BIO 201 - Nervous System

My nervous system is SCREAMING rn im gonna pass out

These immune cells of the nervous system respond to injury

microglia

What is occuring at #5?

resting state

What is occuring at #6?

threshhold

What is occuring at #10?

hyperpolarization

What is occuring at #8?

repolarization

What channel is most likely responsible for area 10 going back to resting membrane potential?

sodium/potassium pump

Oligodendrite is to CNS as ____ is to PNS

Schwann Cell

_____ is to CNS as Schwann Cell is to PNS

Oligodendrite

Ascending portion of the Action Potential graph represents

opening of sodium voltage gated channels

During ____ another action potential cannot occur

absolute refractory period

What happens in depolarization during action potential?

the inside of the cell becomes positive

In myelinated axons, action potentials occur where

only at the nodes of Ranvier

All Na+ inactivation gates are completely closed at

C

this graph shows (IGNORE THE ARROW)

hyperpolarization

At RMP leaky channels allow Na+ to move in what direction?

into the cell

Describe metabolism of neurons

very metabolically active

What three things play a role in the conduction velocity of an axon

presence of oligodendrocytes or Schwann cells, diameter of the axon, degree of myelination

How would you describe a membrane channel protein that opens when bound by a neurotransmitter?

ligand gated

If a stimulatory (excitatory) neurotransmitter bound to a protein, which would happen?

depolarization

Which letter corresponds to Na+ RAPIDLY coming into the cell?

B

Which letter shows where K+ is leaving the cell?

Both B and C

During ____ a depolarization event can not occur

absolute refractory period

In terms of an AP, what is threshold?

its the voltage at which an AP will definitely occur

Which structure carries a signal away from a neuronal cell body?

axon

What two things GENERATE the RMP?

leaky Na+ channels and leaky K+ channels

Does Na+ or K+ have a greater concentration inside the cell?

K+

What are astrocytes?

cells that can provide nourishment to neurons

What is a synapse?

where two neurons meet

Place the events that occur at a synapse in order

I. Graded potential generated

II. Gates open on post-synaptic cell

III. Ca2+ enters an axon terminal

IV. Neurotransmitter released into cleft

III, IV, II, I

Do graded potentials summate? (Y/N)

Yes

Are Graded Potentials all-or-nothing? (Y/N)

No

Graded potentials travel (long/short) distances

short

Graded or Action Potential? These potentials have refractory periods.

Action

Graded or Action Potential? These potentials can be either a depolarizing or hyperpolarizing events.

Graded

These graded potentials cause the neuron to become more permeable to Na+ thus causing depolarization.

EPSP

These graded potentials cause the neuron to become more permeable to K+ thus causing hyperpolarization.

IPSP

This divison of the nervous system consists of the brain and spinal cord

Central Nervous System

Division of the peripheral nervous system involved with voluntary motor control.

somatic

Divisions of the autonomic nervous system. (2)

sympathetic and parasympathetic

What is the autonomic nervous system?

the system that is in charge of involuntary muscle

What nervous system encodes the “fight-or-flight” response?

Sympathetic nervous system

Inhibitory postsynaptic potentials (IPSPs) are associated with what?

hyperpolarization of the cell membrane

An IPSP from three neurons and two EPSPs from two other neurons at the same time describe ___ summation

spatial

What two things do EPSPs do?

depolarize the membrane and open cation channels

When the action potential reaches the axon terminal, Ca2+ does what?

ca++ rushes in

What happens once an action potential reaches the axon terminal?

Channels open and CA+ will enter the presynaptic cell

What three mechanisms can remove neurotransmitters from the synaptic cleft?

degradation by enzymes, diffusion out of the synaptic cleft, reuptake by astrocytes or back into axon terminal

Why is it so important to remove neurotransmitters from the synaptic cleft?

if they remain, the post-synaptic cleft will be continually stimulated.

