BIOL 2160 exam 3

during temporal summation, ___ cause an action potential?

a single cell

benefit of action potentials

action potentials can travel further without getting smaller

the cells permeability to Na is higher during the?

rising phase

why does the rising phase happen before the falling phase?

because K channels are activated more slowly than Na channels

at rest, which conformation are most Na channels found in?

closed but capable of being open

what causes an undershoot phase(phase 3)?

the slow closing of K channels

an increase in the size of the stimulus will result in?

an increase in the frequency of action potentials.

the release of neurotransmitters opens?

voltage-gated Calcium channels the postsynaptic ion channels.

what is the post-synaptic response to open all K channels?

IPSP

which of these will not turn off synaptic transmission?

pumping Calcium into the cytoplasm

smooth muscle contraction is under control from?

the sympathetic nervous system

commissures can be found in the?

CNS

membrane conductance is lower than the conductance in?

both intracellular and extracellular solution

what cells make up the immune response in the nervous system?

microglia

the GI tract is controlled by the?

autonomic nervous system

both the cell bodies of axons and interneurons are found entirely in the CNS. True or false?

True. Cell bodies of axons and interneurons are located within the central nervous system (CNS), where they process and transmit information.

the autoimmune disease that attacks the myelin sheath in the nervous system affects what cell?

oligodendrocytes

what is the characteristic of a membrane responsible for creating the membrane potential?

high resistance to ion flow across it.

when calculating ionic current, which of the factors does not influence driving force?

conductance

spatial summation involves ___ synaptic input

more than one

the cell’s permeability to Na will be lowest when?

the membrane potential is more negative than -70

during the following phase, voltage-gated Na channels will be?

closed and incapable of being opened

which doesn’t contribute to the relative refractory period?

Na channels are still open

why is a stronger stimulus needed to invoke an action potential during the relative refractory period?

because the membrane is still very permeable to K and not very permeable to Na

what causes the transition from the rising to the falling phase?

opening of voltage-gated channels

during the relative refractory period, the activation gate of most Na channels is?

closed, while some are inactivated.

NUMBER 29 is A

A

why is propagation in myelinated axon faster than in unmyelinated?

myelin doesn’t contain ion channels

the nicotinic acetylcholine receptors are permeable to both Na and K, stimulates an opening, the result is an?

EPSP

The reason for nicotinic acetylcholine receptors permeable to Na and K, stimulating an opening and resulting in EPSP is becasue?

the driving force for Na is greater than driving force for K

exocytosis of synaptic vesicles is a result of?

increased calcium in these terminals

atropine blocks ___ acetylcholine receptors in the heart?

muscarinic

making new glucose from fats and proteins is called?

gluconeogenesis

positive energy balance occurs during the?

absorptive state

during LTP, calcium entering the post-synaptic cell has which effect?

it causes more AMPA receptors to be inserted in the membrane and it releases Nitric oxide

word understanding originates in?

Wernickes area

brain waves observed during ___ resemble those of a person who is awake?

paradoxical sleep

being able to remember your phone number is?

declarative/semantic

___insulin levels will lead to blood that is thicker, causing dehydration

decreased

what percentage of diabetes cases is juvenile onset?

5-10%

how does insulin lower blood sugar?

making cells more permeable to glucose by inserting GLUT4

during negative energy balance-

energy output is larger

which of the following is an anabolic hormone?

insulin

why do most cells metabolize proteins and fars in the post-absorptive state?

because glucose has to be spared for the nervous system

why are type 1 diabetes at risk for Ketoacidosis?

higher blood sugar levels means low cellular sugar, this results in fats and proteins being burned which lowers the blood

why are type 1 diabetics often very thin?

high blood sugar results in the increased burning of fat for energy

decreasing insulin production will result in?

increased urine output

damaged ___ will result in decreased insulin release?

beta cells