A&P Chapter 11 Flashcards Preview

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Flashcards in A&P Chapter 11 Deck (61)
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1
Q

Nervous System functions

A
  • receiving sensory input
  • integrating information
  • controlling muscles and glands
  • maintaining homeostasis
  • establishing and maintaining mental activity
2
Q

Central Nervous System

A

brain and spinal cord

3
Q

Peripheral nervous system

A

all nervous tissue external to CNS

- everything else (neurons in fingers and arms)

4
Q

PNS - Sensory receptors

A
  • end of neurons that detect stimuli (hot,cold, rough, smooth)
5
Q

PNS- Nerves

A

bundles of axons

6
Q

PNS- Cranial nerves

A

12 total and originate form the brain

7
Q

PNS- Spinal nerves

A

31 pairs; originate form the spinal cord (branch on to both sides)

8
Q

PNS- Ganglion

A

collection of cell bodies outside the CNS

9
Q

PNS- Plexus

A

Extensive network of axons outside the CNS

10
Q

PNS- Sensory Division (afferent)

A
  • transmits action potentials from sensory receptors to CNS.

- cell bodies located in the dorsal root ganglion.

11
Q

PNS- Motor Division (efferent)

A
  • Transmits action potential to effectors

- divided into somatic (voluntary) and automatic nervous system

12
Q

Division of PNS

A

Sensory(afferent : transmits action potential from receptors to CNS.
Motor(efferent): transmits action potential from the CNS to effectors (muscles, gland).

13
Q

Neuron cell body

A
  • contains centrally located nucleus
  • extensive rough ER (nucleus is found here)
  • organelle rich
  • neurofilaments organize cytoplasm into different regions
  • Nissl bodies are primary site of protein synthesis (make Protein)
14
Q

Dendrites (receive)

A
  • highly branched cytoplasmic extensions
  • tapered bases at neuron cell body tips
  • receive input from other axons of other neurons
  • stimulation generates electrical currents
  • dendritic spines
    _ axons of other neurons from synapses
15
Q

Axon(send)

A
  • Propagate action potential
  • trigger zone generates action potential
  • terminate by branching into presynaptic terminals
  • presynaptic terminals contain neurotransmitters
16
Q

Sensory neurons

A

conduct action potential to CNS

17
Q

Motor Neurons

A

conduct action potential away from CNS to muscles or glands (brain -> effector)

18
Q

Interneuron

A

conduct action potential from neuron to neuron within the CNS

19
Q

multipolar neurons

A

many dendrites and a single axon (brain)

20
Q

bipolar neurons

A

one dendrite and one axon (down the arm)

21
Q

Pseudo-unipolar neurons

A

single process extending from cell body (fingers)

22
Q

Neuroglia of the CNS (supporting)

A
  • major supporting cells of the CNS
  • barrier between blood and neurons
  • phagocytizes foreign substance
  • produce cerebrospinal fluid
  • form myelin sheath around axons
23
Q

Astrocytes

A
  • cover surfaces of blood vessels, neurons, and pia mater.
  • extensive cytoskelaton
  • regulate extracellular composition of brain fluid (what comes in and out)
  • regular synaptic activity
24
Q

ependymal cells

A
  • line brain ventricles and central canal of the spinal cord
  • produce cerebrospinal fluid in brain ventricles
  • Cilia aids circulation of cerebrospinal fluid (major protectant of the brain and spinal cord)
25
Q

Microglia

A

(between the brain and spinal cord)

  • phagocytic in response to inflammation
  • targets
    1. necrotic tissue
    2. microorganism
    3. foreign substances
    4. dying tissue and bacteria in the brain
26
Q

oligodendrocytes

A
  • extensions surround axons
  • form insulating material
  • myelin sheaths (insulation)
  • quick nerve impulses
27
Q

Neuroglia of PNS

A
Schwann cells(outside CNS)
- myelinate axons 
Satelite cells
- surround cell bodies in sensory ganglia 
- absorb heavy metals to protect
28
Q

Myelination

A
  • cytoplasmic extension that wrap axons
  • protects axons
  • electrically insulates axons
  • increase speed of action potential
  • not continuous
  • Node of Ranvier (gaps in the myelin sheath)
29
Q

White Matter

A

because of myelinated axons. Nerve tracts propagate actin potentials from one areas in the CNS to another. outer in spinal cord and deeper in the brain

30
Q

Gray matter

A

unmyelinated axons, cell bodies, dendrites, neuroglia. Integrative functions. deeper in spinal cord and outer in the brain.

