Lymphatics And Immunity

Question 0

Lymphatic capillaries: (not present in bones, teeth, bone marrow and CNS)

Answer 0

• Extremely permeable tissue.
• Weave between tissue cells and blood capillaries in loose connective tissue and collect excess protein containing fluid = lymph.
• When interstitial fluid pressure exceeds that in lymphatic capillary fluid moves in through “mini-valves”.
From capillaries lymph flows - collecting vessels - trunks -ducts

Question 1

What does the lymphatic system consist of?

Answer 1

Lymphatic vessels which transport fluid that has left the vascular system back to the blood and lymph organs that house phagocytes

Question 2

which two large ducts in the thoracic region is lymph delivered to?

Answer 2

1. Right lymphatic duct

2. Thoracic duct

Question 3

What is lymph

Answer 3

Lymph is a transparent, colourless, watery liquid which is derived from tissue fluid and contained within lymphatic vessels.

Question 4

Lymph Nodes (Lymph tissue and organs)

Answer 4

• Large clusters near skin surface in inguinal, axillary and cervical regions.
• Macrophages in lymph nodes destroy pathogens and cellular debris.
• Lymphocytes search for antigens.
• Lymphadenopathy = inflamed, painful nodes due to bacterial infection.

Question 5

Spleen ( Lymph tissue and organs)

Answer 5

• Site of lymphatic proliferation, immune surveillance and response.
• Stores breakdown products of RBC
• Site of RBC production in fetus until birth.
• Stores platelets and old or defective RBC

Question 6

Thymus (Lymph tissue and organs)

Answer 6

• Involved in storage and activation of T lymphocytes in immune response.
• Atrophies after puberty

Question 7

What is Palantine and where is it located? (Tonsils (Lymph tissue and organs))

Answer 7

2, large paired tonsils at posterior end of oral cavity

Question 8

Where is Lingual Located? (Tonsils (Lymph tissue and organs))

Answer 8

base of tongue

Question 9

Where is Pharyngeal (adenoids if enlarged) Located? (Tonsils (Lymph tissue and organs))

Answer 9

in posterior wall of nasopharynx

Question 10

Where is Tubal Located? (Tonsils (Lymph tissue and organs))

Answer 10

around opening of auditory tubes

Question 11

Peyer’s Patches: (Lymph tissue and organs)

Answer 11

Isolated clusters of lymph follicles in distal small intestine

Question 12

What are 2 divisions of the immune system?

Answer 12

innate and adaptive: that work both independently and in conjunction to provide resistance to disease.

Question 13

Innate (Non-specific) Immunity :

This system provides immediate response to all _______ substances

Answer 13

This system provides immediate response to all foreign substances

Question 14

First line of defense = skin, mucous membranes and secretions.(Innate Immunity)

Answer 14

• Provide physical barrier
• Acidity of secretions
• HCl and enzymes kill pathogens
• Saliva cleans mouth and lacrimal fluid in the eyes contain bacteriocidal lysozymes..
• Mucous traps organisms

Question 15

Second line of defense (Innate Immunity)

Answer 15

innate cellular and chemical defences

Question 16

What do Phagocytes do?

(Second line of defense (Innate Immunity))

Answer 16

engulf and destroy pathogens that breach membrane

Question 17

NK cells causes ?

Second line of defense (Innate Immunity)

Answer 17

cause apoptosis of virus infected and cancer cells

Question 18

What does Inflammation do?

Second line of defense (Innate Immunity)

Answer 18

prevents spread of injurious agents, disposes of pathogens and dead tissue, promotes tissue repair. Chemical mediators attract phagocytes and other immune cells to the area.

Question 19

What are Interferons ?

Antimicrobial Proteins (Innate Immunity)

Answer 19

secreted by virus infected cells to protect surrounding cells from infection by “interfering” with viral replication. Not virus specific .
Alpha ( from white blood cells)
Beta ( from fibroblasts)
Gamma ( from lymphocytes)

Question 20

What happens when Complement is activated?

Antimicrobial Proteins (Innate Immunity)

Answer 20

when activated unleashes mediators that amplify the inflammatory process.

Question 21

What is a Fever?

Antimicrobial Proteins (Innate Immunity)

Answer 21

– systemic response to invading organisms. Pyrogens secreted by leukocytes and macrophages when exposed to foreign substances.

Question 22

Adaptive (Specific) Defences

This system differs from the Innate Defences how? ( 4 points)

Answer 22

This system differs from the Innate Defences:

1. It needs to be “primed” by prior exposure to an antigen before it can mount a response.
2. Response is directed against specific substances.
3. Response is systemic.
4. Has memory

Question 23

Adaptive Immunity has 2 separate systems

Answer 23

Humoral Immune Response

Cell-Mediatedd Immune responce

Question 24

What is Humoral Immune Response?

Answer 24

• Lymphocyte activated is B cell
• Made, stored and mature in red bone marrow. Once mature, B cells circulate and “seed” in lymph nodes, spleen and other lymphoid organs where they encounter antigen.

Question 25

What is Cell – Mediated Immune Response (CMI):?

Answer 25

• Lymphocyte activated = Tcell.
• Made in red bone marrow. Mature in thymus. Constantly circulate through the body however, increased in numbers in the lymph nodes.
• Respond to and recognize antigen fragments displayed on cells surfaces

Question 26

active immunity

Answer 26

occurs when the person is exposed to a live pathogen, develops the disease, and becomes immune as a result of the primary immune response.

Question 27

passive immunity

Answer 27

is a short-term immunization by the injection of antibodies, such as gamma globulin, that are not produced by the recipient’s cells.

Question 28

Allergy

Answer 28

Under certain circumstances abnormal responses or allergic reactions occur when a foreign substance or antigen, enters the body.

Question 29

AIDS

Answer 29

This is a condition contracted as result of the human immunodeficiency virus (HIV) which progressively destroys the immunity of the individual.