Immunology + Haematopoiesis

Question 1

State the Functions of Blood.

Answer 1

Deliver nutrients + oxygen (Transporting fluids)
Collect waste products
Homeostasis (Aids in heat distribution + Regulates acid-base balance)
Defense-Immune system

Question 2

State the Composition of Blood.

Answer 2

8% of body weight split into:
55% Plasma (7% proteins, 91% water, 2% other solutes)
45% formed elements (250-400,000 platelets, 5-9000 leukocytes, 4.2-5.8,000,000 erythrocytes)

Question 3

State the Plasma Electrocytes.

Answer 3

Cations: Na+, K+, Ca2+, Mg2+
Anions: Cl-, Bicarbonate, PO4(2-)

Question 4

State the substances Plasma Transport.

Answer 4

Nutrients: Glucose, fatty acids, vitamins
Waste: Urea, lactic acid
Gases: Oxygen, Carbon dioxide, Nitrogen
Hormones

Question 5

Describe the Proteins in Plasma.

Answer 5

Most produced in liver
95% are same 8 proteins
Most are glycoproteins (excluding albumin)

Functions:
Osmotic balance
pH buffering
Specific roles

Question 6

Describe Erythrocytes (RBCs).

Answer 6

Approx. 5 million per ul of blood
In mammals they have no nucleus
O2, CO2 transport
High surface area: volume ratio 
Haemoglobin (tetramer) has an O2 carrying potential

Functions:
Transport of O2 + nutrients
Removal of waste + CO2
Distribute Heat
Myoglobin: O2 binding/storage in muscle cells

Question 7

Describe Erythropoiesis.

Answer 7

Development of Erythrocytes (RBCs)
Occurs in bone marrow
Erythropoietin: Hormone controlling erythropoiesis
RBCs have 120 day lifespan -> degraded by liver

Question 8

Describe Leukocytes (WBCs).

Answer 8

Approx. 5-10,000 per ul of blood
Defence
Amoeba - like cells but independent movements
Made in red bone marrow
Humans: 5 types (either granular or agranular)

Functions:
Phagocytosis (engulf pathogens)
Synthesis of antibodies 
Inflammatory response
Production of heparin - Treat thrombosis/blood clotting

Question 9

State the Granular Leukocytes

Answer 9

Neutrophils
Eosinophils
Basophils

Question 10

State the Agranular Leukocytes

Answer 10

Lymphocytes

Monocytes

Question 11

State the Stem cell which all blood cells develop.

Answer 11

Multipotential hematopoietic stem cell

Question 12

Describe Platlets.

Answer 12

150-400,000 per ul of blood
Cell fragments
No nuclei
Function in blood clotting + homeostasis 
Disc shaped

Roles:
Adhesion
Secretion
Aggregation

Question 13

Explain the 4 Blood Types.

Answer 13

A - A antigens on RBC, Anti-B antibodies on plasma
B - B antigens on RBC, Anti-A antibodies on plasma
O - No antigens on RBC, Anti-A+B antibodies on plasma
AB - A+B antigens on RBC, No antibodies on plasma

Question 14

Explain the difference between +ve and -ve blood.

Answer 14

Positive - Resus factor present
Negative - Resus factor not present
Resus factor is a protein on blood

Question 15

State the Importance of O- blood and AB+ blood.

Answer 15

O- blood is a universal donor (no antigens)

AB+ blood is a universal recipient (no antibodies)

Question 16

Describe the Haemopoeitic System.

Answer 16

System of organs + tissues (incl. bone marrow, spleen, thymus + lymph nodes) involved in production of cellular blood components

Question 17

State the Cell life of RBCs, Platelets and Granulocytes.

Answer 17

RBCs - 120 days
Platelets - 7 days
Granulocytes - 7 hours

Question 18

Describe the important roles of Bone Marrow.

Answer 18

Only source of blood cells in infants + adults
6weeks-7months gestation blood islands migrate to liver + spleen
At birth, haemopoesis is present in the marrow of every bone
Adult confined to central skeleton + proximal ends of long bones
Pathological processes result in resumption of activity in liver + spleen - extra medullary haemopoiesis

Lymphocytes originate in bone marrow
Lymphoid tisse + organ
Primary - Development + maturation
Bone marrow (B cells), Thymus gland (T cells)
Secondary - Mature lymphocytes meet pathogens
Spleen, adenoids, tonsils, appendix, lymph nodes, Pever’s patches, mucosa-associated lymphoid tissue (MALT)

Question 19

Describe the Lymphatic System.

Answer 19

Lymph
- Fluid + cells in lymphatic vessels

Lymphatic Vessels

• Collect + return interstitial fluid to body
• Transport immune cells
• Transport lipid from intestine to blood

Lymph Nodes
- Kidney shaped organs along side lymph vessels

Other secondary lymphatic tissues + organs

Question 20

Describe the Spleen.

Answer 20

Lymphoid organ in upper left abdomen

Functions:
Remove damaged/old erythrocytes
Activation of lymphocytes from blood borne pathogens

Red Pulp: Erythrocytes removed
White Pulp: Lymphocytes removed

Question 21

Describe Haematopoiesis.

Answer 21

HSCs reside in the medulla
Produce all different mature blood cell types + tissues
Self-renewing cells: Some daughter cells remain as HSCs

Question 22

Describe the ways to Stimulate Maturation.

Answer 22

Growth factors (GFs) are polypeptides that instruct cellular responses
Transcription factors are proteins that control rate of transcription
Cytokines are small (glyco-)proteins that allow cell communication + attract cells (chemotaxis)
Interleukins + Interferons are a type of cytokines
Haematopoietic Cytokines - stimulate HSCs to differentiate into blood cells