Test One Study Guide Flashcards

1
Q

Glucose enters absorptive cells this way

A

secondary active transport

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2
Q

ATP is hydrolyzed by the same protein that moves a solute against its gradient

A

primary active transport

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3
Q

Oxygen crosses membranes this way

A

simple diffusion

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4
Q

Glucose enters non-absorptive cells this way

A

facilitated diffusion

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5
Q

A general term describing the movement of solutes FOLLOWING their concentration gradient

A

diffusion

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6
Q

A general term describing the movement of solutes AGAINST their concentration gradient

A

active transport

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7
Q

Diffusion of water through an aquaporin (a specific name for facilitated diffusion of water)

A

osmosis

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8
Q

Water moves into cells by osmosis (diffusion of water), which means it moves:
from low to high water concentration, which corresponds to high to low solute concentration
from high to low water concentration, which corresponds to high to low solute concentration.
from low to high water concentration, which corresponds to low to high solute concentration.
from high to low water concentration, which corresponds to low to high solute concentration.

A

from high to low water concentration, which corresponds to low to high solute concentration.

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9
Q

Which of the following statements best describes substrate phosphorylation (SP)?

SP occurs in all cells during glycolysis and the Krebs cycle. During SP, a kinase enzyme removes a phosphate from a molecule and adds it to ADP. Cytochrome oxidase is an enzyme in the electron transport chain.

In the process of SP, reduced coenzymes (NADH and FADH2) are used to create a hydrogen ion (H+) gradient via the electron transport chain that provides the energy to power the addition of a free phosphate to ADP by the enzyme ATP synthase.

A

SP occurs in all cells during glycolysis and the Krebs cycle. During SP, a kinase enzyme removes a phosphate from a molecule and adds it to ADP. Cytochrome oxidase is an enzyme in the electron transport chain.

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10
Q

Which is the correct sequence of events in cellular metabolism?

Electron transport chain followed by the citric acid cycle followed byglycolysis.

Citric acid cycle followed by the electron transport chain followed by glycolysis.

Glycolysis followed by the citric acid cycle followed by the electron transport chain

Glycolysis followed by the electron transport chain followed by the citric acid cycle

A

Glycolysis followed by the citric acid cycle followed by the electron transport chain

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11
Q

Which is the correct statement about lactic acid?

Lactic acid is converted to pyruvate when oxygen is in short supply

Lactic acid is converted to pyruvate when oxygen is abundant.

Lactic acid is formed from pyruvate when oxygen is in short supply

Lactic acid is formed from pyruvate when oxygen is abundant

A

Lactic acid is formed from pyruvate when oxygen is in short supply

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12
Q

Cyanide would affect cellular respiration by:

Inhibiting glycolysis

Inhibiting oxidative phosphorylation

Inhibiting substrate phosphorylation

A

Inhibiting oxidative phosphorylation

Oxidative phosphorylation occurs when high energy electrons are passed through the electron transport chain to create a hydrogen ion gradient to power ATP synthase. Oxygen is the final acceptor of electrons and H+ ions.

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13
Q

If administered quickly, in some cases cyanide antidotes can save a patient but treatment with oxygen alone is ineffective. Why would this be so?

Cyanide prevents the electron transport chain from creating a hydrogen ion gradient, so hydrogen ions and electrons stop moving through ATP synthase and are not available to form water.

Cyanide blocks oxygen transport proteins

Cyanide prevents the electron transport chain from converting oxygen into water so oxygen has already built up to high levels

A

Cyanide prevents the electron transport chain from creating a hydrogen ion gradient, so hydrogen ions and electrons stop moving through ATP synthase and are not available to form water.

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14
Q

The pH scale ranges from 0 to 14. A low numerical pH value is associated with a high concentration of H+ (or low OH-) and a high pH value with a low concentration of H+ (or high OH-). Which statement about pH is correct?

An alkaline solution has a low pH and low concentration of H+

An acidic solution has a high pH and low concentration of H+

An acidic solution has a low pH and high concentration of H+.

A

An acidic solution has a low pH and high concentration of H+.

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15
Q

CO2 + H2O H+ + HCO3-

This is a reversible reaction catalyzed by the enzyme carbonic anhydrase. The more you breathe, the more CO2 you lose from your blood. If you breathe less, or hold your breath, then more CO2 is held in your blood. The Law of Mass Action (Links to an external site.) thus dictates that your rate of breathing influences your plasma pH. Take a look at this short video about the Law of Mass Action, and dust off your knowledge about pH and hydrogen ions to help you answer the following question.

