The Cardiovascular System Flashcards
What is the cardiovascular system made of?
heart, blood vessels and blood
What is pulmonary circulation?
the right side of the heart accepts the deoxygenated blood returning from the body and moves it to the lungs by the way of pulmonary arteries
What is systemic circulation?
the left side of the heart receives oxygenated blood from the lungs by the way of the pulmonary veins and forces it out to the body through the aorta
What are atria?
thin-walled structures where blood is received from either the venae cavae or the pulmonary veins
What is the venae cavae?
a large vein carrying deoxygenated blood into the heart
What are the pulmonary veins?
oxygenated blood entering the left heart
What are ventricles?
the chambers of the heart that pump blood into pulmonary and systemic circulation
What are atrioventricular valves?
valves that separate the atrias from ventricles
What are semilunar valves?
valves that separate ventricles from the vasculature
What is the tricuspid valve?
valve that separates the right atrium from the right ventricle; has three leaflets
What is the bicuspid/mitral valve?
valve that separates the left atrium from the left ventricle; has two leaflets
What is the pulmonary valve?
a valve that separates the right ventricle from the pulmonary circulation
What passage does the blood take through the heart and body?
Right Atrium —> Tricuspid Valve –> Right Ventricle —> Pulmonary Valve —> Pulmonary Artery —> Lungs —> Pulmonary Veins —> Left Atrium —> Mitral Valve —> Left Ventricle —> Aortic Valve —> Aorta —> Arteries —> Arterioles —> Capillaries —> Venules —> Veins —> Venae Cavae —> repeat
What is the pathway for electrical conduction?
SA Node —> AV node —> Bundle of His —> purkinje fiber
What does the SA node do and where is it?
Located in the right atrium; causes the atria to contract simultaneously which helps force the blood into the ventricles
What does the AV node do and where is it?
Located between atria and ventricle; this is where the signal is delayed here to allow the ventricles to fill
What does the Purkinje fibers do?
distributes the electrical signal through the ventricular muscle
What is the human heart rate?
60-100 beat per minute
What does systole mean? ignore this one
contraction
What does systole mean?
contraction and closure of the AV valves occurs and the blood is pumped out of the ventricles
What happens during diastole?
ventricles are relaxed, semilunar valves are closed and blood from the atria fills the ventricles
What is cardiac output?
total blood volume pumped by a ventricle in a minute
What is the equation for cardiac output?
CO = HR x SV CO = cardiac output HR = heart rate (beat per minute) SV = stroke volume (volume of blood pumped per beat)
What are the major types of vessels?
arteries, veins and capillaries
What do arteries do?
they move blood away from the heart
What is the largest artery?
the aorta
What are arterioles?
the vessels taking blood away from the heart that are smaller and in the tissue
What are capillaries?
very small vessels that perfuse into tissue and bring it oxygenated blood and take away the used blood
What are capillaries?
vessels with a single endothelial cell layer and are so small red blood cells can only go one at a time; thin wall allows for easy diffusion of gases, etc
What are venules?
small vessels that take deoxygenated blood back to the heart and connect capillaries to veins
What are veins and what do they do?
take deoxygenated blood BACK to the heart; thin-walled, inelastic vessels
What do endothelial cells do?
release chemicals that help with vasodilation and vasoconstriction; allow white blood cells to pass through and into tissue to help with inflammatory response
What do endothelial cells do?
release chemicals that help with vasodilation and vasoconstriction; allow white blood cells to pass through and into tissue to help with inflammatory response; help with blood clots
Which has more smooth muscle? arteries or veins?
arteries
What are arterioles?
smaller muscular arteries
What makes umbilical arteries and pulmonary arteries unique?
they are the only ones that carry deoxygenated blood
Which holds more blood volume? arteries of veins
veins
What are two mechanisms that help veins move blood upwards?
(1) Valves that open to let blood up but close when it tries to go down
(2) Skeletal muscle that surrounds the veins contracts, squeezing blood upwards
Superior vena cava vs Inferior vena cava
Superior returns blood to portions of the body above the heart while inferior goes below
What are portal systems?
systems in which blood will have to flow through two capillary beds before going back into circulation
What is the heptic portal system?
blood leaves capillary beds in the walls of the gut passes through the hepatic portal vein before reaching the capillary beds in the liver
What is the hypophyseal portal system?
blood leaving capillary walls in the hypothalamus travels to capillary bed in the anterior pituitary to allow for paracrine secretion of releasing hormones
What is the renal portal system?
blood leaving the glomerulus travels through an efferent ateriole before surrounding the nephron in a capillary network called the vasa recta
What is the composition of blood?
