Synapses

Question 1

Synapse

Answer 1

junction between two cells where they communicate with each other

Question 2

Presynaptic cell

Answer 2

The cell that transmits a signal toward the synapse

Question 3

Postsynaptic cells

Answer 3

The cell that receives the signal from the synapse

Question 4

Types of synapses (2)

Answer 4

Electrical

Chemical

Question 5

Electrical synapses

Answer 5

Occur between gap junctions, where local currents flow directly form one cell to a neighboring cell

Important in cardiac muscle cells and many types of smooth muscle

Question 6

Connexons

Answer 6

Structures that separate adjacent cell membranes in gap junctions.

They are 6 tubular proteins

Question 7

Chemical synapses

Answer 7

Occurs where a neurotransmitter (chemical messenger) communicates a message to an effector

Question 8

3 components of a chemical synapse

Answer 8

Presynaptic terminal - end of an axon
Synaptic cleft - space between the end of the axon and the cell with which is synapses
Postsynaptic membrane - membrane of the postsynaptic cell

Question 9

What causes the neurotransmitter release?

Answer 9

Action potentials in the presynaptic terminal

Question 10

Synaptic vesicles

Answer 10

an organelle in the cytoplasm that contains neurotransmitters

Question 11

Neuromodulators

Answer 11

Substances released from neurons that influence the likelihood of an action potential being produced in the post-synaptic cell

Question 12

Excitatory postsynaptic potentials (EPSP)

Answer 12

the graded potential that results from the depolarization of the postsynaptic cell.

Might produce an action potential

Occurs because the membrane becomes more permeable to Na+

Question 13

How do local anesthetics work?

Answer 13

The block voltage-gated Na+ channels, which prevent action potentials from propagating along sensory neurons, which means neurotransmitters are not released and EPSPs can’t be produced.

Question 14

Inhibitory postsynaptic potential IPSP

Answer 14

when neurotransmitter and receptor results in hyperpolarization of the postsynaptic membrane

Move the membrane further from threshold, decreasing the likelihood of an action potential

Question 15

Acetylocholine // effect and clinical examples

Answer 15

Effect: excitatory in CNS; inhibitory or excitatory in ANS

Myasthenia Gravis - weakness & even paralysis

Question 16

Serotonin // effect and clinical examples

Answer 16

Inhibitory and excitatory
Antidepressant (Depression
Anxiety (OCD)
Halucinogens (LSD)

Question 17

Dopamine

Answer 17

Excitatory or inhibitory
Drug Addiction
Parkinson Disease (results from destruction of dopamine producing neurons)

Question 18

Norepinephrine

Answer 18

Excitatory
AHDH
Amphetamines

Question 19

Gamma-Amino Butyric Acid

Answer 19

Inhibitory
Barbiturates - sedatives, treatmnet for epilepsy
Benzodiazepines - antianxiety drugs
Alcholo Dependence

Question 20

Glycine

Answer 20

inhibitory

Strychnine poisoning > powerful muscle contractions and convulsions, may cause death

Question 21

Glutamate

Answer 21

Excitatory
Stroke and Excitotoxicity
Cognition

Question 22

Adensoine

Answer 22

Inhibitory
Neutoprotective agent
Caffein

Question 23

Substance P

Answer 23

Excitatory

Pain therapy

Question 24

Endorphins

Answer 24

Inhibitory

Opiates // produce feeling of euphoria and reduce pain

Question 25

Nitric oxide

Answer 25

Excitatory Stroke damage Treatment of ED

Question 26

Types of summation (2)

Answer 26

Spatial summation | Temportal summation

Question 27

Spatial summation

Answer 27

multiple action potentials from separate neurons arrive simultaneously at the same postsynaptic neuron

Question 28

Temporal summation

Answer 28

two or more action potentials arrive very close together at the postsynaptic cell First AP > depolarizing graded potenta=ial 2) a second graded depolarization returns membrane to resting value

Question 29

4 types of neuronal pathways

Answer 29

Convergent pathways Divergent pathways Reverberating circuits Parallel after-discharge circuits

Question 30

Convergent pathway

Answer 30

Multiple neurons converge upon and synapse with a smaller number of neurons EG-

Question 31

Divergent pathway

Answer 31

info from one neuronal pathways diverges into two or more pathways EG - sensory input can go to both the spinal cord and the brain

Question 32

Reverberating circuits

Answer 32

A positive feedback loop that causes an after-discharge, which prolongs the response to a stimulus EG - respiration

Question 33

Parallel after-discharge circuits

Answer 33

Neurons that stimulate several neurons in a parallel organization, converging upon a common output cell. Involved in complex neuronal processes - mathematics,