Deck 4: Principles of Neural and Hormonal Communication

Question 1

Voltage-gated sodium channels can exist in how many different conformations?

A)​one
B)two
C)three
D)four
E)five

Answer 1

C

Question 2

As the triggering event gets stronger,what type of gated channels open up more frequently or for longer duration?

A)​calcium channels
B)sodium channels
C)potassium channels
D)oxygen channels
E)​water channels

Answer 2

B

Question 3

What ensures the one-way propagation of an action potential away from the initial site of activation?

A)​The refractory period
B)The activation period
C)The rest period
D)The salutatory period
E)​The electrical period

Answer 3

A

Question 4

A typical synaptic delay lasts for approximately ____.

A)​0.5 to 1 millisecond
B)5 milliseconds
C)10 milliseconds
D)25 milliseconds
E)​0.5 to 1 second

Question 5

The binding of a neurotransmitter to inhibitory synapses increases the permeability of the subsynaptic membrane to ____.

A)​sodium or chloride
B)potassium or calcium
C)potassium or chloride
D)potassium or sodium
E)​calcium or chloride

Question 6

In addition to myelination,what else influences the speed with which an axon can conduct action potentials?​

A)​number of dendrites
B)fiber diameter
C)fiber length
D)size of the cell body
E)​proximity of the nerve to spinal cord

Question 7

​What extensions project like antennae away from the nerve's cell body and conduct signals towards the body?

A)​organelles
B)axons
C)mitochondria
D)endoplasmic reticulum
E)​dendrites

Question 8

What substance is secreted by electrical synapses between neurons in the brain?

A)​ATP
B)ACTH
C)GnRH
D)GRH
E)​glucose

Question 9

On what three structures can a neuron terminate?

A)​spinal cord,peripheral nerve,or organ
B)smooth muscle,striated muscle,or cardiac muscle
C)gland,other neuron,or blood vessel
D)peripheral nerve,spinal nerve,or brain neuron
E)​muscle,gland,or other neuron

Question 10

Membrane potential is related to the uneven distribution of what two positively charged ions?

A)​salt and sugar
B)calcium and magnesium
C)hydrogen and oxygen
D)sodium and potassium
E)​chloride and phosphorus

Question 11

What are the two basic forms of electrical signals?

A)​high potentials and low potentials
B)physical and action potentials
C)graded potentials and action potentials
D)graded potentials and chemical potentials
E)​physical potentials and chemical potentials

Question 12

In general terms,what sort of distance do graded potentials die out over?

A)​graded distances
B)active distances
C)long distances
D)medium distances
E)​short distances

Question 13

Depolarization from the resting potential of -70 mV proceeds slowly until it reaches a critical level known as ____.

A)​polarizing action
B)electrical action
C)depolarizing potential
D)active potential
E)​threshold potential

Question 14

The resting membrane is ____ more permeable to potassium than to sodium.

A)​2x
B)5x
C)10-15x
D)25-30x
E)​100x

Question 15

Due to its recorded appearance,an action potential often referred to a ____.

A)​plateau
B)hockey stick
C)spike
D)table
E)​bell

Question 16

What is the temporarily depolarized region of a membrane called?

A)​active area
B)temporary area
C)charged area
D)depolarized area
E)​electrical area

Question 17

What are the two types of synapses between neurons?

A)​physical and chemical
B)primary and secondary
C)active and passive
D)electrical and chemical
E)​open and closed

Question 18

What property do insulators demonstrate that greatly hinders movement of electrical charge?

A)​high resistance
B)low resistance
C)high conductance
D)low conductance
E)​absence of electrons

Question 19

The strength of a stimulus is coded by the ____.​

A)​strength of action potentials
B)frequency of action potentials
C)duration of the resting period
D)duration of the refractory periods
E)​frequency of salutatory periods

Question 20

What is stored in synaptic vesicles?

A)​hormones
B)neurotransmitters
C)sodium ions
D)glucose
E)​ATP

Question 21

Messenger binding to a ____ activates tyrosine kinase.

