Cardiovascular System I Flashcards
- Delivers oxygen and nutrients to the body tissues.
- Carries away wastes such as carbon dioxide via blood.
Cardiovascular System
Pumps blood throughout the body in blood vessels.
Heart
Requires both the pumping action of heart and changes in blood pressure.
Blood Flow
Can make exchanges only with the interstitial fluid in their immediate vicinity.
Cells
Major function of the cardiovascular system.
Transportation
Transport vehicle that carries oxygen, nutrients, cell wastes, hormones, and other substances vital for body homeostasis.
Blood
Force to move the blood around.
Beating Heart and Blood Pressure
Includes a muscular pump equipped with one-way valves and a system of large and small blood vessels.
Cardiovascular System
Size and shape of the heart.
- Approximately the size of a person’s fist.
- Hollow, cone-shaped heart.
- Weighs less than a pound.
Medial section of the thoracic cavity where the heart is snugly enclosed with and flanked on each side by the lungs.
Inferior Mediastinum
- Directed toward the left hip and rests on the diaphragm, approximately at the level of the 5th intercostal space.
- Where to place the stethoscope to count the heart rate of the apical pulse.
Pointed Apex
- Broad posterosuperior aspect from which the great vessels of the body emerge.
- Points toward the right shoulder and lies beneath the second hip.
Base
- Sac that encloses the heart.
- Made up of three layers: outer fibrous layer and a pair of inner serous membrane.
Pericardium
- Loosely fitting superficial part of the pericardium.
- Helps protect the heart and anchors it to surrounding structures (diaphragm and sternum)
Fibrous Pericardium
Slippery, two-layered deep to the fibrous pericardium.
Serous Pericardium
Parietal layer of the serous pericardium that lines the interior of the fibrous pericardium.
Parietal Pericardium
Attaches to the large arteries leaving the heart, makes U-turn, continues inferiorly over the heart surface as the visceral layer.
Parietal layer at the superior aspect of the heart.
- Visceral layer of the serous pericardium which is part of the heart wall.
- Innermost layer of the pericardium and outermost layer of the heart wall.
Visceral Pericardium or Epicardium
Produces lubricating serous fluid.
Serous Pericardial Membranes
Where the serous pericardial membranes is collected.
Pericardial Cavity
Allows the heart to beat easily in a relatively frictionless environment.
Lubricating Serous Fluid
- Inflammation of the pericardium.
- Decrease in already small amounts of serous fluid.
- Causes pericardial layers to rub, bind, and stick to each other.
- Form painful adhesions that interfere with heart movements.
Pericarditis
Three layers that compose the heart walls.
- Outer Epicardium
- Myocardium
- Innermost Endocardium
- Thick bundles of cardiac muscle formed into ringlike arrangements.
- Layer that actually contracts.
- Reinforced internally by a network of dense fibrous connective tissue.
Myocardium
Linked together by intercalated discs that contain both demosomes and gap junctions.
Myocardial Cells
Allow ions to flow from cell to cell.
Gap Junctions at Intercalated Discs
- Thin, glistening sheet of endothelium that lines the heart chambers.
- Continuous with the linings of the blood vessels leaving and entering the heart.
Endocardium
Four hollow cavities or chambers of the heart.
- Two Atria
- Two Ventricles
Lines each chamber to help blood flow smoothly through the heart.
Endocardium
- Receiving chambers.
- Not important in the pumping activity of the heart.
- Assist with filling the ventricles.
- Blood flows under low pressure from the veins of the body and continues on to fill the ventricles.
Superior Atria
- Discharging chambers.
- Actual pumps of the heart.
- When they contract, blood is propelled out of the heart and into circulation.
Inferior, Thick-Walled Ventricles
Forms most of the heart’s anterior surface.
Right Ventricle
Forms the heart’s apex.
Left Ventricle
Septum that divides the atria longitudinally.
Interatrial Septum
Septum that divides the ventricles longitudinally.
Interventricular Septum
- Arteries carrying blood away from the heart.
- Veins carrying blood toward the heart.
Heart as a Double Pump
Function of the right side of the heart.
