endocrine system (ch 15) Flashcards
in the endocrine system, neurotransmitters are secreted at
the synapse
a hormone is
a chemical messenger secreted into extracellular fluid (blood/lymph) that affects target cells at the same distance
major endocrine organs are
pineal, hypothalamus, pituitary, thyroid, parathyroid glands, thymus, adrenal glands, pancreas, gonads (ovaries/testes)
types of hormone target cell mechanisms
water soluble, lipid soluble
water soluble hormones cannot
get through the membrane
receptor for water soluble hormones
located on cell membrane outer surface (G-protein), uses 2nd messenger CAMP and activates protein kinases (enzyme that adds a phosphate)
structure of water soluble hormones
based on amino acids (contains nitrogen) - amino acids, peptides, amines
result of adding a phosphate
proteins are turned on/off
speed of water soluble hormones
rapid acting (seconds to minutes) - short lived
receptor of lipid soluble hormones
located inside the cell, hormone receptor, binds to DNA in nucleus and changes protein synthesis (cell changes the proteins that are available)
lipid soluble hormones are able to
get through the cell membrane
structure of lipid soluble hormones
steroid (mainly carbon and hydrogen) or thyroid
speed of lipid soluble hormones
slow acting (minutes to hours) - longer lived
how do hormones affect their target cells
changing enzyme activity (increase/decrease enzyme - regulated chemical reaction)
secretion changes (increase/decrease)
membrane change (change in permeability or charge of the cell)
protein synthesis (increase/decrease within the cell, on the cell surface, or secreted by the cell)
types of hormone control mechanisms
humoral control
neural control
hormonal control
purpose of hormone control mechanisms
regulating hormone release
humoral control refers to
levels of solutes in the blood control/are controlled by hormone
examples of humoral control
Ca++ and parathyroid hormone
glucose and insulin
neural control refers to
the nervous system regulating hormone release
examples of neural control
sympathetic nervous stimulation/release of epinephrine
childbirth
hormonal control refers to
hormones regulating hormone release (levels of hormones in blood that control other hormones)
example of hormonal control
release of thyroid hormone
hypothalamus anatomy
many nuclei (groups of somas) for releasing hormones
connects to pituitary by infundibulum
pituitary anatomy
pituitary = hypophysis (undergrowth)
adenohypophysis - anterior lobe
neurohypophysis - posterior lobe
adenohypophysis details
glandular (epithelial) tissue, develops from the roof of the mouth early, and is connected to the hypothalamus via the hypothalamic-hypophyseal portal system
run of the hypothalamic-hypophyseal portal system
hypothalamic capillaries, hypothalamic-hypophyseal portal vein, anterior pituitary capillaries
neurohypophysis details
nervous tissue, axon endings of neurons are an extension off the brain, located in the hypothalamus
chemical structure:
releasing stimulus:
target cells/effect:
disease:
(hormones of the hypothalamus)
polypeptide
hormonal/nervous
pituitary
tropic hormones result in
some sort of change in the effector
chemical structure:
releasing stimulus:
target cells/effect:
disease:
(Follicle Stimulating Hormone)
polypeptide
hormonal (GnRH) - start of puberty
females - stimulates ovarian follicles (egg/estrogen), males - stimulates testes (sperm production)
chemical structure:
releasing stimulus:
target cells/effect:
disease:
(Luteinizing Hormone)
polypeptide
hormonal (GnRH) - start of puberty
females - ovulation, meiosis, development of the corpus luteum (progesterone), males - testosterone production
chemical structure:
releasing stimulus:
target cells/effect:
disease:
(Thyrotropin/Thyroid Stimulating Hormone)
polypeptide
