Respiratory/Circulatory/Urinary Systems

If you hold your breath for a long time, body CO2 levels

are likely to ____, and the pH of body fluids is likely to ____.

• increase; increase

• decrease; increase

• increase; decrease

• decrease; decrease

Which of the following is the primary method by which carbon

dioxide is transported to the lungs?

• Dissolved in plasma

• Bound to hemoglobin

• As carbon monoxide

• As bicarbonate

Respiratory organs of invertebrates and vertebrates are similar

in that

• they use negative pressure breathing.

• they take advantage of countercurrent flow systems.

• they increase the surface area available for diffusion.

• the air flows through the organ in one direction.

During exercise more oxygen is delivered to the muscles because

• active muscles produce more CO2, lowering the pH of the blood.

• active muscles produce heat.

• Both a and b are correct.

• Neither a nor b is correct.

When you take a deep breath, your stomach moves out because

• swallowing air increases the volume of the thoracic cavity.

• your stomach shouldn’t move out when you take a deep breath

  because you want the volume of your chest cavity to increase,

  not your abdominal cavity.

• contracting your abdominal muscles pushes your stomach out,

  generating negative pressure in your lungs.

• when your diaphragm contracts, it moves down, pressing your

  abdominal cavity out.

Systole is vitally important to heart function and begins in the heart

with the

• activation of the AV node.

• activation of the SA node.

• opening of the voltage-gated potassium gates.

• opening of the semilunar valves.

Which of the following is the correct sequence of events in the

circulation of blood?

• Heart - arteries - arterioles - capillaries - venules - lymph - heart

• Heart - arteries - arterioles - capillaries - veins - venules - heart

• Heart - arteries - arterioles - capillaries - venules -

  veins - heart

• Heart - arterioles - arteries - capillaries - venules - veins - heart

Blood clots are made of

• fibrin.

• fibrinogen.

• prothrombin.

• All of the choices are correct.

The difference between the amphibian and mammal hearts is that

• in the amphibian heart, oxygenated and deoxygenated blood

  mix completely in the single ventricle.

• in the amphibian heart, there are two SA nodes so that

  contractions occur simultaneously throughout the heart.

• in the ventricle in the amphibian heart, internal channels

  reduce mixing of blood.

• in the amphibian heart, only the left aorta pumps oxygen

  obtained by diffusion through the skin.

A molecule of CO2 that is generated in the cardiac muscle

of the left ventricle would not pass through which of the following

structures before leaving the body?

• Right atrium

• Left atrium

• Right ventricle

• Left ventricle