Nervous Tissue CH 11

Question 1

Functions of the nervous system

Answer 1

1. Sensory input (PNS)
2. Integration (CNS)
3. Motor output (PNS)

Question 2

Peripheral Nervous System (PNS)

Answer 2

Not including the CNS (brain and spinal cord)

Consists or spinal and cranial nreves

Question 3

PNS functional subunits

Answer 3

Afferent

Efferent

Question 4

Afferent Division

Answer 4

Sensory “carrying towards”

1. Somatic sensory fibers: convey impulses from skin, muscles and joints
2. Visceral sensory fibers: transmit from visceral organs (in ventral body cavity)

Question 5

Efferent Division

Answer 5

Motor “carrying away”

1. Somatic NS: voluntary, controls skeletal muscles
2. Autonomic NS: involuntary, controls heart pumping digestion ect.

Question 6

Neuroglia (or glial cells)

Answer 6

6 cells that make us neurons:

Question 7

Neuroglia of the CNS

Answer 7

Astrocytes
Microglial
Ependymal
Oligodendrocytes

Question 8

Neuroglia of the PNS

Answer 8

Satellite cells

Schwann Cells

Question 9

Astrocytes

Answer 9

Most abundant & versatile
Making exchanges between capillaries and neurons
Mopping up leaked K+
Recycling released neurotransmitters

Question 10

Microglial Cells

Answer 10

Type of macrophage
Phagocytize microorganisms and neural debres
Janitor

Question 11

Ependymal Cells

Answer 11

Line CNS cavities

Cilia helps circulate CSF

Question 12

Oligodendrocytes

Answer 12

Form myelin sheaths around CNS fibers

Question 13

Satellite cells

Answer 13

unknown function may be similar to astrocytes

Question 14

Schwann Cells

Answer 14

Vital for regeneration of peripheral nerve fibers.
Form myelin sheath
Similar to oligodendrocytes

Question 15

Dentrites

Answer 15

Receptive, input region
Each neuron has many dentrites
Motor neurons, off the cell body
Short, tapering, diffusley branching extentions

Question 16

Axons

Answer 16

Each neuron has one axon
spender process
long axon = nerve fiber
Conducting region

Question 17

Axon Hillock

Answer 17

cone shaped initial region of the axon

Question 18

Axon Collaterals

Answer 18

Extend from axon at right angles

Question 19

Axon terminals

Answer 19

Secretory region

knoblike distal ends of axon terminal branches

Question 20

Myelin Sheath

Answer 20

White, fatty fibers (protein-lipiod)
Protects, electronically insulates and increases speed on nerve impulse
Only on axons not dendrites.

Question 21

White matter

Answer 21

Myelinated regions of the CNS, primary fiber tracts.

Question 22

Grey matter

Answer 22

Unmyrlinated fibers and contains mostly nerve cell bodies.

Question 23

Nodes of Ranvier

Answer 23

Gaps in myelin sheath

Question 24

Neuron structural classifications

Answer 24

Multipolar
Bipolar
Unipolar

Question 25

Multipolar neurons

Answer 25

3 or more processes (1 axon the rest dendrites)
Most common
Major type in CNS

Question 26

Bipolar neurons

Answer 26

2 processes
(1 axon 1 dendrite)
retina and olfactory mucosa

Question 27

Unipolar neurons

Answer 27

Single short process
emerges from cell body
divides T-like into proximal and distal branches
Found in PNS ganglia

Question 28

Interneurons

Answer 28

Multipolar
lie between sensory and motor
In CNS

Question 29

Action Potential

Answer 29

Nerve impulse, conduction impulse that travels down the axon.

Question 30

Voltage

Answer 30

Potential energy generated by separated charge.

Question 31

Current

Answer 31

Flow of electrical charge from one point to another

Question 32

Resistance

Answer 32

The hindrance to charge flow provided by substance it passes through

Question 33

Ohm’s Law

Answer 33

Current= voltage/resistance

Question 34

2 membrane ion channels

Answer 34

1. Chemically gated

2. Voltage gated

Question 35

Chemically gate ion channels

Answer 35

Open when neurotransmitter binds

Question 36

Voltage gated ion channels

Answer 36

Open and close in response to changes in membrane potential.

Question 37

Resting membrane potemtial

Answer 37

The potential difference in a resting neuron

Question 38

Generating resting membrane potential depends on:

Answer 38

1. Differences in K+ and Na+ concentrations in and out of the cell.
2. Differences in permeability of plasma membrane to those ions.

Question 39

Change in membrane potential can produce:

Answer 39

1. Graded potentials:Incoming signals over short distances

2. Action potentials: long dostance signals of axons

Question 40

Depolarization

Answer 40

Decrease in membrane potential

Question 41

Hyperpolarization

Answer 41

Increase in membrane potential