MCAT Biology Lymph, Circulatory, and Immune System Flashcards
A constant nervous input to the arteries that keeps them somewhat constricted to maintain a basal level of blood pressure
Adrenergic tone
__are proteins secreted by active B-cells (plasma cells) that bind in a highly specific manner to foreign proteins (such as those found on surface of pathogens and transplanted tissues).
Antibodies
___do not destroy antigens directly, rather, they mark them for destruction through other methods, and can inactivate antigens by clumping them together or by covering necessary active sites
Antibody
A molecule (usually a protein) capable of initiating an immune response
Antigen
Cells that possess MHC 2 (B cells and macrophages) and are able to display bits of ingested antigens on their surface in order to activate T cells
Antigen-Presenting cells
Also known as the bundle of His
Antrioventricular (AV) bundle
The ___ separates the right atrium from the right ventricle
Tricuspid valve
The ___ separates the left atrium from the left ventricle
Bicuspid valve
The tricuspid and bicuspid valves close at the beginning of ___ preventing the backflow of blood from ventricles to atria, and producing the first heart sound
Systole
A type of lymphocyte that can recognize (bind to) an antigen and secrete an antibody specific for that antigen.
B cell
When activated by binding an antigen ___ mature into plasma cells (that secrete antibodies) and memory cells (that patrol the body for future encounters with that antigen)
B cell
A sensory receptor that responds to changes in pressure they are located in the carotid arteries and the aortic arch to monitor blood pressure
Baroreceptor
The tendency of certain factors to stabilize hemoglobin in the tense conformation, thus reducing its affinity for oxygen and enhancing the release of oxygen to the tissues
Bohr effect
An enzyme present in erythrocytes (As well as other places) that catalyzes the conversion of CO2 and H20 into carbonic acid
Carbonic anhydrase
The specialized cells of the heart that spontaneously initiate action potentials and transmit them to the cardiac muscle cells. The cells of the conduction system are essentially cardiac muscle cells, but lack the contractile fibers of the muscle cells, but lack the contractile fibers of the muscle cells, thus they are able to transmit impulses (AP’s) more quickly and efficiently than cardiac muscle tissue
Cardiac conduction system
The volume of blood pumped out of the heart in one minute (Vol/minute)
Cardiac output
A group of blood proteins that bind non-specifically to the surface proteins of foreign cells (such as bacteria), ultimately leading to the destruction of the foreign cell
Complement system has four major function, including lysis of infectious organisms, activation of inflammation, opsonization and immune clearance.
The pressure measured in the arteries while the ventricls are relaxed (during diastole)
Diastolic pressure
Cells that form the inner linings of arteries,veins, and the walls of capillaries involved in a number of important vascular functions
Endothelial cells
The specific site on an antigenic molecule that binds to a T-cell receptor or to an antibody
Epitope
The conversion of __ to its active form___is among the final steps in the clot formation, and is triggered by thrombin
Fibrinogen (inactive) fibrin (active)
Formed elements include__,___,___
erythrocytes, leukocytes, and platelets
A mechanism by which the stroke volume of the heart is increase by increasing the venous return to the heart ( thus stretching the ventricular muscle)
Frank-Starling mechanism
A tissue in which the cytoplasms of the cells are connected by gap junctions, allowing the cells to function as a unit. Ex: cardiac and smooth muscle)
Functional syncytium
