The Nervous System

Question 1

Central nervous systems (CNS)

Answer 1

The part of the nervous system that comprises the brain and spinal cord.

Question 2

The peripheral nervous system (PNS)

Answer 2

The part of the nervous system that comprises all the nerve cells in the body outside the central nervous system.
Somatic and Autonomic nervous system. Autonomic Nervous system has two main branches, sympathetic and parasympathetic system.

Question 3

Somatic nervous system

Answer 3

(voluntary) Nerve cells of the peripheral nervous system that serve the skeletal muscles. Somatic nerves transmit from the central nervous system (CNS) to the skeletal muscles and sensory information from the skeletal muscles back to the CNS.

Question 4

The autonomic nervous system (ANS)

Answer 4

(involuntary) All the nerves of the peripheral nervous system that serve involuntary systems of the body, such as the internal organs and glands. Autonomic means “self-governing”.

Question 5

Sympathetic nervous system

Answer 5

(arousing) The branch of the autonomic nervous system that activates bodily systems in times of emergency.
• Dilates pupil (Enhanced vision)
• Relaxes bronchi (Increased air to lungs)
• Accelerates, strengthens heartbeat (increased oxygen)
• Inhibits activity (blood sent to muscles instead)
• Contracts vessels (increased blood pressure)
• Inhibits bladder contraction
• Allows blood flow to sex organs

Question 6

Parasympathetic nervous system

Answer 6

(calming) The autonomic nervous system branch usually relaxes or returns the body to a less active restful state.
•	Constricts pupil
•	Constricts bronchi
•	Slows heartbeat
•	Stimulates activity
•	Dilates vessels
•	Contracts bladder
•	Stimulates ejaculation in male

Question 7

The Nervous System

Answer 7

The central nervous system processes incoming information and crafts a response, if one is needed. The peripheral nervous system transmits information between the external environment and internal systems of the body and the central nervous system.

Question 8

Walter Cannon

Answer 8

Physiologist that labeled the flight-or-fight response.

Question 9

The Sympathetic and Parasympathetic Nervous Systems

Answer 9

The sympathetic nervous system prepares the body for action, whereas the parasympathetic nervous system returns it to a relaxed and resting state.

Question 10

Glial Cells

Answer 10

The central nervous system that provides structural support, promote efficient communication between neurons, and serve as scavengers, removing cellular debris.

• Primary function of holding the CNS together
• Key role in the control of breathing, regulate neuronal transmission
• May play a role in neural regeneration repair after brain injury
• Glial cell abnormalities may also play a role in the development of Schizophrenia.

Question 11

Neurons

Answer 11

The cells that process and transmit information in the nervous system.

• There are more than 10 billion neurons in the human brain
• Each Neuron has approximately 10,000 connections to other Neurons, making for trillions of neural connections in the human brain.

Question 12

Three major principles of Neuroscience

Answer 12

Over the last 125 years, There has been a study of neurons and how they communicate with other neurons.

1) Neurons are the building blocks of the nervous system. all the major structures of the brain are composed of neurons.
2) Information travels within a neuron in the form of an electrical signal by action potentials.
3) Information is transmitted between neurons by means of chemicals called neurotransmitters.

Question 13

Neurotransmitters

Answer 13

Chemicals that transmit information between neurons.

Question 14

Santiago Ramon y Cajal

Answer 14

Spanish anatomist deciphered the precise nature and structure of nerve cells, which he named neurons. he identified the three major parts of the neuron: Cell body, dendrites, and axon.

Question 15

Soma

Answer 15

The cell body of the neuron. contains the nucleus and other components needed for cell maintenance and function.

Question 16

Axon

Answer 16

A long projection that extends from a neuron’s soma; it transmits electrical impulses toward the adjacent neuron and stimulates the release of neurotransmitters.

Question 17

Dendrites

Answer 17

Fingerlike projections from a neuron’s soma that receive incoming messages from other neurons.

Question 18

Structure of the neuron

Answer 18

When an electrical impulse is received at the dendrites, it moves through the axon to the terminal buttons. there it triggers the release of neurotransmitters, which carry the impulse across the synapse to the dendrites of the receiving neuron.

Question 19

Myelin Sheath

Answer 19

The fatty substance wrapped around some axons, which insulates the axon, making the nerve impulse travel more efficiently.

Question 20

Myelination

Answer 20

The process of myelination is a gradual one that starts before birth, facilitated in breast-fed babies, and continues into early adulthood.

Question 21

Synapse

Answer 21

The junction between an axon and the adjacent neuron, where information is transmitted from one neuron to another.

