Chapter 20 Fleshcards

Exercise Physiology 365 with Bryner at West Virginia University

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By: Ben Jack
Created: 2011-10-31
Size: 143 flashcards
Views: 47

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The two categories of hormones are

Steroid-derived hormones and polypeptide hormones

Steroid hormones are (soluble/insoluble) in blood plasma; receptors are usually found _________.

Insoluble in blood plasma; receptors usually within the target cell

Polypeptide hormones are (soluble/insoluble) in blood plasma; receptors are usually located _________.

Soluble in blood plasma; receptors usually on cell membrane of target cell

The major function of hormones is

to alter the rates of cellular reactions of specific target cells.

The 4 mechanisms by which hormones work are:

1. Modifying the rate of intracellular protein synthesis via DNA stimulation

2. Changing rate of enzyme activity

3. Altering plasma membrane transport via 2nd messenger

4. Inducing secretory activity

Target cell's activation by hormone depends on 3 factors:

1. Blood hormone concentration

2. Relative number of target cell receptors for that hormone

3. Sensitivity/Strength of bond between hormone and receptor

_______ is an intracellular messenger produced from the binding hormone reacting to the enzyme andenylate cyclase.

Cyclic AMP

The "2nd Messenger" (___________) works by activating

Cyclic AMP works by activating a specific protein kinase, which then activates a target enzyme to alter cellular function

Hormones increase enzyme activity in one of 3 ways:

1. Stimulating enzyme production

2. Combining with the enzyme to alter its shape and ability to act (allosteric modulation)

3. activating inactive forms of the enzyme thereby increasing total amount of the enzyme

All protein hormones secrete in a ______ manner.

pulsatile

Plasma concentration of hormone depends on 4 factors:

1. Amount synthesized in host gland

2. rate of either catabolism or secretion into the blood

3. Quantity of transport proteins available (steroids only)

4. Plasma volume changes

Endocrine glands are stimulated by one of three methods:

1. Hormonal stimulation

2. Humoral stimulation

3. Neural Stimulation

The master gland is another name for the

pituitary gland

The pituitary gland is located

beneath the base of the brain

The pituitary gland secretes ______ different peptide hormones.

6 Different Hormones

The pituitary gland is controlled by

the Hypothalamus

The hypothalamus secretes ______________ for each of the primary hormones released from the anterior pituitary

Releasing Factors

The 6 hormones produced in the anterior pituitary are:

1. Growth hormone

2. Thyrotropin

3. Adrenocorticotropic hormone

4. Prolactin

5. Follicle-Stimulating hormone

6. Luteinizing hormone

Growth hormone is an insulin (agonist/antagonist).

Antagonist

Both fit and sedentary individuals show similar increases in GH when exercising to __________; sedentary individuals show greater response during _____________.

Exhaustion

Submaximal exercise

The cause of GH release during exercise is unknown. Three possibilities are:

1. Direct Stimulatory Effect

2. May stimulate cholinergic pathways to cause release

3. May work through endogenous opioids

The function of Insulin-like growth factors is to

mediate many of growth hormone's effects

_______ cells synthesize IGF-1 and IGF-2 in response to ________________.

Liver cells synthesize IGF in response to GH stimulation.

IGF is released ________ hours after GH stimulation

8 - 30 hours

Thyrotropin also known as Thyroid-Stimulating Hormone (TSH) is secreted from __________.

The Anterior Pituitary

The three functions of Thyrotropin are:

1. Controlling the amount of hormone secretion by the thyroid

2. Increases thyroid cell metabolism

3. Maintains growth and development of the thyroid gland

Increase in TSH occurs (consistently/inconsistently) in response to exercise.

inconsistently

Adrenocorticotropic Hormone (ACTH), also known as Corticotropin, in secreted from _________.

The Anterior Pituitary

ACTH functions as part of the __________axis and regulates hormones secreted by the _________.

The hypothalamic-pituitary-adrenal axis regulates secretion by the adrenal cortex

The three DIRECT actions of ACTH are:

1. Enhance FFA mobilization from adipose

2. Increase gluconeogenesis

3. Stimulate protein catabolism

Release of ACTH is controlled by _________ and _________.

Corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP)

Limited data has indicated that ACTH concentration may (increase/decrease) proportionally with exercise intensity and duration.

increase

Prolactin is secreted from _______.

the anterior pituitary

The main function of Prolactin is to

initiate and support milk secretion

Prolactin (increases/decreases) at high exercise intensities and recovers toward baseline within ____ minutes.

Increases, and recovers within 45 minutes

A consequence of repeated exercise-induced prolactin release is

alteration of the menstrual cycle

Gonadotropic hormones are secreted by

the anterior pituitary

The 2 gonadotropic hormones are

Follicle stimulating hormone (FSH) and Luteinizing hormone (LH)

In males, FSH functions to

aid in sperm development

In females, FSH functions to

initiate growth in the ovaries and stimulate them to secrete estrogen

In males, LH functions to

stimulate testes to release testosterone

In females, LH functions to

cause estrogen secretion and rupture of follicle

Gonadotropic hormones are released in a ________ manner.

pulsatile

_______ exercise may stimulate the release of gonadotropic hormones (especially _____ )

Acute exercise.......LH

______________________ training has been reported to decrease the pulse amplitude and frequency of gonadotropic hormones.

Chronic High-Intensity Aerobic Training

The posterior pituitary gland is an outgrowth of the ________, and is thus composed of ______ tissue

outgrowth of the hypothalamus, composed of nervous tissue

Hormones secreted from the _________ are actually made in the hypothalamus and then secreted into the _________ to be stored until needed.

posterior pituitary

The 2 hormones secreted by the posterior pituitary are:

ADH and Oxytocin

ADH functions to

stimulate water reabsorption in the kidneys, decreasing urine output

The 2 functions of oxytocin are

1. Initiating muscle contraction in uterus

2. Stimulating ejection of milk

Exercise (is/is not) and important stimulant for ADH secretion and release

exercise IS an important stimulant for ADH release

The thyroid is located

in the neck, just below the larynx

The two protein-iodine-bound hormones secreted by the thyroid are

Thyroxine (T₄) and Triiodothyronine (T₃)

Thyroxine (T₄) functions to raise the metabolism of all cells except

all cells except: brain, spleen, testes, uterus, and thyroid itself

An abnormal increase of thyroxine (T₄) raises BMR up to ____ times.

up to 4 times

Triiodothyronine (T₃) acts faster/slower than T₄, and is secreted more/less quantity than T₄.

T₃ acts faster than T₄, but is secreted in less quantity

Thyroid hormones provide important regulation for:

1. Tissue growth and development

2. Skeletal and nervous system formation

3. Maturation and reproductive capabilities

Thyroid hormones play a role in increasing blood pressure by causing

an increase in adrenergic receptors in blood vessels

During exercise, blood levels of free T4 increase by approx. ___%. (possibly caused by elevated ____)

Increase ~35% (possibly caused by elevated core temperature)

The parathyroid gland is made of ___ small glands embedded in the posterior aspect of the _________.

4 small glands in the posterior aspect of the thyroid gland

Blood calcium balance is controlled by

parathyroid hormone

Release of parathyroid hormones is triggered by a decrease in ________ and is inhibited by increasing levels.

blood calcium levels

Parathyroid hormone stimulates three target organs:

bone, kidney, and small intestine

Physical activity may __________ PTH, an effect that may contribute to the positive effects of exercise on _________.

may INCREASE PTH....positive effects of BONE MASS

The adrenal medulla is part of the _______ NS.

sympathetic

Adrenal medulla works to prolong sympathetic effects by secreting two hormones collectively called ________

catecholamines

The 2 catecholamines are

Epinephrine and norepinephrine

Norepinephrine serves as __________ precursor and also acts as a _________ when secreted by sympathetic nerve endings.

