Cardiovascular System (Heart) Flashcards
It’s when the heart relaxes, the chambers of the heart fill with blood, and a person’s blood pressure decreases.
Diastole
The upper right chamber that receives deoxygenated blood from the body via both the superior vena cava and inferior vena cava, pumping blood into the right ventricle
Right atrium
Blood normally flows continually from the great veins
into the ________
atria
________ carry blood away from the heart, looking bright red because it’s full of oxygen
Arteries
Two circuits/circulation loop
Systemic circuit; pulmonary circuit
Layer of the pericardium that acts as a barrier, a fibrous tissue that protects and anchors
the heart and makes sure that it stays in place
Parietal pericardium
______ carry it back toward the heart, looking dark red because of its lack of oxygen
Veins
The three layers of the heart wall
Epicardium
Myocardium
Endocardium
________ body temperature, as occurs when one has
fever, causes a greatly increased heart rate, sometimes to double normal.
Increased
It is a specialized conductive system, a bundle of conductive fibers several millimeters in diameter
A-V bundle
Strong stimulation of the ___________ nerve fibers in the vagus nerves to the heart can stop the heartbeat for a few seconds
parasympathetic
When heart rate ________, the duration of each
cardiac cycle _________, including the contraction and
relaxation phases.
increases; decreases
Two layers of the pericardium
Visceral pericardium
Parietal pericardium
_________fluid fills the space
between the layers of pericardium.
Serous/pericardial fluid
Cardiac muscle is a _______ of many heart muscle cells in which the cardiac cells are so interconnected that when one of these cells becomes excited, the action potential spreads to all of them, from cell to cell throughout the latticework interconnections.
syncytium
Inner layer of the heart wall
Endocardium
The dark areas crossing the cardiac muscle fibers in are called ___________
intercalated discs
_______ prevent backflow of blood from the
ventricles to the atria during systole
A-V valves (the tricuspid and mitral valves)
__________ exhibit either automatic rhythmical electrical discharge in the form of action potentials or conduction of the action potentials through the heart, providing an excitatory system that controls the rhythmical beating of the heart
specialized excitatory and conductive fibers
The _____ then supply the main pumping force of the heart that propels the blood
ventricles
Three major types of cardiac muscle
atrial muscle
ventricular muscle
conductive muscle fibers
The heart is actually two separate pumps: a RIGHT heart that pumps blood through the _______, and a LEFT heart that pumps blood through the _________.
lungs; peripheral organs
_________ pericardium produce pericardial fluid, lubricating the heart
Serous
________ pericardium attach great vessels (top of heart) to central tendon of diaphragm (bottom of heart)
Fibrous
A fibrous sac that lubricate heart, prevent friction, and maintain hollow space for heart expansion
Pericardium
These are the semilunar valves
aortic and pulmonary artery valves
___________ are cell membranes that separate individual cardiac muscle cells from one another, ensuring that the cardiac muscle functions as a single and well-coordinated unit
Intercalated discs
Two main chambers of the heart
Atrium
Ventricle
The strength of contraction of cardiac muscle depends
to a great extent on the concentration of _________ ions in the extracellular fluids.
calcium
Excess _________ in the extracellular fluids causes the heart to become dilated and flaccid and also slows the heart rate.
potassium
high pressure caused by ventricular contraction
Systole
_______ increases the permeability of the cardiac muscle membrane to ions that control heart rate, resulting in acceleration of the self-excitation process.
Heat
______________ refers to the mechanism by which the action potential causes the myofibrils of muscle to contract.
Excitation-contraction coupling
These are the A-V valves
tricuspid valve
mitral valve
Innermost layer of the pericardium
Visceral pericardium
__________ prevent backflow from the aorta and pulmonary arteries into the ventricles during diastole
Semilunar valves (the aortic and pulmonary artery valves)
Two Serous Pericardium Layers
Parietal (outside pericardial cavity)
Visceral (directly outside of heart)
The outside layer of the heart wall
Epicardium
the rate of oxygen consumption by the heart is an excellent measure of the _______ energy liberated while the heart performs its work.
chemical
[Reason for Long Action Potential and Plateau]
the _________ (increased, decreased) potassium permeability greatly decreases the outflux of positively charged potassium ions during the action potential plateau and thereby prevents early return of the action potential voltage to its resting level.
decreased
________ cells keep the heart beating at the correct rhythm and ensure that each cardiac muscle cell contracts in coordination with the others.
Pacemaker
The __________ and _________ are the big exception to the artery/vein, oxygen/no oxygen rule
pulmonary veins and arteries
Middle layer of the heart wall
Myocardium
__________ stimulation increases the force of heart contraction to as much as double normal, thereby increasing the volume of blood pumped and increasing the ejection pressure.
sympathetic
They are the receiving chambers
Atria
The circulatory system is a _____ tubular system
closed
__________ allow rapid diffusion of ions so action potentials travel easily from one cardiac muscle
cell to the next, past the intercalated discs.
Gap junctions
It is a double serous membrane that lines the entire heart.
Pericardium
a big vessel that splits to form the left and right pulmonary arteries
Pulmonary trunk
The upper left chamber that receives oxygenated blood from the lungs via the pulmonary veins, pumping it into the left ventricle
Left atrium
Each ______ is a weak primer pump for the ventricle, helping to move blood into the ventricle.
atrium
Each cycle in cardiac cycle is initiated by spontaneous generation of an action potential in the _________
sinus node
The lower right chamber that receives blood from the right atrium, carrying blood to the lungs to be oxygenated via pulmonary artery
Right ventricle
The cardiac events that occur from the beginning of
one heartbeat to the beginning of the next
Cardiac cycle
The lower left chamber that receives blood from the left atrium, pumping it into the aorta
Left ventricle
