Neurobiology

Question 1

The function of acetylcholine on post-synaptic cells

Answer 1

Ach binds to receptors and depolarizes the membrane (chemically gated); depolarization is graded (greater Ach released, the more channels open, larger depolarization)

Question 2

Function of different receptors on post-synaptic cells

Answer 2

Nociceptors - pain
Thermoreceptors - temperature
Mechanoreceptors
Tactile - touch, pressure, vibration
Baroreceptors - blood vessel wall
pressure changes
Proprioceptors- joint/skeletal
position
Chemoreceptors - concentration of chemicals/compounds *only respond to water/lipid-soluble substances ie blood, CSF

Question 3

What determines stimulus strength

Answer 3

frequency of AP (action potentials)

Question 4

Features of graded potentials

Answer 4

Take place in dendrites, quick changes over a short distance (stimulus changes neuron surroundings, an ion channel opens)

Question 5

Features of inhibitory post-synaptic potentials

Answer 5

IPSP - inhibits stimulus (can cancel out an EPSP in the event both fire simultaneously) and moves neuro-t away from the threshold (decreasing stimulus)

Question 6

Features of excitatory post-synaptic potentials

Answer 6

EPSP - depolarized at membrane, opens ligand-gated channels for Na and K (need to be close by to reach threshold)

Question 7

Generator potentials

Answer 7

AKA receptor potential; Involves sensory receptor + stimulus (MH pg.404)

Question 8

Resting neuron plasma membrane

Answer 8

The membrane of an unstimulated resting cell (start of neural activity - resting potential) pg.402

Question 9

Excitatory neurotransmitters

Answer 9

Norepinephrine, Glutamate

Question 10

Function of GABA on post-synaptic cells

Answer 10

Inhibiting in the neural pathway

Question 11

Function of endorphins

Answer 11

CNS: thalamus, hypothalamus, basal nuclei
Pain control, emotion/behavior …not well-understood pg.423

Question 12

Features of the neuromuscular junction

Answer 12

A synapse between a neuron and skeletal muscle (pg.417) is made of an axon terminal (synaptic terminal), with a synaptic cleft (space) that separates it from the motor end plate (pg.303)

Question 13

Temporal summation stimulation

Answer 13

2 fast EPSP’s present and close (causes neuro-t firing)

Question 14

Result of excitatory neurotransmitters on post-synaptic membrane

Answer 14

excitatory PSP brings the neurotransmitter closer to the threshold (depolarizes)

Question 15

Function of GABA

Answer 15

Direct; opens Cl- channels
Indirect; open K and blocks Ca -pg 422

Question 16

Function of serotonin

Answer 16

Impacts emotions, mood, body temp (pg.422)

Question 17

Function of Glutamate

Answer 17

excitatory, indirect/direct actions; location: CNS ONLY: cerebral cortex, MOST IMPORTANT excitatory neurotransmitter pg.422

Question 18

Function of dopamine

Answer 18

excitatory or inhibiting; indirect (second messenger) action; CNS: substantia nigra (midbrain); hypothalamus; main neurotransmitter of indirect pathways

Question 19

Function of ACH (acetylcholine)

Answer 19

2 classes of receptors – nicotinic (excitatory) and muscarinic (can be excitatory or inhibiting/direct (nicotinic) or indirect (muscarinic); CNS: found in hippocampus, cerebral cortex, and brainstem; PNS: neuromuscular junctions (skeletal)