Nervous Systems (8.9)

Question 1

The Evolution of a Nervous System started with the evolution of an organism wide _______ ____ in Cnidarians.

Answer 1

Nerve Net

Question 2

The evolution of a _____ (a mass of neurons) leads to control of the system. It uses a nerve cord to control the body.

Answer 2

brain

Question 3

The evolution of other sensory organs in the head region, called __________, allows for reception and response to
stimuli from the environment.

Answer 3

cephalization

Question 4

Stimulus sent into the brain or spinal cord.

Answer 4

Sensory input

Question 5

Sensory Receptors receive a _______ from the environment.

Answer 5

stimulus

Question 6

a form of energy such as electromagnetic (light), mechanical (pressure), and sound waves.

Answer 6

stimulus

Question 7

This is the interpretation of the energy by the Central Nervous System (CNS). (Basically “thinking” about the stimulus. ) This interpretation of the stimulus leads to a determination of the appropriate response.

Answer 7

Integration

Question 8

Out of the brain or spinal cord. The response is carried out by Effector Cells. Effectors are Muscles or Glands. (These can have an effect on your body.)

Answer 8

Motor Output

Question 9

This includes the Sensory receptors and Motor Nerves

Answer 9

Peripheral Nervous System

Question 10

This takes stimuli from different dendrites and compiles the energy into one signal. (Like a funnel.)

Answer 10

cell body

Question 11

These collect and carry stimuli Energy in to the cell body. (They cover a large area.)

Answer 11

Dendrites

Question 12

This one arm carries the one compiled signal away toward the next neuron or effector cell.

Answer 12

Axon

Question 13

This is a lipid layer of insulation around the axon created by Schwann Cells. It prevents the electrical energy of the neuron from burning the overlying muscle tissue. (It is analogous to the rubber covering on electrical wires.)

Answer 13

Myelin Sheath

Question 14

This is the gap between neurons or between a neuron and an effector cell.

Answer 14

synapse

Question 15

This is the chemical, produced by the neuron, used to transmit the signal across the gap.

Answer 15

neurotransmitter

Question 16

The most common neurotransmitter is ____________.

Answer 16

Acetylcholine

Question 17

The simplest neural pathway.

Answer 17

Reflex Arc

Question 18

A stimulus energy is detected by a _____ ______. (Carries the energy signal to the spinal cord.)

Answer 18

sensory neuron

Question 19

An _______ (of the CNS – spinal cord) relays the energy back out to the motor nerve instead of to the brain.)

Answer 19

interneuron

Question 20

The energy is carried out of the CNS by the ______ ______. It carries the energy to an effector cell, usually a muscle.

Answer 20

Motor Neuron

Question 21

This is why you do not think about a reflex, it just happens. The stimulus never made it to the brain for _________.

Answer 21

integration