If you hold your breath for an extended period of time, how will the equilibrium of the above reaction shift, and what will happen to your plasma pH?

The reaction will shift to the right, and pH will increase

The reaction will shift to the right, and pH will decrease.

The reaction will shift to the left, and pH will decrease

The reaction will shift to the left, and pH will increase

A

The reaction will shift to the right, and pH will decrease.

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16
Q

Review the notes about anabolic and catabolic reactions in the Metabolism document (Links to an external site.) and choose the correct statement.

The conversion of glucose to glycogen is called glycogenolysis

The conversion of glycogen to glucose is called glycogenesis

The conversion of glucose to glycogen is called glycogenesis

A

The conversion of glucose to glycogen is called glycogenesis

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17
Q

In the fasted state, when you are mobilizing nutrients (catabolic reactions), what should be happening with carbohydrates?

Glucose should be converted to glycogen for storage in the muscles and liver.

Stored glycogen should be broken down and released into the blood for immediate use

A

Stored glycogen should be broken down and released into the blood for immediate use

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18
Q

Which of the following statements is true?

In the fed state, glycogen is converted to glucose by the process of glycogenolysis.

In the fasted state, glycogen is converted to glucose by the process of glycogenolysis.

In the fed state, glycogen is converted to glucose by the process of gluconeogenesis.

In the fasted state, glycogen is converted to glucose by the process of glycogenesis.

A

In the fasted state, glycogen is converted to glucose by the process of glycogenolysis.

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19
Q

If a toxin disabled a protein in the electron transport chain, which of the following would be true?

There would be no ATP formed at all.

Oxygen would build up inside the cell.

The hydrogen ion gradient across the inner mitochondrial membrane would be lost.

Lactic acid production would stop immediately.

The pH inside cells would increase.

A

The hydrogen ion gradient across the inner mitochondrial membrane would be lost.

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20
Q

Glucose enters intestinal epithelial cells by _____________ and exits those same cells by ______________.

secondary active transport; facilitated diffusion

simple diffusion; primary active transport

facilitated diffusion; secondary active transport

simple diffusion; facilitated diffusion

primary active transport; secondary active transport

A

secondary active transport; facilitated diffusion

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21
Q

The primary structure of proteins is held together by:

van der Waals forces

Ionic and hydrogen bonds

ionic bonds

Covalent bonds

Hydrogen bonds

A

Covalent bonds

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22
Q

Which statement is true about metabolism?

Catabolic reactions generate glucose from glycogen when nutrients are in short supply.

Anabolic reactions generate proteins from amino acids when nutrients are in short supply.

Anabolic reactions generate glycogen from glucose when nutrients are in short supply.

Anabolic reactions generate glycogen from amino acids when nutrients are in short supply.

Catabolic reactions generate lipids from fatty acids when nutrients are in short supply.

A

Catabolic reactions generate glucose from glycogen when nutrients are in short supply.

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23
Q

Which of the following enters cells by facilitated diffusion?

lipids

steroids

glucose

carbon dioxide

oxygen

A

glucose

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24
Q

Which of the following does NOT require a membrane protein to cross cellular membranes?

insulin

carbon dioxide

amino acid

glucose

small peptides

A

carbon dioxide

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25
Q

Which of the following is not a function of the plasma membrane?

Act as transport molecules for various solutes.

Anchor or stabilize the cell membrane.

Bind to ligands.

Produce energy.

Regulate the passage of ions.

A

Produce energy.

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26
Q

This “compartment” holds the smallest proportion of total body water.

extracellular fluid

interstitial fluid

intracellular fluid

interstellar fluid

plasma

A

plasma

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27
Q

When carbon dioxide leaves any living cell, it must first pass through _____________ before it can enter the blood.

the kidneys

intracellular fluid

sweat glands

lymphatic fluid

interstitial fluid

A

interstitial fluid

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28
Q

Regarding gene expression, the process of ____________ produces _______________, and occurs in the cytoplasm of cells.

