Respiratory System Book Notes

What is essential for all life in terms of energy and matter?

Every organism must exchange materials and energy with its environment through diffusion.

What are the three main components of a circulatory system?

A central pump, a vascular system, and a circulating fluid.

What type of circulatory system do many invertebrates have?

An open circulatory system.

What is the closed circulatory system in humans called?

The cardiovascular system.

What are the three types of blood vessels in the cardiovascular system?

Arteries, capillaries, and veins.

What is the primary function of capillaries?

To allow exchange between the blood and interstitial fluid.

What are the two types of cardiovascular systems in vertebrates based on the number of circuits?

Single circulation system and double circulation system.

What is the pulmonary circuit responsible for?

Carrying blood between the heart and lungs.

What is the systemic circuit responsible for?

Carrying blood between the heart and the rest of the body.

What happens to CO2 and O2 in the lungs during the pulmonary circuit?

CO2 diffuses from the blood into the lungs, while O2 diffuses from the lungs into the blood.

What is the path of blood starting from the right atrium?

Right atrium → right ventricle → lungs via pulmonary arteries → left atrium → left ventricle → aorta.

What role do valves play in the heart?

They prevent backflow and keep blood moving in the right direction.

What is the cardiac cycle?

One heartbeat that includes diastole and systole phases.

What is the average resting heart rate for a healthy adult?

Between 60 and 100 beats per minute.

What is the function of the pacemaker in the heart?

It generates electrical impulses that coordinate heartbeats.

How does epinephrine affect heart rate?

It increases heart rate.

What is the function of arteries?

To carry blood away from the heart.

What is the function of veins?

To carry blood toward the heart.

What is the primary function of capillaries in the circulatory system?

To allow for chemical exchange between the bloodstream and tissue cells.

What maintains blood pressure during diastole?

The elastic walls of the arteries snap back, maintaining pressure.

How does blood return to the heart from the capillaries?

Blood flows from capillaries into small venules, then into larger veins.

What aids blood movement through veins against gravity?

Skeletal muscles contracting and squeezing the blood along.

What is the significance of the four-chambered heart in humans?

It supports double circulation and prevents mixing of oxygenated and deoxygenated blood.

What happens during diastole in the cardiac cycle?

Blood returning to the heart flows into all four chambers.

What occurs during systole in the cardiac cycle?

The atria contract, forcing blood into the ventricles, followed by ventricular contraction to pump blood out.

What is the role of smooth muscle in blood vessels?

It regulates blood flow by constricting or relaxing blood vessels.

What is the difference between the arterial end and venous end of capillaries?

At the arterial end, O2 and nutrients exit into interstitial fluid; at the venous end, CO2 and wastes enter the blood.

What is the function of the coronary arteries?

To supply blood to the heart itself.

What happens to blood pressure during systole?

Blood is forced into the arteries faster than it can flow into arterioles, stretching the arterial walls.