55% liquid and 45% cells
What is plasma?
the liquid portion of blood, an aqueous mixture of nutrients, salts, respiratory gases, hormones and blood proteins
What are three major types of blood cells?
erythrocytes, leukocytes and platelets
What are erythrocytes?
aka red blood cells; designed for specialized transport of oxygen. Red blood cells have 250 million molecules of hemoglobin, which binds four oxygen each
What is hematocrit?
a measure of how much of the blood sample contains red blood cells
What is a normal hemoglobin value for males and females?
13.5/17.5 g/dL males; 12.0/16.0 g/dL females
What is a normal hematocrit value for males and females?
41-53% males; 36-46% females
What are two tings that make erythrocytes unique?
(1) biconcave - indented on both sides with increases surface area and helps travel
(2) Loss organelles, like mitochondria, when they mature - so they do not use up the oxygen they are carrying and only use glycolysis
What are leukocytes?
aka white blood cells; less than 1% of blood volume
What are the five types of leukocytes and the two categories they come in?
(1) Granulocytes - neutrophils, eosinophils, basophils
(2) Agranulocytes - lymphocytes and monocytes
What do granulocytes do?
they release toxic compounds from the granules; they are active in inflammatory responses, allergies, pus formation and destruction of bacteria and parasites
What are lymphocytes jobs?
to attack specific pathogens and retain a memory bank of those pathogens
What are the types of lympocytes and where did they come from?
B-cells - matured in the bone marrow
T-cells - matured in the thymus
What do monocytes do?
phagocytize foreign material
What are thrombocytes?
aka platelets; cell fragments/shards released from cells in bone marrow known as megakaryocytes that assist with blood clotting
What is hematopoiesis?
production of blood cells and platelets
What is erythropoietin?
secreted by the kidney and stimulates mainly red blood cell development
What is thrombopoietin?
secreted by the liver and kidney and stimulates mainly platelet development
What is an antigen?
a surface protein/target to which to immune system can react
What are the two major antigen families for blood groups?
ABO antigens and Rh factors
How does the ABO system work?
A,B, and O are three different allele types. A and B are considered dominant. If the allele is on both or one of the chromosomes, then it will be Type A or Type B. If the A allele is on one chromosome and B on another, it’s AB. The O is recessive so to be Type O you need to be homozygous.
Who are universal donors?
Type O
Who are universal recipients?
Type AB
What is the Rh factor?
a surface protein expressed on red blood cells
What is erythroplastosis fetalis?
when the mother and fetus have different Rh factors and the mother produces antibodies during her first pregnancy against the fetus Rh factor. If the second child is also different, there will now be antibodies ready to attack it
What is blood pressure?
measure of the force per unit area exerted on the wall of the blood vessels
What device measures blood pressure?
sphygmomanometer
Blood pressure is ______ over _______.
systolic (ventricular contraction) / diastolic (ventricular relaxation)
What is the equation for cardiac pressure?
deltaP = CO x TPR deltaP = pressure differential across the circulation CO = cardiac output TPR = total peripheral (vascular) resistance
What are baroreceptors?
specialized neurons that detect changes in the mechanical forces on the walls of the vessel
Contraction of blood vessels caused the blood pressure to _______.
increase
What is hemoglobin?
a protein composed of four cooperative subunits, each of which has a prosthetic heme group that binds to an oxygen molecule
What is oxygen saturation?
percentage of hemoglobin molecules carrying oxygen; healthy is around 97%
How is carbon dioxide broken down and excreted?
(1) CO2 enters a red blood cell
(2) Carbonic anhydrase catalyzes reaction between CO2 and H2O to form carbonic acid
(3) Carbonic acid dissociates into a proton and bicarbonate anion
(4) These dissolve into the blood stream and exhaled through the lungs
CO2 + H2O H2CO3 H+ + HCO3-
What is a Bohr effect?
Too much CO2 production will create a lot of H+ ions. These can bind to hemoglobin and reduces the affinity to oxygen. Shifts curse to the right.
Fetal hemoglobin has a ________ affinity to oxygen than adult hemoglobin.
higher
What is hydrostatic pressure?
force per unit area that the blood exerts against the vessel walls; pushes water out of bloodstream, through walls and into the interstitium
What is osmotic/oncotic pressure?
“sucking” pressure generated by solutes as they attempt to draw water into the bloodstream from the interstitium
What are Starling forces?
the balance of the opposing hydrostatic and osmotic pressure
What is edema?
accumulation of excess fluid in the interstitium
What are blood clots?
composed of both coagulation factors (proteins) and platelets, and they prevent (or minimize) blood loss
A coagulation cascade ends with ______ forms ______. This converts ______ into ______.
Prothrombin; thrombin; fibrinogen; fibrin
What breaks blood clots down?
plasmin generated by plasminogen
What starts the coagulation cascade?
exposure of collagen and tissue factor to platelets and coagulation factors
