Ch.17 defintions
Automaticity is the heart’s ability to contract spontaneously without any nerve stimulus.
Normally, electrical impulses begin in the SA node (sinoatrial node), and when these impulses travel through the heart, the myocardial cells contract in order.
However, if no impulse arrives, the heart cells can create their own electrical signal and continue contracting on their own.
⭐ Automaticity – Mnemonic
1⃣ “Auto = self” → “Automaticity = self-start”
→ The heart starts its own impulses without nerves.
⭐ Atrium
Definition: The upper chamber of the heart that receives incoming blood.
Mnemonic:
“A for Above/ Auditorium ” → Atrium is the upper chamber
→ Receives blood coming in.
⭐ Ventricle
Definition: The lower chamber of the heart that pumps blood out to the body or lungs.
Mnemonic:
“V for Vacuum is on the ground so low” → Ventricle pushes blood out with force.
⭐ Aorta
Definition (corrected):
The main artery of the body.
Blood is ejected from the left ventricle into the aorta, which then delivers blood to all arteries that carry oxygen-rich blood to the tissues.
Mnemonic:
“Aorta = Away” → sends blood away from the heart to the whole body
⭐ Autonomic Nervous System – Mnemonic
“Auto = automatic” → automatic body functions
→ Controls everything your body does automatically, without thinking.
The autonomic nervous system is the part of the nervous system that controls body functions that do not require conscious thought, such as:
heartbeat
respiration (breathing)
digestion
constriction and dilation of blood vessels
These functions happen automatically without you thinking about them.
term in depth.
Myocardium
Definition:
The myocardium is the heart muscle that controls heart contractions. It requires a continuous supply of oxygen and nutrients to function properly.
Example: Without oxygen, the myocardium can’t contract effectively, which is why blocked coronary arteries can cause heart attacks.
Mnemonic:
“Myo = muscle” → Myocardium = heart muscle needs oxygen to pump effectively.
Dilation
Definition:
Dilation is the widening of coronary arteries, which allows more blood to flow to the heart muscle when it needs more oxygen.
Example: During exercise, your heart needs more oxygen, so the coronary arteries dilate to supply the heart muscle with more blood.
Mnemonic:
“Dilation = Draw Open”
→ Arteries widen to allow more blood flow.
Coronary Arteries
Definition:
The coronary arteries are blood vessels that supply oxygen-rich blood to the heart muscle, allowing it to contract and pump blood to the body.
Example: If these arteries become blocked, the heart muscle can’t get the oxygen it needs, leading to a heart attack.
Mnemonic:
“Coronary = Core of the heart”
→ These arteries nourish the heart muscle directly.
Aortic Valve
Definition:
The aortic valve controls the blood flow from the left ventricle into the aorta, the body’s main artery. It opens to allow oxygenated blood to be pumped from the heart to the rest of the body.
Example: If the aortic valve is not working properly, blood may leak back into the heart instead of being pumped out to the body.
Mnemonic:
“Aorta = Away”
→ Sends blood away from the heart to the body.
Blood Pressure
Definition:
Blood pressure is the force exerted by circulating blood on the walls of arteries.
Systolic BP is the maximum pressure during the contraction of the left ventricle.
Diastolic BP is the pressure when the left ventricle relaxes.
Example: High blood pressure (hypertension) can lead to damage to blood vessels and organs like the heart and kidneys.
Mnemonic:
“Systolic = Squeeze”
→ Maximum pressure when the heart squeezes blood out.
“Diastolic = Deep Relax”
→ Pressure when the heart relaxes.
Cardiac Output
Definition:
Cardiac output is the amount of blood the heart pumps per minute, calculated by multiplying heart rate by stroke volume (the amount of blood pumped per beat).
Example: An athlete’s heart pumps more blood per beat, so their cardiac output is higher during exercise.
Mnemonic:
“Cardiac Output = Heart × Stroke”
→ Blood pumped = heart rate × stroke volume.
Perfusion
Definition:
Perfusion is the continuous flow of oxygenated blood to tissues, ensuring they receive the nutrients and oxygen they need to function properly.
Example: Good perfusion keeps organs like the brain, kidneys, and liver healthy, while poor perfusion can lead to organ failure.
Mnemonic:
“Perfusion = Perfect Flow”
→ Oxygenated blood flows continuously to tissues.
Ischemia
Definition:
Ischemia refers to decreased blood flow to tissues, which can lead to tissue damage and impaired function if not corrected quickly.
Example: Heart ischemia occurs when the coronary arteries are blocked, leading to chest pain (angina) or a heart attack.
Mnemonic:
“Ischemia = Insufficient Supply”
→ Not enough blood to the tissues.
Atherosclerosis
Definition:
Atherosclerosis is a disorder where calcium deposits and cholesterol build up inside the arteries, forming plaques that narrow and obstruct blood flow.
Example: As plaques accumulate in the arteries, they can restrict blood flow and increase the risk of heart attack or stroke.
Mnemonic:
“Atherosclerosis = Artery Narrowing”
→ Plaques block arteries and reduce blood flow.
Occlusion
Definition:
Occlusion refers to the blockage of a coronary artery by a clot or plaque, preventing blood flow to the heart muscle.