Pulmonary Circuit Pump
Receives oxygen-poor blood from the veins and pumps it through the pulmonary trunk.
Large Superior Vena Cava and Inferior Vena Cava
Splits into the right and left pulmonary arteries.
Pulmonary Trunk
Carry blood to the lungs where oxygen is picked up and carbon dioxide is unloaded.
Pulmonary Arteries
Oxygen-rich blood drains from the lungs and is returned to the left side of the heart.
Four Pulmonary Veins
- A circuit starting from the right ventricle (pump) to the lungs and back to the left atrium (receiving chamber)
- Carry blood to the lungs for gas exchange and return it to the heart.
Pulmonary Circulation
- Where the oxygen-rich blood that returned to the left atrium and flowed into the left ventricle is pumped out.
- From which the systemic arteries branch to supply all body tissues.
Aorta
- Where the oxygen-poor blood circulates from the tissues to the right atrium after oxygen is delivered to tissues.
- Empty into either the superior and inferior vena cava.
Systemic Veins
- Second circuit starting from the left ventricle through the body tissues and back to the right atrium.
- Supplies oxygen- and nutrient-rich blood to all body organs.
Systemic Circulation
- Pumps blood over the much longer systemic pathway.
- Walls are substantially thicker and much more powerful pump.
Left Ventricle
- Allow blood to flow in only one direction through the heart chambers.
- From the atria > through the ventricles > out the great arteries leaving the heart.
Four Valves of the Heart
- Valves located between the atria and ventricles on each side.
- Prevent backflow into the atria when the ventricles contract.
Atrioventricular (AV) Valves
- Left AV valve.
- Consists of two flaps or cusps of endocardium.
Bicuspid or Mitral Valve
- Right AV valve.
- Has three cusps of endocardium.
Tricuspid Valve
- Tiny white cords “tendinous cords.”
- Anchor the cusps to the walls of the ventricles.
- Tighten and anchor the cusps in a closed position.
Chordae Tendineae
When the heart is ____ and blood is passively ____ its chambers, the AV valve cusps hang limply into the ventricles.
Relaxed, Filling
As the ventricles ____ they press on the blood in their chambers and the pressure inside the ventricles (intraventricular pressure) begins to rise.
Contract
Forcing the AV valves cusps upwards results to.
Closing of the Valves
If the cusps were ____ they would blow upward into the atria.
Unanchored
- Second set of valves that guards the bases of the two large arteries leaving the ventricular chambers.
- Each valve has three cusps that fit tightly together when the valves are closed.
Semilunar Valves or Pulmonary and Aortic Semilunar Valve
When the ventricles are ____ and forcing blood out of the heart, the ____ are forced open and flattened against the walls of the ____ by the tremendous force of rushing blood.
Contracting, Cusps, Arteries
When the ventricles ____, the blood begins to flow ____ toward the heart and the cusps fill with ____ closing the valves.
Relax, Backward, Blood
Each set of valves operates at a ____ time.
Different
Open during heart relaxation and closed when the ventricles contract.
AV Valves
Closed during heart relaxation and are forced open when the ventricles contract.
Semilunar Valves
Force blood to continually move forward through the heart by opening and closing in response to pressure changes in the heart.
Valves
Operation of the AV valves.
- Blood returning to the atria puts pressure against AV valves. AV valves are forced open.
- As the ventricles fill, AV valve cusps hang limply into ventricles.
- Atria contract, forcing additional blood into the ventricles.
- Ventricles contract, forcing blood against AV valve cusps.
- AV valves close.
- Chordae tendineae tighten, preventing valve cusps from everting into the atria.
- AV valves open = greater atrial pressure than ventricular pressure.
Operation of the semilunar valves.
- As ventricles contract and intraventricular pressure rises, blood is pushed up against semilunar valves, forcing them to open.
- As ventricles relax and intraventricular pressure falls, blood flows back from arteries, filling the cusps of semilunar valves and forcing them to close.
Forces the heart to pump and repump the same blood because the valve does not close properly = blood backflows.
Incompetent Valve
- Valve become stiff because of repeated bacterial infection of the endocardium (endocarditis)
- Forces the heart to contract more vigorously to create enough pressure to drive blood through the narrowed valve.
