Endocrine System Flashcards
(141 cards)
1
Q
Communicates via chemical messengers (hormones), secretory products of endocrine cells, carried by bloodstream to target tissue containing receptors
A
Endocrine
2
Q
_____ organs composed of secretory cells of epithelial origin, characterized by prominent nuclei & numerous organelles; Lack ducts & secrete hormones into surrounding interstitial space; Possess rich blood supply with fenestrated capillary networks to absorb & transport hormones; integrate function of physiologic systems
A
Endocrine organs
3
Q
______ coordinates endocrine functions of body—acts as intermediary between autonomic nervous system & end
A
Hypothalamus
4
Q
T/F: Most endocrine glands form discreet organs
A
True
5
Q
specialized appendage of brain; Lies beneath third ventricle in sella turcica(“Turkish saddle”) of sphenoid bone
A
Pituitary gland (= hypophysis)
6
Q
Secretion of pituitary hormones controlled by ______, with complex blood supply
A
hypothalamus
7
Q
allows communication with hypothalamus from pituitary gland
A
hypophyseal portal system
8
Q
Hypothalamus controls secretion of anterior pituitary via _________ (hormones)—
A
hypothalamic regulating factors
9
Q
Releasing factors _____ secretion
A
stimulate
10
Q
inhibitory factors ____ secretion
A
inhibit
11
Q
_____ hormones have non-endocrine target organ
A
Direct acting hormones
12
Q
GH, ADH, MSH, oxytocin, prolactin are ___ hormones
A
Direct acting hormones
13
Q
_____ hormones target organ is another endocrine gland
A
trophic hormones
14
Q
TSH, ACTH, FSH, LH are ____ hormones
A
trophic hormones
15
Q
Thyroid gland, adrenal cortex, & gonads all _________ endocrine glands
A
pituitary-dependent
16
Q
_____ portion of pituitary contains glandular epithelial tissue
A
Anterior portion
17
Q
____ portion of pituitary contains neural secretory tissue
A
posterior portion
18
Q
Specialized glandular tissue, arises from evagination of ectoderm from oral cavity in region of pharynx called Rathke’s pouch
A
Anterior pituitary: “Master gland” (=adenohypophysis = pars anterior = pars distalis)
19
Q
Anterior pituitary arises from portion of pharynx called ____ ; oral ectoderm that migrates to brain
A
Rathke’s pouch
20
Q
What are the 3 portions of Rathke’s pouch?
A
pars distalis, pars intermedia, and pars tuberalis
21
Q
Portion of Rathke’s pouch that is bulk of anterior pituitary
A
pars distalis
22
Q
Portion of Rathke’s pouch that is thin layer between anterior & posterior pituitary; Secretes MSH & ACTH; Frequently contains cystic remnants of Rathke’s pouch
A
pars intermedia
23
Q
Portion of Rathke’s pouch that is extension of anterior pituitary; forms collar ~pituitary stalk (=infundibulum)
A
pars tuberalis
24
Q
_____ (portion of anterior pituitary) secretes bulk of pituitary hormones, including both direct acting & trophic hormones
A
Pars distalis
25
Direct acting hormones secreted by pars distalis
GH & prolactin
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Trophic hormones secreted by pars distalis
TSH, ACTH, FSH, LH
27
Secretory cells of anterior pituitary traditionally classified as ____ or _____
chromophils (which stain) or chromophobes (don’t)
28
Do chromophils stain?
Yes
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Do chromophobes stain?
No
30
What are the 2 types of chromophils?
Acidophils and Basophils
31
stain with acidic dye; pink on H&E
Acidophils
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stain with basic dye; pale blue to light purple on H&E
Basophils
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small cells, don’t take up either dye, clear on H&E; represent inactive cells
Chromophobes
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What are the 2 types of acidophils?
Somatotrophs and Mammotrophs
35
What are the 3 types of basophils?
