Lecture 10 - Endocrine System Flashcards
glands classified as either
exocrine or endocrine
secrete onto a surface; either directly or through a duct
exocrine
secrete internally; ductless glands; secrete hormones; primarily utilize cardiovascular system for distribution
endocrine
there are two types of hormones
- circulating hormones
2. local hormones
two types of local hormones
paracrines and autocrines
hormones that act on near by cells, neighboring cells
paracrine hormones
hormone that is same cell secretion and action site
autocrine
what regulates the pituitary gland
hypothalamus
antidiuretic hormone, oxytocin, and a number of regulatory hormones are secreted by
hypothalamus
adrenocorticotropic hormone, FSH, GH, LH, melanocyte-stimulating hormone, prolactin, thyroid-stimulating hormone, all released by
anterior pituitary gland
antidiuretic hormone and oxytocin are secreted by __, regulated by __
posterior pituitary gland
regulated by hypothalamus
release corticosteroids
cortex of adrenal glands
release epinephrine and norepinephrine
medulla adrenal glands
release melatonin
pineal gland
release calcitonin and thyroid hormone
thyroid gland
release parathyroid hormone
parathyroid gland (located on posterior surface of thyroid)
have a huge role in glucose balance
pancreatic islets
release glucagon, insulin, somatostatin, pancreatic polypeptide
pancreatic islets
endocrine role is main visceral(autonomic) control center for the body, vital for homeostasis
hypothalamus
regulates body temp, food intake, water balance/thirst, sleep-wake cycle, sexual behavior and endocrine functioning
hypothalamus
the hypothalamus links __ and __ systems; considered the “command center for the endocrine system” = its secretions can regulate other glands
links nervous and endocrine systems
hypothalamus is connected to the pituitary gland via
infundibulum or pituitary stalk
hypophysis is another name for
pituitary gland
together __ and __ regulate virtually all aspects of growth, development, metabolism, and homeostasis
hypothalamus and pituitary gland
how many hormones does the hypothalamus produce
9 total
5 releasing hormones which impact/control anterior pituitary
2 inhibiting which impact/control anterior pituitary
2 other hormones that are released by posterior pituitary
command center for endocrine system
hypothalamus
master gland for endocrine system
pituitary gland
sits in bony hypophyseal fossa or cella turica of sphenoid bone
pituitary gland
2 functional components of the pituitary gland
anterior pituitary and posterior pituitary
anterior pituitary;
1; cords of epithelial cells interspersed with fenestrated capillaries
2; cells are basophillic corticotropes (MSH), surrounds a series of colloid-filled follicles that represent the residual lumen of Rathke’s pouch
3; forms a collar or sheath around infundibulum, most cells are basophillic gonadotropic cells
- pars distalis
- pars intermedia
- pars tuberalis
posterior pituitary;
1; neurosecretory axons and their endings
2; contains neurosecretory axons forming the hypothalamo-hypophyseal tracts
- pars nervosa
2. infundibulum
another name for anterior pituitary
anterior lobe, adenohypophysis
another name for posterior pituitary
posterior lobe, neurohypophysis
hypothalamus is continuous with __ via infundibulim
posterior pituitary
what turns off hypothalamus
negative feedback loop from anterior lobe of pituitary gland
regulating hormones from the hypothalamus reach the anterior lobe of pituitary gland via the
hypothalamohypophyseal portal system
the control of the anterior pituitary via hypothalamus beings with __ in the hypothalamus synthesize the hypothalamic releasing and inhibitory hormones in their cell body
neurosecretory neurons
hypothalamic hormones travel down the axons of the neurosecretory cells to the axon terminals where they exit via __ to stimulate/inhib anterior pituitary
exocytosis
once hormones released by hypothalamus and exit via exocytosis these hormones diffuse into the hypophyseal portal system at the __
primary plexus of the hypophyseal portal system
hormones from hypothalamus pass from the primary plexus of the hypophyseal portal system to the __ into the secondary plexus of the hypophyseal portal system, bringing these hypothalamic hormones directly to the cells of the pars distalis
hypophyseal portal veins
2 groups of secretory cells in anterior pituitary lobe
chromophils and chromophobes
chromophils of the anterior pituitary:
1; affinity for basic dye (gonadotropes, corticotropes, thyrotropes)
2: affinity for acidic dyes (somatotropes,lactotropes)
- basophils
2. acidophils
anterior pituitary > chromophils > basophils; 1=FSH and LH
2= adrenocorticotropic hormone
3 = thyroid stimulating hormone
- gonadotropes
- corticotropes
- thryotropes
anterior pituitary > chromophils > acidophils;
1; growth hormone
2; prolactin
- somatotropes
2. lactotropes
50% of pars distalis, with few or no secretory granules, stain weakly, clear cells, reserve/primitive cells, undifferentiated cells can become chromophils
chromophobes
acidophil chromophil hormones
human growth hormone and prolactin
which cell type is more prominent, basophil or acidophil
acidophil
which type of cell, basophil or acidophil, a little goes a long way
basopil
__ hormone’s target tissue is the liver
human growth hormone or somatotropin
stimulates liver, muscle, cartilage, bone, and other tissues to synthesize and secrete insulinlike growth factors
hgh
promote growth of the body cells, protein synthesis, tissue repair, lipolysis, and elevation of blood glucose concentration
insulinlike growth factors which are secreted by hgh
_ hormone’s target tissue is thyroid gland
thyroid stimulating hormone or thyrotropin
stimulates synthesis and secretion of thyroid hormones by thyroid gland
thyroid-stimulating hormone
__ target tissue is ovaries or testes
follicle stimulating hormone
FSH in males and females
females - initiates development of oocytes and induces ovarian secretion of estrogens
