Week 6 - Cardiovascular System Flashcards
Blood
liquid connective tissue composed of formed elements—erythrocytes, leukocytes, and platelets—and a fluid extracellular matrix called plasma; component of the cardiovascular system
Red Blood Cells
One of the formed elements of blood that transports oxygen (aka erythrocytes)
White Blood Cells
One of the formed elements of blood that provides defense against disease agents and foreign materials (aka leukocytes)
Platelets
One of the formed elements of blood that consists of cell fragments broken off from megakaryocytes (aka thrombocytes)
Plasma
In blood, the liquid extracellular matrix composed mostly of water that circulates the formed elements and dissolved materials throughout the cardiovascular system
Haematocrit
The volume percentage of erythrocytes in a sample of centrifuged blood
Haemopoiesis
Erythropoiesis
Erythropoietin (EPO)
glycoprotein that triggers the bone marrow to produce RBCs; secreted by the kidney in response to low oxygen levels
Antigen
A molecule recognised by the receptors of B and T lymphocytes
Antibodies
Antigen-specific proteins produced by specialised B lymphocytes that protect the body by binding to foreign objects such as bacteria and viruses
ABO Blood Group
blood-type classification based on the presence or absence of A and B glycoproteins on the erythrocyte membrane surface
Heart
Atrium
upper or receiving chamber of the heart that pumps blood into the lower chambers just prior to their contraction; the right atrium receives blood from the systemic circuit that flows into the right ventricle; the left atrium receives blood from the pulmonary circuit that flows into the left ventricle
Ventricle
one of the primary pumping chambers of the heart located in the lower portion of the heart; the left ventricle is the major pumping chamber on the lower left side of the heart that ejects blood into the systemic circuit via the aorta and receives blood from the left atrium; the right ventricle is the major pumping chamber on the lower right side of the heart that ejects blood into the pulmonary circuit via the pulmonary trunk and receives blood from the right atrium
Valves
in the cardiovascular system, a specialised structure located within the heart or vessels that ensures one-way flow of blood
Heart Sounds
sounds heard via auscultation with a stethoscope of the closing of the atrioventricular valves (“lub”) and semilunar valves (“dub”)
Cardiac Conduction System
Sinoatrial Node
Known as the pacemaker, a specialised clump of myocardial conducting cells located in the superior portion of the right atrium that has the highest inherent rate of depolarisation that then spreads throughout the heart
Atrioventricular Node
A clump of myocardial cells located in the inferior portion of the right atrium within the atrioventricular septum; receives the impulse from the SA node, pauses, and then transmits it into specialized conducting cells within the interventricular septum
Atrioventricular Bundle
A group of specialised myocardial conductile cells that transmit the impulse from the AV node through the inter ventricular septum; form the left and right atrioventricular bundle branches
Left and Right Bundle Branches
specialised myocardial conductile cells that arise from the bifurcation of the atrioventricular bundle and pass through the inter ventricular septum; lead to the Purkinje fibres and also to the right papillary muscle via the moderator band
Purkinje fibres
specialised myocardial conduction fibres that arise from the bundle branches and spread the impulse to the myocardial contraction fibres of the ventricles
Electrocardiogram (ECG)
surface recording of the electrical activity of the heart that can be used for diagnosis of irregular heart function; also abbreviated as EKG
Cardiac Cycle
period of time between the onset of atrial contraction (atrial systole) and ventricular relaxation (ventricular diastole)
Atrial Contraction
Ventricular Contraction
Atrial Diastole
Cardiac Output
amount of blood pumped by each ventricle during one minute; equals HR multiplied by SV
Systemic Circulation
Pulmonary Circulation
Arteries
blood vessels that conducts blood away from the heart; may be a conducting or distributing vessel
Veins
A blood vessel that conducts blood toward the heart
Capillaries
The smallest of blood vessels where physical exchange occurs between the blood and tissue cells surrounded by interstitial fluid
Systolic Pressure
The larger number recorded when measuring arterial blood pressure; represents the maximum value following ventricular contraction
Diastolic Pressure
The lower number recorded when measuring arterial blood pressure; represents the minimal value corresponding to the pressure that remains during ventricular relaxation
Blood Pressure
a force exerted by the blood against the wall of a vessel or heart chamber; can be described with the more generic term hydrostatic pressure
Mean Arterial pressure
The average driving force of blood to the tissues; approximated by taking diastolic pressure and adding 1/3 of pulse pressure
Baroreceptor reflex
autonomic reflex in which the cardiac centres monitor signals from the baroreceptor stretch receptors and regulate heart function based on blood flow
Baroreceptors
mechanoreceptor that senses the stretch of blood vessels to indicate changes in blood pressure
Renin-Angiotensin-Aldosterone system
Renin
The enzyme produced by juxtaglomerular cells in response to decreased blood pressure or sympathetic nervous activity; catalyses the conversion of angiotensinogen into angiotensin
Angiotensin
Aldosterone
hormone produced and secreted by the adrenal cortex that stimulates sodium and fluid retention and increases blood volume and blood pressure
