Lymphatic system

Question 1

How does the lymphatic system travel?

Answer 1

Milking motion from skeletal muscle

Always going towards heart

Located in interstitial spaces

Returns to veins close to the heart

Question 2

What is the process of the lymphatic system?

Answer 2

Lymph from lymph capillaries (intermingled with normal capillaries) carried to LYMPH NODE (filtration and WBC maturation), then carried to SUBCLAVIAN veins near heart

Question 3

What are the two lymphatic ducts and where do they drain from?

Answer 3

Right lymphatic duct (right arm, thorax, head)

Thoracic duct (everywhere else)

Question 4

What is the purpose of lymph?

Answer 4

Returns fluid from interstitial fluid to blood

Water, blood cells, protein

Question 5

What is the purpose of lymph nodes?

Answer 5

Filters lymph before returning to blood

Biological filter- Phagocytosis destroys particles

Mechanical filter- stops particles from moving through body

Question 6

What are the different structures of a lymph node?

Answer 6

Afferent vessels (in)
Efferent vessels (out)- fewer, lymph moves slowly

Question 7

What is the purpose of the tonsils?

Answer 7

Two modes on side of throat that get rid of bacteria and foreign substances going in the mouth

Question 8

What is the thymus and what is its purpose?

Answer 8

Produces hormones

Prepares T cells (adaptive immune system)

Question 9

What is the spleen and what is its purpose?

Answer 9

Stores platelets, filters blood

Active immune response through humor all and cell mediated pathways

Rich in B and T Lymphocytes

Question 10

What is the role of the intestines and appendix in the lymphatic system?

Answer 10

Peyers patches in intestines remove bacteria

Appendix removes bacteria

Question 11

What is innate immunity?

Answer 11

Innate immunity- FIRST and SECOND LINE OF DEFENCE

-genetic mechanisms or mechanisms present at birth before being exposed to any conditions

Protects against NON SPECIFIC INVADERS

Responds immediately

NO MEMORY

Question 12

What is the first line of defence?

Answer 12

SKIN- physical barrier

MUCOUS MEMBRANES- traps microorganisms (along GI tract)

NASAL HAIRS- filter

SECRETIONS OF SKIN- sebum, mucous, acids

GI TRACT- HCL to kill bacteria

TEARS AND SALIVA- clean and lubricate

Question 13

What is the second line of defence?

Answer 13

PHAGOCYTIC CELLS that engulf invaders

• neutrophils
• macrophages
• some are fixed in organs, others float free in body

INFLAMMATION- inhibit iron, zinc- needed by bacteria. Releases histamine a that dilate blood Vessels, making them leaky, allowing easy access at invader

COMPLEMENT MECHANISM- plasma proteins that cause enemy cell to burst- circulate inactive through blood

NATURAL KILLER CELL MECHANISM- group of lymphocytes that kill types of cancer cells and virus infected cells

INTERFERONS- inhibit spread of viral infection

Question 14

What is an antigen?

Answer 14

Anything that can induce an immune reaction

Bacteria, virus, fungi, allergens

Question 15

What is the ADAPTIVE defence system?

Answer 15

THIRD LINE OF DEFENCE

Develops after born in response to specific antigens that enter body

More aggressive and slow than innate

Has memory

Question 16

What is included in the third line of defence?

Answer 16

Lymphocytes

• T cells - mature in thymus
• B cells- mature in bone marrow

Question 17

How do B cells work?

Answer 17

Produce ANTIBODIES that attack PATHOGENS

called antibody mediated immunity or HUMORAL IMMUNITY

antibodies circulate freely in plasma

Question 18

How does HUMORAL IMMUNITY work?

Answer 18

B lymphocytes with specific receptors recognize and bind to antigens

Binding to antigen activates lymphocyte to undergo CLONAL SELECTION AND MULTIPLICATION

//Basically when antigen enters body, lymphocytes can select the specific antibody it needs (CLONAL SELECTION THEORY)

Large number of clones produced to make antibodies (primary humoral response)

B cells secrete produced antibodies, circulating in blood for 4-5 days

B cells become MEMORY B cells- ready to respond to same threat

Question 19

How do T cells work?

Answer 19

Attack pathogens (virus, cancer. Infections) directly

Referred to as CELL MEDIATED IMMUNITY

T cell will activate macrophages to destroy pathogens

2 types of T-cells

-helper T cells- recruit other cells to fight invaders, activate chemical reactions in pathogen by binding to it

Cytotoxic T cells- kill infected cells by inserting toxic chemicals

Question 20

What are allergies? What is happening when we have them?

Answer 20

Hypersensitivity to harmless antigen

Antibodies travel to cells that release histamine S and other inflammatory substances, causing an allergic reaction

Question 21

What is the structure of antibodies?

Answer 21

4 amino acid chains, linked by disulphide bonds

2 identical amino acid chains are linked to form a HEAVY CHAIN (400 amino acids) - these determine type of ig (immunoglobulin- antibody)

2 identical amino acids form LIGHT CHAIN (220 amino acids)- antigen binding sites

Question 22

What are the 5 different types of antibodies?

Answer 22

IgM 5%- protects blood stream

IgG 75%- cross placenta barrier, protect blood and tissues

IgA 15%- mucous membranes, saliva, tears, protects GI tract

IgE- allergies

IgD- activation of B cells

Question 23

What are the different types of adaptive immunity?

Answer 23

Natural immunity
-natural passive: body gets antibody naturally (from mother to fetus)
-natural active: body gets infection then makes long term defence system
ARTIFICIAL IMMUNITY
-artificial active: body gets antigen from vaccine- long term antigen
-artificial passive: administered after exposure to antigen (ie, anti venom. Short lived, 2-3 weeks)

Question 24

What are REGULATORY T CELLS?

Answer 24

• Release chemicals to suppress activity of T and B cells one invasion is conquered
• stop autoimmune diseases

Question 25

What are the main functions of the lymphatic system?

Answer 25

Body defence and disease resistance

Transporting/draining interstitial fluid

Transports fats from GI tract