Unit 8: Blood

Question 1

3 general functions of blood

Answer 1

Transport function: Transport dissolved/suspended materials like nutrients, wastes, gases, and hormones from one place in the body to another
Regulatory function: Regulate body temperature, blood pressure, and pH
Protective function: Contains white blood cells which are part of the immune system, prevents blood loss by clotting

Question 2

Two components of blood

Answer 2

Plasma: Liquid protein of the blood, made up of mostly water with proteins and dissolved/suspended materials
55% of the total volume of blood
Formed elements: Blood cells and cell fragments that make up the rest of the blood: Erythrocytes (red blood cells), Leukocytes (white blood cells), and Thrombocytes (platelets)
45% of the total volume of blood

Question 3

Plasma composition: Water (function and source)

Answer 3

Makes up 90% of the plasma
Function: maintenance of blood volume, transport of cells and dissolved/suspended materials
Source: Absorbed from the large intestine

Question 4

Plasma composition: Plasma (blood) proteins (function and source)

Answer 4

Makes up 7-8% of the plasma 
General function: Help maintain osmotic pressure in the blood
Specific functions:
1. Albumin: Transport bilirubin 
2. Fibrinogen: Blood clotting 
3. Globulins: Fight infection 
Source: Produced in the liver

Question 5

Plasma composition: Salts (function and source)

Answer 5

Function: Maintains blood osmotic pressure, helps in metabolism
Source: Absorbed from the intestine

Question 6

Plasma composition: Gases (function and source)

Answer 6

Oxygen and Carbon dioxide
Function: Oxygen is for cellular respiration, carbon dioxide is waste product of cellular respiration
Source: Lungs produces oxygen, Tissue cells give off CO2 as waste

Question 7

Plasma composition: Nutrients (function and source)

Answer 7

Amino acids, glucose, lipids
Function: Energy source for the repair and growth of the body
Source: Absorbed in the small intestine

Question 8

Plasma composition: Nitrogenous wastes (function and source)

Answer 8

Urea (major component of urine) and uric acid
Function: These wastes are the products of cellular metabolism in the liver, excreted by the kidneys
Source: Produced in the liver

Question 9

Plasma composition: Vitamins (function and source)

Answer 9

Function: Function as coenzymes or precursors to coenzymes, aiding metabolism
Source: Absorbed in the intestine

Question 10

Plasma composition: Hormones (function and source)

Answer 10

Function: Regulate growth, development and metabolism
Source: Endocrine glands

Question 11

How do blood proteins maintain blood volume?

Answer 11

Their size prevents them from readily passing through the tiny, capillary walls. This causes capillaries to always have a lower water concentration compared to tissue fluids, allowing water to diffuse into capillaries automatically.

Question 12

Red blood cells: Shape, Structure, Origin, Function

Answer 12

Shape: Small, no nucleus, biconcave disc shape
Structure: Contains many molecules of hemoglobin, a respiratory pigment that combines with oxygen. Hemoglobin is a four polypeptide molecule with each chain containing iron that gives blood its red color once oxygenated
Origin: Produced in the red bone marrow found in the skull, ribs, vertebrae, and long bones
Function: Allows the blood to remain in liquid form so the heart does not have to work as hard, carries oxygen to tissue cells and carry back carbon dioxide as waste

Question 13

Effect of altitude on red blood cells

Answer 13

There are fewer oxygen molecules per volume of air in high altitudes, meaning there is less oxygen being delivered than what the cells require. To compensate, erythropoietin, one of body’s hormone trigger an increase in the production of red blood cells to aid in oxygen delivery.

