Pulmonary circuit: passage of blood from heart’s right ventricle, through lung’s pulmonary arteries, back through pulmonary veins to heart’s left atrium

Systemic circuit: circulation of blood through arteries, capillaries, and veins of general system

Heart

Four-chambered hollow organ with three layers
- Apex: lowermost tip
- Endocardium: innermost layer
- Myocardium: middle layer; actual heart muscle and thickest of three layers
- Epicardium: outer layer; surrounded by pericardium, a sac that surrounds the heart
Heart Chambers
- Right atrium: upper right chamber that receives blood from all body parts except lungs; receives deoxygenated blood from the vena cava
- Right ventricle: lower right chamber that receives blood from right atrium and pumps it to the lungs
- Left atrium: upper left chamber that receives oxygen-rich blood as it returns from the lungs
- Left ventricle: lower left chamber that pumps blood out of aorta to all parts of the body
Superior and inferior vena cava: large vein carrying deoxygenated blood to the right atrium
Right atrium: receives deoxygenated blood and pumps it to the right ventricle
Tricuspid valve: the valve between the right atrium and the right ventricle
Right ventricle: pumps deoxygenated blood from the heart to he lungs for oxygenation
Pulmonary valve: controls the flow of blood from the heart to the lugs
Pulmonary arteries: blood vessels that carry deoxygenated blood from right ventricle to the lungs for oxygenation
Pulmonary veins: carries oxygenated blood to the left atrium
Left atrium: receives oxygenated blood from the lungs and pumps it into the left ventricle
Mitral valve: keeps blood moving in the right direction from left atrium to left ventricle
Left ventricle: pumps oxygenated blood throughout the body
Aortic valve: regulated the flow of blood from left ventricle into the aorta
Aorta: largest artery in the body; transport oxygenated blood from the heart to the rest of the body

Conducting system of heart generates and transmits signals that stimulate heart to contract and relax in sequence

Sino-atrial (SA) node: pacemaker of the heart
Atrioventricular (AV) nod
Bundle of His
Purkinje fibers

Blood Vessels

Arteries: carry oxygenated blood away from the heart
- Arterioles: smaller branches of the arteries; small vessels that receive blood from the arteries
Capillaries: blood vessels that connect arterial and venous systems; microscopic vessels through which exchanges take place between the blood and cells of the body

Veins: blood vessels that return blood back to the heart
- Venules: smaller branches of the veins; smaller vessels that gather blood from the capillaries into the veins
Lumen: tubular space through which blood flows
- Vasodilation: lumen opened
- Vasoconstriction: lumen closed
- Vasodilation and vasoconstriction can each have an effect on blood pressure (BP)

Blood Elements

Plasma
Erythrocytes: red blood cells (RBCs)
- Main function is to transport oxygen
Leukocytes: white blood cells (WBCs)
- Body’s main defense against harmful organisms
  - Neutrophils
  - Eosinophils
  - Basophils
  - Lymphocytes
  - Monocytes
Thrombocytes: platelets
- Play important role in blood-clotting process

Types of Donors and Recipients

Blood Type	Can Donate To	Can Receive From
A	A or AB only	A or O only
B	A or AB only	B or O only
AB (universal recipient)	AB only	A, B, AB, O
O (universal donor)	A, B, AB, O	O only

Heartbeat

Heart contracts and releases in a rhythmic cycle
Systole = contraction
Diastole = relaxation
Heart rate (HR) = number of contractions per minute
Blood pressure: measurement of amount of pressure exerted against walls of blood vessels; pressure exerted by the blood upon the walls of the blood vessels, especially arteries.
- Recorded as a fractional number, systolic over diastolic
- Measured by an instrument called sphygmomanometer (BP cuff)
- Expressed in mmHg

