immune system (old) Flashcards
Mucous membranes
Mucous membranes act as physical barriers for exposed areas of the body. These membranes produce sticky mucus containing enzymes (glycoproteins and lysozymes) that attack bacterial cell walls. They also have antiseptic properties that reduce the growth of microbes.
Platelets
Platelets are found in the blood and are involved in clotting blood when blood vessels break.
Atheromas
Atheromas are fatty deposits caused by high blood concentrations of cholesterol and fats in the arteries. These deposits build up over time and eventually block arteries which leads to cardiovascular issues.
Thrombosis
Thrombosis is the clotting within a blood vessel that blocks the blood vessel entirely. If a coronary artery is blocked, the cells in that part of the heart die and a heart attack occurs.
Blood clotting
Blood clotting is a result of multiple reactions that are triggered by damage to a blood vessel. Each reaction takes an inactive protein in the blood called a clotting factor and activates it. The last reaction during blood clotting is the conversion of soluble fibrinogen to insoluble fibrin.
Antigen
An antigen is any molecule that enters the body and triggers an immune response.
The 2 types of white blood cells/leukocytes
White blood cells (or leukocytes) have 2 types. The first type are macrophages (or phagocytes) which engulf pathogens. Once the pathogens are inside the macrophage, enzymes will be secreted that will digest the pathogen. The second type are lymphocytes. They recognize proteins and other molecules on the surface of pathogens as foreign.
B lymphocytes/B cells
A B lymphocyte (or B cell) contains receptors, which are essentially antibodies attached to its surface as an integral protein. When the B cell encounters an antigen, the B cells divide through mitosis to create multiple copies of itself in order to recognize the antigen in the future.
T lymphocytes/T cells
T lymphocytes (or T cells) help B cells make antibodies. The Antigen Presenting Cell traps the antigen and presents it to the T helper cell. Once the antigen has been recognized by the T helper cell, it triggers the production of antibodies and activates macrophages to engulf and destroy the antigen.
How does HIV infect the body on a cellular level?
HIV infects T helper cells which causes the inability to activate B cells and for them to produce antibodies, leading to the development of AIDS. HIV infects a cell by making a DNA copy from its RNA, with the help of transcriptase. Then, the cDNA that is produced is then inserted into the host’s cell genome.
Resistance to antibiotics
When a mutation occurs that causes resistance to an antibiotic, after several generations, the strain of bacteria will evolve genes that are resistant to the antibiotic. In some cases, bacteria can exchange genes coding for antibiotic resistance and develop resistance to multiple antibiotics.
Florey & Chain
After the discovery of penicillin by Fleming, Florey & Chain infected 8 mice with pneumonia. Then, 4 out of 8 of the mice were injected with penicillin. The mice that were not treated died within 24 hours, while the mice that were treated survived. Florey & Chain then tested penicillin on human patients with infections and most patients survived.
