Chp 22 23 gas exchange

Question 1

Why do our cells need O2?

Answer 1

to produce ATP

Question 2

Why do our cells produce CO2?

Answer 2

waste product of cellular respiration.

Question 3

what is the role of respiratory system?

Answer 3

designed for gas exchange between organism and enviornment

Question 4

what is the cardiovascular system role?

Answer 4

transport gases within blood

Question 5

what are three phases of gas exchange in humans?

Answer 5

• Breathing (ventilation)
• Transport (of oxygen and CO2)
• Exchange of gases within body cell

Question 6

What are the breathing control centers?

Answer 6

Pons and medula oblongata.

Question 7

What is the pulmonary circuit?

Answer 7

Carries blood from the heart to the lungs (for reoxygenation) and back to heart

Question 8

what is the systemic circuit?

Answer 8

carries blood from heat to body tissues

Question 9

what is diastole?

Answer 9

heart is relaxed, blood flows into all chambers, AV valves open

Question 10

What is Systole?

Answer 10

2 stages of contraction:

• Atria briefly contracts to fill the ventricles with blood
• Ventricles contract and pump blood out

Question 11

what is cardiac output?

Answer 11

Vol, of blood per minute pumped by the ventricles

Question 12

what is SA node?

Answer 12

Sinoatrial node is the pacemaker- generates electrical signals in atria

Question 13

what is the cardiac cycle controlled?

Answer 13

Signals from SA node spread through atria
Signals are delayed at AV node
Specialized muscle fibers pass signals to the heart apex
Signals spread throughout the ventricles

Question 14

Which artery is blocked during a heart attack?

Answer 14

coronary artery feeding the heart

Question 15

what are the 3 layers that make up Arteries and Veins?

Answer 15

• Endothelium
• Smooth Muscle
• Connective tissue

Question 16

how many capillaries are open at one time?

Answer 16

5-10%

Question 17

What is capillary blood flow controlled by?

Answer 17

• Contraction and relaxtion of smooth muscle in arterioles

- Open/close of precapillary sphincters

Question 18

what is another word for White blood cells?

Answer 18

Leukocytes

Question 19

What percentage of plasma is water?

Answer 19

90

Question 20

What substances are contained in plasma?

Answer 20

Water, ions, plasma proteins, substances tranported by blood

Question 21

What are 2 clotting factors?

Answer 21

Platelets (circulating cell fragments which form a plug)

fibrinogen (blood vessel injury leads to a chain of reactions)

Question 22

What is the process of blood clotting?

Answer 22

1 Platelets adhere

2. platelet plug forms
3. fibrin clot forms

Question 23

What is bloods pathway through the heart?

Answer 23

1. blood enters riht atrium from superior and inferior vena cavae, and the coronary sinus
2. From right atrium, it goes through the tricuspid valve to the right ventricle
3. from right ventricle, it goes through the pulmonary semilunar valves to pulmonary trunk
4. from trunk, it moves to right and left pulmonary arteries into the lungs
5. lungs -> oxygenated blood is returned to heart through pulmonary veins
6. pulmonary veins -> blood flows into left atrium
7. left atrium -> blood flows through bicuspid valve itnto L ventricle
8. L vent -> aortic semilunar valves nto ascending aortal.
9. blood is distributed to rest of body from aorta.