Thyrotrophs, Gonadotrophs, and Corticotrophs
36
Acidophil: ~50% of cells; sec GH
Somatotrophs
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Acidophil: ~20% of cells; secrete prolactin (controls lactation)
Mammotrophs— (= lactotrophs)
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Basophil: ~5% of cells; secrete TSH (= thyrotropin)
Thyrotrophs
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Basophil: ~5% of cells; secrete FSH & LH
Gonadotrophs
40
Basophil: ~20% of cells; secrete ACTH, MSH, endorphins
Corticotrophs
41
Where are the cell bodies of posterior pituitary neurons?
Hypothalamus
42
Axons of posterior pituitary are surrounded by support cells called
pituicytes
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Located ventral to hypothalamus(plus short stalk, infundibulum, which contains axons of neurosecretory origin)•Consists of downgrowth of nervous tissue from floor of diencephalon (third ventricle)
Posterior pituitary
44
Secretion of posterior pituitary hormones by axons from nerve cells in hypothalamus known as _____(regulated by hypothalamic hypophyseal feedback loop)
neurosecretion
45
Hypothalamus secretes what 2 hormones via posterior pituitary
ADH(= vasopressin) & oxytocin
46
Posterior pituitary hormones are Stored in neurosecretory granules in dilations of axons of posterior pituitary known as
Herring bodies
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controls blood pressure by altering permeability of renal collecting tubules
ADH
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production of ADH => __ urine production (as in diabetes insipidus)
↑ urine production
49
ADH is Synthesized by neuron cell bodies in _____ of hypothalamus
supraoptic nucleus
50
promotes smooth Mm contraction in uterus & breast (especially during labor & lactation)
Oxytocin
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Oxytocin is Synthesized by neuron cell bodies in _______ of hypothalamus
paraventricular nucleus
52
Bilateral, lobulated, endocrine gland on anterior/ventral neck; L & R sides connected by narrow isthmus; Surrounded by loose connective tissue capsule with fine connective tissue septa; Embryologically derived from epithelial downgrowth of fetal tongue
Thyroid glands
53
L & R sides of thymus connected by ____
narrow isthmus
54
Thyroid gland unique among endocrine glands in storage of large amounts of inactive hormone, an eosinophilic glycoprotein colloid called _____
thyroglobulin
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thyroglobulin stored in extracellular _____; structural units of thyroid gland, lined by simple, cuboidal epithelium
follicles
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______ cells concentrate iodine 30-40X blood levels, secrete it as thyroglobulin via apical microvilli
Follicular epithelial cells
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____ leads to an active thyroid hormone
Iodination
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What are the 2 active hormones secreted by thyroid?
T3 and T4
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T4 is _____ in liver to form T3
deiodinated
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___ is more potent biologically active thyroid hormone; regulates BMR
T3
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Thyroid hormone deficiency during fetal development impairs _____ and ______—results in physical stunting & mental retardation (cretinism)
neural development & myelination
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Secondary secretory cells in thyroid gland are called _______ cells; Located at periphery of follicles, or scattered within connective tissue; In lower vertebrates, make up separate organ
parafollicular cells (= C cells, clear cells)
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C cells secrete ____
calcitonin
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regulate blood Ca levels along with parathyroid hormone↓ serum Ca, inhibits osteoclasts
calcitonin
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Synthesis, storage & release of thyroid hormones under control of ___ from anterior pituitary (adenohypophysis)
TSH
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(enlargement of thyroid) that may be due to hyper or hypo thyroidism
goiter
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increase in number & size of follicle cells of thyroid
Hyperthyroidism
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autoimmune rxn; results in ↓ in size of glandInsufficient dietary iodine => ↓ TH production, possible hypertrophy with non-functional thyroglobulin
Hyopthyroidism
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Small, oval endocrine glands associated with thyroid•Usually two pairs in mammals (superior & inferior),present on posterior surface of thyroid gland•Embryologically derived from third & fourth branchial (pharyngeal) pouches
Parathyroid gland
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Parathyroid secretes ____ that regulates serum Ca and P; antagonistic to calcitonin
parathyroid hormone - PTH
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_____ slowly ↑ serum Ca;
parathyroid hormone
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____ rapidly ↓ serum Ca
calcitonin
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PTH increases serum Ca in what 3 ways?
