Nervous System

Question 1

Contents of Central Nervous System (CNS)

Answer 1

Brain and spinal chord

Question 2

Contents of the Peripheral Nervous System (PNS)

Answer 2

-Nerves

Question 3

3 Functions of the Nervous System

Answer 3

1. Receives sensory input
2. Processes info
3. Generates motor output

Question 4

Nuerons

Answer 4

Cells that transmit nerve impulses between parts of the nervous system.

Question 5

Neuroglia

Answer 5

Support and nourish neurons

Question 6

Sensory Neuron

Answer 6

Takes nerve signals from sensory receptors to the CNS

Question 7

Sensory receptors

Answer 7

Structures that detect change in the internal and external environments.

Question 8

Effectors

Answer 8

Carry out the responses to internal and external environmental changes.

Question 9

Structure of a Neuron

Answer 9

A neuron contains a cell body (contains organelles), dendrites (short extensions that receive signals from sensory receptors or other neurons), axons (the portion of a neuron that conducts nerve impulses)

Question 10

Myelin Sheath

Answer 10

Protective covering of the axons that develops when Schawann cells PNS or oligodendrocytes (CNS) wrap their membranes around an axon many times.

Question 11

Nodes of Ranvier

Answer 11

The gaps where there is no myelin sheath

Question 12

Nerve signals

Answer 12

Electrochemical changes that convey information within the nervous system

Question 13

Generation of an action potential

Answer 13

1. Resting Potential: Na+ outside the axon K+ and large anions inside the axon. The separation of changes polarizes the cell and causes the resting potential.
   2: Stimulus causes the axon to reach its threshold: the axon potential increases from -70 to -55. The action potential has begun.
   3: Depolarization continues as Na+ gates open and Na+ moves inside the axon
   4: Action potential ends: repolarization occurs when K+ gates open and K+ moves outside the axon. The sodium-potassium pump returns the ions to their resting postions.

Question 14

Action potential

Answer 14

The process of conduction

Question 15

Depolarization

Answer 15

Sodium gates open and Na+ rush into the cell, and the cell´s charge changes from positive to negative

Question 16

Repolarization

Answer 16

Inside of the axon resumes a negative charge as potassium exits the axon

Question 17

Axon terminal

Answer 17

Small swellings at the ends of axons

Question 18

Synapse

Answer 18

Region of close proximity

Question 19

Synaptic cleft

Answer 19

What separates the sending neuron from the receiving neuron

Question 20

Neurotransmitters

Answer 20

Transmit signals between nerves

Question 21

The events at a synapse

Answer 21

1. Nerves signals traveling along an axon to reach an axon terminal
2. Calcium ions entering the terminal and stimulating synaptic vesicles to merge with the sending membrane
3. Neurotransmitter molecules released into the synaptic cleft and differing across the cleft to the receiving membrane

Question 22

Acetylchonlinsterase (AChe)

Answer 22

Breaks down the neurotransmitter acetylcholine

Question 23

Integration

Answer 23

The summing up of excitatory and inhibitory signals

Question 24

Cerebrospinal Fluid

Answer 24

Cushions and protects the CNS

Question 25

Ventricles of the Brain

Answer 25

Four interconnecting chambers produce and serve as a reservoir for cerebrospinal fluid.

Question 26

Inter vertebral foramina

Answer 26

What the spinal nerves project through

Question 27

Cerebrum

Answer 27

The largest portion of the brain in mammals. It communicates and coordinates the activities of other parts of the brain.

Question 28

Cerebral Hemispheres

Answer 28

Right and left halve of the brain divided by the longitudinal fissure

Question 29

Corpus Callosum

Answer 29

An extensive bridge of nerve tracts that allows the two hemispheres of the brain to communicate

Question 30

Cerebral Cortex

Answer 30

Thin, highly convoluted outer layer of grey matter that converts the cerebral hemispheres

Question 31

Primary Motor Area

Answer 31

Located in the frontal lobe. Spot where voluntary commands to skeletal muscles begin.

Question 32

Primary Somatosensory Area

Answer 32

The spot where sensory information from the skin and skeletal muscles arrives

Question 33

Wernickes Area

Answer 33

Allows one to comprehend speech

Question 34

Bronca´s Area

Answer 34

Allows one to speak and write

Question 35

Ganglia

Answer 35

Collections of nerve bodies outside the CNS

Question 36

12 pairs of Cranial Nerves

Answer 36

• Attached to the brain
• Collection of sensory and motor nerves
• Largely concerned with the head neck, and facial regions of the body

Question 37

Spinal Nerves

Answer 37

• Emerge from either side of the spinal cord
• 31 pairs of spinal nerves
• The roots of a spinal nerve physically separate the axons of sensory neurons from the axons of motor neurons that form a ´Y´
  shape.

Question 38

Divisions of the PNS

Answer 38

The somatic system (serves the skin, skeletal muscles, and tendons) and the autonomic system (regulates the activity of cardiac and smooth muscles, organs, and glands)

Question 39

Sympathetic division

Answer 39

• Arrises from the middle portion of the spinal cord
• Sympathetic division is especially important during emergency situations when you might be required to take fight or flight

Question 40

Parasympathetic Divison

Answer 40

• Includes a few cranial nerves
• Also called house keeper division
• Promotes all the internal responses we associate with a relaxed state