Nervous System

Question 1

What are the functions of the nervous system?

Answer 1

-sensory input (receptor monitor stimuli inside and outside body)
-integration (process, interprets, assimilates experiences)
-motor output (response; muscle contraction, glandular secretion)

Question 2

What is included in the CNS?

Answer 2

brain and spinal cord

Question 3

What is included in the PNS?

Answer 3

nerves and ganglia

Question 4

Sensory signals

Answer 4

picked up by sensory receptors

Question 5

Motor signals

Answer 5

carried away from the CNS

Question 6

What is included in somatic sensory?

Answer 6

vision, hearing, skin, proprioception

Question 7

What is included in visceral sensory?

Answer 7

smell, taste, hunger, viscera

Question 8

What is the action in somatic motor?

Answer 8

contraction of skeletal muscles

Question 9

What is the action in visceral motor?

Answer 9

secretion of glands, contraction of smooth and cardiac muscles, part of the Automatic Nervous System

Question 10

What are glial cells?

Answer 10

-found in the CNS and PNS
-smaller
-mitosis
-protect and nourish neurons
-provide organized and supporting framework
-more abundant than neurons
-not capable of impulse transmission

Question 11

Astrocytes

Answer 11

-star-shaped
-most abundant
-connect neurons to blood vessels
-control flow of substances
-control chemical composition (bouncer)

Question 12

Ependymal cells

Answer 12

-cuboidal epithelial cells
-found in ventricles and central canal of spinal cord
-have basal projections to contract, produce spinal fluid

Question 13

Microglia

Answer 13

-small cells with projections
-not abundant
-don’t originate in nervous tissues
-modified white blood cells
-remove debris

Question 14

Oligodendrocytes

Answer 14

large with globular bodies and slender projections
-form myelin sheath in axons for insultation, protection, nourishment
-one cell can wrap around multiple axons

Question 15

Satellite cells

Answer 15

-flattened cells
-regulate nutrient and waste exchange

Question 16

Neurolemmocytes

Answer 16

-Schwan cells
-surround axons for insulation and protection

Question 17

What are the functional classifications of neurons?

Answer 17

-Sensory neurons: originate in sensory receptors, respond to stimuli, travel to CNS
-Motor neurons: originate in CNS, travel to effectors
-Interneurons: located btw motor and sensory neurons, found in CNS, make up 99.*% of neurons in the body

Question 18

What are the structural classifications of neurons?

Answer 18

-Unipolar neurons: sensory neurons
-Bipolar neurons: rare, found in nose and inner ear
-Multipolar neurons: most common type, motor and interneurons, cell body mostly in CNS

Question 19

Nuclei

Answer 19

clusters of neuron bodies in CNS

Question 20

Ganglia

Answer 20

cluster of neuron bodies in PNS

Question 21

Tract

Answer 21

clusters of axons in CNS

Question 22

Fibers/nerves

Answer 22

clusters of axons in PNS

Question 23

Gray matter

Answer 23

cell bodies of interneurons and motor neurons, nonmyelinated interneurons (where connections happen)

Question 24

White matter

Answer 24

fiber tracts of myelinated and nonmyelinated axons (highway)

Question 25

What is myelination? Why is it important?

Answer 25

-process by which part of an axon is wrapped with a myelin sheath -speeds up signals and insulates neuron

Question 26

Synapses

Answer 26

junctions where axons contact other neurons, muscle cells, or glands

Question 27

Electrical Synapses

Answer 27

-membranes of pre and post synaptic neurons bound together -bidirectional -fast and secure flow of ions -not common in brain -found in smooth muscle and cardiac muscle

Question 28

Chemical Synapses

Answer 28

-have signaling molecule, neurotransmitter -unidirectional -more common -Ach is most common

Question 29

What are factors that influence the rate of conduction?

Answer 29

Axon diameter: larger diameter = faster Presence of myelin increase rate Continuous conduction Saltatory conduction is only in exposed regions

Question 30

What are the differences between monosynaptic and polysynaptic reflexes?

Answer 30

Monosynaptic: direct communication between sensory and motor neurons Polysynaptic: interneuron facilitates sensory-motor communication