Archive for May 2017

What is the best definition of a vector?

12:55

What is the best definition of a vector?



a. the way a disease is spread
b. an insect that spreads a pathogen
c. an animal that spreads a pathogen
d. a disease-causing organism that moves from one host to another






Answer: C

Amylase is an enzyme that catalyses the breakdown of starch. As the temperature rises, the activity of this enzyme will

12:54

Amylase is an enzyme that catalyses the breakdown of starch. As the temperature rises, the activity of this enzyme will




(A) increase until the enzyme begins to denature.
(B) decrease until the substrate begins to denature.
(C) increase until the optimum pH level is reached.
(D) decrease until the substrate reaches a maximum concentration.




Answer: A

What is a role of the kidney in the excretory system of mammals?

12:53

What is a role of the kidney in the excretory system of mammals?




(A)To remove salt from the body and to keep water in the body
(B)To remove water from the body and to keep salt in the body
(C)To remove nitrogenous waste from the body and to maintain water levels in the body
(D)To remove water from the body and to maintain levels of nitrogenous substances in the body




Answer: C

What is the function of water from the xylem in translocation?

12:53

What is the function of water from the xylem in translocation?



(A) causes a build up of pressure.
(B) allows adhesion for capillarity.
(C) provides water for photosynthesis.
(D) dilutes sucrose for active transport.





Answer: A

How are lipids transported in mammalian blood?

12:53

How are lipids transported in mammalian blood?



(A) They are attached to proteins.
(B) They are dissolved in the blood.
(C) They are part of the membrane of red blood cells.
(D) They are attached to haemoglobin in red blood cells.





Answer: A

What is the most direct function of the juxtaglomerular apparatus?

02:20

What is the most direct function of the juxtaglomerular apparatus?



A) help regulate blood pressure and the rate of blood filtration by the kidneys
B) help regulate blood pressure and the rate of excretion by the kidneys
C) help regulate urea absorption by the kidneys
D) help regulate water and electrolyte excretion by the kidneys





Answer: A

Which of the choices below is the least important role of tubular secretion?

02:20

Which of the choices below is the least important role of tubular secretion?



A) disposing of substances not already in the filtrate, such as certain drugs
B) eliminating undesirable substances such as urea and uric acid that have been reabsorbed by passive processes
C) ridding the body of bicarbonate ions
D) ridding the body of excessive potassium ions





Answer: C

Select the correct statement about urinary system development.

02:20

Select the correct statement about urinary system development.





A) Kidneys develop from urogenital ridges.
B) The metanephric ducts will become the urethras.
C) The pronephros (first tubule system) develops during the tenth week of gestation.
D) The mesonephros will develop into the kidneys.



Answer: A

In the ascending limb of the nephron loop the ________.

02:19

In the ascending limb of the nephron loop the ________.



A) thin segment is freely permeable to water
B) thick segment is permeable to water
C) thin segment is not permeable to sodium and chloride
D) thick segment moves ions out into interstitial spaces for reabsorption




Answer: D

Excretion of dilute urine requires ________.

02:19

Excretion of dilute urine requires ________.




A) relative permeability of the distal tubule to water
B) impermeability of the collecting tubule to water
C) transport of sodium and chloride ions out of the descending nephron loop
D) the presence of ADH





Answer: B

If one says that the clearance value of glucose is zero, what does this mean?

02:19

If one says that the clearance value of glucose is zero, what does this mean?



A) The glucose molecule is too large to be filtered out of the blood.
B) Most of the glucose is filtered out of the blood and is not reabsorbed in the convoluted tubules.
C) Normally all the glucose is reabsorbed.
D) The clearance value of glucose is relatively high in a healthy adult.




Answer: C

If the Tm for a particular amino acid is 120 mg/100 ml and the concentration of that amino acid in the blood is 230 mg/100 ml, the amino acid will ________.

02:18

If the Tm for a particular amino acid is 120 mg/100 ml and the concentration of that amino acid in the blood is 230 mg/100 ml, the amino acid will ________.




A) be actively secreted into the filtrate
B) be completely reabsorbed by the tubule cells
C) appear in the urine
D) be completely reabsorbed by secondary active transport



Answer: C

Which of the following best describes kidney function in older adults (70 years or older)?

02:17

Which of the following best describes kidney function in older adults (70 years or older)?




A) Kidney function remains the same throughout life, regardless of age.
B) Only about 3% of older adults have any loss of kidney function.
C) Only obese and diabetic older adults have any kidney dysfunction.
D) Kidney function decreases due to kidney atrophy.



Answer: D

Which of the choices below is a function of the nephron loop?

