Nervous Tissue CH 11 Flashcards Preview

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Flashcards in Nervous Tissue CH 11 Deck (41)
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1
Q

Functions of the nervous system

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

Peripheral Nervous System (PNS)

A

Not including the CNS (brain and spinal cord)

Consists or spinal and cranial nreves

3
Q

PNS functional subunits

A

Afferent

Efferent

4
Q

Afferent Division

A

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)
5
Q

Efferent Division

A

Motor “carrying away”

  1. Somatic NS: voluntary, controls skeletal muscles
  2. Autonomic NS: involuntary, controls heart pumping digestion ect.
6
Q

Neuroglia (or glial cells)

A

6 cells that make us neurons:

7
Q

Neuroglia of the CNS

A

Astrocytes
Microglial
Ependymal
Oligodendrocytes

8
Q

Neuroglia of the PNS

A

Satellite cells

Schwann Cells

9
Q

Astrocytes

A

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

10
Q

Microglial Cells

A

Type of macrophage
Phagocytize microorganisms and neural debres
Janitor

11
Q

Ependymal Cells

A

Line CNS cavities

Cilia helps circulate CSF

12
Q

Oligodendrocytes

A

Form myelin sheaths around CNS fibers

13
Q

Satellite cells

A

unknown function may be similar to astrocytes

14
Q

Schwann Cells

A

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

15
Q

Dentrites

A

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

16
Q

Axons

A

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

17
Q

Axon Hillock

A

cone shaped initial region of the axon

18
Q

Axon Collaterals

A

Extend from axon at right angles

19
Q

Axon terminals

A

Secretory region

knoblike distal ends of axon terminal branches

20
Q

Myelin Sheath

A

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

21
Q

White matter

A

Myelinated regions of the CNS, primary fiber tracts.

22
Q

Grey matter

A

Unmyrlinated fibers and contains mostly nerve cell bodies.

23
Q

Nodes of Ranvier

A

Gaps in myelin sheath

24
Q

Neuron structural classifications

A

Multipolar
Bipolar
Unipolar

25
Q

Multipolar neurons

A

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

26
Q

Bipolar neurons

A

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

27
Q

Unipolar neurons

A

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

28
Q

Interneurons

A

Multipolar
lie between sensory and motor
In CNS

29
Q

Action Potential

A

Nerve impulse, conduction impulse that travels down the axon.

30
Q

Voltage

A

Potential energy generated by separated charge.

31
Q

Current

A

Flow of electrical charge from one point to another

32
Q

Resistance

A

The hindrance to charge flow provided by substance it passes through

33
Q

Ohm’s Law

A

Current= voltage/resistance

34
Q

2 membrane ion channels

A
  1. Chemically gated

2. Voltage gated

35
Q

Chemically gate ion channels

A

Open when neurotransmitter binds

36
Q

Voltage gated ion channels

A

Open and close in response to changes in membrane potential.

37
Q

Resting membrane potemtial

A

The potential difference in a resting neuron

38
Q

Generating resting membrane potential depends on:

A
  1. Differences in K+ and Na+ concentrations in and out of the cell.
  2. Differences in permeability of plasma membrane to those ions.
39
Q

Change in membrane potential can produce:

A
  1. Graded potentials:Incoming signals over short distances

2. Action potentials: long dostance signals of axons

40
Q

Depolarization

A

Decrease in membrane potential

41
Q

Hyperpolarization

A

Increase in membrane potential