Synapses

Question 1

Storage granule

Answer 1

Large compartment that holds synaptic vesicles

Question 2

Electrical synapse

Answer 2

Gap junction; direct connection between two cells that allows passage of ions and other small molecules

Question 3

Types of chemical synapses

Answer 3

1) dendrodendritic
2) axodendritic
3) axoextracellular
4) axosomatic
5) axosynaptic
6) axoaxonic
7) axosecretory

Question 4

Resting potential is due to these three factors

Answer 4

1) intracellular excess of anions
2) K+ accumulates in cell
3) Na+ is pumped out of cell by pumps

Question 5

Graded potential

Answer 5

Brief change in polarity that is local

Question 6

Three ways to obtain graded potentials

Answer 6

1) movement of K+ ions
2) movement of Na+ ions
3) movement of Cl- ions

Question 7

Hyperpolarization is due to…

Answer 7

K+ efflux or Cl- influx

Question 8

Depolarization is due to…

Answer 8

Na+ influx

Question 9

Action potential

Answer 9

Short event in which electrical membrane potential of a cell rapidly rises and falls following consistent trajectory

Question 10

Tetramethylammonium (TEA) blocks…

Answer 10

K+ channels

Question 11

Tetrodotoxin blocks…

Answer 11

Na+ channels

Question 12

Digitalis blocks…

Answer 12

Na/K pumps

Question 13

Node of Ranvier

Answer 13

Breaks in myelin sheath contains many voltage sensitive channels

Question 14

How action potentials are passed on

Answer 14

1) action potential arrives at axon
2) voltage-gated Ca channels open and release Ca
3) causes vesicles to release contents
4) neurotransmitters diffuse across synaptic cleft and bind to ligand-gated ion channels
5) binding opens channels causing graded potentials
6) neurotransmitter is removed from cleft in various ways

Question 15

Temporal summation

Answer 15

Graded potentials that occur at approximately the same time on a membrane are summed

Question 16

Spatial summation

Answer 16

Graded potentials that occur at approximately the same location and time on membrane are summed

Question 17

Parts of synapse

Answer 17

Presynaptic membrane
Postsynaptic membrane
Synaptic cleft
Microtubules
Mitochondria
Vesicles
Storage granules