hormone (TRH)
thyroid - production of thyroid hormone
chemical structure:
releasing stimulus:
target cells/effect:
disease:
(AdrenoCorticoTropic Hormone)
polypeptide
hormone (CRH)
adrenal cortex (outer) - production of cortisol
chemical structure:
releasing stimulus:
target cells/effect:
disease:
(PRoLactin)
polypeptide
hormone (PRH, PIH)
breast - develop milk glands
most common benign tumor of the pituitary
chemical structure:
releasing stimulus:
target cells/effect:
disease:
(Growth Hormone/somatotropin)
polypeptide
hormone (GHRH, GHIH), somatostatin
liver mediated growth factors - stimulates skeleton/cartilage, inhibits fat
in kids - dwarfism (low), giantism (high)
in adults - acromegaly
chemical structure:
releasing stimulus:
target cells/effect:
disease:
(AntiDiuretic Hormone/vasopressin)
polypeptide
nervous
kidney - retain H2O (decreases urine output), BVs - constrict (increase BP)
lack of ADH leads to diabetes insipidis
chemical structure:
releasing stimulus:
target cells/effect:
disease:
(Oxytocin)
polypeptide
nervous - babies head, suckling, physical touch
uterus - contracts, breast - expresses milk, brain - positive feelings/bonding
types of thyroid hormone and their characteristics
T4 - more secreted (can be made into T3)
T3 - more active
- both are assembled off tyrosine from thyroglobulin
chemical structure:
releasing stimulus:
target cells/effect:
disease:
(Thyroid Hormone)
amine
hormonal (TSH)
all over - increases metabolic enzymes
in kids/adults - hypothyroid (cretinism), adults - hyperthyroid (thyroiditis, graves D2), goiter
calcitonin…
…puts bone in
chemical structure:
releasing stimulus:
target cells/effect:
disease:
(Calcitonin)
polypeptide
humoral (increase in blood Ca++)
osteoblasts - form bone, decreasing blood Ca++
chemical structure:
releasing stimulus:
target cells/effect:
disease:
(ParaThyroid Hormone)
polypeptide
humoral (decrease in blood Ca++)
bone - breaks down, kidney - retains Ca++, activates vitamin D, intestines - absorb Ca++ (increasing blood Ca++)
chemical structure:
releasing stimulus:
target cells/effect:
disease:
(Melatonin)
amine
nervous (decrease in light exposure)
brain - stimulates sleep and regulates mood
SAD - Seasonal Affective Disorder
stress hormones include
catecholamines (epinephrine/norepinephrine), mineralocorticoids, glucocorticoids, gonadocorticoids
chemical structure:
releasing stimulus:
target cells/effect:
disease:
(Catecholamines)
amine
sympathetic nervous system stimulation
all over sympathetic activity, brain - more awake/alert, heart - increase HR, BP, decrease GI, increase respiration
pheochromocytoma - influx of epinephrine
chemical structure:
releasing stimulus:
target cells/effect:
disease:
(Mineralocorticoids)
steroid
nervous (sympathetic stimulation), humoral (increase in Na+, decrease in K+), hormonal (ACTH, angiotensin II)
kidney - retain Na+, rid of K+, retain H2O, increase BP
chemical structure:
releasing stimulus:
target cells/effect:
disease:
(Glucocorticoids)
steroid
hormonal (ACTH - cyclic)
all over - increase blood glucose for stress
cushing’s syndrome (more), addison’s disease (less)
cortisol is used pharmaceutically for
anti-inflammatory steroids
chemical structure:
releasing stimulus:
target cells/effect:
disease:
(Gonadocorticoids)
steroid
hormonal (ACTH)
females - androgens
females - androgenital syndrome (high level)
chemical structure:
releasing stimulus:
target cells/effect:
disease:
(Glucagon)
polypeptide
humoral (fall in blood glucose)
liver - makes glucose break down glycogen
chemical structure:
releasing stimulus:
target cells/effect:
disease:
(Insulin)
polypeptide
humoral (rise in blood glucose)
most cells of the body (not neurons) - allows glucose into cells
diabetes mellitus - increases urine (type I: pancreas stops making insulin, type II: insulin receptor problem)
