Chapter 8: Cardiovascular System Flashcards
What composes the cardiovascular system?
The heart and blood vessels. When this system fails, life at the cellular level isn’t possible and death occurs.
Define leaflets
Flat, leaf-shaped structures that comprise the valves of the heart and prevent backflow of blood.
Define lumen
Tubular space or channel within an organ or body structure; space within an artery, vein, intestine, or tube.
Define regurgitation
Backflow or ejecting of contents through an opening.
Define sphincters
Circular muscles found in a tubular structure or a hollow organ that constrict/dilate to regulate passage of substances through its opening.
Vasoconstriction
Narrowing of the lumen of a blood vessel that limits blood flow, usually as a result of diseases, medication, or physiological processes.
Vasodilation
Widening of the lumen of a blood vessel caused by the relaxing of the muscles of the vascular wall.
Viscosity
Thickness or measure of how resistant a liquid is to flowing. High viscosity = thick and slow-flowing.
3 major types of blood vessels
arteries, capillaries, and veins.
Function of arteries:
Carry blood from the heart to the body’s cells. Arteries carry blood with a high concentration of O2; only exception is the pulmonary artery.
3 layers of artery walls:
tunica externa, tunica media, tunica interna.
Tunica externa
Outer layer of the artery wall, composed of connective tissue that provides strength and flexibility.
Tunica media
Middle layer of the artery wall, composed of smooth muscle, which can alter the size of the lumen of the vessel; either vasoconstriction or vasodilation.
Tunica interna
Inner layer of the artery wall, composed of endothelial cells that create a smooth surface on the inside of the vessel.
Define pulse
A surge of blood felt in the arteries when blood is pumped from the heart.
Function of capillaries:
Microscopic blood vessels that join the arterial system with the venous system. Walls are composed of only a single layer of epithelial cells to allow for O2/CO2 exchange between the cardiovascular system and body cells.
Function of precapillary sphincters:
Regulate blood flow into the capillaries. When more blood is required in a tissue they open and they close when less blood is required in a tissue.
Function of veins:
Return deoxygenated blood to the heart; blood in these vessels has a characteristic purple color due to lack of O2. Blood in the veins contains a high concentration of CO2, with the exception of the pulmonary vein.
Methods used by veins to return blood to the heart (4):
1) Skeletal muscle contraction
2) Gravity
3) Respiratory activity
4) Valves
Define valves:
Small structures within veins that prevent backflow of blood. Found mainly in the extremities and are important for returning blood to the heart from the legs.
Function of the heart:
Muscular pump that propels blood throughout the entire body through a closed vascular network.
Pulmonary circulation
Occurs on the right side of the heart and delivers blood to the lungs, where CO2 is exchanged for O2.
Systemic circulation
Occurs on the left side of the heart and delivers blood to the body tissues, where O2 is exchanged for CO2.
What’s the pericardium?
A sac that encases the heart and is composed of 3 distinct layers; the epicardium, myocardium, and endocardium.
Epicardium
Outermost layer of the heart.
Myocardium
Muscular layer of the heart.
Endocardium
Serous membrane that lines the 4 chambers of the heart and its valves.
4 chambers of the heart:
right atrium (RA), right ventricle (RV), left atrium (LA), and left ventricle (LV). The atria collect blood and ventricles pump blood from the heart.
Where does the right ventricle pump blood?
Pumps deoxygenated blood to the lungs (pulmonary circulation).
Where does the left ventricle pump blood?
Pumps oxygenated blood to the entire body (systemic circulation).
Superior vena cava
Collects and carries deoxygenated blood from the upper body and deposits in the right atrium.
Inferior vena cava
Collects and carries deoxygenated blood from the lower body and deposits in the right atrium.
Tricuspid valve
Prevents backflow of blood from the right ventricle to the right atrium; has 3 leaflets.
Pulmonary arteries
Separate into left and right branches and carry deoxygenated blood to the lungs from the right ventricle. These branch into capillaries that lay next to alveoli where CO2/O2 are exchanged.
Mitral (bicuspid) valve
Prevents backflow of blood from the left ventricle to the left atrium; has 2 leaflets.
