Please help me with biology?

Blood is prevented from "pooling" in the legs due to

a) the contraction of the heart and function of the AV-valves.
b) a system of valves in arteries and the contraction of smooth muscles.
c) the contraction of arterial wall elastic tissue and a system of valves.
d) a system of valves in veins and the contraction of skeletal muscles.

All of the following are true regarding the nervous control of the heart beat except the
a) SA node, also called the pacemaker sets the basic rhythmical beat of the heart.
b) AV node in the right atrium will stimulate both ventricles to contract.
c) SA node initiates the contraction of both atria.
d) AV node located in the right atrium is the origin of the initial heart impulse.

The maximum blood pressure is during

a) left atrium contraction, the lub sound occurs.
b) right ventricular contraction, the dub sound occurs.
c)left ventricular contraction, the lub sound occurs.
d) right atrium contraction, the dub sound occurs.

The maximum blood pressure is
a) diastolic blood pressure when atria relax and ventricles contract.
b) systolic blood pressure when atria relax and ventricles contract.
c)diastolic blood pressure when atria contract and ventricles relax.
d)systolic blood pressure when atria contract and ventricles relax.

A blood pressure reading of 140/90 would indicate that an individual is
a)eating a big meal loaded with protein.
b) engaging in vigorous exercise.
c)sitting on a park bench watching the ducks swim.
d)having an afternoon nap.

All of the following are true statements about regular cardiovascular exercise except
a) Increases the resting stroke and promotes a quicker return to the resting heart rate after exercise.
b) Improves the efficiency of the impulses from the SA node, the pacemaker.
c) Enlarges the ventricular chambers promoting a larger stroke volume.
d) Strengthens the ventricular muscle promoting a stronger stoke volume.

The time lapse between activation of the sinoatrial (SA) node and the activation of the atrioventricular (AV) node is necessary to allow the

a) atria to contract before the ventricles.
b) atria and ventricles to relax simultaneously.
c) atria and ventricles to contract simultaneously.
d) left and right ventricles to contract simultaneously.

Both the lymphatic and venous transport systems

a)produce blood platelets.
b) carry red blood cells to the heart..
c) aid in the blood clotting process.
d) utilize skeletal muscle contractions to move their fluids

Blood vessels that contain valves and rely on skeletal muscles to move blood are called
a)arterioles.
b) arteries.
c) capillaries.
d) veins.

A blood pressure reading of 80/50 mm of mercury would be a

a)symptom of anger.
b) hemorrhage.
c) extremely strenuous exercise.
d) narrowing of the arteries.

The receptors that respond to changes in blood pressure are located in the
a)deep veins.
b) aorta and carotid arteries.
c) capillaries and lymph system.
d) arterioles.

A blood vessel is BEST described as an artery if it carries

a)deoxygenated blood.
b) oxygenated blood.
c) blood away from the heart.
d) blood to the heart.

If impulse conduction within the heart is rapid and irregular, the result may be high-frequency unco-ordinated muscle contractions (fibrillation). The most probable effect of fibrillation is that the

a) blood leaving the heart will be under higher than normal pressure.
b) blood will clot more readily, thereby causing strokes.
c) atria or ventricles will fail to pump sufficient amounts of blood.
d) atria or ventricles will pump sufficient amounts of blood to the body but not to the heart muscle.

please help me

1) D
2) O
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9) N
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do your own homework XD