transcription; polypeptides

translation; mRNA

replication; peptides

transcription; mRNA

translation; polypeptides

A

translation; polypeptides

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29
Q

Cortisol binds with this receptor

A

glucocorticoid receptor

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30
Q

This type of signal travels through the blood to reach its target cell

A

hormone

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31
Q

This type of signal diffuses through the plasma membrane and activates gene expression

A

steroid

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32
Q

Isoprenaline is a drug that is prescribed for an abnormally low heart rate. It binds with the adrenergic receptors on the pacemaker cells of the heart. This drug would be an __________of the receptor

A

agonist

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33
Q

This hormone is released from the anterior pituitary and binds with receptors in the adrenal cortex

A

adrenocorticotropic hormone

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34
Q

This type of control is how EPI/NE and ACh control heart rate

A

antagonistic control

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35
Q

A non-steroid hormone might cause one of these to open

A

ion channel

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36
Q

Epinephrine and norepinephrine bind with this type of receptor

A

Adrenergic receptor

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37
Q

Insulin is the _____________ of the insulin receptor

A

primary ligand

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38
Q

This type of signal influences the same cell that released it

A

autocrine signal

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39
Q

This hormone is released from the posterior pituitary gland and causes conservation of water

A

Antidiuretic hormone

40
Q

The binding of cortisol with a glucocorticoid receptor on the hypothalamus, reducing the secretion of corticotropin releasing hormone is an example of this process.

A

negative feedback

41
Q

The normal action of EPI/NE is to increase heart rate. Propranalol is a drug that slows heart rate by binding to beta-adrenergic receptors. This type of drug is an______ of the receptor

A

antagonist

42
Q

This type of control is how EPI/NE control blood vessel diameter

A

tonic control

43
Q

This gland releases oxyticin and antidiuretic hormone

A

posterior pituitary

44
Q

This type of signal diffuses through some interstitial fluid before binding with its receptor

A

paracrine signal

45
Q

Which of the following signals would be acting as an agonist of the receptor?

Tamoxifen blocks the estrogen receptor to prevent estrogen from binding and causing a breast tumor to grow bigger

Insulin binds to the insulin receptor, causing a decrease in blood sugar levels.

Cortisol binds with the glucocorticoid receptor in the anterior pituitary gland and decreases the secretion of ACTH

Albuterol is given to an asthma patient where it binds with beta-adrenergic receptors in the smooth muscle of the bronchioles, making it easier to breathe

A

Albuterol is given to an asthma patient where it binds with beta-adrenergic receptors in the smooth muscle of the bronchioles, making it easier to breathe

46
Q

Which is the correct sequence of movement for a molecule of carbon dioxide produced by a cell?

Intracellular fluid to plasma to interstitial fluid.

Interstitial fluid to intracellular fluid to plasma

Intracellular fluid to interstitial fluid to plasma.

Plasma to interstitial fluid to intracellular fluid.

A

Intracellular fluid to interstitial fluid to plasma.

47
Q

Three of the following are characteristics of steroids, and one is not. Which trait does NOT describe a steroid?

Can only bind with a membrane-bound receptor

Receptor is in the cytosol or nucleus, but the steroid-receptor complex activates transcription.

Action is slow and sustained.

Lipid soluble and able to diffuse through the plasma membrane.

A

Can only bind with a membrane-bound receptor

48
Q

Which of the following statements is true?

To bind with its receptor in the nucleus, insulin must first pass through the cytosol after it leaves the blood.

To bind with its receptor on the plasma membrane, insulin must first pass through lymphatic fluid after it leaves the blood.

To bind with its receptor in the nucleus, insulin must first pass through interstitial fluid after it leaves the blood.

To bind with its receptor on the plasma membrane, insulin must first pass through interstitial fluid after it leaves the blood.

A

To bind with its receptor on the plasma membrane, insulin must first pass through interstitial fluid after it leaves the blood.

49
Q
Choose the hormone category most likely to increase the amount of cAMP in its target cells.  
  Thyroid hormones 
  Steroids 
  Testosterone 
  Proteins
A

Proteins

50
Q

Which of the following is an example of tonic control of a tissue?

Insulin is released from the beta cells of the pancreas Islets of Langerhans and causes a reduction in blood sugar. Glucagon is released from the alpha cells of the pancreatic Islets of Langerhans and causes an increase in blood sugar.

Epinephrine binds with adrenergic receptors on the pacemaker cells on the heart to increase heart rate and acetylcholine binds with cholinergic receptors on the pacemaker cells to slow it down.

