The Lymphatic System and Immunity

Flashcards about the lymphatic system and immunity.

What is the function of lymph?

It's a fluid in tissue spaces that carries protein molecules and other substances back to the blood.

What are the major functions of the lymphatic system?

Draining interstitial fluid, transporting dietary lipids, and facilitating immune responses.

What type of movement do lymphatic vessels permit?

Only one-way movement of lymph.

Describe lymphatic vessel capillaries.

Tiny, blind-ended tubes in tissue spaces made of one cell layer of simple squamous epithelium.

What is the special name for lymphatic capillaries in the intestinal wall and what is their function?

Lacteals, for fat transportation.

What areas does the right lymphatic duct drain lymph from?

The right upper extremity, right side of the head, neck, and upper torso.

What is the largest lymphatic vessel?

The thoracic duct.

What is the cisterna chyli?

An enlarged pouch along the thoracic duct's course.

What are the functions of lymph nodes?

Filter lymph, defense, and WBC formation.

How does lymph flow through lymph nodes?

Via several afferent lymph vessels to the node and drained from the node by a single efferent lymph vessel.

What are the functions of the thymus?

Plays a vital role in immunity, produces T-lymphocytes, and secretes thymosins.

What happens to the lymphoid tissue in the thymus with age?

It's largely replaced by fat in a process called involution.

What are the three masses of lymphoid tissue that compose the tonsils?

Palatine tonsils, pharyngeal tonsils (adenoids), and lingual tonsils.

What is a potential issue with enlarged pharyngeal tonsils?

May impair breathing.

What are the functions of the spleen?

Phagocytosis of bacteria and old RBCs, and acts as a blood reservoir.

What is a splenectomy?

Surgical removal of the spleen.

What does the immune system protect the body from?

Pathologic bacteria, foreign tissue cells, and cancerous cells.

What are examples of nonspecific immunity?

Skin, tears, mucus, and inflammation.

What is the function of tears and mucus in immunity?

Wash eyes and trap and kill bacteria.

What are the effects of inflammation in immunity?

Attracts immune cells, increases blood flow and vascular permeability, promotes WBC movement.

What are the two types of specific immunity?

Inherited/inborn immunity and acquired immunity.

What are the two types of natural immunity?

Active (due to active disease) and passive (mother to fetus/child).

What are the two types of artificial immunity?

Active (vaccination) and passive (protective material from another individual).

What are antibodies?

Protein compounds with specific combining sites that attach to specific antigens.

What is an antigen-antibody complex called and what type of immunity is it?

Humoral or antibody-mediated immunity.

What are the possible effects of antigen-antibody complexes?

Neutralize toxins, clump enemy cells, promote phagocytosis.

What is the function of complement proteins?

Important mechanism of action for antibodies and Causes cell lysis

What are the types of phagocytes?

Neutrophils, monocytes, and macrophages.

What are Kupffer's cells?

Macrophages in the liver.

What are dust cells?

Macrophages in the lung.

What are the two stages of B cell development?

Immature B cell and activated B cell.

Where does the first stage of B cell development take place?

Liver and bone marrow before birth, and bone marrow only in adults.

What happens during the second stage of B cell development?

Immature B cell becomes activated by contact with antigens and forms plasma cells and memory cells.

What is the function of plasma cells?

Secrete antibodies into the blood.

What happens during subsequent exposure to an antigen that activated the B cell.

Memory cells become plasma cells and secrete antibodies.

What is the function of B cells?

Produce humoral immunity by developing into plasma cells that secrete antibodies.

Where does the first stage of T cell development occur?

Thymus gland during few months before and after birth.

When does the second stage of T cell development occur?

When and if an antigen binds to the T cells' surface proteins.

What type of immunity do T cells produce?

Cell-mediated immunity.

How do T cells kill invading cells?

Releasing a substance that poisons cells and releasing chemicals that attract and activate macrophages.

What are the roles of active cytotoxic T cells

Directed against intracellular pathogens, some cancer cells, and tissue transplants