Chapter 11 MyL&M Q's

Question 1

The two structural divisions of the nervous system are ______.

Answer 1

CNS and PNS

Question 2

Which nervous system is responsible for the integration of sensory information?

Answer 2

CNS

Question 3

Neurons that relay information within the CNS and are the location of the information processing are called ______.

Answer 3

Interneurons

Question 4

The conducting region of the neuron is the _____.

Answer 4

Axon

Question 5

During an action potential, hyperpolarization is caused by _____.

Answer 5

An efflux of K+ ions after returning to resting potential

Question 6

The channels that open when the axolemma reaches threshold depolarization are the _____.

Answer 6

Voltage-gated Na+ channels

Question 7

The relative refractory period is caused by ______.

Answer 7

Hyperpolarization

Question 8

Action potential propagation in unmyelinated axons happens via ______.

Answer 8

Continuous conduction

Question 9

Depolarization to threshold during action potential propagation in axons is due to ____.

Answer 9

Diffusion of Na+ down to the next segment of the axon

Question 10

Why is the resting membrane potential negatively charged?

Answer 10

More K+ leaks out of the neuron than move in

Question 11

The influx of positive charges makes the membrane potential more positive and is known as ______,

Answer 11

Depolarization

Question 12

The majority of synapses in the nervous system are ______.

Answer 12

Chemical

Question 13

A neurotransmitter may have an excitatory or inhibitory effect on the postsynaptic cell, based on _____.

Answer 13

The receptor to which it binds

Question 14

The most important excitatory neurotransmitter in the brain is _____.

Answer 14

Glutamate

Question 15

A neural circuit pattern in which the signal goes from several neurons to one is called ____.

Answer 15

A converging circuit

Question 16

What part of the neuron communicates with a target cell and serves as the secretory region of the cell?

Answer 16

Axon terminals

Question 17

What is the ciliated neuroglial cell that functions to circulate cerebrospinal fluid?

Answer 17

Ependymal cells

Question 18

What structure found in the PNS promotes regeneration of a damaged axon?

Answer 18

Schwann cells

Question 19

What neuroglial cells surround and support the cell bodies of neurons and have intertwined processes that link them with other parts of the neuron?

Answer 19

Satellite cells

Question 20

What characteristic of the myelin sheath makes it such an excellent insulator for axons?

Answer 20

High lipid content

Question 21

The ANS carries signals to _______.

Answer 21

Glands, smooth muscle, and cardiac muscle

Question 22

What forms the white matter of the spinal cord?

Answer 22

Myelinated axons

Question 23

Most sensory neurons, such as ones found in special sense organs, are structurally classified as _____.

Answer 23

Bipolar

Question 24

The most common type of neuron in the human body is ______.

Answer 24

Multipolar

Question 25

The majority of neurons are functionally classified as _______.

Answer 25

Interneurons

Question 26

Regulation of heart rate, blood pressure, and digestive functions are carried out by the _____.

Answer 26

ANS

Question 27

What structure contains the bulk of the Schwann cell’s cytoplasm and organelles?

Answer 27

Neurolemma

Question 28

What are clusters of cell bodies within the PNS called?

Answer 28

Ganglia

Question 29

Which neuroglial cells help form the blood-brain barrier?

Answer 29

Astrocytes

Question 30

What type of neuron carries info toward the CNS?

Answer 30

Afferent / sensory

Question 31

What cell type forms the myelin sheath in the CNS?

Answer 31

Oligodendrocytes

Question 32

Which division of the PNS carries signals from bones, joints, skin, and organs of vision to the CNS?

Answer 32

Somatic Sensory

Question 33

What is the most metabolically active part of the neuron?

Answer 33

Soma / Cell body

Question 34

Which neuroglia would be more likely to form a brain tumor because of their ability to rapidly divide following brain injury?

Answer 34

Astrocytes

Question 35

What neuron structure does not contain protein-making organelles?

Answer 35

Axon

Question 36

Bundles of axons known as "tracts" are part of the _____, whereas "nerves" are part of the ______?

Answer 36

CNS; PNS

Question 37

Which effector is controlled by the somatic motor division: smooth muscle, cardiac muscle, skeletal muscle, or glands?

Answer 37

Skeletal muscle

Question 38

What must be intact for a neuron to regenerate in the PNS?

Answer 38

Cell body

Question 39

What is the sequence of structures that indicates the direction of an electrical signal carried through a multipolar neuron?

Answer 39

Dendrites --> Cell body --> Axon

Question 40

What type of channel opens in response to a chemical binding to a receptor on the channel?

Answer 40

Ligand-gated

Question 41

The influx of positive charges makes the membrane potential more positive and is known as _____.

Answer 41

Depolarization

Question 42

What is the period during an action potential when a nerve fiber cannot be stimulated to produce an additional action potential no matter how strong the stimulus?