Antidiuretic hormone (ADH) binds with receptors on the collecting duct cells of the kidney to cause water to reabsorbed. The amount of water reabsorbed is proportional to how much ADH binds.

Epinephrine binds with adrenergic receptors on the bronchioles to open up the airway and acetylcholine binds with cholinergic receptors on the bronchioles to constrict it.

A

Antidiuretic hormone (ADH) binds with receptors on the collecting duct cells of the kidney to cause water to reabsorbed. The amount of water reabsorbed is proportional to how much ADH binds.

51
Q

Which statement is correct about ligands?

An antagonist binds with the same receptor as the primary ligand but invokes the same or an increased cellular response.

The primary ligand is the one that decreases the normal cellular response.

An agonist binds with the same receptor as the primary ligand, but decreases the cellular response.

An agonist binds with the same receptor as the primary ligand but invokes the same or an increased cellular response.

A

An agonist binds with the same receptor as the primary ligand but invokes the same or an increased cellular response.

52
Q

Which of the following is an example of a mechanism that would terminate, or reduce the amount of cellular activity following a signal’s release?

Monoamine oxidase is an enzyme that breaks down epinephrine

Isoprenaline, which can bind with beta adrenergic receptors is administered to increase heart rate and force of contraction of the heart.

Caffeine inhibits the action of phosphodiesterase (PDE). PDE normally breaks down cAMP, an importat second messenger molecule in cells.

Sarin gas poisoning occurs. Sarin gas is an antagonist of acetylcholinesterase which normally breaks down acetylcholine.

A

Monoamine oxidase is an enzyme that breaks down epinephrine

53
Q

Which is the correct description of the pathway leading to the secretion of cortisol?

Secretion of CRH from the hypothalamus leads to secretion of ACTH from the posterior pituitary which leads to secretion of cortisol from the adrenal cortex.

Secretion of cortisol from the hypothalamus leads to secretion of ACTH from the anterior pituitary which leads to secretion of CRH from the adrenal cortex.

Secretion of CRH from the hypothalamus leads to secretion of ACTH from the anterior pituitary which leads to secretion of cortisol from the adrenal cortex.

Secretion of ACTH from the hypothalamus leads to secretion of CRH from the anterior pituitary which leads to secretion of cortisol from the adrenal cortex.

A

Secretion of CRH from the hypothalamus leads to secretion of ACTH from the anterior pituitary which leads to secretion of cortisol from the adrenal cortex.

54
Q

Which statement correctly describes negative feedback?

Cortisol secreted from the adrenal cortex binds with glucocorticoid receptors in the liver, increasing the conversion of glycogen to glucose.

In the stress axis, negative feedback happens when ACTH binds with receptors in the adrenal cortex, increasing the amount of cortisol secretion.

Cortisol secreted from the adrenal cortex binds with glucocorticoid receptors in the anterior pituitary, increasing the secretion of ACTH.

Cortisol secreted from the adrenal cortex binds with glucocorticoid receptors in the hypothalamus, decreasing secretion of CRH.

A

Cortisol secreted from the adrenal cortex binds with glucocorticoid receptors in the hypothalamus, decreasing secretion of CRH.

55
Q

What pattern of hormone secretion would be observed in a patient with hypercortisolism if the tumor was in her anterior pituitary gland? Assume that the tumor is OVER producing its normal product and the tumor cells do NOT respond to negative feedback signals.

high cortisol, but low levels of CRH and ACTH.

high CRH, but low levels of ACTH and cortisol.

high CRH, ACTH, and cortisol.

high ACTH and cortisol, but low levels of CRH.

A

high ACTH and cortisol, but low levels of CRH.

56
Q
The physiological effects of this signal depend on the presence of cholinergic receptors.
  insulin 
  testosterone 
  epinephrine 
  cortisol 
  acetylcholine
A

acetylcholine

57
Q

A target cell’s response to a hormone is the activation of a second messenger system. Choose the hormone most likely to evoke this response.

  epinephrine 
  testosterone 
  aldosterone 
  cortisol 
  estradiol
A

epinephrine

58
Q
Signals that affect neighboring cells after diffusing through interstitial fluid are:
  not found in humans 
  paracrine signals 
  endocrine signals 
  autocrine signals
A

paracrine signals

59
Q
Regulation of heart rate is an example of 
[ Select ]
 control involving 
[ Select ]
 signal-receptor combinations.
A

antagonistic, two

60
Q
Glucose enters intestinal epithelial cells by 
[ Select ]
 and exits those same cells by 
[ Select ]
 .
A

secondary active transport, facilitated diffusion

61
Q

NON-Steroid hormones can initiate responses in target-cells by activating:
a second messenger system only
enzymes only
ion channels, a second messenger system or an enzyme.
ion channels only
gene transcription

A

ion channels, a second messenger system or an enzyme.

