Week 9- Blood

Question 1

Functions of blood

Answer 1

1. Transports nutrients, gases, hormones and waste.
2. Maintains pH of body.
3. Regulates body temperature.
4. Regulation of fluid and ions.
5. Protection though immunity and blood clotting.

Question 2

Blood plasma

Answer 2

Liquid portion of blood cells.

Is 90% water, 2% other substance and 7% plasma proteins.

Question 3

Cellular components

Answer 3

Is formed in red marrow of spongy bone.

Contains erythrocytes and leukocytes.

Question 4

Blood platelets

Answer 4

Are also called thrombocytes. Fragments in bone marrow are called megakaryocytes.
They have no nuclei or hemoglobin.
Are involved in blood clotting and wound healing.

Question 5

Factors contributing to viscosity.

Answer 5

Both blood cells and proteins contribute.

Viscosity is affected by the amount of blood cells and proteins called albumins.

Question 6

Functions of the lymphatic system

Answer 6

1. Transport fats and proteins to circulatory system.
2. Production of active immune cells.
3. Return fluids back to circulatory system.

Question 7

Lymph

Answer 7

Like blood but with no red blood cells.

Functions - returns fluid to cardiovascular system, maturation of lymphocytes and transport of dietary substances.

Question 8

Lymphatic vessels

Answer 8

Network of capillaries in tissue that start at dead ends, pick up tissue fluid and drains it into cardiovascular system

Question 9

Drainage of lymph

Answer 9

Right lymphatic duct drains into right subclavian vein while left subclavian duct drains into left subclavian vein.

Question 10

Pericardium

Answer 10

Outermost layer that protects the heart. It has two layers.

1. Fibrous pericardium consisting of dense irregular connective tissue
2. Serous pericardium consisting of parietal pericardium, pericardial cavity and visceral pericardium.

Question 11

Events of conduction system

Answer 11

Step 1: SA bode generates impulse
Step 2: impulse pauses at AV node.
Step 3: AV bundle connects atria to ventricle.
Step 4: bundle branches conduct impulses through intraventricular septum.
Step 5: Purkinjie fibers in charge of subendocardial conducting polarizes contractile cells of ventricle.

Question 12

The cardiac cycle

Answer 12

Step 1: Pacemaker generates wave of signals to contact.
Step 2: Atria contracts, signals are delayed for 0.1 seconds at AV node.
Step 3: Signals pass through septum to heart apex.
Step 4: Signals spread throughout ventricles and ventricles contract.

Question 13

Mechanisms that control heart rate

Answer 13

1. Autonomic nervous system
2. Hormones
3. Ions in blood stream
4. Body temperature

Question 14

Homeostasis if blood press’s is too high.

Answer 14

1. Stimulus- increase blood pressure.
2. Baroreceptors in carotid sinuses and aortic arch are stimulated.
3. Impulses from baroreceptors are received by cardiovascular system in the brain.
4. Decreased sympathetic impulses to heart create decreased heart rate and decreased contractility. Decreased sympathetic impulse to blood vessels cause vasodilation and decreased peripheral resistance.

Question 15

Homeostasis if blood pressure is too low

Answer 15

1. Stimulus- decrease in blood pressure
2. Baroreceptors are inhibited.
3. Decreased impulses from bar receptors are inhibited.
4. Increased sympathetic impulses to heart cause increased heart rate, increased contractility and increased cardiac output. Increased sympathetic impulses to blood vessels cause vasoconstriction and increased peripheral resistance.