Answer 42

Absolute refractory period

Question 43

What ion triggers synaptic vesicles to release neurotransmitters into the synaptic cleft?

Answer 43

Calcium

Question 44

What are the structural components of chemical synapses?

Answer 44

Synaptic vesicles, synaptic cleft, and neurotransmitter receptors (NOT gap juntion)

Question 45

Where are voltage-gated channels most abundant?

Answer 45

Axolemma

Question 46

What characteristic is the fundamental process for most functions of the nervous system?

Answer 46

Synaptic transmission

Question 47

What is the resting membrane potential of a typical neuron?

Answer 47

-70 mV

Question 48

Influx of which ions can cause an inhibitory postsynaptic potential (IPSP) to be produced?

Answer 48

Chloride ions

Question 49

What is the process of putting together all the excitatory and inhibitory stimuli that determine whether a neuron will or will not fire an action potential?

Answer 49

Neural integration

Question 50

The majority of synapses in the nervous system are ____.

Answer 50

Chemical

Question 51

What type of fiber has the largest diameter?

Answer 51

Type A Type B fibers are intermediate and Type C fibers are the smallest/slowest

Question 52

During saltatory conduction, action potentials are generated where?

Answer 52

Only at nodes of Ranvier of myelinated axons

Question 53

What are the characteristics of local potentials?

Answer 53

they are reversible, also called graded potentials, and decremental in nature (NOT useful for long distances)

Question 54

What mechanisms terminate the effects of a neurotransmitter?

Answer 54

1. Degradation by enzymes in the synaptic cleft 2. Reuptake by the presynaptic neuron 3. Diffusion away from the synaptic cleft and uptake by glial cells

Question 55

A series of measurements with a voltmeter show a neuron's membrane potential becoming more negative, from –70 mV to –85 mV. This neuron is experiencing a _____.

Answer 55

Hyperpolarization phase

Question 56

Resting membrane potential is maintained by the Na+/K+ ATPase, which brings ______ potassium ions into the cytosol and ______ sodium ions into the extracellular fluid.

Answer 56

2 K+ and 3 Na+

Question 57

What are the structural types of synapses?

Answer 57

Axodendritic, axoaxonic, and axosomatic

Question 58

What type of ion channel is always open?

Answer 58

Leak

Question 59

What type of fiber has the slowest conduction speed?

Answer 59

Type C (smallest & slowest)

Question 60

What event occurs when EPSPs arrive repidly at a single synapse?

Answer 60

Temporal summation

Question 61

What channels open in response to changes in membrane potential?

Answer 61

Voltage-gated

Question 62

How many connections from different presynaptic neurons does an average neuron have?

Answer 62

10,000

Question 63

What kind of conduction occurs when each section of the axolemma has to be depolarized to threshold in sequence along the entire axolemma for a current to spread down the length of the axon?

Answer 63

Continuous

Question 63

Which neuron delivers a message to a target cell: presynaptic or postsynaptic?

Answer 63

Presynaptic

Question 63

What are the three types of catecholamines?

Answer 63

Norepinephrine, epinephrine, and dopamine

Question 64

Which neuropeptide neurotransmitter is released from fibers transmitting sensory information about pain and temperature?

Answer 64

Substance P

Question 65

Which neurotransmitter is widely used by the autonomic nervous system (ANS), where it influences functions such as heart rate, blood pressure, and digestion?

Answer 65

Norepinephrine

Question 66

What is the response of the presynaptic neuron after acetylcholinesterase (AChE) acts?

Answer 66

Reabsorbs choline

Question 67

What effects occur when neuromodulators bind to metabotropic receptors?

Answer 67

1. Increase or decrease in neurotransmitter release from a presynaptic neuron 2. Affect the sensitivity of the postsynaptic membrane 3. Alter gene transcription (NOT degenerate synaptic vesicles)

Question 68

Cholinergic synapses use the neurotransmitter ______.

Answer 68

Acetylcholine

Question 69

What is thought to be one of the major neurotransmitters involved in mood regulation, motor behaviors, feeding behaviors, and daily rhythms and is a common target in the treatment of depression?

Answer 69

Serotonin

Question 70

Neuronal pools are located within ______.

Answer 70

The CNS

Question 71

Which neurotransmitters are strictly inhibitory?

Answer 71

Glycine and GABA

Question 72

What is considered to be the most important excitatory neurotransmitter in the brain?

Answer 72

Glutamate

Question 73

How many neurotransmitters operating in the human nervous system have been identified?

Answer 73

Over 100

Question 74

What type of neurotransmitter receptors elicit much slower changes in the membrane potential of the postsynaptic neuron, but the effects are typically longer lasting and more varied?

Answer 74

Metabotropic receptors