Aorta
Largest artery in the body that leads blood away from the left ventricle. Branches into smaller arteries and arterioles to deliver blood to body tissues.
Aortic (semilunar) valve
Prevents regurgitation of blood from the aorta to the left ventricle.
What arteries supply blood to the myocardium of the heart?
Coronary arteries. If blood flow is disrupted to the myocardium, part of the heart muscle may die.
Coronary arteries (2)
right and left coronary arteries
Right coronary artery
Vascularizes the right side of the heart.
Left coronary artery
Vascularizes the left side of the heart. Splits into 2 branches; left anterior descending artery and circumflax artery.
Define conduction tissue:
Specialized cardiac tissue that has the sole function of initiating and spreading conduction impulses.
Sinoatrial (SA) node
Located in the upper portion of the right atrium and possesses its own intrinsic rhythm. It has the ability to initiate and propagate its own heartbeat, which sets the basic pace for the cardiac rate; commonly known as the pacemaker of the heart.
Atrioventricular (AV) node
SA node transmits impulses to the AV node, which causes the atria to contract. AV node is located at the base of the right atrium.
Bundle of His (AV bundle)
Tract of conduction fibers, composed of a right and left branch.
Purkinje fibers
Impulses are directed here from the bundle of His. These fibers extend up the ventricle walls and transmit impulses to the right and left ventricles, causing them to contract.`
Electrocardiograph
Picture produced by recording the weak impulses on the surface of the body caused by electrical impulses from the conduction system of the heart. This produces waves or peaks designated by the letters P, Q, R, S, T.
P wave
Depolarization (contraction) of the atria.
QRS complex
Depolarization (contraction) of the ventricles.
T wave
Repolarization (recovery) of the ventricles.
Blood pressure
The force exerted by blood against arterial walls during 2 phases of heartbeat.
Systole
Contraction phase when blood is forced out of the heart; provides maximum force.
Diastole
Relaxation phase when ventricles are filling with blood; produces the weakest force.
Sphygomomanometer
Instrument that measures blood pressure; recorded as 2 figures separated by a diagonal line; systole/diastole, example: 120/80 mm Hg.
Factors that influence blood pressure:
1) Resistance of blood flow in the blood vessels.
2) Pumping action of the heart.
3) Viscosity of blood.
4) Elasticity of arteries.
5) Quantity of blood in the vascular system.
aneurysm/o
aneurysm (widened blood vessel).
angi/o
vascul/o
vessel (usually blood or lymph).
aort/o
aorta
arteri/o
artery
arteriol/o
arteriole
atri/o
atrium
ather/o
fatty plaque
cardi/o
coron/o
heart
electr/o
electricity
embol/o
embolus (plug)
hamangi/o
blood vessel
my/o
muscle
phleb/o
ven/o
vein
sept/o
septum
scler/o
hardening
sphygm/o
pulse
sten/o
narrowing; stricture
thromb/o
blood clot
valv/o
valvul/o
valve
ventricul/o
ventricle
-cardia
heart condition
-stenosis
narrowing; stricture
brady-
slow
endo-
in, within
extra-
outside
peri-
around
trans-
across
What are some common signs and symptoms of cardiac disorders?
Thoracodynia, dyspnea, cardiac irregularities, and LOC.
Define cardiologist
Specialist in the study and treatment of cardiovascular diseases/disorders.
Define cardiology
Medical specialty concerned with disorders of the cardiovascular system.
What is arteriosclerosis?
A progressive, degenerative disease of arterial walls that causes them to become thickened and brittle, which restricts the flow of blood to tissues and organs. Causes include build up of plaque on the interior artery wall. Arteries usually affected include coronary, carotid, cerebral, and femoral arteries, and the aorta. Sx include angina, diaphoresis, hemiplegia, blurred vision, confusion, and myalgia. Risk factors include HLD, HTN, DM, age, smoking, and family hx. Tx includes statins, antihypertensives, anticoagulants and surgery.
Thrombus
Clot; formed when blood hemorrhages into arterial plaque and this piece breaks off and travels to a more distal part of the body, which can lead to infarction and ischemia.
Infarction
Tissue death that occurs when an artery is completely blocked.