Lymphatic System, Resistance & Immunity

What are pluripotent stem cells?

stem cells with the ability to differentiate to many, but not all cell types.

What are totipotent stem cells?

Earliest stem cell that has the ability to specialize into any cell (present n fetus)

List the 2 types of leukocytes

granulocytes and agranulocytes

List the 3 kinds of granulocytes

Eosinophil, Basophil & Neutrophil

List the 2 kinds of agranulocytes

Lymphocyte & Monocyte

What is the origin, function & % of blood of Eosinophils.

origin:

function: kill parasitic worms, complex role in allergy & asthma (allergic reactions & parasitic infestations)

%: 2-4

What is the origin, function & % of blood of Basophils.

origin:

function: release histamine or other inflammation mediators, contain heparin (allergic reactions)

%: 0.5-1.0

What is the origin, function & % of blood of Neutrophils.

origin:

function: phagocytize bacteria (bacterial infections)

%: 60-70

What is the origin, function & % of blood of Lymphocytes.

origin:

function: mount immune response via direct cell attack or via antibodies (antigen/antibody or viral infections)

%: 20-25

What is the origin, function & % of blood of Monocytes.

origin:

function: phagocytosis; develop into macrophages (antigen/antibody, viral & chronic infections)

%: 3-8

What is leukocytosis? What does this usually indicate?

- any WBC count >10,000/ml of blood

- an infectious process or a cancer

What is leukopenia? What does this usually indicate?

- any WBC count <5,000/ml of blood

- severe disease (AIDS, bone marrow failure, severe malnutrition, or chemotherapy)

Leukocytes make up what % of blood volume? How long do they usually live? Except for?

- 1 %

- a few days

- lymphocytes which live for months-years

How does lymph drain back into the blood? (why does it do so at this location?)

via ducts that open into the subclavian veins (restoring blood volume before it enters the heart)

How does lymph travel back towards the heart (through what mechanisms)?

- valves prevent backflow

- skeletal movement

- muscle contraction

- pressure differences

What are the 3 functions of the lymphatic system?

1. fluid recovery (one way transport of lymph from interstitial fluid back to into the blood)

2. immunity (lymph passes through nodes, where WBCs initiate defense & immune responses)

3. lipid (& some vitamins) absorption from the GI tract

What are the lymphoid organs?

lymph nodes, spleen, thymus, tonsils, peyer's patches (& appendix)

What are the primary lymphoid organs?

bone marrow and thymus

What are the secondary lymphoid organs?

lymph nodes, spleen, lymphoid nodule (tonsils)

Where is the thymus gland located?

What is it's function?

- in the mediastinum

- site of T cell maturation & hormone secretion

Where are lymph nodes located? What is their function?

- along lymphatic vessels

- macrophages, dendritic cells & lymphocytes carry out defensive actions

Where is the spleen located? What is it's function?

- upper left quadrant of the abdomen

- removes debris, foreign material, toxins, bacteria, viruses & dying RBCs

Where are tonsils located? What is their function?

- in the pharynx and oral cavity

- trap & destroy bacteria

What are the two layers of immune system resistance?

1. Innate/Non-specific

2. Adaptive/Specific

What are the 2 components (& subcomponents) of the innate/non-specific resistance?

1. surface barriers (skin & mucous membranes)

2. internal defenses (phagocytes, NK cells, inflammation, antimicrobial proteins & fever)

What components of the skin epidermis form the surface barriers portion of innate defense?

- acid mantel of skin

- keratin

What components of the mucous membranes form the surface barriers portion of innate defense? How do they function?

- urine: acidity inhibits bacterial growth, cleanses urinary tract

- lacrimal secretion (tears); saliva: lubricates & cleans eye & mouth (contains lysosome: microorganism destroying enzyme)

- gastric juices: contains HCI & enzyme that destroy pathogens

- cilia: propels mucus away from nasal cavity & lower respiratory passages

- nasal hairs: filter & trap microorganisms in nasal passage

- mucus: traps microorganisms in respiratory & digestive tracts

- acid mantel of vagina: inhibits growth of most bacteria & fungi

What are the components of the second line of innate defense? How do they function?

