Nervous System

Question 1

Functions of Nervous System

Answer 1

Sensory input, integration, and motor output

Question 2

Central Nervous System

Answer 2

Brain & spinal cord. The command center that interprets input and gives a response.

Question 3

Peripheral Nervous System

Answer 3

Spinal nerves to and from spinal cord and cranial nerves to and from brain. Allows communication between CNS and all of body. Has sensory division and motor division.

Question 4

Sensory/Afferent Division

Answer 4

Convey impulses to CNS from sensory receptors. Part of the PNS.

Question 5

Motor/Efferent Division

Answer 5

Transmit impulses from CNS to effector organs. Part of PNS.

Question 6

Somatic Nervous System

Answer 6

Voluntary. Conducts impulses from CNS to skeletal muscle. Part of the motor division.

Question 7

Autonomic Nervous System

Answer 7

Involuntary. Conducts impulses from CNS to cardiac muscle, smooth muscles, and glads. Part of motor division.

Question 8

Sympathetic Division

Answer 8

Mobilizes body systems during activity. Part of the Autonomic Nervous System.

Question 9

Parasympathetic Division

Answer 9

Conserves energy and “house-keeps”. Part of the Autonomic Nervous System.

Question 10

Neuroglia

Answer 10

Small cells that surround and wrap delicate neurons. Includes astrocytes, microglial cells, ependymal cells, and oligodendrocytes.

Question 11

Neurons

Answer 11

Excitable cells that transmit electrical signals

Question 12

Astrocytes

Answer 12

Most abundant, versatile, & branched. Cling to neurons, support & brace neurons, guide migration, process information, and respond to nerve impulses.

Question 13

Microglia

Answer 13

Small, oviod cells with thorny processes. Touch & monitor neurons and can transform to phagocytize microorganisms & neuronal debris.

Question 14

Ependymal Cells

Answer 14

Line central cavities of brain and spinal column. Form a barrier.

Question 15

Oligodendrocytes

Answer 15

Branched cells that wrap CNS nerve fibers to form insulating myelin sheaths

Question 16

Satellite Cells

Answer 16

Surround neuron cell bodies in PNS. Function similar to astrocytes.

Question 17

Schwann Cells

Answer 17

Form myelin sheaths.

Question 18

Multipolar Neurons

Answer 18

Most common neuron in CNS. 3+ processes

Question 19

Bipolar Neuron

Answer 19

Two processes. One coming off each side.

Question 20

Unipolar Neuron

Answer 20

One, T-like process

Question 21

Sensory Neurons

Answer 21

Bring sensation to brain

Question 22

Motor Neurons

Answer 22

Take impulses out of brain

Question 23

Interneurons

Answer 23

Connect sensory and motor neurons

Question 24

Dendrites

Answer 24

Receptive region of neuron. “Arms”

Question 25

Dendritic Spines

Answer 25

On dendrites. Form in response to increased neurotic activity (learning).

Question 26

Axon

Answer 26

Carries nerve impulses away from cell body. Distal ends are called axon terminals

Question 27

Anterograde

Answer 27

Movement away from cell body

Question 28

Retrograde

Answer 28

Movement toward cell body

Question 29

Myelin Sheath

Answer 29

Protects, insulates, and increases speed of nerve impulse transmission

Question 30

Myelinated Fibers

Answer 30

Surround most long/large fibers/axons

Question 31

Unmyelinated Fibers

Answer 31

Surrounded by Schwann cells, but no myelin coiling. Conduct more slowly.

Question 32

White Matter

Answer 32

Regions of brain and spinal cord with dense collection of myelinated fibers.

Question 33

Gray Matter

Answer 33

Unmyelinated cell bodies

Question 34

Neuron Processes

Answer 34

Gaps between adjacent Schwaan cells

Question 35

Leakage Channel

Answer 35

Always open

Question 36

Gated Channel

Answer 36

Protein changes shape to open/close channel

Question 37

Chemically Gated Channel

Answer 37

Open with binding of specific chemical

Question 38

Voltage Gated Channel

Answer 38

Open/close in response to membrane potential

Question 39

Mechanically Gated Channel

Answer 39

Open by touch/senses

Question 40

Graded Potentials

Answer 40

Incoming signals over short distances

Question 41

Action Potentials

Answer 41

Long distance signals of axons

Question 42

Depolarization

Answer 42

Na+ channels open, charge goes to +30

Question 43

Repolarization

Answer 43

Na+ channels inactivate, K+ channels open

Question 44

Hyperpolarization

Answer 44

K+ channels close slowly, charge is below -70.

Question 45

Nervous System Firing Steps

Answer 45

1) Synapses bring in signals, signals get charge to -55. 2) Depolarization: Voltage gated Na+ channels open, charge gets to +30 3) Repolarization: Voltage gated Na+ channels inactivate, K+ channels open, charge gets to -70 4) Hyperpolarization: Potassium channels close slowly, charge gets below -70. 5) Sodium potassium pumps work to bring charge back to resting.

Question 46

Nervous System Charges

Answer 46

-70: Resting -55: Potential +30: Peak