Flashcards in Cardiovascular System Deck (70)
Primary function of the Cardiovascular System
Service cells of the body, bringing nutrients to cells and helping to remove waste.
How do lymphatic vessels help the cardiovascular system?
Lymphatic vessels help by collecting excess fluid surrounding tissues and returning it to the cardiovascular system.
Three Major Components of the Cardiovascular System
Four Functions of the Cardiovascular System
Generates blood pressure and moves blood
Exchange of nutrients and wastes at the capillaries
Regulates blood flow as needed by the body
Parts of the Closed Circuit Pathway of the Cardiovascular System
Heart -> Arteries -> Arterioles -> Capillaries -> Venules -> Veins
-> Heart again
Carry blood away from the heart
3 Layers in the wall of an artery
Thin inner epithelium
Thick smooth muscle layer
Outer connective tissue
Small arteries that regulate blood pressure
Microscopic vessels between arterioles and venules. They form beds of vessels where exchange with body cells (nutrients out, waste materials in) occur, and have a combined large surface area.
Control blood flow through a capillary bed. They can shut down a blood capillary, and blood then flows through the shunt (direct pass from arteriole to venular). If closed, blood moves to an area where gas exchange is needed. This might happen if it's cold outside - directs blood towards center of body instead of extremities.
Carry blood toward heart. If they carry blood against gravity, they have valves to keep blood flowing toward heart.
Small veins that receive blood from the capillaries.
3 layers of Venules and Vein walls
Thin inner epithelium
Smooth muscle layer (less than arteries)
Outer connective tissue (less than arteries)
Overall, thinner than arteries, allowing for greater expansion
Large, muscular organ consisting of mostly cardiac muscle tissue. It runs the cardiovascular system.
The cardiac muscle tissue in the heart.
Cardiac Muscle Fibers
Branched, uninucleated, striated muscle fibers. Tightly joined by intercalated disks.
Disks that hold the cardiac muscle fibers together very tightly so that there is no "leakage" of fluids such as blood.
Sac that surrounds the heart.
The right and left sides of the heart are separated by what?
The chambers in the upper half of the heart
The chambers in the lower half of the heart
2 sets of valves in the heart
Purpose of heart valves?
Heart valves keep blood flowing in one direction
Atrioventricular Valves are between what?
The atria and the ventricles.
The Left Atrioventricular valve is what?
The right atrioventricular valve is what?
Superior Vena Cava
Primary vein returning to the heart from the top of the body.
Inferior Vena Cava
Primary vein returning to the heart from the bottom of the body.
Process of blood flow through the heart (LONG!)
Inferior and superior vena cava dump blood into the right atrium. The right ventricle then sends the blood into the pulmonary trunk, where two pulmonary arteries lead the blood to the lungs, where the blood becomes oxygenated via capillaries. The pulmonary veins bring blood from the lungs back to the left atrium. The left ventricle then contracts, pumping blood into the aorta and to the rest of the body. It will then be pumped back to each vena cava.
How does the left ventricle compare to the right ventricle?
The left ventricle is more muscular than the right ventricle because it must pump blood to the entire body.
How do arteries compare to veins?
Arteries are more muscular than veins so as to help them withstand the high pressure exerted on them.
How do veins compare to arteries?
Veins have a thinner wall and a larger center to contain blood, and so are more expandable. About 70% of one's blood is stored in veins.
The atria contract together, followed by the ventricles contracting together. This is the first stage of the heartbeat.
A rest phase in the heartbeat during which the chambers of the heart relax.
How often does the cardiac cycle, or heartbeat, occur, on average?
70 times per minute
Nodal tissue has what types of characteristics, and does what?
Muscular and nervous characteristics. It is the locus of internal control.
The sinoatrial node, part of the nodal tissue, is in the right atrium. It initiates the heartbeat and causes the atria to relax.
The atrioventricular node is in the right atrium, and after the sinoatrial node causes the atria to relax, the atrioventricular node causes the ventricular contraction.
What is the external control of the heartbeat?
A cardiac center in the brain and hormones such as epinephrine and norepinephrine gives the external control of the heartbeat.
What is an electrocardiogram?
An electrocardiogram is the record of the electrical changes in the heart muscle (myocardium) during a cardiac cycle.
An electrical current produced by the atria, when it is stimulated by the sinoatrial node.
The QRS complex is the contraction of the ventricles.
The T Wave is the recovery of the ventricles.
Pressure against a blood vessel wall, usually measured in an artery of the arm.
The highest pressure, on the top of a blood pressure reading, is during blood ejection from the heart.
The lowest pressure, on the bottom of the blood pressure reading, occurs when the ventricles relax.
What is the average blood pressure?
What controls one's blood pressure?
What causes blood flow to increase?
Skeletal Muscle Contraction
Name the 2 Major Cardiovascular Pathways
Right side of heart reoxygenates the blood by bringing blood from the body to the heart and then to the lungs.
The left side of the heart that sends oxygenated blood to the entire body, delivers nutrients, and rids of waste.
What causes the exchange of capillary beds?
The exchange at capillary beds is primarily a result of osmotic and blood pressure.
Describe the arterial end of the capillary bed.
Blood pressure is higher than osmotic (fluid driven) pressure. The net pressure is out.
Describe the venous end of the capillary beds.
The osmotic pressure (fluid driven pressure) is higher than blood pressure. Net pressure is in.
What lies next to capillary beds?
Lymphatic capillary beds lie alongside capillary beds.
High blood pressure when blood moves through vessels at a rate higher than normal, often due to arterial plaque. Normally, 140/90 mmHg or higher; it is a silent killer as there are few symptoms but it can lead to a heart attack, stroke, or kidney failure.
Build up of plaque in blood vessels. It is associated with strokes, heart attacks, and aneurysm.
Stationary plaque in atherosclerosis
Arterial plaque that has detached and can move to distant sites. Associated with atherosclerosis.
Cerebrovascular accident; usually occurs when a cranial artery is blocked or bursts. Part of the brain dies due to lack of oxygen.
Myocardial infarction, when part of the heart dies due to lack of oxygen. It can begin with angina pectoris.
Pain that radiates down one's left arm due to blockage of the coronary artery.
A drug that dissolves blood clots
Three ways of treating clogged arteries
Usually a vein from the leg is taken and used to bypass clogged artery.
A wire mesh cylinder inserted into a clogged artery to hold it open.
Tube with a balloon is inserted into clogged artery to inflate it.