Chp 15- Cardiovascular system

pulmonary circuit

transports oxygen-poor blood from heart to lungs and back to heart, blood picks up O2 and drops of CO2

systemic circuit

transports oxygen-rich blood from heart to all body cells and back to heart, blood delivers nutrients and removes

pericardium

covering over heart and large blood vessels

fibrous pericardium

outer layer that surrounds double layered serous membrane

parietal pericardium

deep to fibrous pericardium, outer layer of serous membrane

visceral pericardium

inner layer of serous membrane, attached to surface of heart also called epicardium

epicardium

outer, thin layer called visceral pericardium

myocardium

middle layer, cardiac muscle tissue, thickest layer

endocardium

inner, thin layer and lines all of heart chambers

atria

thin walled upper chambers, receive blood returning to heart

auricles

flap-like projections from atria, which allow atrial expanison

ventricles

thick-walled lower chambers, pump blood into arteries

right atrium

receives blood returning from systemic circuit, pumps blood into right ventricle

right ventricle

receives blood from right atrium, pumps blood into lungs

left atrium

receives blood from pulmonary veins, pumps blood to left ventricle

left ventricle

receives blood from the left atrium, pumps blood to systemic circuit

left ventricular assist device

mechanical half-heart until donor heart is available

implantable replacement heart

titanium and plastic artificial heart, used in ppl that cannot have heart transplant

stem cell technology

cardiac muscle tissue can now be cultured from altered somatic cells or from stem cells

lubb

first heart sound, occurs during ventricular systole, closing of a-v valves

dupp

second heart sound, ventricular diastole, closing of pulmonary and aortic semilunar valves

cardiac conduction system

group of clumps and strands of specialized cardiac muscle tissue which initiates and distributes impulses throughout the myocardium

sinoatrial node

pacemaker, initiates rhythmic contractions of the heart

internodal atrial muscle

conducts impulses from SA node to atria

junctional fibers

conduct impulses from SA node to AV node

atrioventricular node

conducts impulses to AV bundle, delays impulse so that atria finish contracting before ventricles contract

AV bundle

conducts impulses rapidly between SA node and bundle branches

left and right bundle branches

split off from AV bundle, conduct impulses to purkinje fibers on both sides of heart

purkinje fibers

large fibers that conduct impulses to ventricular mocardium

electrocardiogram

a recording of electrical changes that occur in the myocardium during the cardiac cycle

P wave

atrial depolarization, occurs just prior to atrial contraction

QRS complex

ventricular depolarization, occurs just prior to ventricular contraction

T wave

ventricular repolarization, occurs just prior to ventricular relaxtion

fibrilation

uncoordinated, chaotic contraction of small areas of mycardium

ectopic pacemaker

damage to SA node may lead to AV node taking over and act as a secondary pacemaker

arteries

carry blood away from the ventricles of the heart

arterioles

receive blood from the arteries and carry it to the capillaries

capillaries

sites of exchange of substances between the blood and the body cells

venules

receive blood from the capillaries and conduct it to veins

veins

receive blood from venules and carry it back to the atria of the heart

tunica interna

innermost layer of artery

tunica media

smooth muscle and elastic tissue of artery

tunica externa

outer layer and connective tissue of artery

diffusion

lipid soluble substances diffuse through cell membrane, water soluble substances diffuse through membrane channels and slits

filtration

hydrostatic presure forces molecules through membrane, pressure is derived from ventricular contraction

osmosis

presence of impermeant solute, such as plasma protein, inside capillaries creates osmotic pressure, draws water into capillaries opposing filtration

blood pressure

the force of blood exerts against the inner walls of the blood vessels

arterial blood pressure

rises when the ventricles contract, falls when ventricles relax

systolic pressure

the maximum pressure reached during ventricular contraction

diastolic pressure

the minimum pressure remaining before next ventricular contraction

pulse pressure

difference between systolic and diastolic blood pressures

mean arterial pressure

average pressure in arterial system, represents average force driving blood to the tissues

stroke volume

volume of blood that enters the arteries with each ventricular contraction

cardiac output

volume of blood discharged from a ventricle each minute

peripheral resistance

force of friction between blood and walls of blood vessels

viscosity

difficulty with which molecules of fluid flow past each other

central venous pressure

pressure in the right atrium

marfan syndrome

involves an abnormal type of the protein fibrillin, which can weaken wall of the aorta

familial hypertrophic cardiomyopathy

inherited overgrowth of myocardium caused by abnormal myosin chain in cardiac muscle

familial hypercholesterolemia

abnormal receptors on liver cells do not take up cholesterol from blood, high cholesterol

coronary artery disease

involving deposition of cholesterol plaque on inner walls of coronary arteries