Flashcards in Endocrine system Deck (96)
Neurons cannot store glucose so what do we have to do?
keep a good balance of glucose/ ATP in the blood
What are hormones?
chemical messengers that act on specific target tissues; affect metabolism of target cels/ tissue
What are the general functions of hormones?
- biological clock
- cardiac/smooth muscle contraction
- glandular secretinos
- some immune functions
Hormones affect only those cells with _______membrane proteins (receptors; for hormones)
What happens to hormones receptors when hormones increase?
down-regulation (decrease receptors)
What happens to hormone receptors when hormones are too low?
up- regulation (increases receptors)
What are the 2 types of local hormones?
paracrine (act on neighbouring cells)
autocrine (act on the cell secreting them)
What is an autocrine local hormone?
acts on the cell secreting it
What is a paracrine local hormone?
acts on neighbouring cells
What are circulating hormones?
hormones that act on distant targets and travel to them by through the blood
What are the 2 types of chemical hormones?
What are the 3 types of lipid-soluble hormones?
What are steroid hormones?
- cholesterol based
- secrete from adrenal cortex (as cortisol, aldosterone), from testes (as testosterone), from ovaries and placenta (as estrogen and progesterone)
What does aldosterone from the adrenal cortex do?
helps regulate blood volume/pressure by reabsorbing sodium
What does the adrenal cortex secrete?
What do the testes secrete?
What do the ovaries and placenta secrete?
estrogen and progesterone
What are thyroid hormones?
- a lipid soluble hormone that is derived from tyrosine and secreted from the thyroid gland as triiodothyrine (T3), and thyroxine (T4)
What are the 2 types of thyroid hormones?
What is the lipid soluble hormone nitric oxide?
- a gas
- released by endothelial cells lining the blood vessels
What are the 3 categories of water-soluble hormones?
- peptides and protein hormones
What are amine hormones?
- derived from amino acids
-secreted from adrenal medulla (catecholamines- E, NE) and from mast cells (histamines)
What are peptide hormones?
hormones secreted from pituitary, parathyroid, and pancreas
What hormones are secreted from the pituitary?
ACTH, GH, TSH, ADH, oxytocin
What hormone is secreted from the parathyroid?
What hormones are secreted from the pancreas?
insulin & glucagon
What are Eicosanoids?
- derived from arachidonic acid
- secreted from all cells except red blood cells
- important local hormone
- includes prostaglandins, leukotrienes
What are peptides?
typically short proteins
How do protein hormones circulate in the blood?
in free form