BRS Book Exam 2

When a person moves from a supine position to a standing position, which of the following compensatory changes occur?

Increased Contractility

At which site is systolic blood pressure the highest?

Renal artery

A persons electrocardiogram (ECG) has no P wave, but has a normal QRS complex and a normal T wave. Therefore his pacemaker is located in

Atrioventricular (AV) node

If the ejection fraction increases, there will be a decrease in

End-systolic volume

An increase in contractility is demonstrated on a Frank-Starling diagram by

Increased cardiac output for a given end-diastolic volume

The tendency for blood flow to be turbulent is increased by

Partial occlusion of a blood vessel

A patient experiences orthostatic hypotension after a sympathectomy. The explanation for this occurrence is

A suppressed response of the baroreceptor mechanism

The ventricles are completely depolarized during which isoelectric portion of the electro-cardiogram (ECG)

ST segment

In which of the following situations is pulmonary blood flow greater than aortic blood flow?

Left to right ventricular shunt

A person’s electrocardiogram (ECG) shows two P waves preceding each QRS complex. The interpretation of this pattern is

Decreased conduction through the AV node

An acute decrease in arterial blood pressure elicits which of the following compensatory changes

Decreased firing rate of the carotid sinus nerve

The tendency for edema to occur will be increased by

Increased venous pressure

Inspiration “splits” the second heart sound because

The aortic valve closes before the pulmonic valve

During exercise, total peripheral resistance (TPR) decreases because of the effect of

Local metabolites on skeletal muscle Arterioles

An increase in arteriolar resistance, with-out a change in any other component of the cardiovascular system, will produce

An increase in arterial pressure

Which of the following is the result of an inward NA+ current ?

Upstroke of the action potential in Purkinje fibers

The greatest pressure decrease in the circulation occurs across the Arterioles because

They have the greatest resistance

Pulse pressure is

Determined by stroke volume

In the sinoatrial (SA) node, phase 4 depolarization is attributed to

An increase in Na+ conductance

Which receptor mediates constriction of arteriolar smooth muscle

A1 receptors

During which phase of the cardiac cycle is aortic pressure highest ?

Reduced ventricular ejection

Myocardial contractility is best correlated with the intercellular concentration of

Ca2+

Which of the following is an effect of histamine?

Vasodilation of the Arterioles

Carbon dioxide (CO2) regulates blood flow to which one of the following organs

Brain

The physiologic function of the relatively slow conduction through the atrioventricular (AV) node is to allow time for

Filling of the ventricles

Blood flow to which organ is controlled primarily by the sympathetic nervous system rather than by local metabolites

Skin

Which of the following parameters is decreased during moderate exercise

Total peripheral resistance (TPR)

Which receptor is blocked when propranolol is administered to reduce cardiac output?

B1 receptors

During which phase of the cardiac cycle is ventricular volume lowest?

Isovolumetric ventricular relaxation

Which of the following changes will cause an increase in myocardial O2 consumption?

Increased size of the heart

Which of the following substances crosses capillary walls primarily through water filled clefts between the endothelial cells?

Glucose

A 24 year old woman presents to the emergency department with severe diarrhea. When she is supine (lying down) her blood pressure decreased and heart rate increased. When she is moved to a standing position her heart rate increased. Which of the following accounts for the further increase in heart rate standing ?

Decreased venous return

A 60 year old business man blood pressure is significantly elevated. Lab tests reveal an increase in plasma renin activity, plasma aldosterone level, and left renal vein level. His right renal vein renin level is decreased. What is the most likely cause of the patients hypertension?

Left renal artery stenosis

Propranolol has which of the following effects ?

Decreases heart rate

Which receptor mediates slowing of the heart ?

Muscarinic receptors

Which of the following agents or changes has a negative inotropic effect on the heart ?

Acetylcholine (ACH)

The low resistance pathways between myocardial cells that allow for the spread of action potentials are ?

Gap junctions

Which agent is released or secreted after a hemorrhage and causes an increase in renal Na+ reabsorption

Aldosterone

During which phase of the cardiac cycle does the mitral valve open ?

Isovolumetric ventricular relaxation

Which of the following lung volumes or capacities can be measured by spirometry?

