ANIMALS: STRUCTURE AND FUNCTION

Question 1

Pathway of blood flow throughout the body (i.e, trace the pathway of O2 as it moves from the lungs to the cells in the leg muscles)

Answer 1

The pathway of blood through the body is…
1. Body cells
2. Capillaries for gas exchange (O2 out, CO2 in)
3. Vena cava (main vein)
4. Right atrium
5. Right ventricles
6. Pulmonary Artery
7. Arteries
8. arterioles
9. Capillaries of the lungs for gas exchange (CO2 out, O2 in)
10. Venules
11. Veins
12. Pulmonary vein
13. Left atrium
14. Left ventricle
15. Aorta
16. Body Cells
17. Capillaries for gas exchange (O2 out, CO2 in)

Question 2

What important protein molecule binds oxygen in the lungs and carries it to the rest of the body?

Answer 2

• Hemoglobin: protein that binds oxygen in the lungs and carries oxygen to the rest of the body.
• 4 oxygen molecules can be carried by one molecule of hemoglobin.

Question 3

Label the P, QRS, and T waves on an electrocardiogram (ECG) diagram and briefly explain each.

ON EXAM

Answer 3

• First P wave – SA node fires, atria contract.
• QRS complex – AV node stimulates ventricles to contract.
• Final T wave – ventricles relax

Question 4

Bradycardia

Answer 4

a type of abnormal heart rhythm, or arrhythmia. It occurs when the heart beats very slowly — less than 60 beats per minute.

Question 5

Tachycardia

Answer 5

heart rate exceeds 100 beats per minute

Question 6

Normal Blood Pressure

Answer 6

about 120/80 mmHg.

Question 7

High Blood Pressure

Answer 7

140/90 mmHg or greater

Question 8

What causes high BP? - What is happening to the blood vessels? What can a person do to lower their high BP?

Answer 8

• High blood pressure can be caused by many factors: obesity, lack of exercise, stress, genetics, smoking, etc.
• When blood passes through the vessels it is called blood pressure. When the ventricles contract and force blood into the pulmonary arteries and the aorta, the pressure increases in these vessels.
• Factors that can lower a person’s blood pressure are an increase in exercise, healthy diet, reduce stress, etc.

Question 9

Sinoatrial (SA) node

ON EXAM

Answer 9

• Located in wall of right atrium
• stimulates muscle cell to contract and relax rhythmically
• Also called pacemaker because it sets the rate of contraction
• This nodal tissue has characteristics of both muscle & nerve.
• When it contracts, it generates electrical impulse.
• The SA node contracts, causing the 2 atria to contract.
• As atria contract signal reaches A 2nd node, the atrioventricular (AV) node
  *

Question 10

Atrioventricular (AV) node

ON EXAM

Answer 10

• is located at the base of the interatrial septum.
• Transmits electrical signal to bundle of His which are related to purkinje fibres and this initiates the contraction of both ventricles.

Question 11

The % composition of blood is:

Answer 11

• 55% plasma
• 1% white blood cells (leukocytes) & platelets
• 44% Red blood cells (erythrocytes)

Question 12

Lub and Dub sounds of heart

ON EXAM

Answer 12

The two heart sounds are caused by the closing of the heart valves.
* “Lub” sound - is caused by the AV valves (tricuspid and bicuspid/mitral) closing
* “Dub” sound - is caused by the closing of the semilunar valves