Ch. 17 - Endocrine System Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Endocrine system

A

composed of ductless glands of epithelial tissue within a connective tissue framework that synthesize and secrete hormones to be transported to target cells.

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

target cells

A

have specific receptors for a hormone

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

How do hormones travel

A

Hormones are released into interstitial fluid and then into the blood where they are transported. They randomly leave the blood and enter into interstitial fluid where they bind to target cells’ receptors.

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

Nervous system vs. Endocrine

A

Both are the control systems of the body and release ligands that bind to receptors on particular target cells. Unlike nervous, endocrine is more widespread and transfers hormones everywhere, has longer reaction times and effects

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

Functions of the Endocrine system

A

regulating development, growth, and metabolism, maintaining homeostasis of blood comp. and volume, controlling digestive processes and reproductive activities

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

Regulating development, growth, and metabolism

A

regulate embryonic cell division and differentiation. Regulate metabolism (anabolism and catabolism.

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

ligands

A

chemical messangers

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

maintaining homeostasis of blood comp & volume

A

regulate blood solute concentrations, blood volume, cellular concentration, and platelet #

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

controlling digestive processes

A

hormones influence secretory processes and movement of materials in digestive tract

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

controlling reproductive activities

A

hormones affect development and function of reproductive systems and the expression of sexual behaviors.

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

Endocrine glands with solely endocrine function

A

pituitary, pineal, thyroid, parathyroid, adrenal

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

endocrine cells found in clusters in organs with other functions

A

hypothalamus, skin, thymus, heart, liver, stomach, pancreas, small in., adipose ct, kidneys, gonads

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

hormonal stimulation

A

a gland cell releases its hormone when some other hormone binds to it

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

humoral stimulation

A

a gland cell releases its hormone when there is a certain change in levels of a nutrient or ion in the blood.

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

nervous stimulation

A

a gland cell releases its hormone when a neuron stimulates it.

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

Steroids

A

lipid-soluble made from cholesterol
gonadal steroids (estrogen) adrenal steroids (cortisol)
calcitriol is more accurately a sterol

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

biogenic amines (monoamines)

A

modified amino acids, water soluble except for TH.

Includes catecholamines, thyroid hormone, melatonin

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

Thyroid hormone

A

a biogenic amine made from a pair of tyrosines. is nonpolar and lipid soluble.

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

Proteins

A

most hormones, water-soluble chain of amino acids

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

Local hormones

A

signaling molecules that don’t circulate in blood

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

Eicosanoids

A

type of local hormone formed from fatty acids within phospholipid bilayer of membrane. Synthesized through an enzymatic cascade; stimulate pain and inflammatory response. NSAIDS block prostaglandins (type of eicosanoid)

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

Eicosanoid formation

A

Phospholipase A2 removes arachidonic acid from phospholipid. Other enzymes then convert arachidonic acid to a type of eicosanoid

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

Water-soluble hormones

A

are polar and can’t diffuse so must use membrane receptors. Goes through a signal transduction pathway. This works in that the hormone (first messenger) binds to a receptor on cell membrane. this activates a g-protein which causes activation of a membrane enzyme (like adenylate cyclase). This activated enzyme makes the second messenger- the chemical that modifies cellular activity.

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

Action/Results of water-soluble hormones

A

with different signal transduction pathways comes different results. Enzymes can be activated/inhibited, muscles contract/relax, membrane permeability changes, cellular secretions released, growth stimulated.

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

Hormone interactions on target cell

A

different hormones bind simultaneously and can react as synergistic, permissive, or antagonistic

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

Synergistic interactions

A

One hormone reinforces activity of another hormone. ex: estrogen and progesterone.

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

Permissive interactions

A

One hormone requires activity of another hormone. ex: for oxytocin to stimulate milk ejection there has to be prolactin to make milk.

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

Antagonistic interactions

A

One hormone opposes activity of another hormone. ex: glucagon vs. insulin

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

Hypothalamus controls the…

A

pituitary gland.