62
Q

Choose the pair that is the correct match of hormone and source.

oxytocin – hypothalamic/posterior pituitary axis.
cortisol – hypothalamus
corticotropin releasing hormone –anterior pituitary
antidiuretic hormone –anterior pituitary
epinephrine – adrenal cortex

A

oxytocin – hypothalamic/posterior pituitary axis.

63
Q

Which of the following is the best example of an antagonist?

Atenolol binds to β-adrenergic receptors preventing an increase in heart rate.

Insulin binds to the insulin receptor and causes glucose transporters to be inserted into the membrane of the cell.

A drug that increases the activity of dopamine receptors to treat Parkinson’s disease.

Cortisol binds to the glucocorticoid receptor and cause proteolysis.

Epinephrine and norepinephrine each bind to α- and β-adrenergic receptors.

A

Atenolol binds to β-adrenergic receptors preventing an increase in heart rate.

64
Q

Which is the correct order of hormone secretions in the tripartite axis activated by stress?
Corticotropin releasing hormone, cortisol; ACTH.

Cortisol; corticotropin releasing hormone, ACTH.

Corticotropin releasing hormone; ACTH; cortisol.

ACTH; cortisol; corticotropin releasing hormone.

ACTH; corticotropin releasing hormone; cortisol.

A

Corticotropin releasing hormone; ACTH; cortisol.

65
Q

Patients that are treated with Prednisone (a synthetic form of cortisol), to control inflammation or reduce other immune functions, experience lower levels of endogenous (made by their own glands) CRH and ACTH. What type of effect is this?

agonistic
postiive feedback
negative feedback

A

negative feedback

66
Q

The physiological effects of this signal depend on the presence of cholinergic receptors

testosterone
cortisol
insulin
epinephrine
acetylcholine
A

acetylcholine

67
Q

a target cell’s response to a hormone is the activation of a second messenger system. Choose the hormone most likely to evoke this response.

cortisol
epinephrine
estradiol
testosterone
aldosterone
A

epinephrine

68
Q

signals that affect cells after traveling through the blood are called

paracrine signals
endocrine signals
autocrine signals
not found in humans

A

endocrine signals

69
Q

Regulation of blood vessel diameter by epinephrine at beta adrenergic receptors is an example of _____ control involving _____ signal receptor combinations:

tonic, at least two
antagonistic, only one
tonic, only one
synergistic, only one
antagonistic, at least two
A

tonic, only one

70
Q

glucose enters the intestinal epithelial cells by ____ and exists those cells by ____.

secondary active transport, facilitated diffusion
simple diffusion, facilitated diffusion
facilitated diffusion, secondary active transport
primary active transport, secondary active transport
facilitated diffusion, simple diffusion

A

secondary active transport, facilitated diffusion

71
Q

steroid hormones can initiate responses in target cells by activating

ion channels
an enzyme or ion channel
a second messenger system
ion channels, a second messenger system, or an enzyme
gene transcription
A

gene transcription

72
Q

choose the pair that is the correct match of hormone and source

cortisol - hypothalamus
antidiuretic hormone - hypothalamic/posterior pituitary axis
epinephrine - adrenal cortex
oxytocin - parasympathetic neurons
corticotropin releasing hormone - anterior pituitary

A

antidiuretic hormone - hypothalamic/posterior pituitary axis

73
Q

which of the following is the best example of an agonist?

insulin binds to insulin receptors and causes glucose transporters to be inserted into the membrane of the cell

cortisol binds to the glucocorticoid receptor and causes proteolysis

epinephrine and norepinephrine each bind to a and b - adrenergic receptors

a drug that increases the activity of dopamine receptors to treat parkinson’s disease

atenolol binds to b adrenergic receptors preventing an increase in heart rate

A

a drug that increases the activity of dopamine receptors to treat parkinson’s disease

