Lecture 5
100: Exchange of gases, nutrients, and waste products occurs primarily in the _____ by the process of _______.
A. Capillaries…filtration and absorption
B. Capillaries…diffusion
C. Arterioles…diffusion
D. Venules…diffusion
E. Venules…filtration and reabsorption
B. Capillaries ... Diffusion
Cardiac output can be increased by all of the following EXCEPT…
A. Decreased parasympathetic activity to the ventricular muscle cells causing decrease Ca2+ release from the SR.
B. Increased cytosolic Ca2+ in ventricular muscle cells due to increased sympathetic activity.
C. Decreased parasympathetic activity to the SA node causing increased rate of depolarization to threshold.
D. Increased opening of SA node cell F-type and T-type channels due to increased sympathetic activity.
A. Decreased parasympathetic activity to the ventricular muscle cells causing decrease Ca2+ release from the SR.
Diastole…
A. Begins as cytosolic Ca2+ decreases in ventricular muscle cells
B. Ends when the P wave occurs
C. Is a phase during which the AV valves are open throughout the entire time
D. A and C
E. A, B, and C
A. Begins as cytosolic Ca2+ decreases in ventricular muscle cells
200: Only the right bicep muscle is contracting with high intensity for 1 minute, but the rest of the muscles are in resting conditions during that 1 minute. During the 1 minute of right bicep activity, blood flow to…
A. all muscles will increase equally due to increased sympathetic activity and circulating epinephrine causing global vasodilation
B. the right bicep will increase due to epinephrine binding to only b receptors on the arteriolar smooth muscle
C. all muscles other than the right bicep will significantly decrease due to circulating epinephrine binding to preferentially to a receptors on their arteriolar smooth muscle, thereby causing an increase in TPR
D. the right bicep will be increased due to a significant increase in MAP to overcome the increased R in the right bicep’s arterioles
E. the right bicep will increase primarily due to accumulation of metabolites within the muscle causing local vasodilation
E. the right bicep will increase primarily due to accumulation of metabolites within the muscle causing local vasodilation
An increase in EDV causes an increase in the force of ventricular contraction by increasing…
A. Sympathetic activity to the ventricle
B. The number of cycling cross bridges without an increase in cytosolic Ca2+
C. The rate of SERCA activity
D. The myosin ATPase rate
E. A, C and D
B. The number of cycling cross bridges without an increase in cytosolic Ca2+
During the cardiac cycle, the pressure in the aorta drops to its lowest value of 80 mmHg during which phase?
A. Isovolumetric contraction
B. Ventricular ejection
C. Isovolumetric relaxation
D. Passive filling
E. Atrial contraction
A. Isovolumetric contraction
300: Normally, reabsorption occurs at the venous end of a capillary bed because…
A. Capillary oncotic (osmotic) pressure (pcap) increases significantly across the capillary bed whereas capillary hydrostatic pressure (Pcap) remains constant across the capillary bed.
B. Pcap and pcap both remain constant across the capillary bed
C. Pcap decreases significantly across the capillary bed whereas pcap remains relatively constant.
D. Hydrostatic pressure of the interstitial fluid (Pisf) is significantly increased at the venous end of the capillary bed.
C. Pcap decreases significantly across the capillary bed whereas pcap remains relatively constant.
Contractions of skeletal muscle are important for…
A. Compressing peripheral veins and driving blood flow to the right atrium.
B. Generating inspiration, which causes an increased pressure difference between the abdominal and thoracic cavity veins, driving blood flow to the right atrium.
C. Causing increased TPR
D. A and B
E. A, B and C
D. A and B
A patient has a murmur that is heard during systole. Further analysis indicates the following:
*Right ventricular (RV) EDV is normal
*RV ejection fraction is decreased
*Right atrial (RA) pressure is increased during systole
This patient’s valve problem is…
A. Aortic insufficiency
B. Left AV (mitral) insufficiency
C. Right AV (tricuspid) insufficiency
D. Pulmonary stenosis
E. Right AV (tricuspid) stenosis
C. Right AV (tricuspid) insufficiency