A)​chemically gated receptor-channel
B)G-protein-coupled receptor
C)lipid dependent receptor
D)receptor-enzyme complex
E)​cholesterol-coupled complex

Question 22

Scientists recently discovered a possible new route for direct exchange of materials between cells: ____.

A)​piggy back molecules
B)tunneling nanotubes
C)microcrystals
D)protein carriers
E)​lipid bridges

Question 23

What is a type of paracrine that is a collection of protein signal molecules secreted by cells of the immune system,largely acting locally to regulate immune responses?

A)​cytokines
B)eicosanoids
C)peptides
D)enzymes
E)​white blood cells

Question 24

What type of eicosanoids involve local messengers in inflammatory responses and cause profound airway constriction characteristic of asthma?

A)​prostaglandins
B)thromboxanes
C)arachidonic acid
D)cortisol
E)​leukotrienes

Question 25

What paracrine is released from a specific type of connective tissue cell during an inflammatory response?

A)​serotonin
B)dopamine
C)cytosine
D)histamine
E)​cytokinin

Question 26

What term refers to the branching of axon terminals so that a single cell synapses with and influences many other cells?​

A)​divergence
B)convergence
C)integration
D)termination
E)​bifurcation

Question 27

Hormones fall into two chemical groups based on their solubility: ____.

A)​hydrophilic and lipophobic
B)soluble and insoluble
C)lipophilic and lipophobic
D)hydrophilic and lipophilic
E)​acidic and alkaline

Question 28

What proportion of all drugs prescribed today act on G-protein-coupled receptors?

A)​about 1/4
B)about 1/3
C)about 1/2
D)about 2/3
E)​about 3/4

Question 29

What neurotransmitter is made from tryptophan?

A)​acetylcholine
B)serotonin
C)dopamine
D)glutamate
E)​norepinephrine

Question 30

Eicosanoids are modified from ____.

A)​arachidonic acid
B)cytokines
C)growth factors
D)histamine
E)​glucose

Question 31

What term refers to any enzyme that transfers a phosphate group from ATP to a particular intracellular protein?

A)​cytosine
B)cytokinin
C)phosphatase
D)ATP-ase
E)​protein kinase

Question 32

Endocrine specificity is a result of ____.

A)​anatomic proximity
B)anatomic specialization
C)proximity and specialization of hormones
D)receptor proximity
E)​receptor specialization

Question 33

What is the largest type of neuromodulator?

A)​ATP 
B)nitric oxide
C)serotonin
D)dopamine
E)​neuropeptides

Question 34

Hormones can be classified according to their chemical structure,i.e.,____.

A)​amino acids,amines and thyroid hormones
B)peptides,amines and steroids
C)peptides,catecholamines and indoleamines
D)catecholamines,amines and cholesterol
E)​steroids,amino acids and thyroid hormones

Question 35

What are the chemical messengers for the nervous system?

A)​hormones released into the blood
B)hormones released into the synaptic cleft
C)hormones released in the spinal canal
D)neurotransmitters released into the synaptic cleft
E)​neurotransmitters released into the blood

Question 36

How many types of extracellular chemical messengers or signal molecules are used for indirect cell communication in the body?

A)​two
B)three
C)four
D)five
E)​six

Question 37

What class of drugs selectively blocks the reuptake of serotonin into presynaptic axon terminals?

A)​phosphodiesterase-type 5 (PDE-5)inhibitors
B)selective serotonin reuptake stimulators (SSRSs)
C)phosphodiesterase-type 5 (PDE-5)stimulators
D)selective serotonin reuptake inhibitors (SSRIs)
E)​phosphodiesterase-type 2 (PDE-2)inhibitors

Question 38

G-proteins are bound to ____.

A)​glucose
B)guanine nucleotides
C)glutathione
D)gyroscopic proteins
E)​gamma phosphate

Question 39

What is the precursor for all steroid hormones?

A)​amino acids
B)peptides
C)cholesterol
D)amines
E)​thyroxin

Question 40

Where do hydrophilic peptide hormones dissolve?

