Chapter 14- Lymphatic system and immunity

Question 1

what is the purpose of the lymphatic system?

Answer 1

returning tissue fluid to the blood and protecting the body against foreign material.

Question 2

what parts make up the lymphatic system (3)?

Answer 2

lymph vessels
lymphatic tissue (nodules, spleen, thymus gland)
lymphs

Question 3

Define lymph

Answer 3

tissue fluid that enters the lymph capillaries

Question 4

describe lymph vessels?

Answer 4

lymph capillaries, which are permeable and collect fluid and proteins,
Lymph viens, return lymph to heart

Question 5

What do you call the specialized lymph capillaries in the villi of the small intestine?

Answer 5

lacteals

they absorb fat-soluable end products for digestion *fatty acids, and Vit A, D, E, K.

Question 6

how is fluid moved through the lymphatic system?
How about in the lower extremities?
How about in the chest cavity?

Answer 6

same structure as venous system. smooth muscle layer of larger lymph vessels constricts with one-way valves.
in the extremitires the vessels are compressed by skeltal muscles, AKA skeletal muscle pump.
In the chest = respiratory pump

Question 7

Where does the lymph end up?

Answer 7

back into the blood to become plasma- this is done in front the lower lumbar where lymph vessels from the lower body company with the cisterna chyli when ends up in the thoracic duct.
upper body system travels to duct via subclavian vien

Question 8

describe lymphatic tissue

Answer 8

lymphocytes in a mesh-like framework of connective tissues. ++ stem cells

Question 9

What is a lymph nodule/node?

Answer 9

masses of lymphatic tissue
they differ by size/location.
nodes 10-20mm and are encapsulated.
nodules <1mm-10mm no capsules.

Question 10

Where are lymph nodes found?

Answer 10

groups along pathways of lymph vessels. lymph passes through these nodes on its way to subclavian vein. macrophages phagocytize the foreign material in lymph

Question 11

how are plasma cells implicated in the lymph nodes?

Answer 11

they’re developed from B-lymphocytes and when exposed to pathogens that produce antibodies.

Question 12

What are 3 strategically located lymph nodes in the body and why are they important?

Answer 12

cervical
axillary
inguinal
* located at the junctions of the head and extremities. They are locations more septable to pathogens entering from breaks in skin, and will clear bacteria before lymph enters the trunk

Question 13

Where are lymph nodules located?

Answer 13

beneath the epithelium of all mucous membranes.

respoatory, digestive, urinary and reproductive.

Question 14

What is the specific name given to the lymph nodules found in the pharynx ?

Answer 14

tonsils

Question 15

What is a tonsillectomy?

Answer 15

surgical removal of the palatine tonsils and the adenoids - usually when tonsils are chronically inflamed and swollen

Question 16

What do you call the lymph nodules of the small intestine?

Answer 16

peyer’s pathces- these learn food [good vs. bad]

Question 17

What is the role of the spleen from the fetus to adult hood.

Answer 17

in the fetus- produces red blood cells
after birth- acts as a large lymph node and does the following:
1. contains plasma cells that produce antibodies
2. contains monocytes and fixed macrophages that phagocytize pathogens and old RBC and form bilirubin.
3. stores platelets and destroys them when they are no longer useful.

Question 18

what is the Thymus?

Answer 18

located in the thyroid gland
steam cells from the thymus produce T lymphocytes (T-CELLS)
thymus hormone required for immunological competence.

Question 19

what is Hodgkins disease?

Answer 19

malignant disorder of the lymph nodes. Cause unknown

early tx results in a better prognosis

Question 20

in the thymus, immature T cells are “introduced” to the cells and organic molecules of the body and develop two capabilities: Self-recognition or self-tolerance. Define Self-recognition

Answer 20

ability to distinguish cells that belong to the body and those that do not - this is done via proteins.
T-cells that do not accept proteins, will undergo apoptosis.

Question 21

in the thymuys, immature T cells are “introduced” to the cells and organic molecules of the body and develop two capabilities. Self-recognition or self-tolerance. Define self-tolerance

Answer 21

ability to not react to proteins and other organic molecules our cells produce.

Question 22

Define immunity

Answer 22

ability to destroy pathogens or other foreign material and to prevent further cases of certain infection diseases

Question 23

define antigens

Answer 23

chemical markers that identify cells.

HLA- self identifying antigens

Question 24

What are the two main components of immunity?

Answer 24

1. innate immunity (non-specific)

2. adaptive immunity (specific to target receptors- usually involves antibodies and memory)

Question 25

THE INNATE immunity has several aspects.

1. anatomic and physiological barriers
2. phagocytic barriers
3. defensive cells
4. chemical secretions and reactions

Briefly describe each

Answer 25

1. skin has layers and its own bacteria to fight off pathogens. Fatty acid helps limit bacteria growth. Mucous membranes are living tissue and produce mucus to trap environmental pathogens. Stomach acid kills bacteria. lysozyme enzyme in saliva and tears inhibit bacteria growth.
2. Phagocytic cells use intracellular enzymes and chemicals (H2O2) to destroy ingested pathogens. Langerhans cells in the skin. Macrophages in the blood stream.
3. Natural Killer Cells (NK cells) circulate the blood and in Red bone marrow, spleen and lymph nodes. - kills foreign material by rupturing their cell membrane. Basophils and mast cells work in areolar connective tissue- produce histamine and leukotriene.
4. Interferons, complement, and inflammation help body resit infection. Interferons are proteins produces by cells infected with viruses and by T cells, and blocks reproduction of viruses. complement is 20 plasma proteins that activate and release histamines, and attract WBC. Inflammation = vasodilation which increases blood flow and capillaries become permeable. WBC are also rushed to the site.

