Learning Objective 4

Question 1

Function of blood

Answer 1

Transport: 
-carries nutrients
-carries carbon dioxide and oxygen
-transports nutrients and waste
-transports hormones
Protection:
-white blood cells (protects against infection)
-platelets
-immune system
-preventing blood loss
Regulation:
-ph
-water (fluid body)
-tempurature

Question 2

Composition of blood

Answer 2

• Plasma

- overall cells (RBC, WBC, platelets)

Question 3

Components in Plasma and their function

Answer 3

Water- solutes dissolved in this, absorbs heat
Electrolytes
Proteins eg. globulins such as antibodies
Fibrinogen- produced by the liver, important in blood clots
Nonprotein nitrogenous substances eg. Urea (waste production when you break down proteins)
-Nutrients eg. amino acids and glucose (to make ATP)
-Respiratory gases - oxygen in cells to make ATP=waste gas carbon dioxide
Hormones-produced when you need them

Question 4

What are the formed elements

Answer 4

Erythrocytes, Leukocytes and platelets

Question 5

What is the main function of red blood cells

Answer 5

transports oxygen (gases)
-carries oxygen around the body and then gets rid of the carbon dioxide in the body

Question 6

Structure of red blood cells

Answer 6

• no nucleus
• biconcave disc shape (increases the surface are to volume ratio)
• packed with hemoglobin (carries oxygen)
• more diffusion into the cell
• cytoplasm is very close to the cell membrane = oxygen does not travel far, very close to the heoglobin

Question 7

Structure of hemoglobin

Answer 7

• no nucleus
• no mitochondria (mostly all organelles are gone to make more room for hemoglobin
• molecule inside RBC
• protein molecule
• needs DNA so it has a nucleus in the younger cell but degenerates when the cell matures
• contains protein and iron
• the oxygen will attach to the oxygen (4 can attach)
• transports oxygen, carbon dioxide, carbon monoxide and hydrogen ions

Question 8

Erythopoiesis

Answer 8

• production of red blood cells
• in pelvic girdle, pectoral gridle, skull, ribs etc
  1. Hematopoietic stem cells
  2. Proerythroblast
  3. Reticulocyte -can still make hemoglobin (ribosome and mRNA)
  4. Erythrocytes (out of the bone marrow now

Question 9

How is red blood cells regulated?

Answer 9

homeostasis

Question 10

Negative feedback loop for blood regulation

Answer 10

• on the oxygen level in the blood
  1. stimulus (hypoxia=inadequate oxygen delivery)
  2. Control centre is the brain
  3. Effector (kidney releases erythropoietin)
  4. Erythropoietin stimulates bone marrow
  5. Enhanced erythropoiesis increases RBC count
  6. Oxygen carrying ability of blood rises

Question 11

List the main types of leukocytes

Answer 11

Granulocytes=
- neutrophils
- eosinophils
- basophils
Agranulocytes=
- lymphocytes
-monocytes

Question 12

Neutrophils

Answer 12

phagocytize bacteria

Question 13

Eosinophils

Answer 13

kills parasitic worms; complex role in allergy and asthma

Question 14

Basophils

Answer 14

releases histamine and other mediators of inflammation; contains heparin, an anticoagulant

Question 15

Lymphocytes

Answer 15

mount immune response by direct cell attack or via antibodies

Question 16

Monocytes

Answer 16

Phagocytosis; develop into macrophages in the tissue

Question 17

Difference between T and B lymphocytes

Answer 17

• Both T and B lymphocytes origin is in the bone marrow
• B cells mature in the bone marrow and then leave the bone marrow and circulate through the blood and end up in the lymph nodes (waiting to be activated)
• T cells leave the red bone marrow into the thymus to mature then leaves the thymus and circulates through the blood and eventually ends up in the lymph nodes`

Question 18

Platelets

Answer 18

• produced in the bone marrow

- essential for blood clotting

Question 19

Formation of platelet

Answer 19

1. Hematopoietic stem cell
2. Megakaryoblast
3. Platelet (no longer in the bone marrow)

Question 20

Hemostasis

Answer 20

-preventing blood loss
3 mechanisms:
1. vascular spasm
2. formation of the platelet plug
3. Coagulation