hormonal communication

Created by

Bupe katebe

Cards (16)

What’s the difference between trophic and tropic hormones?
Tropic hormones act on other endocrine glands, whereas trophic hormones stimulate growth in target tissues
What is a hormone?
regulating chemical produced by an endocrine or exocrine gland
send information about stimuli in the environment to target cells or tissues, to bring about a response
through what medium are hormones transported in and what are they transported to?
In blood/lymph (endocrine glands) through a duct (exocrine glands)
transported to target cells with complementary receptors on their cell (plasma) membranes
what is meant by an endocrine gland?
group of cells specialised to secrete chemicals (hormones) by a mechanism called secretion into the bloodstream
Name/label the different glands within the endocrine system
glands:
A) pineal gland
B) pituitary gland
C) thyroid gland
D) adrenal gland
E) thymus
F) pancreas
G) ovary
H) testes
state the general characteristics of hormones
effective in small quantities
widespread and permanent effect
small molecules
proteins/polypeptides/steroids/glycoproteins/amines/tyrosine derivatives
produced by endocrine and exocrine glands
true or false? endocrine glands secrete hormones directly into the bloodstream or lymph
true
outline the general action of a first messenger and a second messenger
protein hormone secreted from cell in endocrine organ (first messenger)
hormone circulates in bodily fluids
hormone binds to receptor on plasma membrane of target cell
leads to the activation of second messenger inside the cell
This process is known as cell signalling
state comparisons between the hormonal and nervous system
Differences between both systems:
what two main parts are the adrenal glands made up of? What do each of them do?
ADRENAL CORTEX: (produces hormones vital to life)
glucocorticoids- eg cortisol
they regulate metabolism by controlling how body converts fats carbs and proteins into energy.
Regulate immune response, supress inflammatory responses.
Regulation of blood pressure in response to stress.
use cholesterol to produce steroids.
Release of these hormones controlled by hypothalamus
mineralocorticoids-
eg aldosterone- controls bp by maintaining balance between salt and water concentrations
ADRENAL MEDULLA: (produces non-essential hormones)
Secretes adrenaline in response to stress, and noradrenaline which works alongside adrenaline, producing similar effects (eg- widening air passages)
prepares the body to fight or take flight
state the roles of adrenaline
relaxes smooth muscle in bronchioles
increases stroke volume of heart
increases heart rate
causes general vasoconstriction
stimulates breakdown of glycogen
dilates pupils
increases mental awareness
inhibits the action of the gut (digestion)
what are the differences between endocrine and exocrine tissues?
endocrine glands usually secrete chemicals directly into the bloodstream, whereas exocrine glands secrete them into ducts into organs, or at the surface of the body
endocrine glands usually secrete hormones, exocrine glands can secrete enzymes
why are the hypothalamus and the pituitary gland so close together?
ensures nervous and hormonal responses are closely linked and co-ordinated
state the general events that are involved in hormone secretionin endocrine systems
hormones secreted directly into the blood when a gland is stimulated
can occur because of a change in concentration of a substance or by stimulation of another hormone or nerve impulse
hormones transported into blood plasma all over the body
diffuse out blood and bind to specific receptors for that hormone on the membranes of target cells
stimulate target cells to produce response
why is hormonal communications slower than neuronal communication?
because hormones aren't released directly onto target cells but stimulate their receptors
why do hormones have a longer lasting effect than neurotransmitters?
they are not broken down as quickly