Question 22

Terminal button

Answer 22

A little knob at the end of the axon that contains tiny sacs of neurotransmitters.

Question 23

Synaptic cleft

Answer 23

gap between neurons

Question 24

Three kinds of neurons

Answer 24

Sensory, motor, and interneurons

Question 25

Sensory Neurons

Answer 25

Nerve cells that receive incoming sensory information from the sense organs (eye, ear, skin, tongue, nose.)

Question 26

Motor Neurons

Answer 26

nerve cells that carry commands for movement from the brain to the muscles of the body.

Question 27

Mirror neurons

Answer 27

Nerve cells that are active when we observe others performing an action as well as when we are performing the same action.

Question 28

Interneurons

Answer 28

Neurons that communicate only with other neurons. common neurons in the brain. outnumbering sensory and motor neurons by at least 10 to 1.

Question 29

Neural Communication

Answer 29

is a two-step process: action potential and neurotransmission.

Question 30

Action Potential

Answer 30

The impulse of positive charge that runs down an axon. It’s an electrical and chemical process.

Question 31

Ions

Answer 31

Chemically charged particles that predominate in bodily fluids; found both inside and outside cells.
Common ions are positively charged sodium and potassium ions and negatively charged chloride ions.

Question 32

Voltage-dependent channels

Answer 32

Some channels in the membrane of the neuron are always open, others, called voltage-dependent channels, open only when certain electrical conditions are met.

Question 33

Potential

Answer 33

The charge difference, when a neuron is at rest, between the inside and the outside of the axon is -70 millivolts.
This value is the resting potential.

Question 34

Resting Potential

Answer 34

The difference in electrical charge between the inside and outside of the axon when the neuron is at rest.

Question 35

Refractory period

Answer 35

The spam of time, after an action potential has been generated, when the neuron is returning to its resting state and the neuron cannot generate an action potential.

Question 36

Node of Ranvier

Answer 36

The gap (s) in the myelin Sheath across which the action potential jumps.

Question 37

All-or-none Principle

Answer 37

The idea that, once the threshold has been crossed, either an action potential fires or it does not.

Question 38

Depolarized

Answer 38

If an incoming impulse increases the positive charge inside the neuron to a certain threshold, the neuron to becomes depolarized, and fires an action potential.

Question 39

Propogation

Answer 39

The process of how an impulse moves down the axon.

Question 40

Synaptic Vesicles

Answer 40

Tiny sacs in the terminal buttons that contain neurotransmitters.

Question 41

Postsynaptic Neuron

Answer 41

The neuron on the receiving end

Question 42

Two removal methods of excess neurotransmitters in the synaptic cleft.

Answer 42

Enzymatic degradation and reuptake

Question 43

Enzymatic degradation

Answer 43

A way of removing excess neurotransmitter from the synapse in which enzymes specific for that neurotransmitter bind with the neurotransmitter and destroy it

Question 44

Reuptake

Answer 44

A way of removing excess neurotransmitter from the synapse, in which excess neurotransmitter is returned to the sending, or presynaptic neuron for storage in vesicles and future use.

Question 45

Graded potentials

Answer 45

Small changes in membrane potential that by themselves are insufficient to trigger an action potential.

Question 46

Glutamate

Answer 46

A major excitatory neurotransmitter in the brain that increases the likelihood that a postsynaptic neuron will fire; important in learning, memory, neural processing, and brain development.

Question 47

Acetylcholine

Answer 47

A neurotransmitter that controls muscle movement and plays a role in mental processes such as learning, memory, attention, sleeping, and dreaming.

Question 48

Dopamine

Answer 48

A neurotransmitter released in response to behaviors that feel good or rewarding to the person or animal; also involved in voluntary motor control.

Question 49

Epinephrine

Answer 49

Also known as adrenaline, a neurotransmitter that arouses the bodily system (such as increasing heart rate)
It tends not to affect mental states.
operates the organs, the autonomic nervous system.

Question 50

Norepinephrine

Answer 50

A neurotransmitter that activates the sympathetic response to stress, increasing heart rate, rate of respiration, and blood pressure in support of rapid action.

Question 51

Serotonin

Answer 51

A neurotransmitter with wide-ranging effects’ involved dreaming and controlling emotional states, especially anger, anxiety, and depression.

Question 52

GABA - gamma-aminobutyric acid

Answer 52

A major inhibitory neurotransmitter in the brain that tells postsynaptic neurons not to fire; slows CNS activity and is necessary to regulate and control neural activity.