↑ osteoclast activity (inhibits osteoblasts)•↑ renal tubular absorption of Ca in kidneys (& inhibits resorption of phosphate)•↑ Ca absorption from gut via Vit D
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Parathyroid hormone secretion stimulated by _____ in blood Ca
↓ in blood Ca
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Damage or removal of parathyroid gland in surgical removal of thyroid leads to _____
Hypoparathyroidism
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excess PTH production=> bony erosion & lysis
Hyperparathyroidism
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What are the 2 types of cells in parathyroid gland?
Chief and Oxyphil cells
78
(PT cells) most abundant, secrete parathyroid hormoneStain clear to light pink, with dark nuclei & moderate amount of cytoplasm
Chief (principal) cells
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(PT cells) larger, less numerous, stain dark pink, with more cytoplasmOccur in clusters; contain large # of mitochondria, but no secretory vessicles; function unknown
Oxyphil cells
80
Located superior to kidneys•Covered by thin connective tissue capsule•In mammals, single endocrine gland with two different embryological origins•In lower vertebrates, medulla & cortex are two separate glands
Adrenal gland (suprarenal gland)
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mesodermal embryological origin, similar to gonads
Adrenal cortex
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Steroid hormones structurally related to _____ precursor
cholesterol
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Adrenal cortex Regulated by ___ secreted by anterior pituitary
ACTH
84
What are the 3 functional classes of adrenal hormones?
Mineralocorticoids, Glucocorticoids, and Sex hormones
85
control electrolyte & fluid balanceRegulate Na & K levels via Na pumps, especially in renal tubules; Regulates blood pressure via JGA (e.g., aldosterone)
Mineralocorticoids
86
Stimulate gluconeogenesis & glycogenolysis—both ↑ blood glucoseAlso ↑ metabolism & breakdown of proteins, carbohydrates, & lipids (e.g., cortisol)
Glucocorticoids
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very small amount; supplement gonadal production (e.g., androgens)
Sex hormones
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What are the 3 layers of adrenal cortex from superficial ot deep?
Zona glomerulosa, Zona fasciculata, Zona reticularis
89
~15% of cortex: thin, dark-staining band; Secretes mineralocorticoids, e.g., aldosterone
Zona glomerulosa
90
~80% of cortex; broad, light-staining band Contains cells called spongiocytes Secrete glucocorticoids; e.g., cortisol; Small amounts of androgens also secreted
Zona fasciculata
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~5% of cortex; thin, dark-staining band; Secretes small quantities of androgens & glucocorticoids
Zona reticularis
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Zona fasciculata Contains cells called ____
spongiocytes
93
____ promotes secretion of cortisol, which ↓ immune response
Stress
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•Failure of adrenal cortex to produce hormone(mineralo- & glucocorticoids),•Usually due to atrophy of gland (often caused by autoimmune disease)
Hypoadrenocorticism (Addison’s disease)
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↓ ______ => ↓ ECF volume, hyponatremia, hyperkalemia, mild acidosis => shock, death
aldosterone
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↓ _____ => ↓ blood glucose
cortisol
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Treatment of Hypoadrenocorticism (Addison’s disease)
exogenous administration of mineralocorticoids & glucocorticoids
98
______ is Due to general adrenal hyperplasia or functional tumor of adrenal cortex => excess cortisol secretion
Primary adrenal hyperadrenocorticism
99
______ is Due to ↑ ACTH from anterior pituitary(pituitary tumor, e.g., adenoma or carcinoma)or other cortisol-producing tumor
Secondary pituitary hyperadrenocorticism, aka “Classical form”)
100
↑ _____ secretion => adrenal hyperplasia & excess cortisol secretion
ACTH
101
Embryologically originates from neuroectoderm; Contains chromaffin cells; Controlled directly by preganglionic, sympathetic nerve fibers
Adrenal medulla
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Adrenal medulla Contains ________—modified, post-ganglionic neuronal cells with secretory function (epithelioid in appearance)•
chromaffin cells
103
Chromaffin cells secrete _____
catecholamines
104
What are the catecholamines secreted by adrenal medulla?
