Week 1 - Neurons & Glia, Synapses & Neurotransmitters; Action Potentials & Synaptic Transmission Flashcards

1
Q

What structures make up the Central Nervous System?

A

Brain & spinal cord

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2
Q

What structures make up the Peripheral Nervous System?

A

Cranial nerves, spinal nerves, ganglia, sensory receptors, somatic nervous system, autonomic nervous system, enteric nervous system

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3
Q

The spinal cord connects to the brain via what opening in the skull?

A

Foramen magnum

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4
Q

Afferent neurons are involved in what nervous system function?

A

sensory function - send sensory signals to the brain

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5
Q

Efferent neurons are involved in what nervous system function?

A

Motor function - brain sends signal to these neurons to act

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6
Q

What are cells contacted by efferent neurons called?

A

Effectors

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7
Q

Interneurons are involved in what function?

A

integrative function - spinal cord and brain level - signal relay

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8
Q

How many cranial nerves are there?

A

12 pairs

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9
Q

How many spinal nerves are there?

A

31 pairs

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10
Q

Describe what happens when the sympathetic nervous system is active

A

increased heart rate, blood vessels of digestive system vasoconstrict, pupils dilate, blood vessels to muscles vasodilate

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11
Q

Which part of the PNS is involuntary?

A

autonomic nervous system - breathing, heart beat

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12
Q

The autonomic nervous system consists of what two subdivisions?

A

sympathetic and parasympathetic

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13
Q

What is the function of enteric motor neurons?

A

govern contraction of the GI tract

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14
Q

List the general functions of neurons

A

sensing, thinking, remembering, controlling muscular activity, regulating glandular secretions

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15
Q

What is the function of neuroglia?

A

nourish, support and protect neurons

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16
Q

What are dendrites of a neuron?

A

the receiving (input) portion of the neuron

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17
Q

What is the function of a neuronal axon?

A

propagate impulses toward another neuron, muscle fiber or gland cell

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18
Q

What is the function of synpatic end bulbs?

A

store and release neurotransmitter

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19
Q

Define synapse

A

site of communication between two neurons or between a neuron and an effector cell

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20
Q

Describe the structure of multipolar neurons

A

one axon, many dendrites

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21
Q

What is the function of astrocytes?

A

provide structural support for neurons in CNS
form the blood/brain barrier
regulate chemical environment for generation of nerve impulses
influence formation of neural synapses (memory/learning)

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22
Q

What is the function of oligodendroctyes?

A

form myelin sheath around axons in the CNS

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23
Q

What is the function of microglia?

A

Responsible for phagocytosis in the CNS - removing cellular debris, microbes, damaged nerve tissue

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24
Q

What is the function of ependymal cells?

A

Form cerebrospinal fluid, form blood-CSF barrier

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25
Q

What is the function of Schwann cells?

A

Form myelin sheath around axons in the PNS

Assist axon regeneration

26
Q

What is the function of satellite cells?

A

Provide structural support
Repair peripheral neurons
regulate transport between neuronal cell bodies and interstitial fluid

27
Q

What is the function of the myelin sheath on an axon?

A

Form segments of insulation to increase speed of nerve impulse conduction

28
Q

What is the average resting membrane potential of a neuron?

A

-70mV

29
Q

Name the 4 types of ion channels

A

Ligand-gated channel, leakage channel, voltage-gated channel, mechanically gated channel

30
Q

Describe the electrochemical gradient

A

An electrical difference and a concentration difference across a membrane

31
Q

What is the threshold for action potentials?

A

-55mV

32
Q

What are ganglia?

A

small masses of nervous tissue, consisting primarily of neuron cell bodies, that are located outside the CNS

33
Q

Two homeostasis-controlling systems are ________

A

nervous system

endocrine system

34
Q

The Effector Organs/Targets of Somatic Nervous System are the following:

A

external & internal lining of the body wall
extremities
special senses - smell, taste, vision, hearing, equilibrium

35
Q

Two Effector Organs/Targets of the Autonomic Nervous System but located within the soma are ___________

A

sweat glands

erector pilli muscles

36
Q

The Effector Organs/Targets for the Autonomic Nervous system are __________

A

smooth muscle
cardiac muscle
secretory glands

37
Q

There are ___ types of neurons, namely ________

A

3
motor/efferent
sensory/afferent
interneurons

38
Q

The most ubiquitous neurons within the CNS and PNS are _________. Their major function is to maintain the ___________

A

interneurons

balance between excitatory and inhibitory impulses

39
Q

The principal difference between the functions of neuron versus glia is ________

A

glia cells are unable to transmit potentials

40
Q

The major common function of oligodendrocytes and Schwann cells is _______

A

they form myelin sheaths around axons

41
Q

The major functional difference between oligodendrocytes and Schwann cells is ___________

A

Schwann cells assist regeneration of axons

Oligodendrocytes resist regeneration of axons

42
Q

A neuron consists of the following parts _________

A
cell body / perikaryon / soma
dendrite
axon
axon hillock
axon terminal
synaptic bulb
Nissl's bodies
Nodes of Ranvier
43
Q

Describe the resting membrane potential

A

an electrical potential difference across a plasma membrane. The interior side of the membrane has a relative negative charge while Na+ ions on the exterior of the membrane form a relative positive charge

44
Q

How do leakage channels operate?

A

randomly alternate between open and closed positions

facilitate passage of K+ and some Na+ ions across concentration gradient

45
Q

How do voltage channels operate?

A

open in response to change in membrane potential

participate in generation and conduction of action potentials

46
Q

How do ligand channels operate?

A

open and close in response to specific chemical stimulus

47
Q

How do mechanical channels operate?

A

open and close in response to mechanical stimulation - vibtration, touch, pressure, tissue stretching

48
Q

How do Light channels operate?

A

open and close in response to light stimuli

49
Q

What is the major ion, which is guarding a resting membrane potential and why?

A

K+

The cell membrane is more permeable to K+ than any other ion at rest

50
Q

What ion channels are open during depolarization phase of action potential?

A

voltage-gated Na+ channels

51
Q

What ion channels are opening during re-polarization phase of action potential?

A

voltage-gated K+ channels

52
Q

What are two types of synapses?

A

electrical synapse

chemical synapse

53
Q

What type of synapse is the most abundant within the human organism?

A

chemical synapse

54
Q

The intrinsic nervous system of the GI tract, which is called ________, is represented by the clusters of functionality related and interconnected neurons. The clusters are called _______ and they represent _________

A

enteric nervous system
ganglia
Meissner’s plexus - GI secretion
Auerbach’s plexus - peristalsis

55
Q

The axon hillock is most effective site of ______________ because _______

A

action potential initiation

it is densely populated by Na+ channels

56
Q

White matter is compose primarily of ___________

A

myelinated axons

57
Q

Gray matter of the nervous system contains ________

A

neuronal cell bodies, dendrites, unmyelinated axons, axon terminals, and neuroglia

58
Q

Gray matter is gray because __________

A

Nissl bodies impart a gray color

59
Q

The nodes of Ranvier have a high density of ____

A

Na+ channels

60
Q

What ion is needed for the transmission of a signal in a chemical synapse?

A

Ca2+