscle is using glucose at a higher rate, its diffusion gradient is higher. Exercise also increases the number of glucose transporters on the cell membrane

69
Q

What is the cellular signaler for glucose transporter activation?

A

Calcium. Exercise increases intramuscular calcium concentrations which in turn recruits inactive glucose transporters so that more glucose is transported for the same concentration of insulin

70
Q

How does FFA delivery capacity change at different exercise intensities?

A

Highest at 25% VO2 max, decreased at 65% and 85% VO2 max

71
Q

How do blood lactate levels influence FFA mobilization?

A

When blood lactate levels are increased, there is also an increase in alpha glycerol phosphate which is the activated form of glycerol used to form triglycerides. So as fat is burned, it is created just as quickly.

72
Q

What are the four reasons FFA mobilization decreases during heavy exercise?

A

1) Higher H+ levels which may inhibit HSL
2) Increased lactate=increased triglycerides
3) inadequate blood flow to adipose tissue (hypoxia)
4) insufficient albumin to transport the FFA in the plasma

73
Q

What are the six ways that cortisol affects glucose, protein, and FFA metabolism?

A

1) Promotes breakdown of amino acids into proteins
2) supports actions of other hormones
3) serves as an insulin antagonist by inhibiting cellular glucose uptake and oxidaiton
4) promotes triglycerol breakdown to glycerol and FFA
5) suppresses immune system function
6) produces negative calcium balance

EPHE 441 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions