The Immune System

Question 1

Innate immunity

Answer 1

– Immediate (within minutes) and non-specific

– Complement, Neutrophils, monocytes, macrophages

– Useless against infected cells (virus), malignant cells, allogenic cells

Question 2

Acquired (Adaptive) immunity

Answer 2

– Delayed (days to weeks) and
specific
–  directed by T and B lymphocytes

 Features

•  Specificity, diversity, memory, self-regulation, self tolerance
– Can be cell mediated (t cells) or Humoral (B cells)

Question 3

Classes of Cytokines

Answer 3

– Interlukins (IL), Interferions (INF), Tumor necrosis Factors (TNF)

Question 4

Primary lymphatic tissue

Answer 4

– Site of lymphatic cell maturation

Question 5

Secondary lymphatic tissue

Answer 5

– Organs and lymph nodes

– Site of Ag presentation site of Ab production

Question 6

T cells Lymphocyte maturation

Answer 6

– Mature in the thymus (taught host tolerance)

– As they proceed through clonal selection, they are tested against host cells

– If they respond aggressively they are destroyed

– Mature helper T cells move to secondary lymphatic tissue and wait to be stimulated.

Question 7

B cells Lymphocyte maturation

Answer 7

– Mature in bone marrow

– Hang out in secondary lymphatic tissue

– Wait to be stimulated by antigen

Question 8

Sequence of immune response to microorganisms.

Answer 8

Infection	
↓
Innate response 
↓	
APC on MHC	
↓
Helper T cells	
↓
Cytokine release
↓	
Complement & B-cell Ab 
↓	
Phagocytosis

Question 9

Sequence of immune response to infected cells

Answer 9

Virus infects cell	
↓
Cell changes surface markers
↓	
T cells read markers	
↓
LYSIS

Question 10

Sequence of immune response to Allogenic Cells

Answer 10

Foreign cell enters body	
↓
T cells read markers	
↓
LYSIS

Question 11

Sequence of immune response to Malignant Cells

Answer 11

Cell becomes	malignant	
↓
Foreign protein is produced	
↓
Granulocytes respond to proteins and produce TNF	
↓
Broad Immune response

Question 12

Sequence of immune response to Foreign Surface

Answer 12

Granulocytes stimulated by foreign surface
↓
Cytokines released
↓
Marginated granulocytes become stimulated
↓
WBIR

Question 13

Type I Hypersensitivity reaction

Answer 13

•  Immediate allergic reaction on the second exposure

•  IgE mediated histamine release
– Bronchiole constriction, capillary leakage, hypotension, myocardial ischemia, increased secretions, hemorrhage, laryngeal edema
•  Susceptible patients (food allergies)
– Shellfish, peanuts, eggs, milk, beans, bug/reptile venom, drug allergies, others

Question 14

Hyperacute Graft Rejection

Answer 14

– Organ has a surface antigen to which the recipient has an antibody at the time of transplant.

Question 15

Acute rejection

Answer 15

– Organ has a surface antigen to which the recipient recognizes as foreign and creates and antibody against– Rejection is in weeks
– Immunosuppression is used to prevent these reactions

Question 16

Chronic rejection

Answer 16

– T cell mediated

– Rejection occurs over months

Question 17

When a donor organ is being destroyed by the host, the symptoms presenting in the host are referred to as what?

Skin rash, liver failure, weight loss, and even death can ensue

Answer 17

Graft Versus Host Disease