Intro Endocrine Physiology Flashcards
Name the 3 types/groups of hormone?
peptide - protein
lipid
non-peptide AA-based
Name 2 outcomes of a hormone binding a receptor?
Activate 2nd messenger
transcription
How is hormone activity terminated?
Hormone-Receptor complex is endocytosed and degraded by proteosomes and lyzosomes
Describe the hormone hierarchy
hypothalamus - release/inhibit horomones
pituitary - trophic horomones
+/- endocrine gland: final hormones
to target cell
Name the hormones released by the hypothalamus
GNRH CRH TRH GHRH Somatostatin da
Hormones of anterior pituitary.
Posterior?
ACTH, TSH, FSH, LH, GH, Prolaction
Vasopressin(ADH), oxytocin
Hormones of the thyroid
T3, T4, Calcitonin
Name the hormones of the adrenal gland?
cortisol, aldosterone, androgens, estrogens, epinepherine
What hormones do the ovaries make?
Estradiol, progesterone
Where are oxytocin and ADH synthesized?
hypothalamic neurons, then stored in posterior pituatary
Describe the difference in response time between the posterior and anterior axis of the pituatary
Posterior - stored protein hormones released - fast response
Anterior - hormones have to be produced, then steroid hormones released to a 3rd endocrine organ - slow process
What type of feedback is used to regulate hormones?
Negative feedback
Describe the progression of peptide-protein hormone synthesis and secretion
pre-prohormone is cleaved in RER to prohormone. Golgi cleaves it to mature. Hormone is packaged into secretory granules. via stimulus it fuses with plasma membrane and is released
How are steroid hormones made?
made from cholesterol via enzymes in mitochondria and SER - are secreted immediatley
What 3 enzymes make eicosanoid hormones?
COX 1 and 2- prostaglandins, thromboxanes
Lipoxygenases - leukotrienes
Cytochrome p450 - epoxides
What type of receptors are used for each type of hormone?
Peptide - protein - cell surface receptors
steroid - cytosolic or nuclear receptors
eicasonids - GPTC-receptors
amines - GPCR, nuclear receptors, or protein receptors
What are the 3 main groups of amine hormones?
catecholamines
thyroid hormones
tryptophan hormones
How are receptors downregulated?
By a decrease in receptor #’s or increase in hormonal degradation
ADH function and source
Retain water
produced in V2 cells of pos. pituitary
What is GHRH fucntion and source
Stimulates GH
From Somatotroph cells of ant. pituatary
What is ACTH function and source?
Stimulates cortisol, source is zona fasiculata of adrenal cortex
What are the functions of LH?
W - follicular maturation and ovulatoin
M - testosterone production and spermatogenesis
What are the functions of FSH?
W - follicular development
M - spermatogenesis
What are the functions of PTH?
increase serum Ca+2
PTH-1: kidney, bones
PTH-2: CNS, bones, kidneys
What are the functions of Calcitonin?
decrease serum Ca+2 , receptors in CNS, bones, kidneys, intestines
What is the function and source of epinephrine?
glycogenolysis, adrenal medulla
What type of receptors do estrogen and progesterone bind?
homodimer with 2 hormones and 2 receptors required for activation -> act as transcription factor
Describe the receptor complex for thyroid hormone and active Vit. D
unliganded RXR heterodimer (2 complexes 1 binds hormone and other does not)
In steroid signalling: hormone dissociates, enters the cells and does what?
binds cytoplasmic receptor, goes to nucleus, forms dimer, and acts as transcription factor
Which receptor is a target for type II DM?
PPAR (peroxisome proliferator-activated receptor) nuclear superfamily receptor
What are the two elimination “fates” of hormones?
- oxidized to a metabolite
- glucuronidated into stable adjunct
then to bile by liver or urine by kidney
Why are hormones secreted in a pulsatile manner instead of continuous?
decrease desensitization, continuous can downregulate receptor transcription and decrease signalling response
Describe the ways multiple hormones can interact
synergistic, antagonistic, permissive, additive
What needs to happen for hormones to travel in the body?
attachment to specific/non-specific binding proteins