An EPINEPHRINE precursor...acts as a NEUROTRANSMITTER

Nerve impulses from the _________ stimulate adrenal medulla to increase catecholamines.

hypothalamus

Epinephrine's major effects are on the

heart, vessels, and glands

Norepinephrine inceases at ____% of VO₂ Max; Epinephrine increases at ____% of VO₂ Max

NE at 50%, epinephrine at 60%

Increased epinephrine from adrenal medulla is proportional to the _________ of exercise.

intensity/duration

The three types of hormones secreted by the adrenal cortex are

1. Mineralcorticoids

2. Glucocorticoids

3. Gonadocorticoids

Mineralcorticoids function to

regulate salts such as Na⁺ and K⁺ in the ECF

_______ is the most important mineralcorticoid, comprising ___% of all mineralorticoids.

Aldosterone is 95% of all mineralcorticoids

Aldosterone regulates _________ in the _______ of the kidneys.

sodium reabsorption in the distal tubules

For every Na⁺ reabsorbed in the kidneys, a _______ is secreted, which helps maintain proper mineral balance.

a K⁺ of H⁺ is secreted

Increased aldosterone triggers and increase in Na⁺ reabsorption resulting in

little Na+ or fluid voided in the urine

An increase in aldosterone triggers an increase in Q and BP via the ________ mechanism.

Renin-Angiotensin

Hypothalamus will release ____ causing the anterior pituitary to release ______ which promotes the release of glucocorticoids by adrenal cortex.

Corticotropin-releasing factor and ACTH

________ is the major glucocorticoid and affects the metabolism of

Cortisol affects metabolism of glucose, protein, and FFA

Glucocorticoids are ________ hormones with actions similar to certain sex steroids.

androgen

The primary gonadocorticoid is _______, which has effects similar to ____________.

DHEA similar to testosterone

Gonadocorticoids are responsible for small amounts of ________ and _________.

estrogen and progesterone

Testosterone initiates ____ production and __________ characteristics.

sperm production and male secondary sex characteristics

Testosterone causes ____ to be released.

In untrained males, both resistance exercise and moderate aerobic exercise increase serum and free levels after __________ minutes.

15 - 20 minutes

Testosterone interacts with neural receptors to ________ neurotransmitter release; alters ____of NMJ.

increases neurotransmitter release; alters size of NMJ

The two estrogens are

estradiol and progesterone

The three functions of progesterone are:

1. regulating female reproductive cycle

2. uterine smooth muscle contraction

3. lactation

The two functions of estradiol are:

1. increased FFA mobilization from adipose

2. inhibits glucose uptake by peripheral tissues

Oligomenorrhea is defined as

35 - 90 days between periods

Secondary amenorrhea is the cessation of mentruation due to

excessively low body fat

The three conditions of the Female Athlete Triad are:

1. Disordered eating

2. Amenorrhea

3. Osteoporosis

Disordered eating occurs in ___% of female athletes.

15 - 60 %

The prevalence of amenorrhea in weight-related sports ranges from ______% (versus 5% in general population).

25 - 65%

The 4 ways that estrogen affects bone metabolism are:

1. Increased intestinal calcium absorption

2. Reduced urinary calcium excretion

3. Inhibits bone resorption

4. Decreases bone turnover

The ASCM recommends intervention begins within _____ of onset of amenorrhea.

3 months

The 4 recommendations for remedying the female athlete triad are:

1. Reduce training level by 10 - 20%

2. Gradually increase energy intake

3. Increase bodyweight 2 - 3%

4. Maintain calcium intake of 1500 mg daily

The pancreas is located ________ and secretes __________.

located below the stomach, secretes insulin and glucagon

The pancreas is composed of two different types of tissues:

1. Acini (exocrine function)

2. Islets of Langerhans (endocrine cells)

The Acini secrete

digestive juices

Glucagon is secreted by ______; insulin is secreted by ________

Glucagon secreted by α-cells; insulin secreted by β-cells, both types in the islets of langerhans

Glucagon is an insulin (agonist/antagonist) whose main function is to

antagonist; main function is to stimulate glycogenolysis and gluconeogenesis by the liver

Glucagon is regulated by

the amount of glucose in the bloodTh

The major function of insulin is to regulate glucose entry into all tissues except

the brain

Secretion of insulin is directly controlled by ______ in the blood that passes through ______.

glucose levels in the blood, passes through pancreas

Non-insulin glucose transporter is called _____; insulin-mediated glucose transporter is called ______

GLUT-1 and GLUT-4

At rest, most glucose enters the cell by a ______ carrier.

GLUT-1

When glucose and insulin levels are high or during exercise, most glucose enters the muscle by _____ transporter.