Question 14

White blood cells: Shape, origin, function

Answer 14

Shape: Larger than RBC, has a nucleus, spherical or ameboid in shape
Origin: Produced in red bone marrow
Function: Fight infection and develop immunity

Question 15

5 types of white blood cells

Answer 15

Neutrophils (40-70%): Most common, phagocytize pathogens
Eosinophils (1-4%): Phagocytize antigen-antibody complexes and allergens
Basophils (0-1%): Releases histamine, which promotes blood flow to injured tissues
Lymphocytes (20-45%): Responsible for specific immunity, produce antibodies
Monocytes (4-8%): Become macrophages that phagocytize pathogens and cellular debris

Question 16

Platelets: Shape, origin, function

Answer 16

Shape: Irregular shape with no nucleus
Origin: They are broken fragments of larger blood cells called megakaryocytes, in the red bone marrow.
Function: Clumps at a site of blood “leak” and forms a plug

Question 17

Sequence of blood clotting (6)

Answer 17

Requires the following: Prothrombin, Fibrinogen, and Platelets

1. Platelets clump at damaged blood vessel site and partially seal the leak
2. Clotting factors promote the release of prothrombin activator from blood vessel, damaged tissue cells release thromboplastin, which stimulates further production of prothrombin activator
3. Prothrombin activator converts prothrombin to thrombin (requires calcium ions Ca2+)
4. Thrombin converts fibrinogen into fibrin (requires Ca2+)
5. Fibrin wrap around the platelets plug, forming a temporary clot
6. As soon as vessel repair is initiated, enzyme called plasmin destroys the fibrin network and restores the fluid nature of plasma

Question 18

Vitamin K and blood clotting

Answer 18

Necessary for the production of prothrombin, which later activates to convert fibrinogen into fibrin.

Question 19

Exchange of materials in capillary beds (3 stages)

Answer 19

Two forces control the movement of fluids: osmotic pressure and blood pressure. Osmotic pressure tend to move water from tissue fluid to blood, and blood pressure tend to move water in the opposite direction.
At the arteriole end: Blood pressure is greater than osmotic pressure, water diffuses out of the capillaries into tissue fluid.
Midway: Blood and osmotic pressure is equal; no movement of water. Instead, amino acids/glucose/oxygen will diffuse out of capillaries and CO2/nitrogenous wastes will diffuse into the capillaries due to the concentration gradients.
At the venule end: Osmotic pressure is greater than blood pressure, water moves back into the capillaries. However, some of the tissue fluid is absorbed by the lymph capillaries to be returned to the cardiovascular system via the lymphatic system.

Question 20

What is an antigen

Answer 20

any substance that causes your immune system to produce antibodies against it. This means your immune system does not recognize the substance, and is trying to fight it off.

Question 21

Structure of antibody and how it interacts with antigens

Answer 21

Y-shaped molecule with two arms. Each arm has a heavy (long) polypeptide chain and a light (short) chain. Each chains have a variable and a constant region, where the variable regions make up the “tips” of the Y. The variable regions form anti-gen binding sites for a particular antigen. The antigen combines with the antibody at the binding site in a lock-key manner.
Now an antigen-antibody complex is formed, which marks the antigens for destruction.

Question 22

Blood types (antigen and antibody)

Answer 22

Each blood type corresponds to the attached antigen, and there are antibodies within the body for antigens that the individual does not have.
Type A: antigen A on RBC, anti-B in plasma
Type B: antigen B on RBC, anti-A in plasma
Type AB: antigen A and B on RBC, no antibody
Type O: no antigen on RBC, anti-A and anti-B in plasma

Question 23

Transfusion of blood according to blood types

Answer 23

Individual can receive blood from other with the same blood type or from type O as it has no surface antigens. (A-A,O; B-B,O; AB-A,B,AB,O; O-O)
If the wrongly-compatible blood is mixed, agglutination occurs. The antigen and antibody interact to from an antibody-antigen complex which can block blood flow, leading to organ damage/death.

Question 24

Rh system and pregnancy

Answer 24

Rh system is another way of blood typing, where RBC may or may not contain antigen D. This categorizes the blood from Rh+ (have antigen) and Rh-(no antigen).
During pregnancy, an Rh- mother may carry a baby that is Rh+. There is possibility of exposure of the baby’s Rh+ blood to the mother, in which the mother will react by producing Rh+ antibodies. The first baby will not be affected, but a second Rh+ baby may trigger the Rh+ antibody from the mother to start destroying the baby’s RBC. This is hemolytic disease.

Question 25

Hemolytic disease prevention

Answer 25

Mother can be injected with a globulin called RhoGAM during pregnancy or within 72 hours of birth. This globulin will destroy the baby’s RBC in the mother’s system so the mother will not produce any Rh+ antibody.