74
Q

which is the correct order of hormone secretions in the tripartite axis activated by stress?

corticotropin releasing hormone, cortisol, ACTH

Cortisol, corticotropin releasing hormone, ACTH

ACTH, cortisol, corticotropin releasing hormone

ACTH, corticotropin releasing hormone, cortisol

corticotropin releasing hormone, ACTH, cortisol

A

corticotropin releasing hormone, ACTH, cortisol

75
Q

Patients that are treated with Prednisone (a synthetic form of cortisol), to control inflammation or reduce other immune functions, experience lower levels of endogenous (made by their own glands) CRH and ACTH. This is called _____ effect.

a postive feedback
an agonistic
a negative feedback

A

a negative feedback

76
Q

Which of the following statements about potassium is false?

When a potassium channel is opened potassium enters the cell because there is more potassium outside the cell than inside.

When potassium channels open the membrane potential of the cell moves towards -90 mV.

Opening of potassium channels causes the membrane potential to become more negative.

When a potassium channel is opened potassium leaves the cell because there is more potassium inside the cell than outside.

A

When a potassium channel is opened potassium enters the cell because there is more potassium outside the cell than inside.

77
Q

Which of the following statements about sodium is false?

Opening of sodium channels causes the membrane potential to become more positive

When sodium channels open the membrane potential of the cell moves towards +60 mV.

When a sodium channel is opened sodium leaves the cell because there is more sodium inside the cell than outside.

When a sodium channel is opened sodium enters the cell because there is more sodium outside the cell than inside.

A

When a sodium channel is opened sodium leaves the cell because there is more sodium inside the cell than outside.

78
Q

When ligand- gated potassium channels open, what is the most likely consequence?

Potassium enters the cell a graded hyperpolarization occurs.

Potassium leaves the cell a graded depolarization occurs.

Potassium leaves the cell a graded hyperpolarization occurs.

Potassium enters the cell and a graded depolarization occurs

A

Potassium leaves the cell a graded hyperpolarization occurs.

79
Q

A drug that causes voltage-gated sodium channels to stay open for an abnormally longer period of time will cause the resting membrane potential of a neuron to be:

more negative than normal.

less positive than normal.

unchanged from normal.

more positive than normal.

A

more positive than normal.

80
Q

Which statement is correct about neurotransmitters?

Neurotransmitters are released by endocytosis and demonstrate endocrine signaling when they cross the synapse to bind with their receptor.

Neurotransmitters are released by exocytosis and demonstrate paracrine signaling when they cross the synapse to bind with their receptor.

Neurotransmitters are released by endocytosis and demonstrate paracrine signaling when they cross the synapse to bind with their receptor.

Neurotransmitters are released by exocytosis and demonstrate endocrine signaling when they cross the synapse to bind with their receptor.

A

Neurotransmitters are released by exocytosis and demonstrate paracrine signaling when they cross the synapse to bind with their receptor.

81
Q

Which of the following signals would be acting as an agonist of the receptor?

Albuterol is given to an asthma patient where it binds with beta-adrenergic receptors in the smooth muscle of the bronchioles, making it easier to breathe.

Insulin binds to the insulin receptor, causing a decrease in blood sugar levels.

Tamoxifen blocks the estrogen receptor to prevent estrogen from binding and causing a breast tumor to grow bigger.

Cortisol binds with the glucocorticoid receptor in the anterior pituitary gland and decreases the secretion of ACTH.

A

Albuterol is given to an asthma patient where it binds with beta-adrenergic receptors in the smooth muscle of the bronchioles, making it easier to breathe.

82
Q

Benzodiazepine is an agonist of the GABAA receptor. When GABA binds with it’s receptor on the dendritic membrane of a neuron it causes ligand-gated chloride channels to open. Which would be true about the consequence of treatment with benzodiazepine?

Benzodiazepine would decrease the opening of the chloride channels, increasing the excitability of the neuron.

Benzodiazepine would increase the opening of the chloride channels, reducing the excitability of the neuron.

Benzodiazepine would decrease the opening of the chloride channels, reducing the excitability of the neuron.

Benzodiazepine would increase the opening of the chloride channels, increasing the excitability of the neuron.

A

Benzodiazepine would increase the opening of the chloride channels, reducing the excitability of the neuron.