GLUT-4

GLUT-4 is expressed exclusively in these 3 tissues:

1. Cardiac muscle

2. Skeletal muscle

3. Adipose tissue

GLUT-4 is specifically responsible for glucose utilization that is stimulated by _____.

insulin

Exercise increases peripheral clearance in the presence of insulin through an _____ and an ______ mechanism.

insulin-dependent and insulin-independent mechanism

During rest, GLUT-4 resides near

the T-tubules of the sarcoplasmic reticulum

When there is an influx of ions such as Na⁺ or Ca²⁺, what does GLUT-4 do?

It relocates to the cell surface through a separate insulin-independent mechanism to promote glucose uptake.

Why does exercise facilitate blood glucose transport?

there are more transporters present (GLUT-4 relocates to cell surface)

During exercise, insulin levels ____ significantly, most likely due to ______.

insulin decreases, most likely due to epinephrine which suppresses insulin secretion

Levels of insulin ____ as a function of exercise duration and intensity.

decrease

Acute exercise takes away the inhibitory effects of insulin on

gluconeogenesis

Acute exercise minimizes glucose uptake by

inactive tissues

With prolonged exercise, glucose and insulin decrease which enhances ____ and ____ availability.

lipolysis and FFA availability.

Described the effects of exercise on insulin levels in trained versus untrained subjects.

insulin levels do not fall as far in TRAINED individuals

___% of cardiac patients have diabetes.

40%

Diabetes is the ___ leading cause of death by disease.

6th

A RANDOM blood glucose of greater than or equal to___ mg/dL is indicative of diabetes.

200 mg/dL

A FASTING blood glucose of greater than or equal to ____mg/dL is indicative of diabetes.

126 mg/dL

A FASTING blood glucose of greater than or equal to ____ mg/dL is indicative of impaired glucose tolerance.

110 - 125

Explain the Oral Glucose Tolerance Test. What criteria indicative of diabetes? of impaired glucose tolerance?

Ingest a glucose drink, then 2 hours later glucose readings taken.

A positive reading for diabetes is >200 mg/dL

A positive reading for impaired glucose tolerance is 140 - 200 mg/dL

Define diabetes.

A syndrome characterized by hyperglycemia resulting from impaired insulin secretion and/or effectiveness.

Type 1 diabetes represents ___% of all diabetes cases.

5 - 10%

Type 1 diabetes is characterized by

an absolute deficiency of insulin

Which type of diabetes is more severe for glucose homeostasis, especially during exercise?

Type 1

How many cases of diabetes are there in the U.S.?

about 16 million

Type 2 diabetes is related to 3 factors:

1. inability to respond properly to insulin's actions

2. abnormal but relatively well-maintained insulin secretion

3. increased hepatic glucose production

What capacities of skeletal muscle are negatively affected by insulin resistance?

glycolytic and oxidative capacities

What are the 5 benefits of physical activity as it relates to Type 2 diabetes?

1. decreased plasma glucose levels

2. reduced CVD risk

3. weight loss

4. psychological profile

5. delayed onset/prevention of disease

Three potential systemic problems when exercising with type 2 diabetes are:

1. retinal hemorrhage

2. proteinuria

3. macrovascular lesions

4 potential cardiovascular problems when exercising with type 2 diabetes are:

1. cardiac arrhythmia

2. ischemic heart disease

3. high BP

4.post-exercise orthostatic hypertension

2 potential metabolic problems when exercising with type 2 diabetes are:

1. hyperglycemia

2. ketosis

3 potential musculoskeletal problems when exercising with type 2 diabetes are:

1. Foot ulcers

2. neuropathy-related injury

3. degenerative joint disease

Short-term exercise, lasting ____ minutes, causes few changes in immune system. Long-term exercise, lasting _____ minutes alters the immune system for ___ hours post-exercise.

short-term exercise lasts 5 - 75 minutes

long-term exercise lasts 90 or more minutes, alters immune system for 3- 72 hours

Describe the "Open-Window" Hypothesis. How long does the immunodepression last?

Immune system is elevated during both moderate and severe exercise, but sever is followed by immunodepression.

The immunodepression may last for 1 - 24 hours

About this deck

By: Ben Jack
Created: 2011-10-31
Size: 143 flashcards
Views: 47

About StudyBlue

“I have been getting MUCH better grades on all my tests for school. Flash cards, notes, and quizzes are great on here. Thanks!”
Kathy