Chapter 21 & 22: Blood and Heart

Question 1

Discuss the functions of blood. (3)

Answer 1

1. Transportation (O2, CO2, Nutrients, waste)
2. Regulation (Body temp, pH, fluid levels)
3. Protection (immune system response and production of antibodies)

Question 2

List the basic components of blood.

Answer 2

1. Formed Elements (RBC, WBC, platelets)

2. Plasma

Question 3

Describe the formed elements of blood (3) and their basic functions.

Answer 3

1. RBC
   - erthrocytes: transport respiratory gases in the blood
2. WBC
   - leukocytes: defend body against pathogens
3. Platelets
   - blood clotting

Question 4

List the steps of the RBC life cycle. (5)

Diagram Pg. 641

Answer 4

1. RBC form in red bone marrow.
2. RBC circulate in bloodstream for 120 days.
3. Aged RBC are phagocytized in liver and spleen.
4. Heme components of blood are recycled.
5. RBC membrane proteins and globin proteins broken down into mini acids and some are used to make new RBCs

Question 5

List the different blood types.

Answer 5

A (with A antigens, B antibodies)
B (with B antigens, A antibodies)
AB (with A and B antigens, no antibodies) - universal recipient
O (with neither antigen, A and B antibodies) - universal donor

Question 6

List and identify the major vessels and chambers of the heart.

Diagram Pg. 659 and 661

Answer 6

1. Superior and inferior vena cava
2. Right and left atrium
3. Right and left ventricle
4. Aorta/Aortic arch
5. Pulmonary trunk, arteries, veins
6. Papillary muscles
7. Cordae tendineae
8. Auricles
9. Coronary Sinus, artery
10. Right and left AV valves
11. Interventricular septum
12. SA node
13. AV node
14. Bundle of His
15. Purkinji fibers
16. Pulmonary and Aortic semilunar valves
17. Conus arteriosus

Question 7

Describe the pericardial sac and supportive connective tissue.

Answer 7

Fibrous sac held in place within the mediastinum by connective tissue that supports the great vessels’ external walls

• Restricts heart movement in the thoracic cavity and prevents it from over filling with blood
• Outer portion: tough, dense pericardium
• Inner portion: thin, serous pericardium with 2 layers
  
  • Visceral and parietal layer

Question 8

Describe flow of blood through the heart (cardiac cycle). (15)

Answer 8

Contraction of heart chamber: systole “Lub”
- forces blood out of the chamber
Relaxation of heart chamber: diastole “Dub”
- chamber is relaxed and fills with blood

Blood flow:

1. Superior and inferior vena cava with deoxygenated blood
2. Right atrium
3. Through R AV Valve (tricuspid)
4. Right ventricle
5. Through Pulmonary semilunar valve
6. Pulmonary trunk and arteries
7. To the lungs for gas exchange
8. Pulmonary veins with oxygenated blood
9. Left atrium
10. Through L AV valve (bicuspid)
11. Left ventricle
12. Through Aortic semilunar valve
13. Ascending aorta, aortic arch, descending aorta
14. To the rest of the body (systemic arteries) for gas exchange in the tissue
15. Systemic veins (now back up to #1)

Question 9

Describe the conduction system of the heart.

Answer 9

• Autoarythmicity
  1. SA node
  2. Atria contract
  3. AV node
  4. Bundle of His
  5. L and R bundles
  6. Purkinje fibers
  7. Ventricular contraction