17. Blood - Theory

Question 1

3 transport functions of blood

Answer 1

1. Delivering oxygen from the lungs and nutrients from the digestive tract to body cells
2. Transporting metabolic waste to elimination sites (lungs for CO2, kidneys for nitrogenous waste)
3. Transporting hormones from endocrine organs to their target organs

Question 2

3 regulatory functions of blood

Answer 2

1. Regulation of body temperature. Absorption and distribution of heat throughout the body and to the skin surface to encourage heat loss.
2. Maintaining normal pH in tissues. Many blood-borne proteins act as buffers, blood also acts as an alkaline reserve of bicarbonate ions.
3. Maintaining adequate fluid volume. Blood proteins prevent excessive fluid loss and ample fluid volume supports efficient circulation to all parts of the body.

Question 3

2 protective functions of blood

Answer 3

1. Prevention of blood loss (hemostasis). If a blood vessel is damaged, platelets and plasma will initiate clot formation.
2. Prevention of infection. Antibodies, complement protein and leukocytes (white blood cells) help defend the body against pathogens.

Question 4

Components and % of centrifuged blood (bottom to top)

Answer 4

Erythrocytes (45%)
Buffy coat (<1%)
Plasma (55%)

Question 5

What is normal blood viscosity and volume in males and females?

Answer 5

Males: 5-6 L of 4.7-6.1 red blood cells/µL of blood
Females: 4-5 L of 4.2-5.4 red blood cells/µL of blood

Question 6

What are the components of plasma

Answer 6

Water (90%)
Inorganic ions
Nutrients
Products from cell activity
Hormones
Gases
Proteins (8% by weight)

Question 7

What is the most abundant plasma protein and what are its 2 functions?

Answer 7

Albumin

1. Shuttles certain molecules
2. Contributes to plasma osmotic pressure

Question 8

How long do erythrocytes live?

Answer 8

120 days

Question 9

What are the 2 important proteins found in erythrocytes and what are their functions?

Answer 9

Hemoglobin: carries oxygen
Spectrin: maintains the cell’s shape

Question 10

Name 3 structural characteristics of red blood cells which contribute to the gas transport function.

Answer 10

1. High SA/V ratio
2. 97% of RBC is erythrocytes
3. No mitochondria: do not consume the oxygen they transport

Question 11

What are the 2 components of hemoglobin?

Answer 11

Heme pigment

Globin (2 α chains and 2 β chains)

Question 12

What atom is carried in the ringlike group of hemoglobin? How many Oxygen atoms can it carry?

Answer 12

Fe2+

4 atoms of oxygen

Question 13

What are the three states of hemoglobin?

Answer 13

Oxyhemoglobin
Deoxyhemoglobin
Carbaminohemoglobin

Question 14

Where is red bone marrow found?

Answer 14

Long bones (femur, humerus)
Iliac crest