Chemical Messengers Flashcards
It can be can be hormones that arrive via the
bloodstream or neurotransmitters released by nerve cells, such
messengers ultimately connect with a target
Messenger Molecules
pituitary gland, pineal gland, parathyroid gland, pancreas, thymus, adrenal gland, ovary and testes together with the hypothalamus of the brain
ENDOCRINE GLANDS
sweat glands, salivary, and mammary glands
EXOCRINE GLANDS
A system of specialized cells, tissues, and
ductless glands that secretes hormones and
shares with the nervous system the responsibility
for maintaining constant internal body conditions
and responding to changes in the environment.
Endocrine system
biochemically active molecule interacts to
initiate a response in a target cell
Receptor
biochemically active molecule interacts to
initiate a response in a target cell
Receptor
it occurs when the product of the system shuts down or limits its operation
Feedback inhibition
testosterone, estrogen, progesterone
steroids
melatonin, epinephrine, thyroid hormone
Amines
glucagon, oxytocin, antidiuretic hormone, calcitonin, parathyroid
hormone
Peptides
growth hormone, insulin, prolactin, follicle stimulating hormone, leuteinizing hormone
Proteins
The place where the tip of a neuron and its target cell lie adjacent to each other
synapse
a neurotransmitter responsible for the control of skeletal muscles. It is also widely distributed in the brain, where it may play a role in the sleep– wake cycle, learning, memory, and mood.
Acetylcholine
Any substance that alters body function when it is introduced from an
external source.
drug
A substance that interacts with a receptor to cause
or prolong the receptor’s normal biochemical
response
Agonist
A substance that blocks or inhibits the normal
biochemical response of a receptor.
Antagonist
(an antagonist) It prevents the release of acetylcholine, frequently causing
death due to muscle paralysis
Botulinus toxin
(an agonist) releases excess acetylcholine
*opposite reaction from that of botulism toxin, the synapse is flooded with acetylcholine,
*resulting in muscle cramps and spasms.
Black widow spider venom
Nicotine at low doses is a stimulant (an agonist) because it ___
activates acetylcholine receptors
At high doses, nicotine is an antagonist becase ___
It irreversibly blocks the acetylcholine receptors
the neurotransmitter responsible for the symptoms of the allergic reaction; it is also the chemical that causes an itchy bump when an insect bites
Histamine
a family of drugs that counteract the effect of histamine because they are histamine-receptor antagonists. They competitively block the attachment of histamine to its receptors
Antihistamines
it plays a role in the brain in processes that control movement, emotional responses, and the experiences of pleasure and pain
Dopamine
it blocks re-uptake of dopamine from the
synapse, and amphetamines accelerate release of dopamine
cocaine
it also creates an increase in dopamine levels in the same brain areas
marijuana
A chemical messenger
secreted by cells of the endocrine
system and transported through
the bloodstream to target cells with
appropriate receptors, where it elicits
a response.
Hormone
A chemical messenger
that travels between a neuron
and a neighboring neuron or other
target
cell to transmit a nerve impulse.
Neurotransmitter
