Immunology Exam Review

Function of Lymphatic System

it protects and fights against diseases by collecting, cleaning and draining fluid around cells

Function of Lymph Nodes

filters fluids of harmful particles before returning to the blood stream

Function of Tonsils

filters and destroys bacteria

Function of Thymus

produces hormones that help mature WBC

Function of Spleen

removed worn out RBC, platelets, bacteria, and other particles from the blood; also stores lymphocytes

Function of Histamines

triggers inflammatory response; runny nose, sneezing, watery eyes, coughing.

Function of Pyrogens

hormones that stimulate brain to increase body temp to disable antigen

Function of Cytokines

protein chemical messages produces by T cells so B cells and others of the immune system can become activated.

Function of Interferons

a group of cytokines that are sent in response to viral infections

Function of Interleukins

cytokins that are secreted by leukocytes to produce and immune response amongst other immune cells

Function of Complement

exposes reactive sites on antibody

coats the antigen-antibody bond making antigen more susceptible to phagocytosis

Neutrophil

engulfs small particles

Eosinophil

kills parasites; controls inflammation/allergic reaction

Monocytes

engulfs large particle

Lymphocytes

provides immunity w/ T & B cells

Modes of Infection

**Airborne**: spread by sneezing, coughing, talking

**Waterborne**: contaminated drinking water, spreads disease very rapidly

**Contact**: dirty glassware, silverware, puncture wounds, sexual contact

Signs of a Local Infection

cuts, scrapes, puncture wounds

**symptoms**: redness, swelling, pain, warmth (inflammation)

Signs of a Systemic Infection

whole body

**symptoms**: fever, chills, aches

First Line of Defense

* skins/scabs
* Mucus membranes in the nose, respiratory tract, digestive tract and reproductive tract
* Hairs including cilia in the respiratory tract
* Tears including lysozyme, an antibacterial enzyme
* Stomach acid
* Symbiotic organisms: E. coli living in the stomach provide Vit. K and compete with harmful bacteria

Second Line of Defense

* Inflammatory response/fever


* 5 WBCs (Leukocytes)

Third Line of Defense

* B Lymphocytes (B cells)
* Antibodies (immunoglobins)
* T Lymphocytes (T cells)

Phagocytes vs. Macrophages

digest foreign particles and pathogens

vs.

eat large particles, bacteria, viruses, dead cells

Lymphocyte

immune cell formed in bone marrow and found in blood/lymph tissue; two types: B and T

B Cells vs T Cells

B cells produce antibodies to fight infection, T cells protect us from getting infected by destroying cancerous/infected cells

Antibodies

an immunoglobulin; used by the immune system to counteract a specific antigen

Memory B Cells vs. Plasma B Cells

do not express antibodies but circulate in blood serum seeking out specific pathogens

vs

produces antibodies (immunoglobulins)

Cytotoxic T Cells

destroy virus infected cells and tumors

Helper T Cells

make cytokins which activate and coordinate other cells to participate in the immune system

T4 Cells

coordinate T & B cells; this cell is attacked by HIV

Non specific defenses vs. specific defense

responds in the same way to all germs and foreign substances

vs

they are tailored to particular types of invaders

5 types of antibodies

* **IgM**: 1st to respond in a primary response to an antigen
* **IgA**: most common antibody; protects portals of entry to the body, found in saliva tears, breast milk and mucus
* **IgE**: responds in Allergic reactions; responds to parasite infections
* **IgD**: Found on Mature B cells
* **IgG**: effective against antigens in a secondary response; found in the placenta protecting the fetus; effective against toxins, viruses and bacteria

Events that take place in a primary immune response

\- Initial encounter of a naive B cell with an antigen

\- 5-7 days before antibody levels rise

\- 14 days until antibodies peak

\- IgM is the antibody involved

Events that take place in a secondary immune response

\- 1-2 days for antibody levels to rise

- Memory cells are already present

\- New plasma cells are made

\- Old antibodies are present and new antibodies are formed

\- IgG is the antibody involved

Active vs. Passive Immunity

\- occurs when the person produces an immune response to the antigen

vs

\- occurs when a person receives antibodies produced by another individual, mother’s milk

Live Virus Vaccine

Live virus is often gives orally or nasally, can multiply in the body without harming it, quicker protections

but people with a weak immune system can get sick from the vaccine

Killed Virus Vaccine

safer because it cannot multiply in the body, made quicker

vaccine must be given in larger doses which can cause a reaction with some people

Antibiotics vs Vaccines

antibiotics are used for bacteria, fungi

vaccines are used for viruses; causes immune system to create antibodies against antigen

HIV

can be contracted by contact with blood, sperm, breast milk

symptoms: fever, weight loss, swollen lymph gland, night sweats, sore throat, rash, genital sore

affects T & T4 cells

\
There are antiviral drugs that can keep levels of HIV low

There is no cure since HIV is an RNA virus and it **mutates**

AIDS

acquired immunodeficiency sydrome

the most advanced stage of HIV infection

HIV becomes AIDS when the T4 cell count drops below 200

Polio

path in the body: moves from intestines to the bloodstream, then the nervous system

spread by water

fever, fatigue, headache, vomiting, stiffness of neck, pain in limbs, muscle weakness

there is now a vaccine taken orally when we are babies