BLOOD COMPONENTS FUNCTION

Question 1

Blood Composition and Function

Answer 1

•Blood in vertebrates is a connective tissue
consisting of several kinds of cells suspended in a liquid matrix called plasma
•The cellular elements occupy about 45%of the volume of blood
•The plasmatic elements occupy about 55%of the volume of blood

Question 2

Plasma

Answer 2

•Plasma contains inorganic salts as dissolvedions, sometimes called electrolytes•Plasma proteins influence blood pH and help maintain osmotic balance •Particular plasma proteins function in lipid transport, immunity, and blood clotting

Question 3

Cellular Elements

Answer 3

• Suspended in blood plasma:
• Red blood cells (erythrocytes) transport O2
• Platelets-cells that are involved in clotting
• White blood cells (leukocytes) function in defense

Question 4

Erythrocytes mainly transport oxygen molecules

Answer 4

each molecule of hemoglobin binds up to four molecules of O2

Question 5

Leukocytes

Answer 5

1. Neutrophils
2. Eosinophils
3. Basophils
4. Lymphocytes
5. Monocytes

Question 6

Neutrophils

Answer 6

• ~50% of WBC’s, first to respond against bacterial / viral invasion
• Alert other cells in immune system to respond as well

Question 7

Eosinophils

Answer 7

• Responding to parasite (e.g. worms) infections
• Role in allergy symptoms (overreaction to mistaken invader e.g. pollen)
• ~1% in bloodstream, but highly concentrated in digestive tract

Question 8

Basophils

Answer 8

•~1% of WBC’s, mount non-specific immune response to pathogens

Question 9

Lymphocytes

Answer 9

• T-cells kills foreign invaders directly

* B-cells humoral immunity, produce antibodies that “remember” an infection

Question 10

Monocytes

Answer 10

•~5% of WBC’s, important for migrating into tissues and clean up dead cells

Question 11

Adaptive immune response

Answer 11

• Cell-mediated immune response

* Specialised T cells destroy infected host cells

Question 12

Humoral immune response

Answer 12

• Occurs in blood and lymph

* Antibodies help neutralise or eliminates toxins and pathogens

Question 13

Role of WBC’s in the interaction with the HIV

Answer 13

• Human immunodeficiency virus (HIV)
• Escapes and attacks the adaptive immune response
• Infects helper T cells by binding specifically to the CD4 accessory protein
• Altered proteins on the surface of some mutated viruses reduce interaction with antibodies and cytotoxic T cells.