Chapter 18: The Heart

Chambers of the heart

Chambers of the heart

right atrium, left atrium, right ventricle, left ventricle

Valves of the heart

tricuspid valve, bicuspid valve, pulmonary valve, aortic valve

Great vessels of heart

pulmonary veins, pulmonary arteries, aorta, superior vena cava, inferior vena cava

Deoxygenated structures

right atrium, right ventricle, tricuspid valve, pulmonary valve, pulmonary veins, pulmonary veins

Oxygenated structures

left atrium, left ventricle, bicuspid valve, aortic valve, pulmonary arteries, aorta

Systemic

left side, oxygenated, from heart -> body

Pulmonary

right side, deoxygenated, from heart -> lungs

Step 1 of blood circulation

Deoxygenated blood pools in right atrium

Step 2 of blood circulation

Right atrium fills and tricuspid valve opens

Step 3 of blood circulation

Blood is squeezed through pulmonary valve into pulmonary trunk

Step 4 of blood circulation

Deoxygenated blood continues through the left and right pulmonary arteries to the lungs

Step 5 of blood circulation

Lungs exchange CO2 for O2

Step 6 of blood circulation

Now oxygenated blood collects in left atrium

Step 7 of blood circulation

Left atrium fills and bicuspid valve opens, releasing into left ventricle

Step 8 of blood circulation

Pumped through aorta and into left and right pulmonary veins

Step 9 of blood circulation

Travels through systemic circuit

Step 10 of blood circulation

Returns via the superior vena cava and right atrium

Coronary circuit

Supplies the heart with blood, coronary arteries bring blood to myocardium of the heart, form anastomoses

Mediastinum

cavity in center of chest between lungs (where the heart is located)

Anastomoses

connections between arteries

Atherosclerosis

narrowing of arteries due to fatty plaque

Foam Cell

localized to fatty deposits on blood vessel walls, where they ingest LDLs and become laden with lipids

Angiogram

test injecting dye into vessels to see blockage

Angioplasty

inserting a balloon into artery to smash plaque against wall to open up vessel

Myocardial Infarction

heart attack, blockage of an artery to the heart due to atherosclerosis and blood clot

1st layer of the heart

Epicardium

Epicardium

same as visceral pericardium, outermost layer composed of serous membrane

2nd layer of the heart

Myocardium

Myocardium

middle layer (thickest), cardiac muscle, contracts the heart

3rd layer of the heart

Endocardium

Endocardium

innermost layer, simple squamous epithelium, provides smooth lining for blood

1st layer of the pericardium

Fibrous Pericardium

Fibrous Pericardium

outermost layer composed of dense connective tissue for protection

2nd layer of the pericardium

Parietal Pericardium

Parietal Pericardium

composed of serous membrane producing serous fluid to reduce friction

3rd layer of the pericardium

Visceral Pericardium (epicardium)

Visceral Pericardium (epicardium)

folded part of parietal pericardium, between parietal pericardium and visceral pericardium space called pericardial cavity for the serous fluid

Function of heart valves

one way flaps that close to prevent back-flow of blood

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LDL

bad cholesterol

HDL

good cholesterol, scavenges LDL and brings it back to liver

Coronary bypass surgery

-A vein from the leg is reattached around clotted coronary artery to maintain blood flow

-Used when arteries are too clogged for angioplasty to work

Heart (intrinsic) conduction system #1

SA (sinatrial) node

Heart (intrinsic) conduction system #2

AV (atrioventricular) node

Heart (intrinsic) conduction system #3

AV bundle

Heart (intrinsic) conduction system #4

Right and left bundle branches

Heart (intrinsic) conduction system #5

Purkinje fibers

P wave

depolarization of atria which causes contraction of atria

QRS wave

depolarization of ventricles; atrial repolarization is blocked

T wave

repolarization of ventricles

Arrhythmias

no p wave-> atria/SA node not working, irregular heart rate

Autorhythmic

heart produces its own pulses through electrochemical stimuli originating from a small group of cells in the wall of the right atrium, known as the sinoatrial node (or SA node)

Systole

rate of contraction (depolarization), pressure when heart is squeezed

Diastole

rate of relaxation, heart relaxes

Fibrillation

waves undisguisable, chaotic rhythm, all cells have different electrical impulses and beat out of sync

Tachycardia

heart beats too fast, bpm >100

Bradycardia

heart beats too slow, bpm <60

Hypertension

high blood pressure > 140/90

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Normal heart rate

60-100 bpm

Normal blood pressure

120/80

Systolic pressure

1st # in blood pressure, contraction of heart

Diastolic pressure

2nd # in blood pressure, relaxation of heart

Cardiac output

amount of blood pumped out by each ventricle in 1 minute, blood/min

? * ?=blood/min

Heart rate * stroke volume

70*75=?

5250mL or 5.25L per minute