Lecture 8 - Regulatory Endocrine Flashcards
What speed is an endocrine response initiated?
slowly
What is the duration of an endocrine response?
long
What does the endocrine system release into the bloodstream?
hormones
Where are the endocrine system target areas of the body?
diverse-locations anywhere the blood reaches
Finish the sentence:
Hormones act over ______
long distances
List the endocrine organs located in the brain and what they do.
=pineal gland
-day/night cycle
=hypothalamus
-homeostasis
=pituitary gland
-other endocrine glands
List the endocrine organs located in the throat and what they do.
=thyroid
-energy use
=parathyroid
-Ca2+ levels in the blood
=thymus
-immune system
List the endocrine organs located in the abdominal and what they do.
=adrenal glands
-metabolism, immune system, BP, stress
=pancrease
-blood sugar levels, insulin, glucagon
List the endocrine organs located in the pelvis and what they do.
=ovary
-menstrual cycle, fertility
=testis
-testosterone, androgens
Are hormones selective?
they only bind to very specific receptors
How is target cell activation influenced?
-hormone concentration
-receptor content
-receptor affinity (160pMol)
What is the endocrine reaction to the rise in blood sugar level?
- pancreas sense
- insulin secreted into the blood
- more glucose uptake or the liver converts glucose to glycogen
- blood sugar falls back to normal range
What is the endocrine reaction to the fall in blood sugar level?
- pancreas sense
- glycogen secreted
- liver breaks down glycogen to glucose
- rise in blood sugar level back to normal
Name the 3 structural groups of hormones + 1 not really a hormone
-steroid (cholesterol)
-peptides, amino acids, proteins
-eicosanoids (arachadonic acid)
-inflammatory
What do hormones do? (5)
=alter cell activity
-membrane permeability/ potential
-enzyme synthesis
-enzyme activation/ deactivation
-secretory activity
-mitosis stimulation
What do steroid hormones do?
Enter the nucleus and stimulate gene transcription
What do peptide/ protein hormones do?
Activation of g-protein second messenger chain to regulate the activity of key enzymes
lipid soluble hormone vs water soluble
-consist of
LS - steroid and thyroid
WS - amino acid base
lipid soluble hormone vs water soluble
-sources
LS - adrenal cortex, gonads, thyroid
WS - all endocrine glands
lipid soluble hormone vs water soluble
-stored in secretory vesicles
LS - no
WS - yes
lipid soluble hormone vs water soluble
-transport in blood
LS - bound to proteins
WS - free in plasma
lipid soluble hormone vs water soluble
-life in the blood
LS - long half-life
WS - short half-life
lipid soluble hormone vs water soluble
-location of receptors
LS - inside the cell
WS - on plasma membrane
lipid soluble hormone vs water soluble
-mechanism of action at the target cell
LS - activate genes, synthesis of new proteins
WS - second-messenger systems
Name the 3 hormone-release mechanisms and their function
=humoral
-direct change the [nutrient/ion] blood
=neural
-SNS, epinephrine release by the adrenal medulla
=hormonal
-3 tier, hypothalamus-pituitary-target gland
What happens when Ca2+ levels in the blood decrease?
- thyroid sense
- parathyroid release hormone increase
- osteoclasts release
- Ca2+ increase
What happens when Ca2+ levels in the blood increase?
- Thyroid sense
- less parathyroid release hormone
- calcium deposit rises
- Ca2+ decrease
Exocrine vs endocrine
-structure
exo - ducts
endo - ductless glands
Exocrine vs endocrine
-where secrete
exo - epithelial surface
endo - directly in the blood
Exocrine vs endocrine
-major glands
exo - sweat, salivary, mammary, ceruminous, lacrimal, sebaceous, prostate, mucous
endo - pineal gland, pituitary glans, pancreas, ovaries, testes, thyroid gland, parathyroid gland, hypothalamus, adrenal glands
What is antagonism?
when one hormone opposes the action of another
What are the steps of ADH / oxytocin release into the blood?
- hypothalamic neurons synthesize ADH or oxytocin
- transported down axons of the hypothalamus to the posterior pituitary
- stored in axon terminals
- action potentials cause release into the blood
What are the steps for thyroid-releasing hormone?
- release/inhibit thyroid-releasing hormones (TRH) into the primary capillary plexus of the hypothalamus
- transported down portal veins to the anterior pituitary
- presence of TRH at the anterior pituitary releases thyroid-stimulating hormone (TSH)
- presence of TSH then, secrete thyroid hormones into the secondary capillary plexus which empties into the general circulation
What are the simple 3 steps of hormonal stimulus?
- hypothalamic releasing hormone
- anterior pituitary hormone
- target gland
How does the nervous system moderate the endocrine system?
It makes adjustments to maintain homeostasis by overriding the normal endocrine controls
What is the HPA axis?
hypothalamus-pituitary-adrenal axis
-deals w/ stress
-makes cortisol
-regulates digestion, immune, mood, emotions, energy storage
*-neuroendocrine system
What is the negative feedback loop for cortisol levels in the body?
- paraventricular nucleus (hypothalamus) secretes vasopressin and corticotropin-releasing hormone
- regulation of the pituitary gland
- secretion of adrenocorticotropic hormone
- adrenal cortex release glucocorticoid
- suppression of vasopressin and CRH on the hypothalamus
