exam 5 Flashcards

1
Q

endocrine vs. exocrine gland

A
  • endocrine glands: ductless organs or groups of cells, that secrete hormones directly into the blood or other body fluids. A single gland may secrete multiple hormones
  • exocrine glands secrete their products into a duct, from where the secretions either exit the body or enter the lumen
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2
Q

what hormones does the hypothalamus secrete

A

neurohormones that stimulate of inhibit anterior pituitary gland function. Synthesizes two neurohormones that are stored in and released from the posterior pituitary

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3
Q

what hormone does the heart secrete

A

The heart synthesizes ANP, which lowers blood Na+

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4
Q

what hormones do the adrenal glands secrete

A

makes epinepherine and norepinepherine

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5
Q

what hormones do the adrenal cortex secrete

A

makes aldosterone, which regulates Na+ and K+ balance; makes cortisol, which regulates growth, metabolism, development, immune function, and the response to stress, makes some androgens, which play a role in reproduction

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6
Q

what homrones does the liver secrete

A

produces IGF-1, which controls growth of bones; secretes angiotensinogen, a precursor required for production of angiotensin II

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7
Q

what hromones do the kidneys secrete

A

erythropoietin, which regulates maturation of red blood cells; produce the active hormone 1,25-dihydroxyvitamin D; secrete the enzyme renin, which begins the synthesis of angiotensin II

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8
Q

what hormones does the pancreas secrete

A

makes insulin, which decreases blood glucose. Makes glucagon, which increases blood glucose

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8
Q

what hormones do the blood vessels secrete

A

cells of many blood vessel walls express enzymes that are required to complete the synthesis of angiotensin II, which helps maintain normal blood pressure

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8
Q

what hormone does the adipose tissue secrete

A

produces hormones that regulate appetite and metabolic rate

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8
Q

what hormones does the anterior pituitary gland secrete

A

produces hormones with diverse actions related to metabolism, reproduction, growth, and others (ACTH, FSH, LH, GH, PRL, TSH)

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8
Q

what hormones does the pineal gland secrete

A

makes melatonin

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8
Q

what hormones does the posterior pituitary secrete

A

secretes oxytocin and ADH

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9
Q

what hormones does the parathyroid secrete

A

makes parathyroid hormone, which increases blood Ca 2+, and stimulates the production in the kidneys of the active form of vitamin D

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10
Q

what hormones does the thyroid secrete

A

makes thyroid hormone, which regulates metabolic rate, growth, and differentiation; makes calcitonin, which plays a role in Ca2+ homeostasis in some species

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11
Q

what hormones does the stomach secrete

A

gastrin

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12
Q

what hormones do the intestines secrete

A

secretin and cholecystokinin

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13
Q

what hormones do the ovaries secrete

A

estradil and progesterone

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14
Q

what hormones do the testes secrete

A

testosterone

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15
Q

what major anatomical feature distinguishes endocrine glands from exocrine glands. What organ contains both endocrine and exocrine glands

A

endocrine glands release their secretory products directly into blood, or other bodily fluids. Exocrine glands release their secretory products into ducts.
The pancreas contains both an endocrine (islet of Langerhans that secrete insulin into blood) component and an exocrine component (secretes digestive enzymes into duct that connects with small intestine)

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16
Q

what are amine hormones

A

derivations of the amino acid tyrosine.
- includes thyroid hormones and catecholamines (epi, norepi, dopamine)

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17
Q

what are peptide/protein hormones

A

strings of amino acids
- typically synthesized as larger (inactive) molecules that are cleaved into active fragments by post-translation modification

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18
Q

what are steroid hormones

A

produced from cholesterol by the adrenal cortex and the gonads and from steroid precursors by the placenta
- adrenal cortex produces the mineralocorticoid aldosterone; the glucocorticoid cortisol; and two androgens, DHEA and androstenedione
- ovaries produce mainly estradiol and progesterone
- testes produce mainly testosterone