A)​The blood
B)The cytosol
C)The extracellular fluid
D)The intracellular fluid
E)​The intercellular matrix

Question 41

Eicosanoids typically act locally as paracrines,but some travel in the blood,similar to hormones,to distant target cells to produce systemic responses.

Question 42

When a neuron terminates on a muscle or a gland,the neuron is said to innervate,or supply,the structure.

Question 43

Following the absolute refractory period is a relative refractory period,during which a second action potential can be produced only by a triggering event considerably stronger than usual.

Question 44

Electrical synapses are more common than chemical synapses in the human nervous system.

Question 45

The voltage-gated sodium channel has two gates: an activation gate and an inactivation gate.

Question 46

The terms action potential,spike,and firing all refer to the same phenomenon of slow reversal of membrane potential.

Question 47

Any flow of electrical charges is called resistance.

Question 48

If a graded potential is large enough,it can initiate an action potential before the graded change dies off.

Question 49

The dendrites and cell body are the neuron's output zone because these components send out signals.

Question 50

The space between the presynaptic and postsynaptic neurons is called the synaptic knob.

Question 51

An unmyelinated fiber has a low density of voltage-gated channels along its entire length.

Question 52

Voltage-gated channels open or close in response to changes in membrane potential.

Question 53

The outward movement of sodium ions rapidly restores the negative resting potential.

Question 54

The stronger the triggering event,the larger the resultant graded potential.

Question 55

The most common means by which cells communicate with one another is indirectly through signal molecules.

Question 56

Tetanus toxin prevents release of serotonin from inhibitory presynaptic inputs terminating at neurons that supply skeletal muscles.

Question 57

Several mechanisms can remove the neurotransmitter,such as being inactivated by specific enzymes within the sub-synaptic membrane.

Question 58

Many growth factors that help regulate cell growth and division,such as nerve growth factor and epidermal growth factor,act via the JAK/STAT pathway.

Question 59

Hormones are long-range chemical messengers specifically secreted into the blood by endocrine glands in response to an appropriate signal.

Question 60

Neurotransmitter is released by exocytosis into the synaptic cleft.

Question 61

In myelinated fiber,impulses "jump" from node to node,skipping over the myelinated sections of the axon in a process called ____________________ conduction.

Question 62

Action potentials occur in a(n)____________________ fashion.

Question 63

Neurons are saved from oscillating action potentials by the ____________________ period.

Question 64

In addition to neuromodulation,another means of depressing or enhancing synaptic effectiveness is presynaptic ____________________ or ____________________.

Question 65

All lipophilic hormones bind with intracellular receptors and primarily produce effects in their target cells by activating specific genes that cause the synthesis of new proteins.

Question 66

____________________ is the hindrance to electrical charge movement.

Question 67

At a(n)____________________ synapse,the receptor-channels to which the neurotransmitter binds are nonspecific cation channels that permit simultaneous passage of sodium and potassium through them.

Question 68

____________________ potentials are local changes in membrane potential that occur in varying grades or degrees of magnitude or strength.

Question 69

Nerve and muscle are considered ____________________ tissues because they produce electrical signals when excited.

Question 70

____________________ gated channels respond to stretching or other mechanical deformation.

Question 71

The enzyme cyclooxygenase (COX)initiates a pathway leading to formation of prostaglandins and thromboxanes.

Question 72

The total grand postsynaptic potential (GPSP)is a composite of all ____________________ and IPSPs occurring around the same time.

Question 73

The socially abused drug ____________________ blocks the reuptake of the neurotransmitter dopamine at presynaptic terminals.

Question 74

The endocrine system is specialized to control activities that require speed rather than duration.

Question 75

Hydrophilic hormones are highly water soluble and have low lipid solubility.

Question 76

Two important relationships exist between neurons: ____________________ and ____________________.

Question 77

Myelin forming cells in the peripheral nervous system are called ____________________ cells.

Question 78

Peptides are synthesized in the cytosol of cells.

Question 79

The amino acid ____________________ is a primary excitatory neurotransmitter in the central nervous system.

Question 80

____________________ conduction involves the spread of the action potential along every patch of membrane down the length of the axon.