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

Pituitary gland controls the…

A

thyroid, adrenal glands, liver, testes, ovaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Pituitary gland

A

known as hypophysis. Lies inferior to hypothalamus in sell turcica of sphenoid. It is pea-sized and connected to hypothalamus via the infundibulum. portioned into anterior and posterior parts.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Posterior Pituitary

A

neurohypophysis. smaller part of pituitary that has hypothalamic neurons that project through infundibulum and release hormones in post. pit.
Somas in paraventricular nucleus and supraoptic nucleus
Axons in hypothalmo-hypophyseal tract of infundibulum
Synaptic knobs in pars nervosa.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Anterior Pituitary

A

hypothalmo-hypophyseal portal system of blood vessels connects hypothalamus to ant. pit.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Hypothalamo-hypophyseal portal system

A

has primary plexus (capillary network near hypothalamus), secondary plexus (capillaries near ant. pit. and hypophyseal portal veins that drain primary plexus to transport to secondary.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Interactions between hypothalamus and posterior pituitary

A

Posterior pit. stores and releases oxytocin (ot) and antidiuretic H (ADH). These hormones are made in hypothalamus’ neurosecretory cells, packed into vesicles, transported via fast axonal transport and released from synaptic knobs when neurons fire.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Antidiuretic hormone (vasopressin)

A

made in supraoptic nucleus. Functions to decrease urine production, stimulate thirst, and constrict blood vessels.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Oxytocin

A

made in paraventricular nucleus. Functions: uterine contraction, milk ejection, emotional bonding.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Interactions between hypothalamus and anterior pituitary

A

hypothalamus hormonally stimulates anterior pituitary to release hormones. Hypothalamus secretes regulatory hormones that travel via portal blood vessels to pituitary. This causes ant. pit. to secrete hormones into general circulation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Hormones of the hypothalamus

A

releasing hormones, inhibiting hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Releasing hormones

A

Increases secretion of ant. pit. hormones. Includes thyrotropin-releasing hormone, prolactin-releasing hormone, gonadotropin RH, corticotropin RH and growth hormone RH.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Inhibiting hormones

A

decrease secretion of anterior pituitary hormones. Includes Prolactin-inhibiting hormone and growth-inhibiting hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Hormones of anterior pituitary

A

TSH, PRL, adrenocorticotropic hormone (ACTH), gonadotropins (FSH & LH), Growth hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Thyroid-stimulating hormone (TSH)

A

release is triggered by TRH from hypothalamus. Causes release of thyroid hormone from thyroid gland. (released by ant. pit.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Prolactin (PRL)

A

release triggered by PRH, inhibited by PIH from hypothalamus. Causes milk production, mammary gland growth in females. (released by ant. pit.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Adrenocorticotropic hormone (ACTH)

A

release is triggered by CRH (corticotropin releasing hormone). causes release of corticosteroids by adrenal cortex. (released by ant. pit.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Gonadotropins

A

Follicle-stimulating hormone (FSH) and luteinizing hormone (LH). In females, these regulate ovarian development and secretion of estrogen and progesterone. In males these help with sperm development and secretion of testosterone. (released by ant. pit.)

47
Q

Growth Hormone (GH, Somatotropin)

A

causes liver to secrete insulin-like growth factors 1 & 2. (IGFs). GH and IGFs function synergistically to stimulate cell growth and division. Regulation of release is controlled through hormonal stimulation (GHRH & GHIH) from hypothalamus… amount of GHRH released is determined by age, time, nutrient levels and exercise.

48
Q

Effects of growth hormone (what it does)

A

stimulates IGFs (similar function to GH) from liver - all cells have receptors for IGF or GH. Stimulates increased protein synthesis, cell division, cell differentiation, release of nutrients from storage… Stimulates glycogenolysis, gluconeogenesis, lipolysis and inhibits glycogenesis and lipogenesis.

