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

Question 1

What structures make up the Central Nervous System?

Answer 1

Brain & spinal cord

Question 2

What structures make up the Peripheral Nervous System?

Answer 2

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

Question 3

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

Answer 3

Foramen magnum

Question 4

Afferent neurons are involved in what nervous system function?

Answer 4

sensory function - send sensory signals to the brain

Question 5

Efferent neurons are involved in what nervous system function?

Answer 5

Motor function - brain sends signal to these neurons to act

Question 6

What are cells contacted by efferent neurons called?

Answer 6

Effectors

Question 7

Interneurons are involved in what function?

Answer 7

integrative function - spinal cord and brain level - signal relay

Question 8

How many cranial nerves are there?

Answer 8

12 pairs

Question 9

How many spinal nerves are there?

Answer 9

31 pairs

Question 10

Describe what happens when the sympathetic nervous system is active

Answer 10

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

Question 11

Which part of the PNS is involuntary?

Answer 11

autonomic nervous system - breathing, heart beat

Question 12

The autonomic nervous system consists of what two subdivisions?

Answer 12

sympathetic and parasympathetic

Question 13

What is the function of enteric motor neurons?

Answer 13

govern contraction of the GI tract

Question 14

List the general functions of neurons

Answer 14

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

Question 15

What is the function of neuroglia?

Answer 15

nourish, support and protect neurons

Question 16

What are dendrites of a neuron?

Answer 16

the receiving (input) portion of the neuron

Question 17

What is the function of a neuronal axon?

Answer 17

propagate impulses toward another neuron, muscle fiber or gland cell

Question 18

What is the function of synpatic end bulbs?

Answer 18

store and release neurotransmitter

Question 19

Define synapse

Answer 19

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

Question 20

Describe the structure of multipolar neurons

Answer 20

one axon, many dendrites

Question 21

What is the function of astrocytes?

Answer 21

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)

Question 22

What is the function of oligodendroctyes?

Answer 22

form myelin sheath around axons in the CNS

Question 23

What is the function of microglia?

Answer 23

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

Question 24

What is the function of ependymal cells?

Answer 24

Form cerebrospinal fluid, form blood-CSF barrier

Question 25

What is the function of Schwann cells?

Answer 25

Form myelin sheath around axons in the PNS | Assist axon regeneration

Question 26

What is the function of satellite cells?

Answer 26

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

Question 27

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

Answer 27

Form segments of insulation to increase speed of nerve impulse conduction

Question 28

What is the average resting membrane potential of a neuron?

Answer 28

-70mV

Question 29

Name the 4 types of ion channels

Answer 29

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

Question 30

Describe the electrochemical gradient

Answer 30

An electrical difference and a concentration difference across a membrane

Question 31

What is the threshold for action potentials?

Answer 31

-55mV

Question 32

What are ganglia?

Answer 32

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

Question 33

Two homeostasis-controlling systems are ________

Answer 33

nervous system | endocrine system

Question 34

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

Answer 34

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

Question 35

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

Answer 35

sweat glands | erector pilli muscles

Question 36

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

Answer 36

smooth muscle cardiac muscle secretory glands

Question 37

There are ___ types of neurons, namely ________

Answer 37

3 motor/efferent sensory/afferent interneurons

Question 38

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

Answer 38

interneurons | balance between excitatory and inhibitory impulses

Question 39

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

Answer 39

glia cells are unable to transmit potentials

Question 40

The major common function of oligodendrocytes and Schwann cells is _______

Answer 40

they form myelin sheaths around axons

Question 41

The major functional difference between oligodendrocytes and Schwann cells is ___________

Answer 41

Schwann cells assist regeneration of axons | Oligodendrocytes resist regeneration of axons

Question 42

A neuron consists of the following parts _________

Answer 42

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

Question 43

Describe the resting membrane potential

Answer 43

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

Question 44

How do leakage channels operate?

Answer 44

randomly alternate between open and closed positions | facilitate passage of K+ and some Na+ ions across concentration gradient

Question 45

How do voltage channels operate?

Answer 45

open in response to change in membrane potential | participate in generation and conduction of action potentials

Question 46

How do ligand channels operate?

Answer 46

open and close in response to specific chemical stimulus

Question 47

How do mechanical channels operate?

Answer 47

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

Question 48

How do Light channels operate?

Answer 48

open and close in response to light stimuli

Question 49

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

Answer 49

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

Question 50

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

Answer 50

voltage-gated Na+ channels

Question 51

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

Answer 51

voltage-gated K+ channels

Question 52

What are two types of synapses?

Answer 52

electrical synapse | chemical synapse

Question 53

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

Answer 53

chemical synapse

Question 54

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 _________

Answer 54

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

Question 55

The axon hillock is most effective site of ______________ because _______

Answer 55

action potential initiation it is densely populated by Na+ channels

Question 56

White matter is compose primarily of ___________

Answer 56

myelinated axons

Question 57

Gray matter of the nervous system contains ________

Answer 57

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

Question 58

Gray matter is gray because __________

Answer 58

Nissl bodies impart a gray color

Question 59

The nodes of Ranvier have a high density of ____

Answer 59

Na+ channels

Question 60

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

Answer 60

Ca2+