Adrenaline and noradrenaline
105
Adrenaline and noradrenaline are stored in cytoplasmic granules called _______
dense core granules
106
T/F: Catecholamine release has systemic effect on adrenergic receptors throughout body (especially skeletal, cardiac, & smooth Mm)
True
107
____promotes glycogenolysis in liver as energy source & is responsible for production of enkephalins—endogenous opiates responsible for pain relief
Adrenaline
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______ endogenous opiates responsible for pain relief
enkephalins
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Generally benign, functional tumor of chromaffin cells of adrenal medulla; Symptoms due to ↑ epi & norepi secretion, including:•Hypertension, headache, cardiac arrhythmias, chest pain, anxiety, panic attacks, nausea•Tx: Sx removal of tumor
Pheochromocytoma
110
Bulk of pancreas contains _____ acini
exocrine
111
____ acini of pancreas—secrete digestive products into gut
exocrine
112
_____ cells migrate from duct sys & aggregate around capillaries of pancreas, form islets of Langerhans
endocrine
113
endocrine cells migrate from duct sys & aggregate around capillaries of pancreas, form ________ Distributed throughout exocrine pancreatic tissue
islets of Langerhans
114
What are the 3 main cell types of islet cells of pancreas?
alpha, beta, delta
115
___ cells of pancreas—secrete glucagon; ↑blood glucose, stimulates glucogenesis & glycogenolysis
α-cells (~15-20%)
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____ cells of pancreas secrete insulin; ↓ blood glucose & stimulates intracellular glycogen synthesis
β-cells (~70%)
117
____ cells of pancreas secrete somatostatin; inhibits both insulin & glucagon production
δ-cells (~5-10%)
118
insulin deficiency/abnormality leads to ____
diabetes mellitus
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______ is Characterized by hyperglycemia (↑ blood glucose) & glucosuria (glucose in urine)
diabetes mellitus
120
↑ blood glucose
hyperglycemia
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glucose in urine
glucosuria
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Type _____ DM: juvenile diabetes (↓ insulin production)
Type 1
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Type ____ DM: adult onset diabetes (↓ # of insulin receptors or ↓ responsiveness)
Type II
124
Located anterodorsal to cerebellum•Develops from neuroectoderm as evagination of posterior portion of third ventricle, from roof of diencephalon•Communicates with hypothalamus; acts as photoreceptor in lower vertebrates•Translates light intensity & duration (photoperiod) into endocrine activity—important in circadian rhythms & seasonal reproductive cycles
Pineal gland
125
_____ secretes melatonin and serotonin
pineal gland
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______ (stimulates melanophores,chromatophores (pigment-containing cells) => change in color intensity with reproductive cycle
melatonin
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_____ leads to ↓ GNRH from hypothalamus => ↓ sex hormone secretion from gonads
Melatonin
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___ has anti-gonadal effect to decrease sex activity
Melatonin
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most common cell in pineal glandHighly modified neurons; secrete melatonin & serotonin
Pinealocytes (= pineal chief cells)
130
support cells such as astrocytes, microglial cells
Neuroglial cells (= interstitial cells)
131
What are the 2 cell types in pineal gland?
Pinealocytes and Neuroglial cells
132
Calcified accretions of _____ and ____ in aging individuals in pineal gland
Ca & Mg phosphate
133
T/F: There is A variety of endocrine cells scattered in the mucosa of GI, respiratory tract, & other organs
True
134
______ cells Secrete peptide & amine hormones (e.g., gastrin, secretin, CCK, serotonin)
endocrine
135
Cells that have similar ultrastructure and metabolic pathway for endocrine pathway in GI and respiratory tracts
APUD cells
136
Most of endocrine cells in GI and respiratory system are mostly derived embryologically from ____
neural crest
137
Neuroendocrine cells are derived from ___
neural crest
138
Enteroendocrine cells are derived from ____
endoderm
139
Both _____ and ____ produce amine or peptide hormones or neurotransmitters, with neurosecretory granules & hormone-like activity
enteroendocrine and neuroendocrine
140
chromaffin cells of adrenal medulla(epinephrine & norepinephrine), thyroid C cells (calcitonin), pancreatic islets (insulin, glucagon, & somatostatin) are examples of ______ system
endocrine
141
_____ cells in GI & respiratory tracts have a variety of secretory products like gastrin, CCK, VIP, substance P, serotonin, bombesin
Enteroendocrine