- NK cells: promote apoptosis by direct attack on abnormal cells

- phagocytes: engulf & destroy pathogens

- fever: high body temp inhibits microbe multiplication

- antimicrobial proteins: interferons (protect uninfected tissue cells & help mobilize immune system) & complement (lyse cells, enhance phagocytosis)

- inflammation (prevents spread of injurious agents, promotes tissue repair, attracts phagocytes through chemical releases)

What are the 2 components of the adaptive/specific resistance?

1. humoral immunity (B cells: antibodies - react with antigen on invading organism)

2. cellular immunity (T cells - cytotoxic T cells destroy invading organism))

What are the 4 stages of phagocyte mobilization?

1. leukocytosis: neutrophils enter blood from bone marrow

2. margination: neutrophils cling to capillary wall

3. diapedesis: neutrophils flatten out of capillaries

4. chemotaxis: neutrophils follow chemical trail (inflammatory chemicals diffuse from site of inflammation)

What are the 5 stages of phagocytosis?

1. phagocyte adheres to pathogens/debris

2. phagocyte engulfs particles in pseudopod that becomes phagosome

3. lysosome fuses with phagosome: forming a phagolysosome

4. lysosomal enzyme digest the particles

5. remaining indigestible residual material is exocytosed

What are the four symptoms of inflammation?

1. heat

2. redness

3. pain

4. swelling

Antibody-Antigen Interactions (4).

Results of these?

1. neutralization: antibodies block an antigens binding sites - disable tissue binding, enhance phagocyte activity

2. agglutination: antibodies bind to multiple antigens, clumping them together - limit mobility, enhance phagocyte activity

3. precipitation: phagocytosis

4. complement : phagocytosis, inflammation & cell lysis

How do you naturally acquire active immunity? How do you artificially acquire active immunity?

1. immunity is acquired through recovery from illness

2. immunity is acquired through vaccination

How do you naturally acquire passive immunity? How do you artificially acquire passive immunity?

1. immunity is acquired through antibodies passed through placenta or breast milk

2. immunity is acquired through antibodies harvested from another person (or animal)

What is severe combined immunodeficiency (SCID)?

-group of inherited disorders caused by immune cell defects

- causes high susceptibility to infection - fatal within 1-2 years of life unless treated with gene or blood forming stem cell therapy

What is human immunodeficiency virus (HIV)?

- acquired immunodeficiency syndrome (AIDS)

- chronic, life-threatening condition

- depleted CD4 T cell production: impairs immune response

- treated with antiviral therapy - no vaccine available

Autoimmune responses...

1. Systemic?

2. Mouth & nose?

3. Muscles?

4. Joints?

5. Psychological?

6. Face?

7. Pleura?

8. Pericardium?

9. Fingers & Toes?

1. low grade fever, photosentsitivity

2. ulcers

3. aches

4. arthritis

5. fatigue & loss of appetite

6. butterfly rash

7. inflammation

8. inflammation

9. poor circulation

A type blood antigens? antibodies?

A antigens & anti-B antibodies

B type blood antigens? antibodies?

B antigens & anti-A antibodies

AB blood type antigens? antibodies?

AB antigens & no antibodies

O type blood antigens? antibodies?

No antigens & anti-A & anti-B antibodies

RH + blood type antigen?

D antigen

hemolytic disease of the newborn

This disease occurs in the 2nd RH+ fetus of an RH- mother, when D antibodies are produced by the mother through exposure to the first newborn's blood antigens during birth. If untreated, the mother's antibodies will cross the placenta and attack the 2nd fetus' blood.

Life cycle of T cell

origin?

maturation in & into?

activation?

differentiate into?

- made in red bone marrow

- matures in thymus into CD8 cells & CD4 cells

- activated by APCs (dendritic cells)

- differentiate into Helper T cells (help activate B cells) & Cytotoxic T cells (kill cells directly) (& some Regulatory T cells & Memory T cells)

Life cycle of B cell

origin?

- made in red bone marrow

- mature in red bone marrow

- activated by matching antigen binding to its surface

- proliferate to form more B cells

- differentiate into plasma cells and Memory B cells

- plasma cells produce appropriate antibodies for the antigens