Synapses 1

Question 1

synaptic transmission

Answer 1

the process of information transfer at a synapse

Question 2

electrical synapses

Answer 2

synaptic transmission that’s an electrical current flowing from one neuron to the next
common in mammal brain

Question 3

chemical synapses

Answer 3

the idea that chemical neurotransmitters transfer information from one neuron to another at the synapse
CNS
majority of synapses in brain = chemical

Question 4

presynaptic v postsynaptic

Answer 4

first neuron is pre, target cell is post

Question 5

gap junction

Answer 5

specialized sites where electrical synapses occur
membranes of cells separated by narrow narrow gap
narrow gap spanned by clusters of connexins

Question 6

connexin

Answer 6

special proteins that cluster together and span the narrow gap between cell membranes

Question 7

connexon

Answer 7

six connexins combined

Question 8

gap junction channel

Answer 8

two connexons (one from each cell) combine to form this

Question 9

electrically coupled

Answer 9

cells connected by gap junctions

because electrical current in the form of ions can pass through channels

Question 10

postsynaptic potential (PSP)

Answer 10

caused by current that flows across gap junction channels
when second neuron generates action potential, will induce PSP in first neuron
several occurring at same time may strongly excite a neuron

Question 11

synaptic cleft

Answer 11

separates pre and post synaptic membranes at chemical synapses

Question 12

presynaptic element

Answer 12

presynaptic side of the synapse

Question 13

synaptic vesicles

Answer 13

dozens of small membrane enclosed spheres
in axon terminal
store neurotransmitter

Question 14

secretory granules

Answer 14

larger vesicles
contain soluble protein that appears dark in the electron microscope
sometimes called large dense-core vesicles

Question 15

membrane differentiation

Answer 15

dense accumulations of protein adjacent to and within the membranes on either side of the synaptic cleft

Question 16

presynaptic membrane differentiation

Answer 16

proteins jutting into the cytoplasm of the terminal along the intracellular face of the membrane (tiny pyramids)

Question 17

active zones

Answer 17

pyramids and membrane associated with them
actual sites of neurotransmitter release
synaptic vesicles clustered in cytoplasm adjacent to active zones

Question 18

postsynaptic density

Answer 18

protein thickly accumulated in and just under postsynaptic membrane
contains neurotransmitter receptors which convert intercellular chemical signal (neurotransmitter) into intracellular signal (change in membrane potential or chemical change) in postsynaptic cell

Question 19

axodendritic

Answer 19

if postsynaptic membrane is on a dendrite, synapse is axodendritic

Question 20

axosomatic

Answer 20

if postsynaptic membrane is on cell body, synapse is axosomatic

Question 21

axoaxonic

Answer 21

if postsynaptic membrane is on another axon, synapse is axoaxonic

Question 22

dendrodendritic

Answer 22

when dendrites form synapses with one another

Question 23

gray’s type I vs gray’s type II

Answer 23

type I: membrane differentiation is thicker on postsynaptic side, asymmetrical
type II: membrane differentiations are of similar thickness, symmetrical

Question 24

neuromuscular junction

Answer 24

chemical synapses that occur between the axons of motor neurons of the spinal cord and skeletal muscle
has many structural features of chemical synapses in CNS

Question 25

motor end-plate

Answer 25

postsynaptic membrane | contains series of shallow folds

Question 26

three kinds of chemical categories of neurotransmitters

Answer 26

amino acids, amines, peptides

Question 27

major amino acids

Answer 27

GABA glutamate glycine

Question 28

major amines

Answer 28

``` ACh dopamine epinephrine histamine norepinephrine serotonin ```

Question 29

major peptides

Answer 29

``` CCK dynorphin Enk NAAG neuropeptide Y somatostatin substance P VIP ```

Question 30

amino acids

Answer 30

small organic molecules containing at least one nitrogen atom stored in and released from synaptic vesicles

Question 31

amines

Answer 31

small organic molecules containing at least one nitrogen atom stored in and released from synaptic vesicles

Question 32

peptides

Answer 32

large molecules stored in and released from secretory granules often exist in same axon terminals that contain amine or amino acid neurotransmitters

Question 33

glutamate, gamma aminobutyric acid, glycine

Answer 33

mediate fast synaptic transmission at most CNS synapses

Question 34

acetylcholine (ACh)

Answer 34

mediates fast synaptic transmission at all neuromuscular junctions

Question 35

transporters

Answer 35

special proteins embedded in the vesicle membrane | concentrate neurotransmitters inside the vesicle