Chapter 20: Endocrine System SYDNEY Flashcards
what does the endocrine gland do?
-produce hormones that are released into the bloodstream
-ductless
what are hormones in relation to the endocrine system?
chemical messengers
function of hormones
- change the metabolic activity of the target cells/target organs
what are target cells and target organs?
target cells: cells with specific receptors for the hormone enabling the hormone to bind to the cell
target organs: organs that contain the target cells
what does the feedback do in general?
-hormone levels are regulated by this self-adjusting mechanism
-product of a pathway acts back at an earlier step in the pathway to regulate the pathway’s activities
types of feedback
-positive feedback
-negative feedback
positive feedback
accelerates the original process, either to ensure that the pathway continues to run or to speed up its activities
negative feedback
occurs when a stimulus starts a process, and eventually either the hormone that is secreted or a product of its effects causes the process to slow down or turn off
appearance of the adrenal glands and location
-paired, pyramid-shaped endocrine glands anchored on the superior surface of each kidney
parts of the adrenal gland
-corticosteroids
-epinephrine/norepinephrine
-pancreas
-gonads
-pineal gland
-thymus
what is the location of corticosteroids and what does it regulate?
-cortex
-electrolyte type/amount
what is the outer layer of the adrenal gland called?
adrenal cortex
what is the inner central core of the adrenal gland called?
adrenal medulla
color of adrenal cortex and why? function?
-distinctive yellow color as a consequence of the stored lipids in its cells that synthesize more than 25 different steroid hormones
what are the steroid hormones collectively called?
corticosteroids
color of adrenal medulla
-pronounced red-brown color due to its extensive vascularization
how are the hormones epinephrine and norepinephrine created?
chromaffin cells secrete these hormones when stimulated by the sympathetic division of the ANS
what is epinephrine also known as? what is norepinephrine also known as?
epinephrine = adrenaline
norepinephrine = no adrenaline