males- stimulates testes to produce sperm
__ hormone’s target tissue is ovaries and testes
Luteinizing hormone
LH in males/females
females - stimulates secretion of esttrogens and progesterone, ovulation, and formation of corpus luteum
males- stimulates testes to produce testosterone
__ hormone’s target tissue is mammary glands
prolactin
promotes milk secretion by the mammary glands
prolactin
__ hormone’s target tissue is adrenal cortex
adrenocorticotropic hormone
stimulates secretion of glucocorticoids by adrenal cortex
adrenocorticotropic hormone
__hormone’s target tissue is the brain
melanocyte-stimulating hormone
exact role in humans is unknown but may influence brain activity, when present in excess can cause darkening of skin
melanocyte-stimulating hormone
another name for antidiuretic hormone
vassopressin
posterior pituitary does not synthesize hormones, but stores and release __ and __ hormones
oxytocin and vasopressin(ADH)
found in posterior pituitary, type of glial cell, resembling the astrocyte, that associates with the fenestrated capillaries, cell has many branches, pigment vesicles in cytoplasm, round or oval nuclei
pituicyte
most common cell type in posterior pituitary
pituicyte
the axons of the hypothalamic neurosecretory neurons form the __ in the infundibulum
hypothalamohypophyseal tract
__ hormone’s target tissue is uterus and mammary glands
oxytocin
stimulates contraction of smooth muscle cells of uterus during childbirth, stimulates contraction of myoepithelial cells in mammary glands to cause milk ejection
oxytocin
__hormone’s target tissue is kidneys and sudoriferous (sweat) glands, and arterioles
antidiuretic hormone (vasopressin)
conserves body water by decreasing urine volume, decreases water loss through perspiration, raises blood pressure by constricting arterioles
antidiuretic hormone or vasopressin
where is pineal gland located
diencephalon
regulates daily body rhythm, circadian rhythm
pineal gland
major hormone production of pineal gland
melatonin
pineal gland has 2 cell types
pinealocytes(parenchymal cells) 95%
and interstitial (glial) cells
major characteristic of pineal gland
corpora arenacea (brain sand)
another name for adrenal glands
suprarenal glands
2 parts to the adrenal glands;
1; large area, peripheral, just below capsule, makes up 80-90% of the gland, steroid secreting cells
2; smaller area, centrally located, catecholamine-secreting cells
cortex = 1
- medulla
the __ is the thickest of the 3 adrenal cortex regions, it contains cells that are arranged in long cords/rows
zona fasciculata
zones of adrenal cortex
capsule
zona glomerulosa
zona fasciculata
zona reticularis
region of adrenal cortex that secretes mineralocorticoids, mainly aldosterone
zona glomerulosa
region of adrenal cortex that secretes glucocorticoids, mainly cortisol
zona fasciculata
region of adrenal cortex that secretes androgens
zona reticularis
adrenal medulla produces 3 catecholamine hormones, what are they
epinephrine
norepinephrine
small amount of dopamine
modified neuronal cells that receive direct presynaptic sympathetic axon stimulation
chromaffin cells of adrenal medulla
regulate glucose and fatty acid metabolism, suppresses the immune system, provides resistence to stress
cortisol
assists in early growth of axillary and pubic hair in both sexes, an androgen hormone from zona reticularis
DHEA - dehydroepiandrosterone
adrenal medulla develops from __cells
neural crest cells
__ hormone’s target tissue is the adrenal medulla
epinephrine and norepinephrine
produce effects that enhance those of the sympathetic divison of the autonomic nervous system
epinephrine and norepinephrine
the __ portion of the pancreas; the islets of langerhans, stain pale
endocrine portion
of the endocrine portion of the pancreas, found throughout pancreas but most numerous in the tail, synthesisizes and secrets hormones
islets of langerhans
3 principles of langerhan islets found in endocrine portion of pancreas;
1; insulin, cells found towards center of islet
2; Glucagon, cells found towards periphery of islet
3; somatostatin, cells found towards the periphery of islet
- beta or B cells
- Alpha or A cells
- Delta or D cells
identical to growth hormone-inhibiting hormone from hypothalamus
somatostatin
lowers blood glucose level as it signals for an acceleration of glucose transport into cells and the conversion of the glucose into glycogen
insulin
raises blood glucose level as it signals for the acceleration of the breakdown of glycogen into glucose in the liver, thus glucose is released into the blood
glucagon
inhibits insulin and glucagon secretion
somatostatin
contains thyroid follicles surrounded by follicular (simple squamous to low columnar) that are responsible for the production of thyriod hormones
thyroid gland
__ and __ are important for growth, cell differentiation, and control of basal metabolic rate and oxygen consumption of body cells
T3 and T4
T4- four atoms of iodine
thyroxine
T3- 3 atoms of iodine
Tri-Iodothyronine
stored in the follicles of thyroid gland, a gel-like mass predominantly composed of __, a large iodinated glycoprotein inactive form of thyroid hormones
thyroglobulin
in thyroid gland, larger and paler staining than follicular cells, produce calcitonin
Parafollicular cells or C cells
decreases the level of calcium in the blood by encouraging calcium salts to be deposited in bone matrix and inhibits the action of osteoclasts
calcitonin
2 cells types located in the parathyroid:
1; produce parathyroid hormone, most numerous cells, small, round, centrally located, pale-staining,slightly acidophilic cytoplasm
2; larger cell, VERY acidophillic cytoplasm, more common with age, unknown function
- chief cells or principle cells
2. oxyphil cells
hormone thatt increases the level of calcium in the blood stimulation of osteroclasts to resorb bone which releases calcium into the blood, also acts on kidneys to slow the rate of calcium loss from the blood into the urine
parathyroid hormone