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19
Q

what are catecholamines

A
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20
how is post-translational modification related to hormones
peptide and protein hormones are typically synthesized as larger (inactive) molecules that are cleaved into active fragments by post-translational modifications
21
what are the three general classes of hormones
- peptides/proteins: insulin - steroids: cortisol - amines: thyroid hormone
22
How are peptides and catecholamines transported in the blood
- major form in plasma: free (unbound) - location of receptors: plasma membrane - most common signaling mechanisms: a) second messengers, b) enzyme activation by receptor, c) intrinsic enzymatic activity of receptor - rate of excretion/metabollism: fast (minutes)
23
how are steroids and thyroid hormone transported in the blood
- major form in plasma: protein-bound - location of receptors: intracellular - most common signaling mechanisms: intracellular receptors directly alter gene transcription - rate of excretion/metabolism: slow (hours to days)
24
what accounts for the difference in hormones that are carried in the blood mainly unbound, and hormones that are bound to plasma proteins
the main difference is the solubility of the different classes of hormones
25
what two factors does a hormones concentration depend upon
- rate of secretion by the endocrine gland - rate of removal from the blood
26
What organs remove hormones from the plasma and how is that done
the liver and kidneys remove hormones from the plasma by metabolizing or excreting them
27
peptide hormones and catecholamines are _____ removed from the blood
rapidly removed from the blood
28
Steroid and thyroid hormones are removed ______ from the blood
removed more slowly from the blood mainly because they circulate bound to plasma protiens
29
other than by the liver and kidneys, how else can a hormone be metabolized and cleared from the circulation
some hormones can be take into target tissues via endocytosis after binding to a cell-surface receptor and then metabolized. Other hormones can be transformed intracellularly to a different class of hormone
30
what is up-regulation
increases in a hormones effectiveness
31
what is down-regulation
decreases in hormones effectiveness
32
what does permissiveness mean
hormone A must be present in order for hormone B to exert its full effect.
33
what are the effects of peptide hormones and catecholamines
34
what are the effects of steroid and thyroid hormones
35
Where is the receptors for steroids and thyroid hormones
inside target cells
36
where is the receptor for peptide hormones and catecholamines
on plasma membrane
37
what are the three main things controlling hormone secretion
- changes in the plasma concentrations of mineral ions or organic nutrients - neurotransmitters released from neurons ending on the endocrine cell - another hormone (or a paracrine substance) acting on the endocrine cell
38
how do plasma concentrations of mineral ions or organic nutrients control hormone secretion
39
how do neurons control hormone secretion
40
how do other hormones control hormone secretion
41
what is hyposecretion
42
what is hypersecsretion
43
what is hyporesponsiveness
44
what is hyperresponsiveness
45
what do axons with cell bodies in the hypothalamus do
46
what are hypophysiotropic hormones
47
long-loop negative feedback
the "target gland" hormone exerts negative feedback on the secretion of the hypothalamic and/or anterior pituitary gland hormone in the pathway
48
Short-loop negative feedback
a given anterior pituitary hormone inhibits the hypophysiotropic hormones that control its secretion
49
synthesis of thyroid hormone
50
how could you decrease the action of T4 in the body without directly altering thyroid function
51
what is T3
52
what is T4
53
goiter
54
why does iodine deficiency lead to goiter
adequate thyroid hormone cannot be synthesized and secreted without sufficient iodine. Therefore, because of decreased long-loop negative feedback, the amount of TSH in the blood is increased. Chronic stimulation of the thyroid gland by the trophic effects of TSH lead to increased thyroid size
55
metabolic actions of thyroid hormone
56
permissive actions of thyroid hormone
57
role of thyroid hormone in growth and development
58
hypothyroidism
59
hyperthyroidism
60
what would happen to CRH synthesis in the hypothalamus and the vascular response to norepinephrine if the adrenal cortices of both adrenal glands were not functional
hypothalamic CRH would increase due to a loss of cortisol negative feedback. The vasoconstrictor response to norepinephrine would decrease due to the loss of the permissive action of cortisol on the vasculature
61
effects of increased plasma cortisol concentration during stress
- effects on organic metabolism: stimulation of protein catabolism in bone, lymph, muscle, and elsewhere; stimulation of liver uptake of amino acids and their conversion to glucose (gluconeogenesis); maintenance of plasma glucose concentration; stimulation of triglyceride catabolism in adipose tissue, with release of glycerol and fatty acids into the blood - enhanced vascular reactivity (increased ability to maintain vasoconstriction in response to norepinephrine and other stimuli) - unidentified protective effects against the damaging influences of stress - inhibition of inflammation and specific immune responses - inhibition of nonessential functions
62
how does stress effect hormones
stress causes a disruption of homeostasis; increased cortisol is a critical response increased cortisol mediates gluconeogenesis, lipolysis, and inhibition of insulin actions, all of which liberate energy sources required to cope with stress cortisol inhibits "nonessential" processes during stress (e.g., reproduction, immune function)
63
adrenal insufficiency
64
cushing's syndrome
65
what will happen to ACTH secretion in a patient being given high doses of a glucocorticoid receptor agonist or glucocorticoid receptor antagonist
