Cardiovascular System

Pacemaker cardiac cells are self-rhythmic. They will contract in the absence of stimulation from the nervous system. External stimulation will make them contract at a faster (or slower) rate.

Viscosity will increase as the number of RBC increases. This will also increase the resistance to flow so BP in the aorta will increase a bit.

The capillaries of the BBB are least permeable (they form a “barrier”), while sinusoids are the most permeable.

The LV produces a higher pressure than the right in order to overcome the greater resistance to flow that exists in the systemic circuit.

The pascal (after Blaise Pascal) is the SI unit. It is a small unit so often the multiple kPa is used.

BP oscillates between maximum systolic pressure when the myocardium contracts and minimum diastolic pressure as the myocardium relaxes. These two values measured while at rest provide information about the health of the arterial tree which is why BP is measured. BP pressure rises above the resting systolic value during exercise as it should. The other choices are wrong as they contain a nonsense statement.

Squashing the brachial artery will cause blood flow to be turbulent as it passes through the constriction. This turbulence creates sound that can be detected with a stethoscope.

The larger value (120) is the systolic pressure (i.e. at the end of ventricular contraction) and states by how much the blood pressure is above atmospheric pressure.

Plasma proteins (also called “colloids”) produce colloid osmotic pressure. There should be no proteins in the interstitial fluid.

Vitamin K is needed for the liver to produce prothrombin (inactive thrombin). Plasmin destroys fibrin.