-approximately the size of fist

-weighs < 1lb.

-located in the mediastinum (middle of chest)

-Lowest superficial part of heart

-point directed toward left hip

-rests on diaphragm

-lies behind 5th intercostal muscle

-broad

-points toward right shoulder

-under second rib

-out most layer of heart

-serous membrane surrounding heart

-external surgace of heart

-part of heart wall

-innermost layer of pericardium

-protects heart

-anchors it to diaphragm and sternum

-outer most layer of pericardium

-produced by pericardium membranes

-allows heart to beat easily in a frictionless environment

-a decrease in serous fluid

-constricts heart by sticking outer membranes together

-inflammation of pericardium

-can be fatal

-heart muslce

-thick bundles of cardiac muscle

-ring like arrangement

-responsible for the contraction of the heart

-Thin sheet of endothelium that lines chambers of heart

-overlies Myocardium

-controls Mycoardium function

-4 chambers

-2 = atria

-2 = Ventricles

-2 of the 4 hollow chambers in heart

-lined with endocardium

-superior atria primrily recieving chambers

-not very important in pumping activity of heart

-blood flows into atria under low pressure from veins of body

-2 of 4 hollow chambers of heart

-lined w/ endocardium

-inferior

-thickered walled

-discharging chambers

-collects blood in atria and pumps out of heart

-the dividing wall between the right and left sides of the heart

- aka Interatrial septum

-separates the two upper chambers (r & l atria) of the heart

-aka interventricular

-separates two lower chambers (r & l ventricles) of the heart

-carries blood from the upper part of the body

-brings deoxygenated blood to the heart

-made of smooth muscle

-returns blood low in CO2 into right atrium

- brings deoxygenated blood to the heart

-carries blood from the lower part of the body

-made of smooth muscle

-feeds into the right atrium

-carry blood to lungs where O2 is picked up & CO2 is unloaded

-4 pulminary viens

-carry blood high in O2 fro lungs to left atria

-only veins that carry bright red oxygenated blood

-largest artery in body

-systemic arteries branch

-blood returned to left side of heart is pumped out of heart into aorta

-originating from the left ventricle of the heart and brings oxygenated blood to all parts of the body

-located between atrial & ventricular chambers

-prevent backflow into atria when ventricles contract

*Bicuspid

*Tricuspid

*Chordae tendineae

-left side

-2 cusps (flaps)

-between l. ventricle and l. atrium

-aka Mitral Valve

-right side of heart

-3 cusps (flaps)

-between r. ventricle & r. atrium

-"heart strings"

-tiny white cords

-anchor cusps to walls of ventricle

-double pump: pumps at same time

-three crescent-shaped cusps

-prevents blood from flowing back into the heart

-guards bases of 2 large arteries leaving ventricular chambers

-branch from base of aorta & encircle heart in atrioventricular groove at junction of atria & ventricles

-major branches (right): posterior, interventricular, marginal

(left): anterior, interventricular, circumflex arteries

-empty into enlarged vessel on backside of heart

-drains blood from the muscular tissue of the heart & empties into the coronary sinus

-collection of veins joined together to form a large vessel that collects blood from the myocardium of the heart

-located between the l. atrium and l. ventricle on the posterior surface of the heart

-empties into right atrium

-An area of tissue death due to a lack of oxygen

-cells die during ischemia

-brakes & accelerators

-decreased or increased heart rate depending on which division is activated

-blood vessels' size and blood pressure

-the heart's electrical activity and ability to contract

-sets the basic rhythm of the heart

-"nodal system"

-contraction rate ~ 75 beats/min

-composed of special tissue found nowhere else in body

*cross between muscle tissue & nervous tissue

-SA node or SAN or Sinus Node

-hearts natural pacemaker

-"fires" at regular intervals to cause the a rhythmn of about 60 to 70 beats per minute

-located in the r. atrium of the heart

-"self firing"

-crescent shape

-AV Node

-between the atria and the ventricles of the heart

-conducts the normal electrical impulse from the atria to the ventricles

-Delays impulses from the sinoatrial node to allow the atria to contract and empty their contents first

- atrioventricular bundle

-"Bundle of His"

-transmits the cardiac impulse from the atrioventricular node to the ventricles causing them to contract

-located in the inner ventricular walls of the heart;beneath the endocardium

-specialized myocardial fibers that conduct an electrical impulse that enables the heart to contract in a coordinated fashion

-spread within muscle of ventricle walls

-cardiac arrhythmia; a rapid beating of the heart

-heart rate over 100 beats/min

-rapid uncoordinated shuddering of the heart

-atrial & ventricular fibrillation

-looks like a bag of worms

-makes heart useless as a pump

- heart rate of under 60 beats per minute

-heart rate substantially slower than normal

-period of time when the heart relaxes after contraction

-pressure in heart is low

-blood flowing passively into and thruogh the atria into ventricles from pulmonary & systemic circulations

-semilunar valves closed

-AV valves open

-pressure increases rapidly; atria relaxed

-AV valves close

-intraventricular pressure higher than pressure in large arteries

-semilunar vavles open

-ventricles relax

-semilunar valves shut

-intraventricular pressure drops

-"lub", "dup"

-"lub" caused by closing AV valves

-"dup" caused by semilunar valves closing

-1st sound longer & lounder than 2nd

-abnormal heart sounds

-common in young children

-indicate valve problems

-"incompetent" - when valve does not close tightly

amount of blood pumped out by each side of heart in 1 min.

-product of heart rate & stroke volume

-equal to the stroke volume (SV) multiplied by the heart rate (HR)

*CO=HR(75 beats/min) x SV (70 ml/beat)

CO=5250 ml/min

-blood volume ~ 5000 ml

-difference between the ventricular end-diastolic volume (EDV) and the end-systolic volume (ESV)

-volume of blood pumped out by a ventricle with each heartbeat

-increases as force of ventricular contraction increases

-70 ml/beat

-can be changed temporarily by autonomic nerves

-chemicals, ions, hormones change heart rate

-stimulate SA and AV nodes and cardiac muscle itself

-heart beats more rapidly

-primarily vagus nervers

-slow and steady heart

-gives it more time to rest during non crisis times

epinephrine - mimics effect of sympathetic nerves

throxine - increase heart rate

-increase heart rate and force of heart contraction

-a condition in which the heart can't pump enough blood to the body's other organs

- left side of the heart starts to fail = pulmonary edema (fluid collects in lungs)

-right side of the heart starts to fail fluid collects in feet & lower legs

-more common with increasing age