Chapter 7: Immune System Flashcards
Lymphatic system functions:
- Lymphatic capillaries absorb excess interstitial fluid and return it to the bloodstream.
- Lacteals in small intestine absorb dietary fas and transport them to blood stream.
- Production, maintenance, and distribution of lymphocytes in body.
- Helps in defense against pathogens.
Lymphatic vessels carry a fluid called:
lymph
Lymphatic vessel begin as what in the tissues?
Lymphatic capillaries
What are the two lymphatic ducts?
Thoracic duct and right lymphatic duct.
What does the thoracic duct do?
Collects lymph from the body below the thorax, the left arm, and the left side of the head and neck and empties into the left subclavian vein.
What does the right lymphatic duct do?
returns lymph from the right arm and right side of the head and neck into the right subclavian vein.
What body parts are apart of the lymphatic system?
Tonsil, red bone marrow, thymus, spleen, thoracic duct
What is the function of the spleen in the lymphatic system?
cleanses the blood of cellular debris and bacteria. Connective tissue divides it into white pulp and red pulp. Has thin outer capsule.
Lymphatic vessels have the presence of what and what does it do?
Presence of valves and it prevents the lymph from flowing backward.
Lymphatic Organs
Primary lymphatic organs and secondary lymphatics organ
What are the primary lymphatic organs
Red bone marrow and thymus
What are the secondary lymphatic organs?
Lymph nodes, spleen and tonsils
Red Bone marrow:
site of blood cell reproduction, B cells mature here.
Thymus:
In thoracic cavity superior to the heart. Produces thymosin, a hormone that matures the T cells.
Lymph nodes:
found along the lymphatic vessels, they filter lymph. has a capsule to divide the compartments and it is filled with macrophages that engulfs pathogens. Also houses lymphocytes which fight infections and cancer cells.
What are the two branches of our immune system?
Innate and Adaptive:
Does innate have to be functional with previous exposure to a pathogen?
No
Does innate have memory of pathogens?
No
What do innate immune defenses include?
Physical and chemical barriers to entry, inflammatory response, and protective proteins.
Physical barriers to entry:
Skin and mucous membranes. Skin has keratin to make it tough. Mucous membranes have ciliated cells which sweep away mucus with entrapped pathogens.
Chemical barriers to entry:
Acidic secretions of sebaceous glands weaken and kill bacteria on skin. Sweat, saliva and tears have lysozyme- an antibacterial enzyme. Normal flora prevent pathogens from taking up residence.
Acquired immunity examples:
Vaccine, exposure to virus, another person’s antibodies.
Apoptosis:
death of cells
Adaptive defenses come into play when:
- Innate defenses have failed to prevent an infection.
- Provide some protection against cancer
- Responds to antigens (immune system recognizes as foreign)
