Nervous System

Question 1

Central nervous system (CNS)

Answer 1

– Brain and spinal cord
– Integration and control center
-Interprets sensory input and dictates motor output

Question 2

Peripheral nervous system (PNS)

Answer 2

– Consists mainly of nerves that extend from brain and spinal cord
-Cranial nerves to and from brain
-Spinal nerves to and from spinal cord

Question 3

Parasympathetic

Answer 3

rest and digest

-heart and blood pressure lower

Question 4

Sympathetic

Answer 4

The sympathetic nervous system activates the fight or flight response during a threat or perceived danger.

Question 5

Astrocyte

Answer 5

-Helps form the blood brain barrier
-Regulates tissue fluid composition
-Provides structural support and organization to CNS
-Replaces damaged neurons
-Assists with neuronatal development
-Helps regulate synaptic transmission
-Changes synapse numbers

Question 6

Ependymal cells

Answer 6

-Line ventricles of brain and central canal of spinal cord
-Assists in production and circulation of CSF

Question 7

Microglial cells

Answer 7

-Defends against pathogens
-Removes debris
-Phagocytizes waste

Question 8

Oligodendrocyte

Answer 8

-Myelinates and insulates CNS
-Allows faster nerve impulse conduction through the axon

Question 9

Satellite cells

Answer 9

– Surround neuron cell bodies (in ganglia) in PNS
– Function similar to astrocytes of CNS

Question 10

Shwann cells

Answer 10

– Surround all peripheral nerve fibers and form myelin sheaths in thicker nerve fibers
– Similar function as oligodendrocytes

Question 11

The functional division of the nervous system that transmits information from the viscera to the central nervous system is the ______.

Answer 11

visceral sensory division

Question 12

Which two are components of the sensory nervous system?

Answer 12

Somatic
Visceral

Question 13

The small spaces that interrupt the myelin sheath are called _______.

Answer 13

neurofibril nodes

Question 14

Order the connective tissue wrappings of a nerve from superficial to deep, with the most superficial at the top of the list.

Answer 14

1. Epineurium
2. Perineurium
3. Endoneurium

Question 15

Perineureum

Endoneurium

Epineureum

Answer 15

Composed of cellular dense irregular connective tissue

Composed of areolar connective tissue

Composed of a thick layer of dense irregular connective tissue that encloses the entire nerve

Question 16

The small spaces that interrupt the myelin sheath are called ______.

Answer 16

neurofibril nodes

Question 17

What are the divisions of the peripheral nervous system?

Answer 17

Sensory (afferent)
Motor (efferent)

Somatic
Autonomic

Sympathetic
Parasympathetic

Question 18

Neuroglia (Glial)

Answer 18

small cells that surround and wrap delicate neurons

Question 19

Neurons (nerve cells)

Answer 19

excitable cells that transmit electrical
signals

• Structural units of nervous system
• Large, highly specialized cells that conduct impulses
• Extreme longevity (around 100 years or more)
• Amitotic (with few exceptions)
• High metabolic rate, requires continuous supply of oxygen and glucose
• All have cell body and one or more processes

Question 20

Nuclei vs ganglia

Answer 20

Clusters of nerve cell bodies found in the central nervous system (CNS). Nuclei contain grey matter, where information is processed.

Clusters of nerve cell bodies found in the peripheral nervous system (PNS).

Question 21

Dendrites

Answer 21

In motor neurons
– 100s of short, tapering, diffusely branched processes
* Receptive (input) region of neuron
* Convey incoming messages toward cell body as graded potentials (short distance signals)

Question 22

Multipolar vs bipolar vs unipolar neuron

Answer 22

3 or more processes. 1 axon, others dendrites. Most common. Major neuron in CNS.

2 processes. 1 axon and 1 dendrite. Rare. Retina and olfactory mucosa.

1 short process. Divides T-like – both branches considered axons. Distal (peripheral) process, associated with sensory receptor. Proximal (central) process, enters CNS.

Question 23

What are the three types of neurons?

Answer 23

1. Sensory (afferent)
2. Motor (efferent)
3. Interneurons

Question 24

Myelin sheath gaps (nodes of Ranvier)

Answer 24

– Gaps between adjacent Schwann cells
– Allow for rapid transmission of action potentials
– Sites where axon collaterals can emerge

Question 25

Axon Regeneration

Answer 25

• Only in PNS
• Only in processes (Axon)
  – As long as cell body is intact

Neurolemmocytes (Schwann Cells )
play an important role in regeneration

Question 26

Endoneurium

Perineurium

Epineurium

Answer 26

Endoneurium
– layer of delicate connective tissue
surrounding the axon

• Perineurium
  – connective tissue wrapping
  surrounding a nerve fascicle
  – Nerve fascicles—groups of axons
  bound into bundles
• Epineurium
  – whole nerve is surrounded by tough fibrous sheath

Question 27

Diverging circuit

Converging circuit

Reverberating circuit

Answer 27

Diverging circuit
– one presynaptic neuron
synapses with several other
neurons (divergence)

• Converging circuit
  – many neurons synapse on a
  single postsynaptic neuron
  (convergence)
• Reverberating circuit
  – circuit that receives feedback via
  a collateral axon from a neuron
  in the circuit

Question 28

Parallel-after-discharge

Answer 28

several neurons process the
information simultaneously
(in parallel)
– higher-order thinking