Lymphatics and Immune Systems DYK Questions

Question 1

Can you describe the order of fluid circulation (including spaces and vessels)?

Answer 1

Peripheral tissues —> lymphatic capillaries —> lymphatic vessels —> subclavian veins

Question 2

Do you know the differences in structure and function between lymphatic and blood vessels?

Answer 2

LYMPHATICS
origin - as 'pockets' 
size - larger
wall thickness -  thinner
BLOOD VESSELS
origin - continuous tubes
size - smaller
wall thickness - thicker

Question 3

Can you name the physical barriers we have?

Answer 3

Skin, mucous membranes

Question 4

Can you name the most common phagocytes?

Answer 4

Neutrophils

Monocytes

Question 5

How do phagocytes remove debris and foreign material?

Answer 5

□ Non-specific immune cells
□ Serve as ‘police’
□ Remove cellular debris and foreign material
○ Engulf debris - ‘eating’ debris in a PacMan style
Includes pathogens

Question 6

Which cells carry out immune surveillance?

Answer 6

Natural killer (NK) cells

Question 7

When do interferons most commonly get released?

Answer 7

Released by activated lymphocytes, macrophages, virus-infected cells

Question 8

What cells and immune components does complement work closely with to improve the effectiveness of the immune response?

Answer 8

phagocytes and antibodies

Question 9

What are the 4 characteristics of tissues undergoing inflammation?

Answer 9

Inflammatory mediators
	Blood flow
	Phagocytes
       Capillary permeability
(redness, swelling, heat, pain)

Question 10

What is the aim of inflammation?

Answer 10

• All parts of inflammation increase immune function
  ○ Prevent infection in wound sites
  Increases effectiveness of other defences (both specific and non-specific)

Question 11

Name 2 things that increasing the body temperature does to assist with protecting the body?

Answer 11

○ Inhibits pathogens - not comfortable for them
○ Raises metabolic rate
○ Faster mobilisation of tissue defences
Accelerated repair process

Question 12

Can you briefly describe the difference between an antigen and an antibody?

Answer 12

Antigen: molecule capable of inducing an immune response (production of an antibody) in the host organism, generates a response
Antibody: immunoglobulin, Y shaped proteins that are produced by the immune system, stops intruders from entering the body

Question 13

Can you name the process that occurs that links the non-specific (innate) immune response to the specific (adaptive) immune response?

Answer 13

ANTIGEN PRESENTATION

Question 14

What are the cells called that carry out antigen presentation process?

Answer 14

phagocytes

T and B cells (lymphocytes)

Question 15

Can you name the types of lymphocytes that provide us with specific (adaptive) immunity?

Answer 15

T cells and B cells

Question 16

Is specific (adaptive) immunity present at birth?

Answer 16

no

Question 17

Can you name the 4 key characteristics of specific immunity that make it different to non-specific immunity?

Answer 17

Specific - Activated by specific antigens
Versatile - Diversity of lymphocytes present, can be ready for any antigen at any time
Memory - Antigens previously encountered are remembered (principle behind vaccination)
Tolerance - All cells in the body have antigens, no immune response against those

Question 18

Can you name the cell that carries out cell mediated immunity?

Answer 18

T cells

Question 19

How do cytotoxic T cells remove cells with foreign or abnormal antigens?

Answer 19

Seek out and destroy abnormal cells, Release perforin (perforate cell membrane), Secrete lymphotoxin to kill the cell, Activate genes in nucleus which Tells cell it needs to die

Question 20

Why are memory cells important in protecting against future infection?

Answer 20

Recognise same antigen if re-exposed

Question 21

What is the key role of T helper cells?

Answer 21

Coordinate specific and non-specific defences,
Secrete cytokines
○ Stimulate T cell division (produce memory helper T cells, speed maturation of cytotoxic T cells)
○ Attract macrophages to affected areas - stimulate phagocytic activity
○ Attract cytotoxic T cells - another means of destroying abnormal cells/pathogens
○ Activate B cells - antibody production

Question 22

Why do you think it is important for suppressor T cells to regulate immune responses?

Answer 22

• Supress response of other T cells.
  
  • Once infection is cleared, process needs to stop
  • Like negative feedback of the immune response

Question 23

What is produced by plasma cells (differentiated B cells) as part of the specific immune response?

Answer 23

secrete antibodies (proteins)

Question 24

What key feature do plasma cells (differentiated B cells) have that make it effective?

Answer 24

Antibody has receptors specific for the antigen its just been exposed to

Question 25

Can you name the cell that is activated when you are exposed to an antigen a second (third, fourth, etc) time?

Answer 25

Memory B cells mainly
IgG
IgM

Question 26

Why do you think the secondary response is much faster than the primary response?

Answer 26

There is more IgG now, it already knows how to fight it. Production of IgM is quicker. Both IgG and IgM stay for extended periods of time