Endocrine system t1 Flashcards
What are the two major control systems of the body?
Nervous and endocrine system
What are some differences btwn endocrine and nervous system? 5
- Hormones are transported within the blood
- Exhibit longer reaction times
- more widespread effects
- longer lasting effects
- nervous = electrical , endocrine = chemical
Endocrine system releases what and that goes to where?
releases and synthesizes hormones to target cells
What is a target cell?
cells with a specific receptor for hormone, hormone binds to this
4 main fxns of endocrine system?
- maintaining homeostasis of blood compositon and volume
- controlling reproductive activities
- regulating development, growth and metabolism
- controlling digestive processes
Composition of endocrine system 3
- derived from epithelium with connective tissue framework
- extensive blood supply
- two organizations: single organ with endo fxn, cells in small clusters in organs with another fxn
differentiate perfusion from vascularization
perfusion = measure of amount of blood flowing through an area
- vascularization = measure of number of blood vessels in an area
What are the 5 organs with endocrine fxn?
- pituitary gland
- pineal gland
- thyroid gland
- parathyroid glands
- adrenal glands (suprarenal glands)
Pineal gland is found where? Pinealocytes secrete what hormone and what does that hormone do?
posterior region of the epithalmus, cells secrete melatonin regulating circadian rhythm
The parathyroid glands are found where? What does it regulate?
found on posterior region of thyroid gland
- regulates blood calcium levels
What are the two cells types in the parathryoid? what are their fxns?
- Cheif cells : released in response to decreased blood Ca2+ levels
- Oxphil cells: fxn unknown :)
What are the other organs that have small clusters releasing hormones? 9
skin, thymus, heart, liver, stomach, pancreas, small intestine, kidneys and gonads
What hormone does the kidneys secrete in times of anemia? what does this hormone do?
secrete erythropoietin, RBC production
Endocrine reflexes are initiated by which 3 types of stimulation?
- hormonal, humoral, nervous stimulation
Describe hormonal stimulation
release of hormone in response to another hormone
Describe humoral stimulation
release of a hormone in response to changes in level of nutrient or ion in the blood
Describe nervous stimulation
release of a hormone in response to stimulation by the nervous system
What are the two catgories of ciruclating hormones?
steroid hormones and protein hormones
Sterioid hormones are ___ soluble. and synthesized from ___. Includes what three types of hormones?
lipid soluble, from cholestrol
- steroids produced by gonads, steroids synthesized by adrenal cortex, calcitriol sometimes in group
Protein hormones are ___ soluble. Most hormones in this group (t/f). COmposed of small chains of ____.
water soluble, true, small chains of amino acids
How are water soluble hormones transported?
they readily dissolve, easily transported in aqueous enviornment
How are lipid soluble hormones transported?
require carrier proteins
The lipid soluble carrier proteins are either __ or __.
selective or nonselective
Albumin is a lipid soluble protein that does what?
Acts as a transport in blood :)