Test #1

What's the peak of an action potential?

+55mV

During the resting membrane potential the inside of the neuron is slightly at what millivolts?

-70 millivolts and the inside of the membrane is slightly negative with respect to the outside.

What's the cell the ratio of a neuron-glia cell?

10:1

EPSP

A graded depolarization.

is the first part of the period in which the membrane cannot produce an action potential.

Absolute refractory period

Movement of skeletal muscles

Acetylcholine

messages sent by axons, short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory

Action potential

if threshold potential is reach through summation at the axon hillock, then an ap will fire no matter what, furthermore, once the ap fires and starts propagating down the axon it will stay at a constant strength and speed.

All-or-none law

Histamine

Allergies

A neurons membrane is selectively permeable. This means that it:

Allows some molecules to pass through it, but blocks others

increasing the release of dopamine from the presynaptic terminal.

Amphetamines

they take up the leftover NT and dispose of it via the blood supply.

Astrocyte

Helps synchronize the activity of the axon by wrapping around the presynaptic terminal and taking up chemicals released by the axon.

Astrocytes

Passes messages away from the cell body to other neurons, muscles, or glands

Axon

only spot on a neuron where action potential can be fired

Axon hillock

Why is it important for the Blood brain barrier to block incoming viruses, bacteria or other harmful material from entering?

Because neurons in the brain generally do not regenerate

What do bio psychologists do?

Bio psychologists study the animal roots of behavior, relating actions and experiences to genetics and physiology.

Methylphenidate

Blocks the reuptake of dopamine-at a gradual and more controlled rate.

A mechanism that surrounds the brain and blocks most chemicals from entering.

Blood-brain barrier

Glutamate

Brains main excitatory NT

GABA

Brains main inhibitory NT

Which of the following areas of a neuron typically receives input from other neurons?

Cell body and Dendrites

Soma

Cell body contains the nucleus

Neurons

Cells in the nervous system that receive and transfer information to other cells.

Blocks the reuptake of dopamine,norepinephrine, and serotonin

Cocaine

Sensory neuron

Contain smaller molecules NTS like dopamine, serotonin which are quick.

Receive messages from other cells

Dendrites

What is the process?

Dense core vesicles

the neurons membrane becomes more positively charged

Depolarization

also known as polarization, a difference in electrical charge between the inside and outside of the cell

Electrical gradient

Exocytosis

Excretion of the neurotransmitter from the presynaptic terminal into the synapse, triggered by an action potential; depolarization opens CA++ channels.

What nourishment passes the blood-brain barrier?

Glucose-a sugar/ nutrient, crosses after infancy.

are non action potential, strength voltage changes on the post-synaptic membrane. Through many of these adding together(summation) an action potential can be fired if they summate to threshold at the axon hillock (-65vm).

Graded potentials

Stimulate serotonin at inappropriate times or for longer duration that usual thus causing their subjective effect.

Hallucinogenic drugs

Oligodendrocytes

In the CNS(brain+spinal cord). Specialized fatty flat glial cells that wrap around the axon of some neurons, creating the myelin sheath

Vesicles are located______ and act to _____.

In the presynaptic terminals, store neurotransmitter

Neurons whose dendrites and axons are completely contained within a single structure

Interneurons

Hyper polarization is due to what?

KA+ potassium channels opening

Efferent- refers to carrying information away from the structure

Motor neuron

Which of the following cells is NOT an example of glia?

Motor neurons

a disease in which the myelin sheath is destroyed. The disease is associated with poor muscle coordination.

Multiple sclerosis

Covers the axon of some neurons and helps speed neural impulses

Myelin sheath

Depolarization is due to what?

NA+ sodium channels opening.

What two kinds of cells make up the human nervous system.

Neurons and Glia

Substance P.

Pain

What channels in the membrane are chemically gated?

Post synaptic membrane

When the membrane is at rest sodium channels are closed and:

Potassium channels are partially closed allowing the potassium to slowly leak through.

A Function of the myelin sheath is to:

Provide electrical insulation to help increase the speed of the neural signal.

Enkephalins

Regulate pain and stress

Microglia

Remove waste material and other microorganisms that could prove harmful to the neuron.