Electrocardiogram (ECG, EKG): electrical activity of heart recorded

Electrocardiograph: machine that does the recording

Angiogram: x-ray of blood vessels following injection with radio-opaque material

Echocardiogram: ultrasound of the heart

Diseases

Coronary artery disease (CAD): narrowing of lumen of one or more coronary arteries, usually due to atherosclerosis; disease of arteries surrounding the heart

Atherosclerosis: progressive buildup of plaque or fatty deposits on inner arterial walls, lumen narrows → hardening and narrowing of the arteries

Hyperlipidemia: increased blood fat (lipid)

High-density lipoproteins (HDLs)
Low-density lipoproteins (LDLs)

Arteriosclerosis: hardening and loss of elasticity in artery impeding blood flow to heart muscle caused by fatty deposits

Ischemia: inadequate supply of blood and oxygen to tissues

Thrombus: blood clot in a blood vessel

Thrombosis: formation of a thrombus

Embolus: blood clot that moves throughout the bloodstream

Myocardial infarction (MI): heart attack, results from lack of oxygen supply to myocardium

Symptoms include: chest pain (feeling as if elephant is sitting on chest), diaphoretic, jaw pain, indigestion, pain radiating down the left arm

Congestive heart failure (CHF): heart cannot pump enough blood to meet body’s needs for oxygen and nutrients

Arrhythmia: any irregularity of heart’s rhythm

Bradycardia: slower than normal HR (< 60 bpm)
Tachycardia: faster than normal HR (> 100bpm)

Fibrillation: rapid, random, and ineffective contractions of the heart

Atrial fibrillation (A-fib): atria beats faster than ventricles; rapid, random, and ineffective contraction of the atrium. Most common arrhythmia. May cause blood clots to be formed in the atrium.

Ventricular fibrillation: ventricles ineffectively pump blood, can be fatal

Hypertension: high blood pressure (the force of the blood pushing against artery walls is consistently too high); silent killer

Systolic reading > 140 mmHg or diastolic > 90 mmHg
Secondary hypertension: related to another medical problem

Arteriosclerosis: hardening of the arteries

Left ventricular hypertrophy: oversized left ventricle

Cyanosis: a bluish discoloration of the skin resulting from poor circulation or inadequate oxygenation of the blood

Deep Vein Thrombosis: blood clot forms in a large vein, usually in a lower limb

Phlebitis: inflammation of a vein

Murmur: abnormal swishing sound of the heart caused by improper closure of the heart valves

Ventricular Septal Defect (VSD): a hole in the interventricular septum; occurs during pregnancy; lets venous blood pass from the right to the left ventricle and out to the aorta without oxygenation

Myocarditis: inflammation of the heart muscle

Tetralogy of Fallot (TOF): Rare heart condition where baby is born with four different heart problems that cause altered blood flow through heart and body (a ventricular septal defect, pulmonary stenosis, right ventricular hypertrophy, and an overriding aorta)

Stroke: When blood flow to the brain is blocked

Symptoms: facial palsy, slurred speech and one sided weakness.

Blood Disorders

Anemia: deficiency of RBC or low level of Hb
Leukemia: increased number of WBCs
Clotting disorders
- Hemophilia: genetic bleeding disorder that impairs the body's ability to form blood clots, leading to prolonged bleeding
- Thrombocytopenia: abnormal decrease in number of thrombocytes or platelets
- Disseminated intravascular coagulation (DIC)

Treatments

Antiarrhythmic medication: drug used to treat heart rhythm abnormalities

Cardioversion: treatment for fibrillation; applying electric current to restore normal heart rhythm

Ablation therapy: apply radio frequency waves to the heart

Surgical procedures:

Percutaneous transluminal coronary angioplasty (PTCA)
- Angioplasty: procedure that involves opening up a narrowed or blocked blood vessel → surgical repair of blood vessel; opens a blocked artery by inflating a small balloon within a catheter to widen and restore blood flow in the artery
Arterial stent
Coronary artery bypass graft (CABG)
Endarterectomy

Statin: medicine to take for hypercholesterolemia

Aspirin: can be given to someone with heart attack symptoms