Question 26

What limits inflammation?

Answer 26

cytokines and chemokine.

Question 27

Adaptive immunity is specific and is carries out by lymphocytes and macrophages. What are the main cells involved in this process?

Answer 27

T cells and B cells . both cells can recognize antigens as foreign, but the system is activated when recognition is accomplished by macrophages and T lymphocytes called Helper T cells (CD4T cells). Macrophage eats foreign materia and its flagged on its membrane, helper T cells recognize the flag, and becomes sensitized to this and specific to the foreign antigen. this initiates one or both the mechanism of adaptive immunity.

Question 28

There are two mechanisms of adaptive immunity.

1. cell-mediated immunity (t-cells and macrophages participate)
2. antibody-mediated immunity (T cells, B cells and macrophages.

Define the first.

Answer 28

• doesn’t result in production of antibodies
• affective on intracellular pathogens, fungi, malignant cells, and grafts of foreign material.
• T-cells divide and form Cytotoxic T cells (kills by disrupting cell membrane, and releases cytokines), and memory T cells- these remember the foreign antigen and becomes active s/t reoccurrence.
• Regulatory T cells, produce feedback chemical to limit immune responses once foreign antigen has been destroyed.

Question 29

There are two mechanisms of adaptive immunity.

1. cell-mediated immunity (t-cells and macrophages participate)
2. antibody-mediated immunity (T cells, B cells and macrophages.

Define the second.

Answer 29

• production of antibodies
• B cells and macrophages and Helper T cells are involved.
• B cells divide into plasma and memory B cells- which which are strong stimulus for the activation of B cells for this antigen and generate a rapid response at recurrence
• antibodies are produces, and will bond to antigens to form antibody-antigen complex. this results in opsonization which means the antigen is labled for phagocytosis by macrophages- it also stimulates complement dization.

Question 30

What are antibodies?

Answer 30

called Immunoglobulins (Ig), immunoglobulins or gamma globulins, are proteins shaped somewhat like the letter Y. they attach to antigens to label them for destruction

Question 31

Where is the antibody IgG located and what are its functions?

Answer 31

located: blood and extracellular fluid
Function: monomer; most abundant immune globulin; crosses the placenta to provide passive immunity for newborns; provides long-term immunity to a disease following recovery or a vaccine

Question 32

Where is the antibody IgA located and what are its functions?

Answer 32

located: external and internal secretions
Function: dimer; present in breast milk to provide passive immunity for breast-fed infants’
- found in secretions of all mucous membranes to provide local defence where pathogens enter.

Question 33

Where is the antibody IgM located and what are its functions?

Answer 33

located: blood
Function: pentamer; produced by the maturing immune system of infants; first produced during infection the antibodies of the ABO blood group

Question 34

Where is the antibody IgD located and what are its functions?

Answer 34

located: B lymphocytes
Function: a monomer; forms receptors on B lymphocytes

Question 35

Where is the antibody IgE located and what are its functions?

Answer 35

located: mast cells or basophils
Function: a monomer; is important in allergic reactions, and responses to parasites.

Question 36

What is a complement fixation test?

Answer 36

determines the presence of a particular antibody in the patients blood but does not indicate when the infection occurred.

Question 37

What is an antibody titer test?

Answer 37

determines the level or amount of a specific antibody in the patients’ blood.

Question 38

what is the fluorescent antibody test?

Answer 38

uses antibodies tagged with flueorescent dyes, which are added to a clinical specimen such as blood, sputum or biopsy of tissue. If pathogen is present, the antibodies will bind to it and the antigen-antibody complex will flow when examined.

Question 39

what is a vaccine, and name 3 types of vaccine antigens.

Answer 39

use is to prevent disease. It contains an antigen that the immune system will respond to.
types of vaccine antigens:
1. killed or weakened pathogens (attenuated)
2. part of pathogen such as bacterial capsule
3. inactivated bacterial toxin (toxoid)

Question 40

what is Agglutination?

Answer 40

clumping - which happens when antibodies bind to bacterial cells. Bacterial cells are clumped together by the antibodies and are more easily phagocytixzed by macrophages.

Question 41

Define allergy

Answer 41

hypersensitivity to a particular foreign antigen called an allergen. The body mistakenly responds and over-responds to the allergen and damages the tissue by doing so.

Question 42

What are the 2 general types of Immunity?

Answer 42

1. genetic immunity- conferred by our DNA, no antibodies no immune system.
2. Acquired Immunity - developed or acquired by natural or artificial means. Involves antibodies, 2 kinds: passive or active

Question 43

Differentiate passive and active acquired immunity

Answer 43

passive: antibodies are from another source. IgA from mother to infant, or Hep B and B, german messels and tetanus/rabis shot. temporary
active: antibodies are produced by the individual. naturally when you recover from a disease and antibodies are produced, or artificially when a vaccine stimulates production of antibodies and memory cells.