02:16

Which of the choices below is a function of the nephron loop?



A) form a large volume of very concentrated urine or a small volume of very dilute urine
B) form a large volume of very dilute urine or a small volume of very concentrated urine
C) absorb electrolytes actively and water by osmosis in the same segments
D) absorb water and electrolytes into the tubular network




Answer: B

Which of the following is not true regarding tubular reabsorption?

02:16

Which of the following is not true regarding tubular reabsorption?



A) It occurs via transcellular or paracellular routes.
B) It is a reclamation process.
C) It involves hormonal signals in the collecting ducts.
D) It is a purely passive transport process.





Answer: D

What would happen if the capsular hydrostatic pressure were increased above normal?

02:15

What would happen if the capsular hydrostatic pressure were increased above normal?




A) Net filtration would increase above normal.
B) Net filtration would decrease.
C) Filtration would increase in proportion to the increase in capsular pressure.
D) Capsular osmotic pressure would compensate so that filtration would not change.



Answer: B

Select the correct statement about the nephrons.

02:15

Select the correct statement about the nephrons.




A) The parietal layer of the glomerular capsule is simple squamous epithelium.
B) The glomerulus is correctly described as the proximal end of the proximal convoluted tubule.
C) Podocytes are the branching epithelial cells that line the tubules of the nephron.
D) Filtration slits are the pores that give fenestrated capillaries their name.




Answer: A

The function of angiotensin II is to ________.

02:14

The function of angiotensin II is to ________.




A) constrict arterioles and increase blood pressure
B) decrease the production of aldosterone
C) decrease arterial blood pressure
D) decrease water absorption



Answer: A

Alcohol acts as a diuretic because it ________.

02:13

Alcohol acts as a diuretic because it ________.



A) is not reabsorbed by the tubule cells
B) increases the rate of glomerular filtration
C) increases secretion of ADH
D) inhibits the release of ADH






Answer: D

The macula densa cells respond to ________.

02:13

The macula densa cells respond to ________.



A) aldosterone
B) antidiuretic hormone
C) changes in pressure in the tubule
D) changes in solute content of the filtrate




Answer: D

Most electrolyte reabsorption by the renal tubules is ________.

02:12

Most electrolyte reabsorption by the renal tubules is ________.



A) not limited by a transport maximum
B) in the distal convoluted tubule
C) hormonally controlled in distal tubule segments
D) accomplished after the nephron loop is reached



Answer: C

Which of the following does not describe the juxtaglomerular complex?

02:10

Which of the following does not describe the juxtaglomerular complex?




A) It regulates the rate of filtrate formation.
B) It helps control systemic blood pressure.
C) Its granular cells produce rennin.
D) Its macula densa cells produce aldosterone.





Answer: D

The renal corpuscle is made up of ________.

02:10

The renal corpuscle is made up of ________.



A) Bowman's capsule and glomerulus
B) the descending nephron loop
C) the renal pyramid
D) the renal papilla




Answer: A

The fatty tissue surrounding the kidneys is important because it ________.

02:09

The fatty tissue surrounding the kidneys is important because it ________.




A) ensures adequate energy for the adrenal glands to operate efficiently
B) stabilizes the position of the kidneys by holding them in their normal position
C) is necessary as a barrier between the adrenal glands and kidneys
D) produces vitamin D and other chemicals needed by the kidney



Answer: B

Select the correct statement about the ureters.

02:09

Select the correct statement about the ureters.




A) Ureters contain sphincters at the entrance to the bladder to prevent the backflow of urine.
B) The epithelium is stratified squamous like the skin, which allows a great deal of stretch.
C) The ureters are capable of peristalsis like that of the gastrointestinal tract.
D) The ureter is innervated by parasympathetic nerve endings only.


Answer: C

The descending limb of the nephron loop ________.

02:08

The descending limb of the nephron loop ________.





A) is not permeable to water
B) is freely permeable to sodium and urea
C) pulls water by osmosis into the lumen of the tubule
D) contains fluid that becomes more concentrated as it moves down into the medulla





Answer: D

Which of the choices below is not a function of the urinary system?

02:07

Which of the choices below is not a function of the urinary system?




A) helps maintain homeostasis by controlling the composition, volume, and pressure of blood
B) regulates blood glucose levels and produces hormones
C) maintains blood osmolarity
D) eliminates solid, undigested wastes and excretes carbon dioxide, water, salts, and heat





Answer: D

The kidneys are stimulated to produce renin ________.

02:07

The kidneys are stimulated to produce renin ________.