ACTH secretion will decrease in response to dexamethasone due to negative feedback inhibition of hypophyiotropic CRH and pituitary ACTH synthesis. ACTH secretion would increase withe a glucocorticoid receptor antagonist because the body would perceive a lack of cortisol action
66
actions of the sympathetic nervous system, including epinephrine secreted by the adrenal medulla, during stress
- increased hepatic and muscle glycogenolysis (provides a quick source of glucose) - increased breakdown of adipose tissue triglyceride (provides supply of glyercol for gluconeogenesis and of fatty acids for oxidation) - increased cardiac function - diversion of blood from viscera to skeletal muscles by means of vasoconstriction in the viscera and vasodilation in the skeletal muscles - increased lung ventilation by stimulating brain breathing centers and dilating airways
67
why is an increase in vasopressin a useful response to some stressors
it can be advantageous to minimize free water loss during some stressors to limit need to drink water and to maintain blood pressure
68
what's the role of osteoblasts
produce cartilage
69
what do epiphyseal growth plates do
convert cartilage to bone growth ceases when the plates are completely converted to bine
70
how do hormones influence bone growth
71
what are chondrocytes
72
compare and contrast functions of osteoblasts and chondrocytes
chondrocytes synthesize and lay down new cartilage on the epiphyseal growth plates, while osteoblasts convert that cartilage to bone
73
what are the major effects of growth hormone
- promotes growth: induces precursor cells in bone and other tissues to differentiate and secrete insulin-like growth factor-1 (IGF-1), which stimulates cell division. Also stimulates liver to secrete IGF-1 - stimulates protein synthesis, predominantly in muscle - anti-insulin effects (particularly at high concentrations): a) renders adipocytes more responsive to stimuli that induce breakdown of triglycerides, releasing fatty acids into the blood b) stimulates gluconeogenesis c) reduces the ability of insulin to stimulate glucose uptake by adipose and muscle cells, resulting in higher blood glucose concentrations
74
principal actions of growth hormone
- major stimulus of postnatal growth: induces precursor cells to differentiate and secrete IGF-1, which stimulates cell division - stimulates liver to secrete IGF-1 - stimulates protein synthesis
75
principal actions of insulin influencing growth
- stimulates fetal growth - stimulates postnatal growth by stimulating secretion of IGF-1 - stimulates protein synthesis
76
major principal actions of thyroid hormone influencing growth
- permissive for growth hormone's secretion and actions - permissive for development of the central nervous system
77
principal actions of testosterone on influencing growth
- stimulates growth at puberty, in large part by stimulating the secretion of growth hormone - causes eventual epiphyseal closure - stimulates protein synthesis in males
78
principal actions of estradiol on influencing growth
- stimulates the secretion of growth hormone at puberty - causes eventual epiphyseal closure
79
principal action of cortisol on influencing growth
- inhibits growth - stimulates protein catabolism
80
what is growth hormone
major stimulus of postnatal growth - stimulates the release of hepatic IGF-1, which in turn stimulates cell division in bone - acts directly on many cells, such as muscle cells, to stimulate protein uptake - secretion highest during puberty (period of rapid growth)
81
what are two ways the hypothalamus can increase growth hormone secretion from the anterior pituitary
the hypothalamus can increase the secretion of growth hormone releasing hormone (GHRH) into the portal veins or decrease the secretion of somatostatin into the portal veins. Because somatostatin is an inhibitory hormone, a decrease in its secretion would "take the brake off" of growth hormone secretion, allowing GH to increase
82
effector sites for Ca2+ homeostasis
83
what hormones favor bone formation and increased bone mass
- insulin - growth hormone - insulin-like growth factor-1 (IGF-1) - estrogen - testosterone - calcitonin
84
what hormones favor increased bone resorption and decreased bone mass
- parathyroid hormone (chronic increases) - cortisol - thyroid hormone T3
85
what are the three main sites of Ca2+ homeostasis
bone (where most ca is stored), the GI tract (absored from diet), and kidneys (filtered and reabsored from urine)
86
what does the parathyroid hormone stimulate to influence effector sites
- kidney reabsorption of Ca2+ - bone reabsorption: releases Ca2+ into the blood - 1,25-dihydroxyvitamin D synthesis: stimulates Ca2+ absorption from the GI tract
87
what is the advantage of packaging peptide hormones in secretory vesicles
by storing large amounts of hormone in an endocrine cell, the plasma concentration of the hormone can be increased within seconds when the cell is stimulated. Such rapid responses may be critical for an appropriate response to a challenge to homeostasis. Packaging peptides in this way also prevents intracellular degradation
88
what is cortisol
steriod hormone synthesized in the adrenal cortex - stimulated by ACTH from anterior pituitary - corticotropin-releasing hormone (CRH) from the hypothalamus stimulates ACTH - negative feedback: inhibits ACTH and CRH release Physiological functions: - maintains responsiveness of target cells to epinephrine and norepinephrine - "check" on the immune system - energy homeostasis - differentiation of fetal tissue
89
what does vasopressin do
increased renal water retention (antidiuresis)
90
what do aldosterone, growth hormone, and glucagon do
regulate various aspects of ion balance and metabolism
91
what does beta-endorphin do
may reduce pain
92
what does thyroid hormone do
stimulates growth hormone synthesis and has many growth-promoting effects - essential for normal growth during childhood and adolescence - permissive for brain development during infancy
93
what does insulin do
- stimulates growth mainly during fetal life
94