The Lymphatic System & Immune System

Question 1

What is the structure of the lymphatic system?

Answer 1

• lymph
• lymphatic capillaries
• lymphatic vessels, trunks and ducts
• lymph nodes (glands)
• lymphatic organs
• lymphatic nodule

Question 2

Where are lymphatic nodules found?

Answer 2

• GI tract
• respiratory airways
• urinary tract
• reproductive tract
• tonsils
• Peyer’s patches )in the ileum of small intestine)
• appendix

Question 3

Lymphatic nodules

Answer 3

= mucosa-associated lymphoid tissue strategically positioned to protect the body from pathogens (inhaled, digested or entered vis external openings).

Question 4

Where is the thymus gland, and what is its purpose?

Answer 4

• located in mediastinum behind the sternum and lungs
• produces thymosin hormone for development of T cells

Question 5

Lymph nodes (glands)

Answer 5

= filters the lymph before it returns to the bloodstream; also produce lymphocytes for immune response

Question 6

Lymphatic vessels, trunks and ducts

Answer 6

= carry lymph from lymphatic capillaries through a number of lymph nodes and into large vessels (called trunks and ducts)

Question 7

Lymphatic capillaries

Answer 7

= close-ended vessels with larger diameter than blood vessels that permits fluid into them but not out of them (found throughout body except CNS, splenic pulp and bone marrows).

Question 8

Where is the spleen, and what is its purpose?

Answer 8

• located in abdomen behind the left part of the stomach
• doesn’t filter the lymph, instead it filters and stores platelets and blood as well as lymphocytes
• largest single mass lymphatic tissue

Question 9

Lymph

Answer 9

= clear water derived from interstitial fluid, which contains proteins, lipid, foreign particles (bacteria) and cell debris from damaged tissues and lymphocytes.

Question 10

What is the (4) functions of the lymphatic system?

Answer 10

• drains interstitial fluid
• transportation of dietary lipids
• protection against invasion
• transports clear, straw-coloured fluid from interstitial spaces surrounding to the blood

Question 11

What are the lymphoid structures in humans?

Answer 11

• thymus
• spleen
• red bone marrow
• cervical lymph nodes
• auxiliary lymph nodes
• inguinal lymph nodes
• Peyer’s patches

Question 12

What are common pathologies of the lymphatic and immune system

Answer 12

• Chronic fever of unknown origin
• Recurring fever with night sweats and weight loss
• Anaphylaxis – severe allergic reactions

Question 13

Antibody-mediated (humoral) immune response (AMI)

Answer 13

= antibodies bind to antigens and inactivate them e.g.; B cells develop into plasma cells which secrete antibodies which binds onto antigen and destroys it.
Common response to body fluids and pathogens such as bacteria that have multiplied in body fluids.

Question 14

Cell-mediated (cellular) immune response (CMI)

Answer 14

= ’cells attack cells’ e.g., CD8+ T cells reproduce into killer cells which leave lymphatic tissues to seek out and destroy antigens (fungi, parasites, viruses and some cancer cells).

Question 15

What are the 2 types of immune response?

Answer 15

• cell-mediated (cellular) immune response (CMI)
• antibody-mediated (humoral) immune response (AMI)

Question 16

What are the 2 types of T cells?

Answer 16

CD4+ cells
CD8+ cells

Question 17

T cells

Answer 17

= develop in red bone marrow and migrate to thymus glands to mature; T cells develop antigen receptors

Question 18

B cells

Answer 18

= matures in red bone marrow; develop into plasma cells and secretes antibodies

Question 19

What are the 2 types of lymphocytes?

Answer 19

• B cells
• T cells

Question 20

Fever

Answer 20

= abnormally high body temperature caused by toxins released by microbes. Increase in temperature intensifies the effects of body’s own antimicrobial substances, inhibits microbial growth and increases the growth of tissue repair

Question 21

Natural killer cells (NK cells)

Answer 21

– type of lymphocytes that can kill variety of microbes as well as tumour cells
- found in spleen, red bone marrows, lymph nodes and blood.

Question 22

What are the 2 main types of phagocytes?

Answer 22

• neutrophils
• macrophages

Question 23

What are some examples of chemical barriers to disease (non-specific)?

Answer 23

• Sebum
• Perspiration
• Gastric juices (e.g: hydrochloric acid)
• Vaginal secretions

Question 24

What are (4) non-specific resistance of disease

Answer 24

• mechanical barrier
• chemical barriers
• inflammation
• fever

Question 25

Phagocyte

Answer 25

= a cell that engulfs or digests microbes which includes macrophages and some types of white blood cell

Question 26

Pathogen

Answer 26

= disease-causing microorganism

Question 27

Microbe

Answer 27

= microorganisms (e.g: bacteria, fungus, virus, protozoa)

Question 28

What are some examples of mechanical barriers to disease (non-specific)?

Answer 28

• The skin
• Mucous membranes – traps microbes and moves it away from vital areas
• Lacrimal apparatus – produces tears to wash away microbes and dirt
• Saliva
• Urination, defecation and vomiting

Question 29

Macrophage

Answer 29

= scavenger cells that engulfs and destroys microbes

Question 30

Lymphocyte

Answer 30

= type of white blood cell involved in immunity (e.g: B cells and T cells)

Question 31

Inflammation

Answer 31

= body’s response to tissue damage

Question 32

Antigen

Answer 32

= foreign substance in the body

Question 33

Antibody

Answer 33

= specialised protein that destroys specific antigen

Question 34

Epidemiology

Answer 34

= the study of how diseases spread and affect populations and how to control them