Unit 2.2 Quiz review

how neurons are similar to other cells in the body

similar because of nucleus and cell membrane. different because the neurons,have specialized parts called dendrites and axons.

example of ions

sodium and potassium

resting state

the Na+ and K pump finally brings the membrane back to its resting state

what happens during action potential

there is a sudden reversal of charge carrying a message down the axis

reaction time

time elapsing between the beginning of the application of a stimulus and the beginning of an organism;s reaction to it

unipolar neurons

type of neuron in which only one protoplasmic process extends from the cell body.

multipolar neurons

type of neuron that possesses a single axon and many dendrites, allowing for the integration of a great deal of information from other neurons. These dendritic branches can also emerge from the nerve cell body

what causes the inside of the membrane to revers charge and begin the action potential

when the Na+ channels open

action potentail

momentary reversal in electrical potential across a plasma membrane (as of a nerve cell or muscle fiber) that occurs when a cell has been activated by a stimulus

what is cell fundamental unit of nerve

neurons

bipolar neurons

Type of neuron which has two extensions. Bipolar cells are specialized sensory neurons for the transmission of special senses. As such, they are part of the sensory pathways for smell, sight, taste, hearing and vestibular functions.

Neurotransmitters

chemicals that allow neurons to communicate with each other

Motor Neuron

receive signals from CNS, causing movement -IN PNS, receive infor from CNS

Synaptic Cleft

joint between neurons

refractory period

the na+ channels are closing while the membrane potential charges

Depolarization and Polarization

D is / P is \

How electrical impulses are created in the human body

Na+/K+ pump keeps outise of membrane + and inside - by pumping positive ions out of the membrane, priming the membrane to carry charges

how communication happens within the body

Neurons communicate by sending messages using action potentials (electrically passing through their axons). Each neuron picks up signals at its dendrites, passes the signals down the aon, into the aon terminals, and into the synapses. The synapse then drops neurotransmitters into the synaptic cleft between the first neuron's synapse and the next neurons dendrites. That signals neuron #2 to pass the message on.

describe how the electricity in an action potential is generated

Schwann cells insulate axons to help actions potentials be transmitted more quickly. electricity is created by a sudden reversal in charge

why is involentary reaction faster

because voluntary action uses the brain while involuntary did not go threw the brain making the reaction quicker

neuron

a nerve cell; fundamental unit of the nervous system, having structure and properties that allow it ot conduct signals by taking advantage of electrical charge across it cell membrane

what do we call electrical messages that are sent down the axon of a neuron

action potentials

what moves ions from a low concentration to a high concentration

active transport

Nodes of Ranvier

allow nutrients in wast out

ion

an atom or group of atoms that carries a positive or negative electrical charge as a result of having lost or gained one or more electrons

reflex

and automatic and often inborn response to a stimulus that involves a nerve impulse passing inward from a receptor io the spinal cord and thence outward to an effector without reaching the level of consciousness and often without passing ot the brain

Schwann cell

any cell that covers the nerve fibers in the peripheral nervous system and forms the myelin sheath

dendrites

any of the usually branching protoplasmic processes that conduct impulses toward the body of a neuron (pick up signal)

Axon Terminals

branch to meet other neurons

repolorization

brought about by potassium rushing out of the cell which restores the negative membrane potential

Interneuron

connect sensory neurons to motor neurons -Found in CNS

how do neurons convey info using both electrical and chemical signals?

electrical signals travel down the axon to the axon terminals where it tells the vesicles to release the neurotransmitters (which are chemical signals consisting of hormones like dopamine and adrenaline) into the synaptic cleft which travels to the receptors of the receiving cell which releases the second messages which are chemical signals that start an electrical impulse in the receiving cell

how does the structure of each type of neuron relate to its function in the nervous system

helps it process signals and know how to carry out functions from all the senses interneurons structure allow them to communicate between dendrites and axons which is their job

Myelin Sheath

in a neuron, and insulation coat of cell membrane from Schwann cells that is interrupted by nodes of Ranvier

Axon

long nerve cell process that usually conducts impulses away fro the cell body (carry signal long distances)

do you grow new neurons?

no, you neurons just make new connections throughout you life

neurologist

physician skilled in the diagnosis and treatment of disease of the nervous system

Sensory Neuron

picks up signals through senses (sight, smell, touch) -sends info from PNS to CNS

Synapses

place at which a nervous impulse passes form one neuron to another

2 important function of cell membrane

protecting interior contents present in cell from spilling out into the external environment and protects the cell from harmful substances present in external environment from entering cell. Also maintains shape.

depolirization

rapidly opens the activation gate and slowly closes the inactivation gate