Dopemine

Reward/reinforcement

During the depolarization phase of an action potential, which of the following happens first?

Sodium channels open and NA+ ions flow into the cell

Norepinephrine

Stimulant- energy

Ionotropic receptor

The effect is quick, direct, and short the NT binds to receptor and immediately opens ion channels. hearing, and vision

Metabotropic receptor

The effect is slower, longer-lasting, and a broader area of the membrane is influenced by the NT. hunger,thirst,fear,hunger

Presynaptic terminals

The end which the axon releases chemicals that cross through the junction between one neuron and the next.

During the depolarization phase of an action potential, what electrical change takes place?

The inside of the membrane becomes more positive compared to the outside

Which of the following describes a typical neuron at rest:

The potassium concentration is lower outside the cell than inside.

To keep unequal distribution of sodium and potassium ions on either side of the selectively-permeable membrane of a neuron at rest(rmp), requires the active transport system called:

The sodium-potassium pump

Pre-synaptic membrane

They are voltage-gated channels and they open when the membrane reaches a certain Mv level.

Why are neuron cells unique?

They transfer information within a single cell over long distances and only cell that can communicate with synapse with chemicals.

Type 1 and 2

Type 1/ Type A Later and gradual onset; fewer genetic relatives with alchoholism; equal quantantiy between men and women; less severe. Type 2/ Type B Earlier onset(usually before 25) more rapid onset; more genetic relatives with alchoholism; men outnumber women;often severe; often associated with criminality.

Neurotransmitter

a chemical synthesized by one neuron. The neuron releases the NT thus affecting a second neuron at the synapse.

IPSPS

a graded hyperpolarization of the membrane

Selective permeability of the membrane

a structure that separates the inside of the cell from the outside environment.

Drugs that increase or mimic the effects of NTS.

agonist

Drugs that block the effect of neurotransmitters

antagonist

voltage-gated channels

are membrane channels whose permeability depends upon the voltage difference across the membrane (polarization).

Marijuana(THC)

cerebral cortex, cerebellum, basal, ganglia, and hippocampus. The cannabinoid receptors may account for the subject effects of loss of time, an intensification of sensory experience, and also memory impairment. The receptors are located on the presynaptic neuron.

where there is less concentration of an ion, it will naturally flow that direction if the channels are open

concentration gradient

Reflex arc

connections between neurons, believed the difference must be because it took extra time for communication between neurons.

Opiates

decrease sensitivity to pain and increase relaxation by attaching to endorphin receptors in the brain

MAO

enzyme that inactivates the NTS serotonin, dopamine, and norepinephrine.

Nodes of Ranvier

exposed membrane gaps in the myelin sheath where the ap is boosted or regenerated

Threshold

if enough stimulation causes the neuron to become more excited at the axon hillock, then threshold, -65mv, and the membrane begins to quickly depolarize and can fire an action potential

Schwann cells

in the PNS (everything outside the brain+ spinal cord). Specialized fatty flat glia cells that wrap around the axon of some neurons, creating the myelin sheath.

Are all axons myelinated?

invertebrate axons do not because they are attached to one another.

Sodium-potassium pump

is an active protein complex that continually pumps 3 sodium ions out of the cells while drawing 2 potassium ions into the cells, during rest.

Relative refractory period

is the second part in which it takes a stronger than usual stimulus to trigger an action potential

Propagation of the action potential

is the term used to describe the transmission of the action potential down the axon(how it rapidly travels in one direction)

Saltatory conduction

jumping of an action potential from node to node, it provides rapid conduction of the neural signal and conserves energy

MDMA(ecstasy)

low doses= stimulant effect by increasing dopamine. High doses=hallucinogenic effect by increasing serotonin.

Reuptake

presynaptic neuron takes up most of the neurotransmitter molecules intact and reuses them later. like serotonin

spatial summation

summation over space. cumulative input from different locations on a post-synaptic neuron.

Temporal summation

summation over time. with repeated stimulation within short period of time, a postsynaptic neuron can reach threshold

Hyperpolarization

the membrane becomes more negatively charged.

Resting membrane potential

when the membrane is more negatively charged(not firing an action potential). During rest, the neuron membrane is charging up getting to work and send its signal.