The Lymphatic System and Immune Response

role of the cisterna chyli

enlarged terminus end of the thoracic duct that recieves lymph from the digestive organs empties lymph into venous circulation

Role of the right lymphatic duct

drains lymph from the right upper extremity, head, and thorax

thousand of lymph nodes are usually found ____ and are not ordinarily seen. Large collections of lymph nodes are found in ____ (3) regions of the body.

embedded in connective tissue inguinal, axillary, and cervical regions

explain the adaptive immune system

functional system that recognizes something as foreign and acts to destroy or neutralize it - aka immune response

Explain an Ig molecule

has a 3D shape that is generally Y shaped. the variable region of the light and heavy chains in each "arm" construct one antigen-binding site uniquely shaped to "fit" a specific antigenic determinant (portion) of an antigen Thus, each Ig monomer bears two identical sites that bind to identical antigenic determinants Binding the immunoglobulins to their complementary antigen(s) effectively immobilizes the antigens until they can be phagocytized or lysed by complement fixation

B cells provide this kind of immunity.

humoral immunity (antibody-mediated)

What is autoimmunity?

inability to recognize "self" or our own tissues from foreign antigens ("nonself"

These cells recognize antigens and initiate the immune response.

lymphocytes

cells that recognize antigens and initiate the immune response

lymphocytes - 2nd most numerous members of the leukocytes

The ________ pulp is responsible for the immune functions of the spleen.

white

Characteristics of immune response (3)

(1) memory - has a memory for previously encountered foreign antigens that is accurate and highly specific (2) specificity - each immunocompetent lymphocyte has receptors on its surface that allow it to bind with only one or a few very similar antigens, thus providing specificity (3) self tolerance - as a rule, our own proteins are tolerated, which reflects the ability of the immune system to distinguish our own tissues (self) from foreign antigens (nonself)

Functions of the lymphatic system (2)

(1) transports tissue fluid (lymph) to the blood vessels (2) protects the body by removing foreign material such as bacteria from the lymphatic stream and by serving as a site for lymphocyte "policing" of body fluids and for lymphocyte multiplication

Expalin Antibodies

- aka Immunoglobulins - produced by sensitized B cells and their plasma cell offspring in response to antigen - heterogeneous group of proteins that make up the gamma globulins - not only found in plasma but also in all body secretions - five major classes IgM, IgD, IgG, IgA, and IgE

Describe what happens to B and T cells after maturation

B and T cells leave the red bone marrow and thymus respectively and enter the blood stream and travel to secondary lymphoid organs where clonal selection occurs

primary cells that provide for the immune response

B and T lymphocytes aka B and T cells both originate in the red bone marrow each cell must go through a maturation process where they become immunocompetent and self-tolerant

Germinal centers in the cortex of lymph nodes contain primarily ________.

B cells

Describe the maturation process of B and T lymphocytes

Each cell must go through a maturation process where they become immunocompetent and self-tolerant. Immunocompetence involves the addition of receptors on the cell surface that recognize and bind to a specific antigen Self-tolerance involves the cell's ability to distinguish self from nonself B cells mature in the red bone marrow T cells travel to the thymus for their maturation process

As blood circulates through the body, the hydrostatic and osmotic pressures operating at the capillary beds result in fluid outflow at the arterial end of the bed and in its return at the venous end. However, not all of the lost fluid is returned to the bloodstream by this mechanism. _______ picks up this leaked fluid.

Lymphatic capillaries

Are antibodies cells?

No, they are a heterogeneous group of proteins that make up the general class of plasma proteins called gamma globulins

2 heavy chains that make up antibody monomers consist of ____

a constant (C) region = amino acid sequence is the same in a class of immunoglobulins AND a variable (V) region = amino acid sequence varies considerably between antibodies * same is true for two light chains; each has a constant and variable region

Ouchterlony Double-Gel Diffusion

an immunological technique that detects the presence of particular antigens in sera or extracts antigens and antibodies are placed in wells in a gel and allowed to diffuse toward each other if a antigen reacts with an antibody = precipitin line forms

All Igs are composed of one or more ____

antibody monomers - consists of 4 protein chains bound together by disulfide bridges - 2 of these chains are heavy chains = quite large with a high mol. weight - other 2 chains are light chains = only half as long and have a low mol. weight

Definition of antigen

anything capable of provoking an immune response and reacting with products of the response

In the tonsils, these structures trap bacteria and other foreign material.

crypts

Antigens that can provoke an immune response include ________.

foreign proteins, polysaccharides, and small molecules, called haptens that link to our own body proteins

A monomer consists of _____

four protein chains bound together by disulfide bridges

Although all of the organs below can raise an immune response, only this one filters the lymph.

lymph nodes

as lymph is transported, it filters through ____

lymph nodes which cluster along the lymphatic vessels of the body

secondary lymphoid organs

lymph nodes, spleen, tonsils, appendix

Describe lymphatic capillaries

lymphatic capillaries branch through nearly all the tissues of the body, and picks up leaked fluid, carries it through larger vessels - collecting lymphatic vessels to lymphatic trunks - until the lymph finally returns to the blood vascular system through one of the two large ducts in the thoracic region (right lymphatic duct and thoracic duct)

What makes up the lymphatic system?

lymphoid tissue, lymph nodes, lymphoid organs such as tonsils, thymus, and spleen

This medullary region of the lymph node contains primarily ________.

macrophages

Summarize the lymphatic system

one-way system, carries lymph ONLY towards the heart, pumpless system that depends largely on the milking action of the skeletal muscles and on pressure changes within the thorax that occur during breathing

The functions of the lymph system

protecting the body from foreign substances filtering the lymph fluid returning tissue fluid to the systemic circulatory system

role of the thoracic duct

recieves lymph from the rest of the body not including the right upper extremity, head, and thorax empties lymph into venous circulation

what is immune response

responding to something foreign by destroying or neutralizing it, it protects us from bacterial and viral infections, bacterial toxins, and cancer

Immunoglobulin classes share ____ and differ ____

share common basic structure, and differ functionally and in their localization in the body

collecting lymphatic vessels compared to veins of the blood vascular system

similar to veins b/c they have three tunics and are equipped with valves different b/c they are thinner-walled, have more valves, and branches more than veins

The right lymphatic duct drains ________.

the right side of the head and thorax, and the right upper extremity

Primary lymphoid organs

thymus and red bone marrow

what is clonal selection?

triggered when an antigen binds to the specific cell-surface receptors of a T or B cell which causes the lymphocyte to proliferate rapidly, forming a clone of like cells all bearing the same anti-gen specific receptors. Then in the presence of certain regulatory signals, the members of the clone specialize, or differentiate - some form memory cells and others become effector or regulatory cells