A) when the peritubular capillaries are dilated
B) when the pH of the urine decreases
C) by a decrease in the blood pressure
D) when the specific gravity of urine rises above 1.10



Answer: C

Increased sympathetic stimulation of the heart

12:49

Increased sympathetic stimulation of the heart




a. increases the force of ventricular contraction.
b. opens a larger number of calcium slow channels.
c. increases the heart rate.
d. increases cardiac output.
e. all of these




Answer: E

If blood pH decreases and blood carbon dioxide increases,

12:49

If blood pH decreases and blood carbon dioxide increases,




a. heart rate increases.
b. stroke volume decreases.
c. increased parasympathetic stimulation of the heart occurs.
d. the change is detected by chemoreceptors in the pulmonary arteries.
e. all of these





Answer: A

Parasympathetic nerve fibers

12:49

Parasympathetic nerve fibers




a. are carried to the heart through the Accessory nerve (XI).
b. extend to terminal ganglia within the wall of the heart.
c. release the neurotransmitter norepinephrine.
d. if stimulated, result in an increased heart rate.
e. if stimulated, greatly increase stroke volume.




Answer: B

Preload

12:48

Preload



a. is the extent to which the ventricular walls are stretched.
b. if increased, causes a decrease in cardiac output.
c. is the pressure in the aorta which contracting ventricles must overcome.
d. is part of the extrinsic regulation of the heart.
e. all of these





Answer: A

Which of these conditions is most likely to cause bradycardia?

12:46

Which of these conditions is most likely to cause bradycardia?




a. ectopic action potentials in the atria
b. damage to the tricuspid valve
c. excessive sympathetic stimulation
d. excessive parasympathetic stimulation
e. too much coffee





Answer: D

During the QT interval of the EKG, the

12:46

During the QT interval of the EKG, the



a. atria contract and begin to relax.
b. atria relax.
c. ventricles contract and begin to relax.
d. ventricles relax.



Answer: C

In an EKG, the P wave represents

12:46

In an EKG, the P wave represents



a. depolarization of the atria.
b. repolarization of the atria.
c. depolarization of the ventricles.
d. repolarization of the ventricles.




Answer: A

Which of these conditions results in a prepotential in pacemaker cells?

12:46

Which of these conditions results in a prepotential in pacemaker cells?



a. Na+ ions move into the cell through specialized Na+ ion channels.
b. Membrane permeability to K+ ions increases.
c. Voltage-gated Ca2+ ion channels close.
d. all of these are correct




Answer: A

Early repolarization of cardiac muscle cells occurs when

12:45

Early repolarization of cardiac muscle cells occurs when



a. voltage-gated Ca2+ ion channels open.
b. voltage-gated K+ ion channels open.
c. voltage-gated Na+ ion channels close.
d. both b and c





Answer: D

Action potentials pass rapidly from one cardiac muscle cell to another because of

12:44

Action potentials pass rapidly from one cardiac muscle cell to another because of



a. intercalated disks and numerous gap junctions.
b. large nerves with branches going to each cardiac muscle cell.
c. the large voltage of cardiac action potentials.
d. the plateau phase of the action potential.
e. open Ca2+ channels.





Answer: A

Which of these statements concerning cardiac muscle is correct?

12:44

Which of these statements concerning cardiac muscle is correct?



a. Cardiac muscle has more sarcoplasmic reticulum than skeletal muscle.
b. Cardiac muscle has a prolonged period of slow repolarization called the plateau phase.
c. Cardiac muscle has a shorter refractory period than skeletal muscle.
d. Depolarization of cardiac muscle occurs when K+ and Na+ diffuse into the cell.
e. all of these are correct





Answer: B

If the SA node becomes damaged and nonfunctional, which of these is the most likely to occur?

12:44

If the SA node becomes damaged and nonfunctional, which of these is the most likely to occur?



a. The heart will stop.
b. The ventricles will contract, but the atria will stop.
c. Another part of the heart, possibly the AV node, will become the pacemaker.
d. The heart will beat faster.
e. The atria will keep contracting, but the ventricles will stop.





Answer: C

The skeleton of the heart

12:43

The skeleton of the heart



a. electrically insulates the atria from the ventricles.
b. is composed of bones and cartilage.
c. is the location of the pacemaker.
d. is composed of calcified cardiac muscle.




Answer: A

The epicardium

12:41

The epicardium




a. is also known as the parietal pericardium.
b. is a layer of cardiac muscle.
c. is the visceral pericardium.
d. lines the heart chambers.
e. is the pacemaker of the heart.



Answer: C

Which of these descriptions of the heart's location is correct?

