Exam 1 - Ch. 3 Chemical signaling Flashcards
Presynaptic transmitting
process that releases the chemical messenger/neurochemicals
Postsynaptic receptive
process determines binding of transmitter to receptor molecule in postsynaptic cell
Neurotransmitter
chemical substances released by neurons to communicate with other neurons
What is the criteria of an NT?
- neuron has to be able to produce and store the NT
- there has to be a way to deactivate the NT
- there are postsynaptic receptors specific to it
- if agonists or antagonists are applied, they will act appropriately
What are the processes involved in synaptic neurotrasmission?
AP, presynaptic release of NT, postsynaptic receiving of NT (use fig from slides)
Where are NTs made in small-molecule transmitters? In peptide transmitters?
- terminal buttons for quick release
- cell bodies
Which channels are excitatory?
sodium channels
Where are NTs released into, and what are they released from?
they are released into the active zone from the synaptic vesicles through exocytosis
What chemical is involved in the docking, fusion and exocytosis of synaptic vesicles? What else is this chemical involved in?
- calcium
- release of NT
What 4 factors control the rate of NT release?
- rate of neuron firing
- probability of transmitter release from axon terminal
- presence of autoreceptors
- axon terminals may have heteroreceptors
What are autoreceptors?
inhibitory receptors on the presynaptic cell, decrease synthesis and release of NTs once they sense that there is a lot
Synaptic vessels are filled with NTs due to what channels opening?
calcium
What are the 3 methods of NT inactivation?
- enzymatic breakdown
- reuptake (transporter proteins will take the NT into storage or another vesicle)
- uptake by glial cells (astrocytes have their own transporter proteins)
Ionotropic receptors
- directly gates a channel
- quick, short term (movement)
- K+, Ca2+ channels, etc
Metabotropic
- gate ion channels indirectly
- longer duration, slower (memory and learning)
Tyrosine Kinase receptors
mediate action of neurotrophic factors (growth and survival of neurons)
Drugs can act as either agonists or antagonists. True or false? Explain.
True
- can act as a precursor or inhibit synthesis of NTs
- prevent storage in vesicles
- inhibit or stimulate the release of NTs
- stimulate or block postsynaptic receptors
- inhibit or stimulate autoreceptors
- inhibits degradation of NTs
- blocks NT reuptake
Endocrine system, what are some of the things that this system controls?
- controls body functions by releasing hormones
- reproduction, growth and development, mobilization of body defenses, regulation of metabolism
What are the 3 classes of hormones?
- Amino acid derivatives (adrenaline or noradrenaline)
- Peptide and protein hormones (insulin, neuropeptide Y)
- Steroid hormones (estrogen)
What are some hormonal effects?
- changes in plasma membrane permeability or electrical state
- synthesis of proteins such as enzymes
- activation or inactivation of enzymes
What is the difference between steroid hormone and nonsteroid hormone action?
the receptor of a steroid hormone is inside the nucleus, the receptor protein of a nonsteroid hormone is external
Adrenal cortex
excrete glucocorticoids
Adrenal medulla
excrete epinephrine and norepinephrine
What two hormones do the pancreas excrete?
insulin and glucagon
Pineal gland
secretes melatonin
Thymus
- T-cells mature and are produced here
- produces thymosine, which matures some types of WBCs and is important in developing the immune system
Estrogens
- produced by ovaries
- development of secondary female characteristics
- matures female reproductive organs
Progesterone
- produced by the corpus luteum
- acts with estrogen to bring about the menstrual cycle
Testosterone
- responsible for adult male secondary sex characteristics and growth and maturation of male reproductive system
- required for sperm production