83
Q

There are some poison arrow frog toxins that act as antagonists of acetylcholine gated sodium channels. Which would be a consequence of encountering poison arrow frog toxin?

Poison arrow frog toxin would decrease the opening of the sodium channels, reducing the excitability of the neuron.

Poison arrow frog toxin would decrease the opening of the sodium channels, increasing the excitability of the neuron.

Poison arrow frog toxin would increase the opening of the sodium channels, reducing the excitability of the neuron.

Poison arrow frog toxin would increase the opening of the sodium channels, increasing the excitability of the neuron.

A

Poison arrow frog toxin would decrease the opening of the sodium channels, reducing the excitability of the neuron.

84
Q

Which is true about acetylcholinesterase?

Acetylcholinesterase is an enzyme that breaks down acetylcholine, thus increasing the amount of acetylcholine in the synapse.

Acetylcholinesterase is an enzyme that breaks down acetylcholine, thus reducing the amount of acetylcholine in the synapse.

A

Acetylcholinesterase is an enzyme that breaks down acetylcholine, thus reducing the amount of acetylcholine in the synapse.

85
Q

Acetylcholinesterase is an enzyme that breaks down acetylcholine at cholinergic synapses. VX nerve toxin binds with acetylcholinesterase, preventing it from breaking down acetylcholine. Which statement best describes the consequence of being poisoned with VX?

There would be greater stimulation of nicotinic and muscarinic adrenergic receptors.

There would be greater stimulation of nicotinic and muscarinic cholinergic receptors

There would be less stimulation of nicotinic and muscarinic cholinergic receptors.

There would be less stimulation of nicotinic and muscarinic adrenergic receptors.

A

There would be greater stimulation of nicotinic and muscarinic cholinergic receptors

86
Q

One last question to make sure that you have the organization of the autonomic neurons straight. Which statement about sympathetic and parasympathetic neurons is true?

Epinephrine is released from the post-ganglionic membrane of the post-ganglionic neurons in the sympathetic nervous system.

Acetylcholine is released from the pre-synaptic membranes of the post-ganglionic neurons in the sympathetic nervous system.

Epinephrine is released from the pre-synaptic membrane of the pre-ganglionic neurons in the sympathetic nervous system.

Acetylcholine is released from the post-synaptic membranes of the pre-ganglionic neurons in the sympathetic system

Acetylcholine is released from the pre-synaptic membranes of the post-ganglionic neurons in the parasympathetic nervous system

A

Acetylcholine is released from the pre-synaptic membranes of the post-ganglionic neurons in the parasympathetic nervous system

87
Q

Which of the following is a characteristic of graded potentials?

They require a threshold depolarizaton to be initiated.

They do NOT decay over distance

They are an all-or-none sequence of depolarization and repolarization.

They are always of the same duration

Variable in strength.

A

Variable in strength.

88
Q

Neurotransmitters are typically released from the pre-synaptic membrane of neurons into a synapse.

A

pre-synaptic membrane of neurons

89
Q

The parasympathetic nervous system causes:

a decrease in heart rate
an increase in heart rate

A

a decrease in heart rate

90
Q
Which of the following is part of an afferent neural pathway?  
  parasympathetic neurons 
  motor neurons 
  sympathetic neurons 
  baroreceptor neurons 
  ADH-secreting neurons
A

baroreceptor neurons

91
Q
Delivery of a drug that increases permeability of neuronal membranes to potassium would cause the neurons to:
  depolarize 
  stay at -70 mV 
  hyperpolarize 
  become more positive
A

hyperpolarize

92
Q

Which statement is true about action potentials?

they do not require a threshold level of depolarization to be initiated

they are variable in strength

they vary in amplitude and duration

they decay over short distances

they are an all or nothing sequence of delpolarization and repolarization

A

they are an all or nothing sequence of delpolarization and repolarization

93
Q

neurotransmitters are typically released from the _____ into a synapse

endoplasmic reticulum of glands

post-synaptic membrane of neurons

dendritic membrane

pre-synaptic membrane of neurons

nucleus of neurons

A

pre-synaptic membrane of neurons

94
Q

which branch of the autonomic nervous system would cause an increase in heart rate?

parasympathetic or sympathetic?

A

sympathetic

95
Q

delivery of a drug that increases permeability of neuronal membranes to sodium would cause the neurons to:

depolarize
hyperpolarize
become more negative
stay at -70 mV

A

depolarize