Vital capacity (VC)

An infant bron prematurely in gestational week 25 has neonatal respiratory distress syndrome. Which of the following would be expected in this infant ?

Collapse of the small alveoli

in which vascular bed does hypoxia cause vasoconstriction ?

Pulmonary

A 12 year old boy has a severe asthmatic attack with wheezing. He experiences rapid breathing and becomes cyanotic. Which of the following statements about this patient is most likely to be true?

His arterial PCO2 is lower than normal because hypoxemia is causing him to hyperventilate

Which of the following is true during inspiration?

Intrapleural pressure is more negative than it is during expiration

Which of the following remains in the lungs after a tidal volume (TV) is expired?

Functional residual capacity (FRC)

When a person is standing, blood flow in the lungs is

Highest at the base because that is where the difference between arterial and venous pressure is greatest

Which of the following is the site of highest airway resistance?

Medium sized bronchi

If blood flow to the left lung is completely blocked by an embolism in the pulmonary artery, which of the following will occur ?

Alveolar PO2 in the left lung will be approximately equal to the PO2 in inspired air

Which volume remains in the lungs after a maximal expiration ?

Residual volume (RV)

Compared with the systemic circulation, the pulmonary circulation has a

Lower resistance

Compared with the apex of the lung, the base of the lung has

A higher pulmonary capillary PCO2

Hypoxemia produces hyperventilation by a direct effect on the

Carotid and aortic body chemoreceptors

Which of the following changes occurs during strenuous exercise?

Ventilation rate and O2 consumption increase to the same extent

If an area of the lung is not ventilated because of bronchial obstruction, the pulmonary capillary blood serving area will have a PO2 that is

Equal to mixed venous PO2

in the treatment of CO2 from the tissues to the lungs, which of the following occurs in venous blood?

Conversion of CO2 and H2O to H+ and HCO3- in the red blood cells (RBCs)

Which of the following causes of hypoxia is characterized by a decreased arterial PO2 and an increased A-a gradient?

Right to left cardiac shunt

Which of the following will occur as a result of residing at high altitude

Shift to the right of hemoglobin O2 dissociation curve

The pH of venous blood is only slightly more acid than the pH of arterial blood because

The H+ generated from CO2 and H2O is buffered by deoxyhemoglobin in venous blood

Which volume is expired in a maximal expiration?

Vital capacity (VC)

Secretion of K+ by the distal tubule will be decreased by

spironolactone administration

The reabsorption of filtered HCO3-

Is inhibited by decrease in arterial PCO2

To maintain normal H+ balance, total daily excretion of H+ should equal the daily

Fixed acid production plus fixed acid ingestion

At plasma concentrations of glucose higher than occur at transport maximum the

Excretion rate of glucose increases with increasing plasma glucose concentrations

Which of the following would produce an increase in the reabsorption of isosmotic fluid in the proximal tubule ?

Increased filtration fraction

Which of the following substances or combinations of substances could be used to measure interstitial fluid volume ?

Inulin and radioactive albumin

Compared with a person who ingests 2 L of distilled water, a person with water deprivation will have a

Higher rate of H2O reabsorption in the collecting ducts

Which of the following would cause an increase in both glomerular filtration rate (GFR) and renal plasma flow (RPF)

Dilation of the afferent Arteriole

Which of the following would best distinguish an otherwise healthy person with severe water deprivation from a person with the syndrome of inappropriate antidiuretic hormone ?

Plasma osmolarity

Which of the following causes a decrease in renal Ca2+ clearance

Treatment with chlorothiazide

Which of the following ions has a higher concentration in intercellular fluid (ICF) than in extracellular fluid (ECF)

K+

A woman has a plasma osmolarity of 300m and a urine osmolarity of 1200m the correct diagnosis is

Water deprivation

Which of the following substances has the highest renal clearance?

Para- aminohippuric acid

A woman runs a marathon in 90 F weather and replaces all volume lost in sweat by drinking distilled water. After the marathon she will have

Decreased plasma osmolarity

Which of the following causes hyperkalemia ?

Exercise

Which of the following is a cause of metabolic alkalosis?

Hyperaldosteronism

Which of the following is an action of parathyroid hormone (PTH) on the renal tubule ?

Stimulation of adenylate cyclase