Homeostasis And The Endocrine System Flashcards
Puberty and endocrine systems
Physical maturity and for reproduction
Begins with gonadotropin releasing hormone
Gonads release sex steroid hormones
Sex hormones order
Cholesterol to progestogens and estrogens
To then androgens
To glucocorticoids
Mineralacorticoids
Androgens are
Test and dihydrotest DHT
Stimulate spermatogenesis and development of secondary sexual characteristics in male
Precursor of estrogens not progesterone
Like test estrogens have anabolic effect
Stimulate ovulation
With progesterone regulate menstrual cycle
And also secondary sex characteristics
HPG axis explained quick
Gnrh release from hypothalamus
Then pituitary gland release LH/FSH then gonads release sex hormones that go to other organs
Pancreas is both endocrine and exocrine organ how
Acinar cells exocrine function for digestion enzymes
Islet cells for insulin endocrine function
What are the types of pancreatic islet cells
Alpha cells release glucagon raising blood sugar
Beta cells release insulin lowering blood sugar
Rare Delta cells secrete somatostatin inhibit glucagon
Predictive and reactive homeostasis
Eg reactive is calcitronin for calcium levels
Predictive is eating food can trigger insulin before blood sugar increases even
What if pancreas doesn’t work
Type one diabetes autoimmune beta cell loss
Type two diabetes insulin insensitivity
Coordinated action
Types of ways hormones can act
Antagonism (opposing effects)
Permissivism (some only have an effect if another is present)
And synergism (some hormones together have a greater effect than alone)
Pineal gland?
Pea sized aswell shaped like pine cone
Secretes melatonin
And for circadian Rhythm basically
(Both tryptophan derived) MELATONIN DERIVED FROM SEROTONIN
What does melatonin do
Sleepy reduces insulin secretion and insulin receptor expression
Melatonin receptors on beta cells
Triggers phosphorylation of insulin receptor xells
Cortisol follows melatonin pattern
What if pineal gland doesn’t work?
Insomnia pineal Tumor can block cerebral aqueduct and press on other structures
Endocrine cells in other organs
Heart: ANP cells excess blood volume and high blood sodium concentration
Released during heart failure
Placenta: estrogen and progesterone hCG
Kidneys: juxtaglomerular cells secrete renin
Leading to aldosterone
Skin has vitamin d precursors with UV light these required for Ca uptake
