Lecture Exam 3 - Explanation of the Cardiac Cycle

Question 1

• What are the four main phases of the Cardiac Cycle?

Answer 1

filling, relaxation contraction, and ejection

Question 2

What happens during the Ventricular Diastole phase? It is the filling Phase:

Answer 2

• Ventricles fill with blood and are in diastole
• Atrioventricular (tricuspid and mitral) valves open.
• Atrial Systole occurs.
• Semilunar valves are closed.

Question 3

What happens during the Ventricular Systole Contraction Phase?

Answer 3

• Ventricular systole begins.
• AV and semilunar (aortic and pulmonary) valves close when enough pressure builds in the ventricles.
• Atrial diastole begins.

Question 4

• What do the trachea branch off into?

Answer 4

Bronchi

Question 5

• What does the Bronchi branch off into?

Answer 5

Bronchioles

Question 6

• What does the bronchioles branch off into?

Answer 6

Alveoli

Question 7

• Each alveoli is surrounded by what?

Answer 7

Capillaries

Question 8

• What is the Diaphragm? (It separates the thorax from the abdomen)

Answer 8

It separates the thorax from the abdomen - also as you breath in, the diaphragm pushes up the ribs/lungs within the thorax, when you exhale, the diaphragm comes down. (Imagine holding a pipe pushing it up/pulling it down)

Question 9

• How does the concept of partial pressure explain the diffusion of oxygen into our blood stream? Why does this become more difficult at high altitudes?

Answer 9

since dissolved gases always diffuse down their concentration gradient, when the partial pressure starts to decrease at high altitudes, you start to take in more deoxygenated blood that enters in your lungs, where eventually there is no partial pressure gradient

Question 10

• So where gas exchange occurs, such as the alveoli, this is also called what system?

Answer 10

the Respiratory system