Hormone regulation Flashcards
name 3 examples of chemical messengers
ions
neurotransmitters
hormones
what are hormones
are chemical signals that are secreted into the circulatory system and communicate regulatory messages within the body
describe the function of endocrine system
chemical signalling by hormones
name the three classes of hormones
polypeptides
steroids
amines
what 2 classes of hormones are water soluble and what one is lipid soluble
polypeptides + amines
steroids
what are water soluble hormones
travel freely in the blood stream
bind to cell surface receptors
secreted by expcytosis
what are lipid soluble hormones
diffuse across cell membranes
travel in the bloodstream
transport proteins
diffuse through membranes of target cells
what are PEPTIDE hormones
water soluble
they bind to receptor proteins in the cell membrane then a second messenger molecule initiates
what are STEROID hormones
lipid soluble
bind inside target cells
may directly stimulate transcription
what are the effects of hormones
can sometimes increase blood flow
what is negative feedback
inhibits a response by reducing the initial stimulus, thus preventing excessive pathway activities
what is positive feedback
reinforces a stimulus to produce an even greater response
what is the role of the hypothalamus
receives information from the nervous system
endocrine system
is also attached to the pituitary gland
name 2 examples of roles hormones play
growth
controlling reproductive cycles (sex hormones)
what is growth regulation
GH - growth hormone
stimulates the production of growth factors
