chapter 16 Flashcards
hormones
long distance chemical signals that travel the blood or lymph
two types of hormones?
Amino acid based hormones and steroid hormones
Amino acid based hormone?
amines, thyroxine, proteins, and peptides
what hormone is synthesized from cholesterol? This class includes gonadal and adrenocorticoid homromes
steroid hormones
what are two mechanisms of hormone action?
Water soluble hormones and lipid soluble hormones
Know that all water soluble hormones are all amino acid based except?
thyroid
___________ act on intracellular receptors that directly activate genes ( directly diffuse into cell)
lipid soluble hormones
______ bind to receptors thru secondary messengers
water soluble hormones
Steps of mechanisms of hormone actions
- alter plasma membrane permeability pf membrane potential by opening and closing ion channels
- stimulate synthesis of proteins or regulatory molecules
- activate/ deactivate enzyme systems
- induce secretory activity
- stimulate mitosis
cAMP steps
- hormone binds to receptor
- receptor changes shape, activate G protein inside the cell.
- GTP binds to G protein, activate adenylate cyclase
- Adenylate cyclase converts ATP to cyclic AMP
- cAMP activates protein kinases
What is up regulation?
target cells form more receptors
What is down regulation?
target cell loses receptors
hormones can act in several different ways, what are the 3 ways?
permissiveness
synergism
antagonism
What is it called when one hormone cant work w/o another one present?
permissivness
What is synergism?
more than one hormone can produce the same effect on a target cell
what Is it called when one or more hormone oppose the action of another?
antagonism
intracellular receptors ( steroid hormones and thyroid hormone)
- diffuse into target cell, bond w intracellular receptors
- receptor- hormone complex enters nucleus
- receptor hormone binds to DNA
- prompts DNA transcription-> mRNA
- mRNA direct protein synthesis
target cell activation depends on what three things?
- blood level of hormone
- # of hormone receptors on or in target cell
- affinity of binding between hormone and receptor
blood level of hormones are controlled by
negative feedback systems
hormones are synthesized and released in response to?
- humoral stimuli
- neural stimuli
- hormonal stimuli
changes blood levels of ions and nutrients directly stimulates secretion of hormones is what stimuli?
humoral
ex of humoral stimuli?
Ca2+ in de blood
Declining ca@+ in the blood stimulate PTG to release PTH and then the Ca2+ levels rise and stimulus is removed
Neural/ hormonal stimuli?
nerve fibers stimulate hormone release. hormones stimulate other endocrine organs to release their hormones
the pituitary gland has two lobes called what
anterior pituitary and posterior pituitary
what makes up the anterior pituitary?
pituicytes and nerve fibers
what makes up the posterior pituitary?
glandular tissue
Anterior pituitary hormones are all ______ except _____ activate cAMP
proteins and GH
Which hormones are tropic?
TSH, ACTH, FSH, LH
name all the anterior pituitary hormones
GH, TSH, LH, PRL, ACTH, FSH
_____ are cell of pituitary that directly target body cell growth. These cells produce what hormone?
Somatotrophs and Growth hormone
Hypersecretion of GH
kids- gigantism
adults- acromegaly
Hyposecretion of GH
pituitary dwarfism
Hypersecretion of TH
graves disease
Hyposecretion of TH
myxedema
kids- cretinism
hyperseretion of glucocorticoids
cushings syndrome
hyposecretion of glucocorticoids
addisons disease
alcohol inhibit the release of
ADH
____ also know as vasopressin
ADH
_______ respond to changes in the solute concentration of the blood
hypothalamic osmoreceptors
if solute concentration is high _____ depolarize and transmit impulses to hypothalamic neurons
osmoreceptors
if solute concentration is low, ____ is not released, allowing water loss
ADH
the _____ consists of two lateral lobes connected by a median mass called an _____
thyroid and isthmus
____ Is the most important hormone on Ca2+ homeostasis
PTH
The parathyroid gland contain _____ cells and _____ cells that secret PTH
oxyphil and chief
Adrealn medulla v Adrenal cortex
medulla- nervous tissue, part of SNS
cortex- three layers of glandular tissue that synthesize and secrete corticosteroids
3 layers of adrenal cortex
zona glomerulosa
zone fasiciculata
zona reticularis
zone glomerulosa is
mineralcorticoids- aldosterone
zona fasciculate is
glucocorticoids- cortisol
zona reticularis
sex hormone, androgens, gonadocorticoids
_____ leads to production of androgens and estrogen
DHEA
_____ is the most important mineralcorticoid?
Aldosterone ( regulate electrolytes)
_____ is the most significant glucocorticoid. It’s prime metabolic effect is _____ which is formation of glucose from fats and proteins
Cortisol, gluconeogensis
glycogenolysis
break down of glycogen to glucose
glyconeogenesis
synthesis of glucose from lactic acid and noncarbs
____ ells secrete ___% epinephrine and __% norepinephrine
chromaffin, 80, 20
What is epinephrine?
stimulates metabolic activites, bronchial dilation, and blood flow to skeletal muscles and heart
what is norepinephrine?
influences vasoconstriction and BP, concentration
Alpha cells
produce glucagon ( a hyperglycemic hormone)
beta cells
produce insulin ( a hypoglycemic hormone)
aldosterone secretion mechanism
- RAAS: kidney secrete renin, triggers angitension ll formation
- K+ concentration; increased K+ stimulates zona glomerulosa to secrete aldosterone
- ACTH: cause slight increase in aldosterone during stress
- ANP: block renin and aldosterone; decrease BP
Growth hormone (GH)
S: A. Pituitary
T: body cells, bones, muscles
A: growth and development
Produced by somatotrophs
Thyroid stimulating hormone (TSH)
S: a. pituitary
T: thyroid
A: regulate thyroid hormones
Produced by thyrotrophs
ACTH
S: A. pituitary
T: Cortex
A: regulate cortex hormones
produced by corticotrophs
Follicle stimulating hormone (FSH)
S: A. pituitary
T: ovaries/ testes
A: stimulate egg production
secreted by gonadotrophs
Lutenizing hormone (LH)
S: A. pituitary
T: ovaries/ testes
A: ovulation/ sex hormone release
secreted by gonadotrophs
Prolactin (PRL)
S: A. pituitary
T: breasts
A: milk secretion
ADH
S: P. pituitary
T: kidneys
A: water balance, BP
oxytocin
S: P. pituitary
T: uterus, breasts
A: uterine contraction, milk secretion
Thyroid gland is composed of follicles that produce the glycoprotein
thyroglobulin
_____ ( thyroglobulin+iodine) fills the ___ of the follicles and is the precursor to ____
colloid, lumen, thyroid hormone
Parafollicular cells produce
calcitonin
thyroid hormone (thyroxine)
S: thyroid
T: body cells
A: regulate metabolism
calcitonin
S: thyroid gland
T: adrenal cortex
A: reulate cortex hormones
secreted by parafollicular cells
Parathyroid hormone
S: parathyroid
T: bone matrix
A: raise blood calcium
