A&P II: Lymphatic/Immune System - Midterm Review

Lymphatic System

assists the cardiovascular system by transporting the excess fluid from the body tissues**

Lymphocytes

made in bone marrow; type of WBC**

Lymphokinesis**

Movement (flow) of lymph

Lymphatic Organs & Tissues

Primary lymphatic organs:

1. Red bone marrow - where lymphocytes are produced

2. Thymus - mature and become immunocompetent (able to fight off disease)

Secondary lymphatic organs/tissues:

1. Lymph nodes

2. Spleen

3. Lymphatic nodules

Thymus

• “boot camp”

• immature T cells migrate from the red bone marrow to the thymus where they mature

• most active in the fetus & child

• located below thyroid gland

  • necessary for t cell maturation (immunologically competent)

Lymphatic Nodules

• small unencapsulated masses of lymphatic tissue

• destroys pathogens that penetrate the epithelium

  • Tonsils - lymph nodules of the pharynx**

  • Peyer’s patches - nodules of small intestines**

Two main types of immune responses**

1. Non-specific (innate) immunity - born with it; 1st & 2nd line of defense

2. Specific (adaptive) immunity - cell mediated immunity & antibody mediated immunity

Innate (non-specific) immunity - defense cells**

Natural killer cells: destroys foreign cells by rupturing the cell membranes; lymphocytes that kill many types of tumor cells

5 classes of antibodies:

1. IgM: first produced antibody by B cell; 1st response in allergic reactions

2. IgG: most abundant antibody; can cross placenta immunity from mother to fetus

3. IgA: found in mucous membranes; tears & saliva, colostrum & breast milk

4. IgE: produce allergic responses; can be harmful - hypersensitivities

5. IgD: present in blood; function unknown

T & B cells are responsible for __________ immunity

specific adaptive immunity

Antibodies are made by the

B lymphocytes

T-cell originate in the

bone marrow

There are how many types of antibodies?

5 types - IgM, IgG, IgA, IgE, IgD

The first antibody to be made is

IgM

What antibody is found in tears and saliva?

IgA

T-lymphocytes are responsible for what immunity?

cell-mediated

The largest anatomical defense is the

skin (integument); 1st line of defense

What antibody is made during the second contact with an antigen?

IgG

The proteins on the surface of a cell that identify that cell are called

antigens

T-lymphocytes mature in the

thymus gland

________ are lymphoid tissues found in the small intestines

Peyer’s patches

Thoracic lymphatic collecting ducts empty their contents into the _________ veins

left subclavian

Right lymphatic duct

right upper quadrant

Thoracic duct

rest of the body

Active Vs. Passive Immunity

Active immunity: occurs when our own immune system is responsible for protecting us from a pathogen.

Passive immunity: occurs when we are protected from a pathogen by immunity gained from someone else.

_____ immunity results when immunity to a disease that has developed in another individual or animal is transferred to an individual who was not previously immune.

Passive

Which two special types of lymphocytes play a major role in immunity?

B cells and T cells

Adaptive immunity, part of the body’s third line of defense, is orchestrated by two different classes of a type of white blood cell called the

lymphocyte

The body’s defense mechanisms can be organized into one of two major categories of immune mechanisms; these are

innate and adaptive immunity.

Because T cells attack pathogens more directly, T-cell immune mechanisms are classified as _____ immunity

Cell mediated

The function of T cells is to produce

Cell-mediated immunity

The lymphatic system serves various functions in the body. The two most important functions are

• Fluid balance

• Immunity