C11 1-8

Question 1

List the basic functions of the nervous system.

Answer 1

SENSORY INPUT - INTEGRATION - MOTOR OUTPUT

Question 2

Sensory input

Answer 2

sensory receptors detect changes in the internal and external environments.

Question 3

Integration

Answer 3

the nervous system processes and interprets input and decides what should be done at each moment.

Question 4

Output

Answer 4

the nervous system activates effector organs (muscles/glands) to cause a response

Question 5

Two principle parts of NS?

Answer 5

CNS/PNS

Question 6

CNS

Answer 6

Brain and spinal cord. The integrating and control center of the nervous system.

Question 7

PNS

Answer 7

Nervous system outside of the CNS. The communication lines between the CNS and the rest of the body. Incl. cranial nerves - 12, and spinal nerves 31

Question 8

Divisions of the PNS?

Answer 8

Sensory (afferent) division, Motor (efferent) division

Question 9

Sensory division of PNS

Answer 9

Contains somatic and visceral sensory nerve fibers which conduct impulses from receptors TO the CNS. AFFERENT

Question 10

Motor division of PNS

Answer 10

Contains motor nerve fibers which conduct impulses from the CNS to effectors (muscles/glands) EFFERENT

Question 11

Divisions of Motor division?

Answer 11

Somatic/Autonomic

Question 12

Somatic nervous system

Answer 12

Consists of somatic motor fibers that conduct impulses from the CNS to skeletal muscles. (aka voluntary NS)

Question 13

Autonomic nervous system

Answer 13

Consists of visceral nerve fibers that regulate the activity of smooth and cardiac muscles, glands, adipose tissue and other involuntary tissue. (aka involuntary NS)

Question 14

Divisions of the Autonomic NS?

Answer 14

Sympathetic, parasympathetic

Question 15

Sympathetic?

Answer 15

Mobilizes body systems during activity (fight or flight, E division)

Question 16

Parasympathetic?

Answer 16

Conserves energy, promotes housekeeping functions during rest. (rest and digest, salivation, lacrimation, urination, defacation)

Question 17

Types of neuroglia in the CNS?

Answer 17

Astrocytes, microglia, ependymal cells, oligodendrocytes

Question 18

Neuroglia?

Answer 18

(Or glial cells) Associated with neurons, provide a protective and supportive network

Question 19

Astrocytes

Answer 19

-Most numerous -Control environment around neurons (mop up potassium, recapture and recycle neurotransmitters) -Make exchanges between capillaries and neurons helping determine cap permeability - form blood brain barrier

Question 20

Microglia

Answer 20

-Defense cells - Processes touch nearby neurons monitoring their health - Perform immune functions (when invaders are present they transform into a special type of macrophage)

Question 21

Ependymal cells

Answer 21

• Line the central cavities of the brain and spinal cord - Help in the production and circulation of CSF

Question 22

Oligodendrocytes

Answer 22

• Wrap around neuron fibers forming myelin sheaths (fewer processes than astrocytes)

Question 23

Satellite cells

Answer 23

Function largly unknown. Surround neuron cell bodies within ganglia. (PNS)

Question 24

Schwann cells

Answer 24

(aka neurolemmocytes) Surround nerve fibers forming the myelin sheath. (PNS)

Question 25

Types of neuroglia in the PNS?

Answer 25

Satellite cells, schwann cells

Question 26

Six distinguishing features common to all neurons? Chasee

Answer 26

Conductivity, high metabolic rate, amitotic, secretion, excitability, extreme longevity

Question 27

Define neuron

Answer 27

Specialized cells that conduct messages in the form of electrical impulses throughout the body

Question 28

Structural components of a neuron?

Answer 28

Cell body, Neuron processes

Question 29

What are clusters of neuron cell bodies called?

Answer 29

In the CNS, nuclei. In the PNS, ganglia.

Question 30

Neuron processes?

Answer 30

Dendrites, axons

Question 31

Cell body

Answer 31

aka perikaryon/soma. The major biosynthetic center containing the usual organelles except for centrioles.

Question 32

Collections of axons are called?

Answer 32

Tracts in the CNS, Nerves in the PNS

Question 33

Axon function

Answer 33

- Conducting region of the neuron. - Generates nerve impulses and transmits them, typically away from the cell body. - Secrete neurotransmitters.

Question 34

Dendrite function

Answer 34

- Input regions that provide surface area for receiving signals from other neurons. - Convey messages toward the cell body.

Question 35

Describe Axon

Answer 35

1 Single axon per neuron 2 Starts with a axon hillock on the cell body, tapers into slender process, uniform for the rest of its length. 3 Occasionally has branches (axon collaterals) 4 Ends have terminal branches with synaptic knobs

Question 36

Describe Dendrite

Answer 36

Short, tapering, diffusely branching extensions.

Question 37

Anterograde movement

Answer 37

Movement away from the cell body. Substances: mitochondria, cytoskeletal elements, membrane compnents. Why: renew axon plasma membrane, and enzymes used to synthesize neurotransmitters (axon)

Question 38

Retrograde movement

Answer 38

Movement toward the cell body. Substances: organelles to be degraded or recycled. Also intracellular communication to advise cell body of conditions at axon terminals and deliver cell body vesicles containing signal molecules. (axon)

Question 39

Myelin sheath

Answer 39

Whitish, fatty, segmented covering - protects - electrically insulates fibers - increases the transmission speed of nerve impulses. (axons only)

Question 40

PNS myelin sheaths?

Answer 40

Formed by schwann cells, adjacent cells do not touch each other so there are gaps in the sheath (nodes of ravier)

Question 41

CNS myelin sheaths?

Answer 41

Formed by oligodendrocytes, have multiple flat processes that can coil around as many as 60 axons at the same time. Myelinated fibers in CNS are "white matter", grey matter cont. mostly cell bodies and nonmyelinated fibers.

Question 42

Structural classes or neurons?

Answer 42

Multipolar, bipolar, unipolar

Question 43

Functional classes of neurons?

Answer 43

Sensory/afferent, Motor/efferent, Interneurons/association

Question 44

Multipolar neurons

Answer 44

Have 3 or more processes (brain and spinal cord)

Question 45

Bipolar neurons

Answer 45

Single axon/single dendrite that extend from opposite sides of cell body. Rare, found in special sense organs (retina, inner ear, olfactory_)

Question 46

Unipolar neurons

Answer 46

aka pseudounipolar, single process that branches - distal (peripheral) end is associated with a sensory receptor in PNS, the central process (proximal) enters the CNS. (touch, pain temp vibration)

Question 47

Sensory/afferent neurons

Answer 47

Conduct impulses toward the CNS from receptors. Mostly unipolar with cell bodies that are located in sensory ganglia outside the CNS.

Question 48

Motor/efferent neurons

Answer 48

Conduct impulses from the CNS to effectors. Multipolar

Question 49

Interneurons/association neurons

Answer 49

Conduct impulses between sensory and motor neurons or in integration pathways. CNS only! 99% of neurons in body. Mostly multipolar, but lots of diversity in size and fiber-branch patterns.