PSY 360 exam 2

Question 1

what are Ion channels ?

Answer 1

are proteins that span the membrane and allow ions to pass.

Question 2

what are the two different types of Ion channels ?

Answer 2

sodium potassium pump
potassium leak channels

Question 3

what are gated channels? what two types are there? (neurotransmitter receptors)

Answer 3

they open and close in response to signal; voltage gated and ligand-gated channels

Question 4

what do voltage gated channels do?

Answer 4

the change in voltage, open in responses to changes in the membrane potential

Question 5

what are ligand gated channels

Answer 5

open when a specific signaling molecule (ligand) binds to them

also neurotransmitter binding

Question 6

what are the two types of ligand receptors?

Answer 6

Ionotropic receptors and metabotropic receptors

Question 7

ionotropic receptors

Answer 7

fast, quickly change shape and open or close an ion channel when the transmitter molecule binds

Question 8

what are the two types of Metabotropic receptors? (GPCR)

longlasting and amplification

Answer 8

1. Slow, when activated they alter chemical reactions in the cell, using a system of second messengers to open an ion channel
2. activate enzymes that lead to biochemical cascade (change in membrane potential; gene expression)

Question 9

what are the 4 different types of neurotransmitters?

Answer 9

amino acid neurotransmitters
amime neurotransmitters
neuropeptides
gas neurotransmitters

Question 10

what types are the amino acids

Answer 10

glutamate= 5 carbons
GABA = 4 carbons
Glycine= 2 carbons

Question 11

what are the types of amime neurotransmitters?

Answer 11

Acetylcholine
Dopamine
Serotonin

Question 12

what are the types of neuropeptides?

Answer 12

oxytocin and vasopressin

Question 13

what are the types of gas neurotransmitters?

Answer 13

nitric oxide and carbon monoxide

Question 14

frog heart experiment

Answer 14

stimulate the vagus nerve to slow the heart, collect fluid from around the slowed heart and apply the fluid to a second heart

the second heart slowed

conclusion: the vagus nerve uses a chemical neurotransmitter to communicate to cells of the heart and cause it to slow down

Question 15

what are the steps of synaptic transmission ?

Answer 15

1.) The AP is propagated over the presynaptic membrane

2.) depolarization of the presynaptic terminals lead to influx of CA2+

3.) CA2+ causes vesicles to fuse with the presynaptic membrane and release transmitter into the synaptic cleft

4.) the binding of the transmitter to the neurotransmitter receptors in the postsynaptic membrane opens channels, permitting ion flow and initiating an excitatory or inhibitory postsynaptic potential

5.) excitatory and inhibitory postsynaptic potentials spread passively over dendrites and the cell body to the axon hillock

Question 16

Otto Loewi stimulated which nerve to slow down the frog heart?

Answer 16

Vagus (CN X)

Question 17

Which of the following receptors acts quickly?

Answer 17

Ionotropic

Question 18

Neurotransmitters are designed to either be excitatory or inhibitory

Answer 18

false

Question 19

what does the PNS consist of?

Answer 19

sensory (afferent)
motor (efferent)

Question 20

what does the motor (efferent consist of?

Answer 20

somatic (voluntary) (skin, joints, muscles)
autonomic (involuntary)

Question 21

what does the autonomic nervous system consist of?

Answer 21

sympathetic (fight/flight)
parasympathetic (rest/digest)

Question 22

soma (cell body) consists of

Answer 22

CNS - nucleus
PNS -Ganglion

Question 23

axon (myelin)

Answer 23

CNS tract + Oligodendrocytes
PNS nerves + schwann cells

Question 24

Acetylcholine

Answer 24

all PNS motor neurons release ACh except postganglionic sympathetic neurons (sweat glands)

Question 25

Acetylcholine: storage and release

Answer 25

1k-50k Ach molecules/vesicles 300k vesicles cholinergic neuron

Question 26

Lambert Eaton Myasthenic syndrome (LEMS)

Answer 26

Rare autoimmune disorder ● Antibodies block/destroy v-gated calcium channels ● Ca2+ dependent triggering of synaptic vesicle does not occur ● ACh vesicles do not fuse with membrane ● No ACh release

Question 27

What are the 2 acetylcholine receptors?

Answer 27

Nicotinic and Muscarinic

Question 28

Nicotinic acetylcholine receptors

Answer 28

Agonist: nicotine (tobacco) Antagonist: Curare (arrowtip) - paralysis location: skeletal muscle function: muscle contraction Ligand gated Ion channel

Question 29

Muscarinic acetylcholine receptor

Answer 29

agonist: Muscarine (mushrooms) poison antagonist: atropine location: heart muscle function: decrease blood pressure GPCR's

Question 30

substance A attacks SNARE location Neuromuscular junction

Answer 30

result? stop vesicle binding Acetylcholine PNS No action potential Nicotinic acetylcholine receptor BOTOX

Question 31

how can GABA be excitatory ?

Answer 31

Ionictropic Cl- transporter immature neuron (less than 1 year old) immature Ecl= -30mv mature Ecl= -65 Metabotropic GPCR's not voltage gated can change DNA/Gene expression

Question 32

retina

Answer 32

layer of neurons in the back of the eye detects differences in frequency and intensity of light

Question 33

photoreceptors

Answer 33

converts light energy into neural activity (transduction) are sensory neurons that detect light rods and cones

Question 34

cones

Answer 34

4 million day vision near fovea rapid

Question 35

rods

Answer 35

100 million night vision outside fovea slow

Question 36

fovea

Answer 36

center region of the retina has high density of smaller, tightly packed cones with high acuity this region receives direct light input that does not pass through other cells or blood vessels

Question 37

rods

Answer 37

are more numerous in the periphery and are absent in the fovea

Question 38

lateral inhibition

Answer 38

a process in which sensory receptor cells inhibit information from neighboring receptor cells, producing an effect of contrast at the edges of regions

Question 39

pure tone (amiplitude)

Answer 39

loudness, dB

Question 40

frequency

Answer 40

pitch/tone Hz

Question 41

how sound travels from our surroundings, into the ear, and converted into electrical signals to the brain

Answer 41

1.) Entry: sound waves are channeled into Ear canal 2.) Amplification: sound waves hit eardrum setting 3 small bones in motion 3.) Vibration: Bones push against cochlea causing fluid to move 4.) signaling: fluid moves hair cells, whose motion get translated into nerve impulses which travel to the brain

Question 42

Base of Basilar membrane

Answer 42

Narrow, stiff fibers high frequency and travel short distance

Question 43

Apex of Basilar Membrane

Answer 43

wide, floppy fibers low frequency travels entire distance