Valvular Stenosis
Not nourished by the blood contained in the heart.
Myocardium
Functional blood supply that oxygenates and nourishes the myocardium.
Left and Right Coronary Arteries
Branch from the base of the aorta and encircle the heart in the coronary sulcus (atrioventricular groove) at the junction of the atria and ventricles.
Coronary Arteries
Major branches of the coronary arteries that are compressed when the ventricles are contracting and fill when the heart is relaxed.
- Left = Anterior Interventricular Artery and Circumflex Artery
- Right = Posterior Interventricular Artery and Marginal Artery
Drains the myocardium.
Cardiac Veins
- Where the cardiac veins are emptied into an enlarged vessel on the posterior of the heart.
- Emptied into the right atrium.
Coronary Sinus
Heart beats at a very rapid rate and receives an inadequate blood supply because relaxation periods are shortened.
Myocardium
Situations in which the myocardium is deprived of oxygen resulting in crushing chest pain.
Angina Pectoris
Area formed when the angina is prolonged and oxygen-deprived heart cells may die.
Infarct
Commonly called a heart attack or a coronary.
Myocardial Infarction
As the heart ____ or ____, the blood circulates into and out of the heart, through the rest of the body, and back to heart.
Beats, Contracts
Heart pumps about ____ quarts or ____ gallons of blood in a day.
6000 Quarts or 1500 Gallons
- Contract spontaneously and independently.
- Have different rhythms in different areas of the body.
Cardiac Muscle Cells
Beat about 60 times per minute.
Atrial Cells
Contract more slowly about 20 to 40 times per minute.
Ventricular Cells
One of the systems that act to regulate heart activity involves the nerves of the ____ to decrease or increase the heart rate depending on which division is activated.
Autonomic Nervous System
- Second system that is built into the heart tissue and sets its basic rhythm.
- Composed of a special tissue like a cross between muscle and nervous tissue.
- Causes heart muscle depolarization in only one direction = from the atria to the ventricles.
- Enforces a contraction rate of approximately 75 beats per minute.
Intrinsic Conduction System or Nodal System
Crescent-shaped node of tissue located in the right atrium.
Sinoatrial (SA) Node
A node at the junction of the atria and ventricles.
Atrioventricular (AV) Node
Bundle of His.
Atrioventricular (AV) Bundle
Located in the interventricular septum.
Right and Left Bundle Branches
Fibers that spread within the myocardium of the ventricle walls.
Purkinje Fibers
- Tiny cell mass.
- Has the fastest rate of depolarization and starts each heartbeat and sets the pace for the whole heart.
SA Node or Pacemaker
From the SA node, impulse spreads through the ____ walls to the ____ node and the ____ contract.
Atrial, AV, Atria
- At the AV node, impulse is delayed briefly to give the ____ time to finish contracting.
- It then passes rapidly into the ____, ____, and ____ resulting in a wringing contraction of the ventricles that begins at the heart apex and move toward the atria.
- Atria
- AV Bundle, Bundle Branches, and Purkinje Fibers
- Separates the atria and ventricles from one another.
- Part of the fibrous skeleton of the heart.
- Depolarization waves can reach the ventricles only by traveling through the AV node.
Insulating Connective Tissue
Ventricles begin to beat at their own rate and is much slower.
Heart Block
Lack of an inadequate blood supply to the heart muscle that may lead to fibrillation.
Ischemia
- Rapid, uncoordinated quivering of the ventricles.
- Prevents the heart from pumping any blood and a major cause of death from heart attack in adults.
Fibrillation
Used to help those experiencing sudden cardiac arrest.
Automatic External Defibrillator (AED)
Rapid heart rate of over 100 beats per minute.
Tachycardia
Heart rate that is substancially slower than normal of less than 60 beats per minute.
Bradycardia
- Means heart contraction and relaxation.
- Does most of the pumping work.
Systole and Diastole
- Refers to the events of one complete heartbeat, during which both atria and ventricles contract and relax.
- Average heartbeat = 75 beats per minute.
- Length of this cycle = 0.8 seconds.
Cardiac Cycle