Blood And Immunity

Question 1

Blood

Answer 1

Red blood cells = erythrocytes, ~45%
White blood cells = leukocytes, <1%
Platelets = thrombocytes, <1%
Plasma = ~55%

Question 2

Blood plasma

Answer 2

55% of blood 
90-92% water 
Electrocytes and glucose 
Clotting factors 
Plasma proteins (~7%)
Serum = plasma without clotting factors

Question 3

Clinical measures

Answer 3

RBC count = ~5million/mm3
WBC count = ~10,000/mm3
Hematocrit (Hct) = ratio of RBCs to total blood volume (~45%)
Hemoglobin (Hb) = 12-15mg/dL
Platelets = 150,000-350,000/mm3

Question 4

Red blood cells

Answer 4

Live about 120 days
30 trillion 
Replace ~1% everyday 
Need iron 
Need B12
Need erythropoietin (from kidney, released if blood oxygen is too low)

Question 5

Anemia

Answer 5

Low oxygen carrying capacity (fatigue)
Iron deficiency anemia = low iron, low hemoglobin, small cells, low Hct
Pernicious anemia = low B12, low RBC count

Question 6

White blood cells

Answer 6

Neutrophils = phagocytes, 60-70% of WBCs
Monocytes = macrophages, 2-8% of WBCs
Eosinophils = allergy response, 1-4% of WBCs
Basophils = histamine, <1% of WBCs
Lymphocytes = T cells and B cells, 20-30% of WBCs

Question 7

Blood clotting

Answer 7

Vascular spasm = vasoconstriction 
Platelet plug = sticky platelets 
Coagulation

Question 8

Coagulation

Answer 8

Formation of fibrin threads
2 pathways:
Extrinsic = needs external factor
Intrinsic = slower, more fibrin

Question 9

Immune system

Answer 9

Defence against bacteria, viruses, worms
Removes old cells
Helps with repair (injuries)
Antigen (binds with antibody)

Question 10

Immunity

Answer 10

Non specific (innate) = quick, external defences, inflammation, interferon, natural killer cells/phagocytes, complement system 
Specific (acquired) = slower but stronger, T-cells (kill infected cells), B-cells (antibody response)

Question 11

External defences

Answer 11

Skin 
Mucous 
Acid 
Cough 
Sneeze

Question 12

Inflammation

Answer 12

Increase blood flow to injury/infection site (red/hot)

Increase permeability of capillary (WBCs and clot factors to site)

Question 13

Interferon

Answer 13

Cytokines from infected cell

Prevents infection of other cells

Question 14

Natural killer cells/phagocytes

Answer 14

Macrophages (cancers, bacteria)

Neutrophils (phagocytes)

Question 15

Complement system

Answer 15

Circulating proteins

Forms attack complex (kills anything marked by an antibody)

Question 16

Specific immunity

Answer 16

B-cells = attack free virus
Antibody reaction
T-cells = attack infected cells

Question 17

B lymphocytes

Answer 17

Bind to antigen 
Divide and differentiate into:
Plasma cells (secrete antibodies)
Memory cells (stronger second response)

Question 18

Antibody response

Answer 18

Antibodies bind to antigens (mark them for destruction by phagocytes and complement system)

Question 19

Memory cells

Answer 19

Larger and longer second response

Eg) chicken pox and flu

Question 20

T lymphocytes

Answer 20

Helper T-cells = secrete cytokines
Cytotoxic T-cells = directly attack infected cells, recognize antigen marker
Suppressor T-cells = limits response

Question 21

Helper T-cells

Answer 21

Secretes cytokines
Mediates fever
Increases number of B and T cells
Necessary for strong response

Question 22

Blood mismatch

Answer 22

Antibodies bind antigens (clumping, block small vessels)
Hemolytic anemia
Also Rh mismatch

Question 23

Allergies

Answer 23

Inappropriate response to an allergen 
Activates mast cells 
Mucous secretion 
Inflammation response 
Eg) hay fever, hives, anaphylaxis

Question 24

Allergic response

Answer 24

Inflammatory response to a non pathogenic antigen (allergen)
(Pollen/dust/animal hair/certain foods) -> (overproduction of IgE) -> (affinity for basophils and mast cells) -> (rupture of mast cell, release of histamine/serotonin/bradykinin) -> (local edema, swelling, congestion, hives)