12:41

Which of these descriptions of the heart's location is correct?



a. The heart lies obliquely in the mediastinum.
b. Its base is directed anteriorly and slightly superiorly.
c. Its apex is directed posteriorly and slightly inferiorly.
d. Two-thirds of the heart's mass lies to the right of the midline of the sternum.
e. all of these



Answer: A

The wall of the left ventricle is thicker than the right because

12:38

The wall of the left ventricle is thicker than the right because 




a. the left ventricle does more work than the right ventricle
b. the left ventricle pumps a greater volume of blood than the right ventricle
c. the left ventricle produces a higher pressure than the right
d. both A and B
e. both A and C





Answer: E

The first heart sound is heard when the

12:38

The first heart sound is heard when the 




a. AV valves open
b. AV valves close
c. semilunar valves close
d. atria contract
e. blood enters the aorta





Answer: B

The heart is innervated by ____ nerves.

12:37

The heart is innervated by ____ nerves.




a. parasympathetic
b. sympathetic
c. both parasympathetic and sympathetic
d. neither parasympathetic nor sympathetic
e. somatomotor




Answer: C

Blood is supplied by to the myocardium by

12:37

Blood is supplied by to the myocardium by



a. the coronary sinus
b. contact with blood in the pumping chambers
c. the coronary arteries
d. arteries that branch from the pulmonary arteries
e. both A and C






Answer: C

The hereditary inability of tissue cells to metabolize the amino acid phenylalanine, which can result in brain damage and retardation unless a special diet low in phenylalanine is followed, is called:

12:09

The hereditary inability of tissue cells to metabolize the amino acid phenylalanine, which can result in brain damage and retardation unless a special diet low in phenylalanine is followed, is called:




A) cystic fibrosis
B) cleft lip
C) cleft palate
D) phenylketonuria
E) tracheoesophageal fistula




Answer: D

Which one of the following is NOT true of cholesterol:

12:09

Which one of the following is NOT true of cholesterol:



A) it provides energy fuel for muscle contraction
B) it serves as the structural basis of steroid hormones
C) it serves as the structural basis of vitamin D
D) it is a major building block of plasma membranes
E) only about 15 percent comes from the diet




Answer: A

Nutrients detour through the liver via the:

12:09

Nutrients detour through the liver via the:



A) circle of Willis
B) hepatic portal circulation
C) Bowman's capsule
D) electron transport chain
E) glycogenesis





Answer: B

Which one of the following is NOT a main role of the liver:

12:09

Which one of the following is NOT a main role of the liver:




A) to detoxify drugs and alcohol
B) to degrade hormones
C) to make cholesterol
D) to process nutrients during digestion
E) to add ammonia to the blood




Answer: E

Which one of the following is NOT true of the sensors involved in digestive reflexes:

12:04

Which one of the following is NOT true of the sensors involved in digestive reflexes:



A) they activate or inhibit lacteal absorption
B) they respond to stretch of the organ by the volume of food within its lumen
C) they start reflexes that either activate or inhibit digestive glands
D) they respond to the relative pH content within that particular digestive organ
E) they respond to the presence of breakdown products of digestion





Answer: A

Digestion is primarily controlled by the:

12:04

Digestion is primarily controlled by the:




A) sympathetic division of the autonomic nervous system
B) medulla oblongata
C) somatic nervous system
D) enterogastric reflex
E) parasympathetic division of the autonomic nervous system





Answer: E

The primary function of the small intestine is:

11:39

The primary function of the small intestine is:



A) absorption of nutrients
B) absorption of water
C) waste secretion
D) vitamin conversion
E) mineral secretion





Answer: A

The small intestine extends from the:

11:39

The small intestine extends from the:



A) cardioesophageal sphincter to the pyloric sphincter
B) pyloric sphincter to the ileocecal valve
C) ileocecal valve to the appendix
D) appendix to the sigmoid colon
E) cardioesophageal sphincter to ileocecal valve




Answer: B

Protein digestion begins in the:

11:38

Protein digestion begins in the:



A) mouth
B) esophagus
C) stomach
D) small intestine
E) large intestine





Answer: C

Which one of the following represents the correct order through which food passes in the alimentary canal:

11:36

Which one of the following represents the correct order through which food passes in the alimentary canal:



A) mouth, pharynx, esophagus, stomach, large intestine, small intestine
B) mouth, esophagus, pharynx, stomach, small intestine, large intestine
C) pharynx, mouth, esophagus, stomach, large intestine, small intestine
D) mouth, pharynx, esophagus, stomach, small intestine, large intestine
E) mouth, pharynx, esophagus, small intestine, stomach, large intestine





Answer: D
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