Immunity and coagulation 3

Question 1

Coagulation

Answer 1

Small injuries are healed using platelet plugs -Platelets adhering to each other.
Platelets when exposed to collagen alter cellular characteristics and become swollen and sticky and develop tendrils.

Question 2

Prothrombin

Answer 2

Prothrombin activator formed with damaged blood vessels

Question 3

more info

in presence of ionic calcium

Answer 3

In the presence of ionic calcium prothrombin is converted to thrombin which causes fibrinogen molecules to cohere to form fibrin.
Rate limiting step is time to create prothrombin activator
Liver produces prothrombin continuously.
Vit K required for activation of prothrombin

Question 4

Clot retraction

Answer 4

Within a few minutes of a clot forming retraction begins whereby the fluid is eliminated leaving the fibres.
Platlets are essential for retraction to occur.

Question 5

Fibroblasts invade

Answer 5

the clot and begin to form connective tissue., replacing the clot with fibrous tissue in 1-2 weeks
Clots occurring in tissues where they are not needed are dissolved by tissue enzymes

Question 6

Pathways for initiating clotting

Answer 6

Extrinsic –

Intrinsic-

Question 7

Extrinsic

Answer 7

– damage to vascular wall or extravascular tissue that becomes exposed to blood.

Question 8

Intrinsic-

Answer 8

trauma to blood or exposure of blood to collagen (internal blood vessel wall)

Question 9

Adaptive immunity

Answer 9

The 3rd line of defense is adaptive or acquired immunity.
It responds more slowly than inflammation.
It is more specific
It has memory
Generates antibodies to specific non-self entities

Question 10

Non-self entities

Answer 10

are referred to as antigens when they react with the immune system

Question 11

The product of an antigen reaction with the adaptive system is the forming of:

Answer 11

Immunoglobulins (collective name for all antibodies)
T cells .

At birth a large number of T (thymus) and B (bone marrow) lymphocytes exist. These have the capacity to recognise most foreign antigens.

Question 12

Two components of Adaptive

Answer 12

Cellular immunity

Humoral immunity

Question 13

Cellular immunity

Answer 13

T cells develop from T- lymphocytes and in turn may develop into:
Cytotoxic cells –
Regulatory cells (largely T helper cells)
Memory cells

Question 14

Cytotoxic cells

Answer 14

attack and kill targets directly

Question 15

Regulatory cells (largely T helper cells)

Answer 15

at regulate the immune response. This is done by secreting cytokines that initiate inflammation and stimulate macrophages and other white blood cells. Play a large role in suppressing the immune response

Question 16

Memory cells

Answer 16

recognise previously encountered antigens resulting in a faster initial response

Question 17

Humoral immunity

Answer 17

Immunoglobulin

Question 18

Immunoglobulin

Answer 18

Immunoglobulins are produced by B cells, each specific antibody capable of binding to specific circulating antigens
This inactivates the antigen or stimulates inflammatory mediators that will destroy the antigen

Question 19

5 classes of antibodies based on chemistry and structure, each with specific biological roles

Answer 19

IgG (80% of Ab; blood, lymph)
IgA (10-15% of Ab; sweat, tears, breast milk, secretions)
IgM (5-10% of Ab; blood, lymph)
IgD (0.2% of Ab; on B-cells as an Ab receptor)
IgE (less than 0.1% of Ab; mediates allergic responses)

Question 20

Clonal selection

Answer 20

For specific recognition of an antigen to occur, the antigen is processed by antigen presenting cells which then present to the T – helper cell.
The T-helper cells collaborates with both T and B memory cells to create antigen memory.

Question 21

Atopic allergies

Answer 21

large amounts of IgE antibodies (genetically determined).
When an antigen reacts with a specific IgE antibody an allergic response is seen
IgE antibodies have a high affinity to bind to mast cells and basophils & therefore when they react with antigens the membrane of the mast cell is disrupted leading to large amounts of histamine being released.

Question 22

Anaphylaxis

Answer 22

occurs when the allergin /antigen enters the circulation, directly impacting circulatory basophils and mast cells closely associated with the circulation system causing widespread release of histamine and other chemotactic substances.
More severe form of atopic reaction

Question 23

Delayed allergy reaction

Answer 23

Caused by activated T cells not immunoglobulins.
Activated T cells and cytotoxic T cells will take a day or two to reach the tissue.
Cytotoxic T cells will cause major tissue damage.

Question 24

Adaptive immunity can be:

Answer 24

Primary

secondary

Question 25

Primary

Answer 25

The antibodies and T cells produced in response to antigens by the individual in response to exposure to an antigen.

Question 26

secondary

Answer 26

Does not involve the host’s immune response.
Antibodies or T cells are transferred from a donor to recipient
Occurs naturally during pregnancy/lactation or artificially through immunoglobulin injection