31
Q

Leak ion channels

A

always open and ion specific.

32
Q

gated ion channels

A

closed until opened by a specific signal from sodium or potassium, ion specific.

33
Q

potential difference

A

charge difference across membrane

34
Q

Resting membrane potential

A

permeability of resting membrane; difference in ion concentration

35
Q

Depolarization

A

decrease in membrane potential due to reduction in charge difference.
Inside= -
outside= +

36
Q

Hyper-polarization

A

increase in membrane potential due to decrease in charge difference.

37
Q

Summation

A

one graded potential added to another; essential for action potential generation. Stronger stimuli, greater change.

38
Q

Action potentials

A

electrical signal conducted from neuron to its target(effectors, brain, spinal cord). travel 1-2 milliseconds to occur.
Phases: re-polarization and depolarization.

39
Q

Strong grade potential

A

reaches threshold. all permeability changes proceed w/o stopping. Stronger stimuli, stronger graded potential.

40
Q

Weak graded potential

A

doesn’t reach threshold. permeability changes stop; returns to resting potential. Not sent to next signal.

41
Q

Absolute Refractory

A

complete insensitivity to stimuli.

42
Q

Relative refractory period

A

a stronger than threshold response can induce action potential.

43
Q

Propagation of action potentials

A

Unmyelinated cells: action potential adjacent to original.

Myelinated cells: action potentials conducted between nodes of Ranvier due to lipids(saltatory conduction) can jump form myelinated cell to myelinated cell.

44
Q

Nerve Fiber Types - Type A

A

large diameter, myelinated. conduct at 15-120 m/s. Motor neurons supplying and most sensory neurons. (fingertips[heat,pressure, temp], balance and coordination)

45
Q

Nerve Fiber Types- Type B

A

Medium diameter. lightly myelinated. Conduct at 3-15m/s. part of ANS. quickest sensory neuron.

46
Q

Nerve Fiber Types - Type C

A

Small diameter, unmyelinated. Conduct at 2 m/s or less. Part of ANS. Autonomic digestive system and organs

47
Q

Presynaptic cell

A

transmits signal to synapse (heart and intercalated disks.

48
Q

Postsynaptic cells

A

cell that receives the signal.

49
Q

Presynaptic terminal

A

end of an axon

50
Q

Synaptic cleft

A

space separating axon and adjacent cell

51
Q

postsynaptic membrane

A

membrane opposed postsynaptic cell.

52
Q

Excitatory post-synaptic potential

A

when depolarization occurs;may meet threshold for action potential.

53
Q

Inhibitory post-synaptic potential

A

hyperpolarization is inhibitory. Decreases likelihood of action potential.

54
Q

Axoaxonic Synapses

A

axons synapse with presynaptic terminal of another .

one axon can modulate neurotransmitters of other axons.

55
Q

Presynaptic inhibition

A

reduction in neurotransmitter

56
Q

presynaptic facilitation

A

increase in neurotransmitter production.

57
Q

Spatial summation

A

multiple presynaptic action potentials reach same postsynaptic neuron.

58
Q

Temporal summation

A

multiple action potential at single presynaptic terminal.

59
Q

Convergent pathways

A

many converge and synapse with smaller number of neurons

60
Q

Divergent pathways

A

small number of presynaptic neurons synapse with larger number of post synaptic neurons

61
Q

Oscillating circuit

A

outputs cause reciprocal activation