During depolarization, the inside of the neuron becomes more (positive/negative)

positive

During repolarization the neuron gets more (positive/negative/sad/excited)

negative

Neuron repolarization occurs due to (potassium/sodium) diffusing (in/out)

potassium diffusing out

Hyperpolarization makes the neuron more (positive/negative) and (less/more) likely to fire

more negative; less likely to fire

Propagation of action potential is (unidirectional/bidirectional/multidirectional)

unidirectional

Why is propagation of action potential unidirectional?

inactivated sodium channels

True/False: Myelination slows down propagation of action potentials

False

The propagation of action potentials travels from ______ to ______

axon hillock to axon terminals

Dendrites ______ : Axon ______ (sends/receive)

receive, sends

What are sensory neurons that carry nerve impulses from sensory stimuli towards the central nervous system and brain.

Afferent Neurons

Leakage channels…

are always open

Two differences between oligodendrocytes and schwann cells...

is that the oligodendrocytes can wrap many neurons at once and that the schwann cell wrappings are the entire cell

Positive feedback in an action potential correlates to?

depolarization

What role does positive feedback play in the action potential

the influx of sodium causes more sodium channels to open

Strength of a stimulus is coded by

frequency of action potentials

what do interoceptors do

receive stimuli from internal visceral

Exteroceptors detect:

changes in our external environment

What three things do mechanoreceptors detect?

Vibration, pressure, and touch

Sympathetic preganglionic fibers release this

acetylcholine

in parasympathic fibers: preganglionic release _______ and postganglionic release_______

ACh, ACh

Parasympathetic postganglionic fibers release

acetylcholine

Most sympathetic postganglionic fibers release?

norepinephine

Sympathetic division stimulation causes (increased/decreased) glucose, peristalsis, hr & bp

increased glucose, decreased peristalsis, increased hr & bp

Autonomic Nervous System controls what muscle(s)

Smooth and Cardiac

All spinal reflex arcs start with?

a stimulus

A spinal reflex arc pathway is (6 parts)

Receptor, Sensory Neuron, Relay Neuron, spinal cord, motor Neuron, effector

What does autonomic nervous system do

coordinate and regulate internal organs

Ach can be stimulating or inhibiting. Why?

different postsynaptic cells will have different receptors

Axons of the peripheral nervous system are associated with neuroglia cells called…

Schwann cells

Schwann cells, wrapped repeatedly around the axon, form a coating called a ___

myelin sheath

The myelin sheath consists of multiple layers of the ___ of the neuroglia cells

cell membrane

Myelin consists of protein and large amounts of ___,  giving heavily myelinated tissue a white appearance.

lipid

As the cells wrap around and around the axon, cytoplasm ends up in the outermost wrapping of the cell. Because myelin is nonpolar, it prevents ions from accessing the axon surface, serving as an electrical ___ to the axon.

insulator

Gaps between neighboring segments of the myelin sheath are called ___. At these points, the axon is not insulated.

nodes of ranvier

The ___ of a neuron release(s) neurotransmitters.

presynaptic terminals

What is label 1?

Astrocyte

What is label 2?

Ependymal cell

What is label 3?

Microglial cell

What is label 4?

Oligodendrocyte

What cells for myelin sheaths in the CNS?

Oligodendrocytes

What cells function in the production and circulation of CSF

Ependymal cells

What cells are the macrophages of the CNS?

Microglia

What cells are multi-functioning cells involved with neurogenesis, scar formation, BBB maintenance, etc.

Astrocytes

What cells form myelin sheaths in the PNS?

Schwann cells

What cells are support cells in the PNS that surround neuronal cell bodies?

Satellite cells

The nervous system functions in detecting ___, some of which we are aware and others of which we are not aware.

sensory inputs

The nervous system receives information both internally and from the environment, responding so as to maintain ___.

homeostasis

The nervous system can respond to stimuli using ___ and ___ ___. 

muscles; secretory glands

The nervous system functions in mental activities such as solving ___

problems

the nervous system is able to ___ information in order to either respond to or ignore it.

integrate

(Multipolar/Bipolar/Unipolar) Many dendrites extend from the soma

Multipolar

(Multipolar/Bipolar/Unipolar) Most motor neurons are this type

Multipolar