Life 50- Circulatory Systems. Flashcards
Myocardial infarction
Blockage of an artery that carries blood to the heart muscle
Cardiac cycle
Contraction of the two atria of the heart, followed by contraction of the two ventricles and then relaxation
Platelet
A membrane-bounded body without a nucleus, arising as a fragment of a cell in the bone marrow of mammals. Important to blood-clotting action.
Precapillary sphincter
A cuff of smooth muscle that can shut off the blood flow to a capillary bed
Aorta
The main trunk of the arteries leading to the systemic (as opposed to the pulmonary) circulation.
Erythrocyte
A red blood cell
Atherosclerosis
A disease of the lining of the arteries characterised by fatty, cholesterol-rich deposits in the walls of the arteries
Lymph node
A specialised structure in the vessels of the lymphatic system that contains cells that encounter and respond to foreign cells and molecules in the extracellular fluid as it passes through the vessels.
Plaque
A region of arterial wall invaded by fibroblasts and fatty deposits
Purkinje fibres
Specialised hear muscle cells that conduct excitation throughout the ventricular muscle.
Open circulatory system
Circulatory system in which extracellular fluid leaves the vessels of the circulatory system, percolates between cells and through tissues, and then flow back into the circulatory system to be pumped out again
Capillaries
Very small tubes, especially the smallest blood-carrying vessels of animals between the termination of the arteries and the beginning of the veins; the site of exchange of materials between the blood and the interstitial fluid.
Closed circulatory system
Circulatory system in which the circulating fluid is contained within a continuous system of vessels
Thrombus
A blood clot that forms within a blood vessel and remains attached to the wall of the vessel.
Bundle of His
Fibres of modified cardiac muscle that conduct action potentials from the atria to the ventricular muscle mass.
Baroreceptor
A pressure-sensing cell or rogan. Sometimes called a stress receptor.
Lymphatic system
A system of vessels that returns interstitial fluid to the blood.
Embolism
A blockage of a vessel resulting from a circulating blood clot
Pulmonary valve
A one-way valve between the right ventricle of the heart and the pulmonary artery that prevents back flow of blood into the ventricle when it relaxes.
Electrocardiogram (ECG)
A graphic recording of electrical potentials from the heart.
Ventricle
A muscular heart chamber that pumps blood through the lungs or through the body
Sinoatrial node
The pacemaker of the mammalian heart.
Artery
A muscular blood vessel carrying oxygenated blood away from the heart to other parts of the body
Diastole
The portion of the cardiac cycle when the heart muscle relaxes.
Systemic circuit
Portion of the circulatory system by which oxygenated blood from the lungs or gills is distributed throughout the rest of the body and returned to the heart.
Hypoxia
A deficiency of oxygen.
Vein
A blood vessel that returns blood to the heart.
Lymph
A fluid derived from blood and other tissues that accumulates in intercellular spaces throughout the body and is returned to the blood by the lymphatic system.
Coronary artery
An artery that supplies blood to the heart muscle
Atrium
An internal chamber. In the hearts of vertebrates, the thin-walled chamber(s) entered by blood on its way to the ventricle(s). Also, the outer ear.
Circulatory system
A system consisting of a muscular pump, a fluid, and a series of conduits that transports materials around the body
Plasma
The liquid portion of blood, in which blood cells and other particulates are suspended
Systole
Contraction of a chamber of the heart, driving blood forward in the circulatory system.
Cardiovascular system
The heart, blood, and vessels.
Atrioventricular node
A modified node of cardiac muscle that organises the action potentials that control contraction of the ventricles.
Erythropoietin
A hormone produced by the kidney in response to lack of oxygen that stimulates the production of red blood cells.
Aortic valve
A one-way valve between the left ventricle of the heart and aorta that prevents backflow of blood into the ventricle when it relaxes
Fibrin
A protein that polymerises to from long threads that provide structure to a blood clot
Starling’s forces
The two opposing forces responsible for water movement across capillary walls: blood pressures which squeezes water and small solutes out of the capillaries, and osmotic pressure, which pills water back into the capillaries.
Fibrinogen
A circulating protein that can be stimulated to fall out of solution and proved the structure for a blood clot
Pulmonary circuit
The portion of the circulatory system by which blood is pumped from the heart to the lungs or gills fro oxygenation and back to the heart for distribution
Arteriole
A small blood vessel arising from an artery that feeds blood into a capillary bed.
Coronary thrombosis
A fibrous clot that blocks a coronary artery
Frank-Starling law
The stroke volume of the heart increases with increased return of blood to the heart.
Spleen
Organ that serves as a reservoir for venous blood and eliminates old, damaged red blood cells from the circulation.
Thrombin
An enzyme that converts fibrinogen to fibrin, thus triggering the formation of blood clots
Venule
A small blood vessel draining a capillary bed that joins others of its kind to form a vein.
Embolus
A circulating blood clot
Thoracic duct
The connection between the lymphatic system and the circulatory system.