49
Q

gluconeogenesis

A

conversion of nutrients (outside food) to glucose.

50
Q

Anatomy of thyroid gland

A

inferior to thyroid cartilage of larynx, anterior to trachea. broken into two lobes, left and right connected at midline by an isthmus. Vascularization gives it a red color. Composed of follicles.

51
Q

follicular cells

A

cuboidal epithelial cells surrounding a central lumen in the thyroid gland, synthesize thyroglobulin and TH

52
Q

colloid

A

a viscous, protein-rich fluid that is housed in thyroid gland’s follicle lumen.

53
Q

parafollicular cells

A

cells between follicles that make calcitonin

54
Q

calcitonin

A

synthesized and released from parafollicular cell of thyroid. hormone that decreases blood calcium levels and can be stimulated by stress from exercise. Inhibits osteoclast activity; stimulates kidneys to increase calcium excretion

55
Q

iodine

A

required to make thyroid hormone where it goes through a series of steps in the thyroid

56
Q

T3

A

triiodothyronine (3 iodo made in thyroid) t3 and 4 are moved by carrier molecules. T3 is partially inactivated

57
Q

T4

A

tetraiodothyronine (thyroxine) most target cells convert this to t3 (more active form), but thyroid gland produces more T4

58
Q

Hypothalamic-pituitary-thyroid axis

A

refers to the set of steps and the link between the organs in order to get something done. For example: cold temp, hypoglycemia, high altitude etc. causes hypothalamus to release TRH. TRH causes ant. pit. to release TSH. TSH binds to follicular cell’s receptors which triggers release of TH. Release two forms of TH, T3 and T4.

59
Q

Thyroid hormone

A

increases metabolic rate and protein synthesis in targets. stimulates synthesis of sodium-potassium pumps in neurons. Stimulates increased amino acid and glucose uptake and increases # of cellular respiration enzymes within mitochondria. Fosters ATP production.

60
Q

calorigenic

A

something that generates heat and raises temperature. (TH is calorigenic)

61
Q

hyperthyroidism

A

results from excess TH production. Increased metabolic rate, weight loss, hyperactivity, heat intolerance. Caused by t4 ingestion, excessive pituitary stimulation, or loss of feedback control in thyroid (graves disease). treated by removing the thyroid and giving hormonal supplements.

62
Q

hypothyroidism

A

results from decreased production of TH. low metabolic rate, lethargy, cold intolerance, weight gain. caused by decreased iodine intake, loss of pituitary stimulation of thyroid, or destruction of thyroid (hashimotos thyroiditis) treated with thyroid hormone replacement.

63
Q

goiter

A

enlargement of thyroid usually due to insufficient dietary iodine preventing thyroid from producing TH. Not common in US since iodine was added to table salt.

64
Q

Anatomy of adrenal gland

A

on superior surface of each kidney. retroperitoneal; embedded in fat and fascia. contains two regions: medulla and cortex.

65
Q

Adrenal medulla

A

forms inner core of each adrenal gland. Red-brown due to blood vessels. Releases epinephrine and norepinephrine with sympathetic stimulation.

66
Q

Adrenal cortex

A

synthesizes over 25 corticosteroids. Yellow due to lipids. has 3 regions producing different steroid hormones: zona glomerulosa, fasciculata, and reticularis.

67
Q

Hormones of the adrenal cortex

A

mineralocorticoids, glucocorticoids, gonadocorticoids, cortisol.

68
Q

Mineralocorticoids

A

hormones that regulate electrolyte levels. Made in zona glomerulosa (thin outer layer)

69
Q

Aldosterone

A

type of mineralocorticoid that fosters Na retention and K secretion

70
Q

Glucocorticoids

A

hormones that regulate blood sugar; made in zona fasciculata (larger, middle adrenal cortical layer)

71
Q

effects of cortisol

A

type of glucocorticoid that causes target cells to increase blood nutrient levels. Liver cells increase glycogenolysis and gluconeogenesis; decrease glycogenesis. Adipose cells increase lipolysis and decrease lipogenesis. Many body cells break down proteins to amino acids. Liver cells use amino acids for gluconeogenesis. Most cells decrease glucose uptake, raising bg.

72
Q

Gonadocorticoid

A

sex hormones; made in zona reticularis (thin, inner layer)

73
Q

Androgens

A

male sex hormones made by adrenals; converted to estrogen for females. Amnt. produced from adrenals is less than testes.

74
Q

Theraputic doses of corticosterone

A

used to treat inflammation. Inhibits inflammatory agents and suppresses immune system. At high doses it increases risk of infections, cancer, retention of h20 and sodium, and inhibits ct repair.

75
Q

Cushing syndrome

A

chronic exposure to excessive glucocorticoid hormones in people taking corticosteroids or adrenal gland produces too much. Symptoms include obesity, hypertension, excess hair growth, kidney stones, and menstrual irregularities.

76
Q

Addison disease

A

adrenal insufficiency; chronic shortage of glucocorticoids and sometimes mineralocorticoids. May develop from lack of ACTH or lack of response to it. Symptoms include weight loss, fatigue, weakness, hypotension, skin darkening. Oral corticosteroids treat it.

77
Q

adrenogenital syndrome (congenital adrenal hyperplasia)

A

inability to synthesize corticosteroids which leads to overproduction of ACTH. high ACTH increases size of adrenal gland and production of testosterone-like hormones. This masculinizes hormones

78
Q

Stress Response

A

stressors elicit hypothalamus to initiate a neuroendocrine response. 3 stages

79
Q

3 stress response stages

A

alarm reaction (initial response of epinephrine release and SNS activation), stage of resistance (occurs after depletion of glycogen stores, adrenal secretes cortisol to raise bg to help meet energy demands), and stage of exhaustion (after weeks or months in a stress response, depletion of fat stores results in protein breakdown for energy leading to weakening of the body and illness)

80
Q

Anatomy of the pancreas

A

behind stomach, b/w duodenum and spleen.

81
Q

Acinar cells

A

pancreatic cells that generate exocrine secretions for digestion. They make up the vast majority of the pancreas as saclike acini

82
Q

Pancreatic islets (of Langerhans)

A

contain clusters of endocrine cells (alpha and beta cells)

83
Q

alpha cells

A

pancreatic cells that secrete glucagon

84
Q

beta cells

A

pancreatic cells that secrete insulin

85
Q

delta cells

A

secrete somatostratin

86
Q

f cells

A

secrete pancreatic polypeptide

87
Q

normal bg

A

70-110

88
Q

diabetes mellitus

A

inadequate uptake of glucose from blood. chronically elevated glucose, blood vessel damage. leading cause of retinal blindness, kidney failure, and nontraumatic amputations in US. associated w/ increased heart disease and stroke

89
Q

type 1 diabetes

A

absent or diminished release of insulin by pancreas, occurs in younger individuals. autoimmune, requires daily injections

90
Q

type 2 diabetes

A

decreased insulin resistance, obesity is a major cause in development. older individuals, treated with diet, exercise and meds.

91
Q

gestational diabetes

A

if untreated, causes risk to fetus and increased delivery complications. increases chance of developing t2d.

92
Q

hypoglycemia

A

glucose below 60. Caused by insulin overdose, exercise, alcohol use, liver or kidney disfunction, deficiency in glucocorticoids or GH, genetics. symptoms= hunger, dizziness, confusion, sweating, sleepiness. Glucagon given if unconscious.

93
Q

pineal gland

A

small unpaired body in epithalamus of diencephalon. secretes melatonin to cause drowsiness and regulates circadian rhythm and can effect mood. Melatonin influences GnRH secretion

94
Q

parathyroid gland

A

small structures on back of thyroid gland (between 2-6 of them, usually 4). Contains chief cells and oxyphil cells

95
Q

Chief (principal) Cells

A

make PTH (parathyroid hormone). This increase blood calcium by taking it from bones, decreasing its loss in urine and activating calcitriol hormone

96
Q

Thymus

A

epithelial cells secrete thymic hormones. The thymus is located anterior to top of heart and is only active during childhood. It is a maturation site for T-lymphocyte white blood cells.

97
Q

Endocrine Heart Tissue

A

in heart atria; secretes atrial natriuretic peptide (ANP). This lowers bp by increasing urine output and dilating blood vessels.

98
Q

Kidney Endocrine Cells

A

releases erythropoietin (EPO). Secretions occurs in response to low blood oxygen to increase red blood cell production.

99
Q

Liver Endocrine Secretions

A

Insulin-like growth factors and the inactive hormone angiotensinogen. it is converted into angiotensin II by enzymes from the kidney and lung blood vessels. Angiotensin II helps raises bp by causing vessel constriction, decreases urine output and stimulates thirst.

100
Q

Stomach Endocrine Secretions

A

Gastrin; increases secretion and motility in stomach for digestion.

101
Q

Small intestine endocrine secretions

A

secretes secretin and cholecystokinin (CCK) into blood. Secretin stimulates secretion of bile and pancreatic juice. CCK stimulates release of bile from gall bladder.

102
Q

Skin Endocrine Function

A

light converts modified cholesterol to vitamin D3 which is released into blood. Vit. D3 is converted to calcidiol by liver enzyme which is then converted to calcitriol by kidney enzyme. Calcitriol is the active hormone that raises blood calcium. Stimulates Ca from bone, decreases Ca loss in urine, and stimulates Ca absorption in intestine

103
Q

Adipose Connective Tissue Endocrine secretions

A

leptin; controls appetite by binding to neurons in hypothalamus. Lower body fat is associated with less leptin and this stimulates appetite. Other adipose endocrine effects include increased risk in cancer and delayed puberty in males. Low adipose interferes with menstrual cycle.

104
Q

glycogenolysis

A

breakdown of glycogen into glucose

105
Q

glycogenesis

A

synthesis of glycogen

106
Q

lipolysis

A

breakdown of triglycerides

107
Q

lipogenesis

A

formation of triglycerides

108
Q

Thyroid hormone and ATP production

A

hepatocytes (liver cells) are stimulated to increase blood glucose through glycogenolysis & gluconeogenesis. Adipose cells stimulated to increase blood glycerol and fatty acids. TH increases lipolysis. This saves glucose for the brain. TH also increases respiration rate to meet additional o2 demand (mitochondria), hr increase and force of contraction, more blood flow and causes heart to increase receptors for epinephrine and norepinephrine.

109
Q

glucose-sparing effect

A

body cells use fats and other energy sources to save glucose for the brain to run.

110
Q

Regulation of cortisol release

A

Cortisol and corticosterone increase nutrient level in blood. release regulated by hypothalamic-pituitary-adrenal axis. late stages of sleep, stress, or low level cortisol stimulates hypothalamus to release CRH. CRH stimulates ant. pit. to release ACTH. ACTH stimulates adrenal cortex to release cortisol. Cortisol then inhibits release of CRH and ACTH

111
Q

Lowering high bg with insulin

A

beta cells detect high bg and release insulin. Insulin binds to target receptor cells and initiates 2nd messenger systems. Once blood glucose falls, glycogenesis and lipogenesis is stimulated. Most body cells increase nutrient uptake in response to insulin (amino acid for protein synthesis, glucose)

112
Q

Cells that do not require insulin to take in glucose

A

neurons, kidney, hepatocytes, RBCs

113
Q

Raising low bg with glucagon

A

Alpha cells release glucagon and 2nd messengers cause body cells to release stored nutrients into blood. hepatocytes release glucose, adipose cells release fatty aids and glycerol. lipolysis, glycogenolysis, and gluconeogenesis is stimulated.