Example: A blocked artery due to occlusion can lead to a heart attack.
Mnemonic:
“Occlusion = Obstruction”
→ Artery blocked by a clot.
Lumen
Definition:
The lumen is the inside diameter of an artery. As people age, the lumen narrows due to calcium and fatty material buildup.
Example: A narrower lumen increases the risk of arterial blockages and heart disease.
Mnemonic:
“Lumen = Less space”
→ The inside of the artery narrows with age.
Thromboembolism
Definition:
A thromboembolism is a blood clot that travels through the bloodstream until it reaches a narrow area, where it blocks blood flow.
Example: A thromboembolism that blocks a lung artery can cause a pulmonary embolism.
Mnemonic:
“Thrombo = Thrombus (clot) + Embo = Embolus (travels)”
→ A clot that moves and blocks.
Acute Myocardial Infarction (Heart Attack)
Definition:
An acute myocardial infarction (heart attack) occurs when blood flow to part of the heart muscle is blocked, causing tissue death.
Example: Heart muscle death decreases the heart's ability to pump blood, which may lead to cardiac arrest.
Mnemonic:
“Acute = Sudden”
→ Heart muscle dies due to lack of blood supply.
Acute Coronary Syndrome
Definition:
Acute coronary syndrome refers to a group of symptoms that indicate myocardial ischemia (decreased blood flow to the heart), leading to chest pain and other signs of heart trouble.
Example: Unstable angina (a form of acute coronary syndrome) is a precursor to a heart attack.
Mnemonic:
“Acute = Sudden chest pain”
→ Reduced blood supply to the heart causes chest pain.
Angina Pectoris
Definition:
Angina pectoris is temporary chest pain caused by inadequate blood flow and oxygen to the heart muscle, often triggered by exertion or stress.
Example: Stable angina occurs predictably during exertion, while unstable angina can happen at rest and signals impending heart attack.
Mnemonic:
“Angina = Anguish”
→ Temporary chest pain due to lack of blood and oxygen.
Stable Angina
Definition:
Stable angina occurs predictably with physical exertion or stress and is relieved by rest or medication.
Example: Stable angina can be managed with rest, while unstable angina is more dangerous and unpredictable.
Mnemonic:
“Stable = Predictable”
→ Pain occurs during exertion, goes away with rest.
Unstable Angina
Definition:
Unstable angina occurs unpredictably, can happen at rest, and may signal an impending heart attack.
Example: Unstable angina is a warning sign that immediate medical attention is needed.
Mnemonic:
“Unstable = Unpredictable”
→ Unpredictable pain, dangerous.
Dysrhythmia
Definition:
A dysrhythmia is an abnormal heart rhythm that causes disorganized electrical impulses, often leading to ventricular fibrillation and no blood being pumped.
Example: Ventricular fibrillation is a life-threatening dysrhythmia that requires defibrillation.
Mnemonic:
“Dysrhythmia = Disorganized Rhythm”
→ Heart beats chaotically, unable to pump blood.
Defibrillation
Definition:
Defibrillation is the process of shocking the heart to stop a chaotic rhythm and allow it to return to normal.
Example: When a person goes into ventricular fibrillation, defibrillation is used to restart the heart’s normal rhythm.
Mnemonic:
“Defibrillation = Disrupt to Restart”
→ Shock the heart to restart normal rhythm.
Cardiogenic Shock
Definition:
Cardiogenic shock occurs when the heart can no longer pump enough blood to supply the body, leading to organ dysfunction.
Example: A severe heart attack can lead to cardiogenic shock, where the heart fails to pump enough blood.
Mnemonic:
“Cardiogenic = Heart Failure”
→ Heart fails to pump enough blood to organs.
Congestive Heart Failure (CHF)
Definition:
CHF is a chronic condition in which the heart becomes weakened and cannot pump enough blood to meet the body’s needs, causing fluid to back up.
Example: CHF causes fluid retention in the legs, lungs, and abdomen, leading to symptoms like shortness of breath and swelling.
Mnemonic:
“CHF = Congested Heart, Fluid Fails”
→ Heart can't pump effectively, causing fluid buildup.
Dependent Edema
Definition:
Dependent edema is swelling in the lower extremities due to fluid pooling in gravity-dependent areas, commonly seen in right-sided heart failure.
Example: Swelling in the feet and legs due to poor circulation is a sign of right-sided heart failure.
Mnemonic:
“Dependent = Downward Swelling”
→ Fluid pools in lower body due to poor circulation.
Hypertensive Emergency
Definition:
A hypertensive emergency is defined as systolic blood pressure over 180 with progressive organ damage, requiring immediate medical intervention.
Example: A systolic blood pressure over 180 can lead to stroke, heart attack, or kidney failure if untreated.
Mnemonic:
“Hypertensive = High Pressure Emergency”
→ Blood pressure over 180 causes organ damage.
Aortic Aneurysm
Definition:
An aortic aneurysm is a bulging of the wall of the aorta, which is at risk of rupturing, leading to severe internal bleeding.
Example: A ruptured aortic aneurysm can cause death from massive internal bleeding.
Mnemonic:
“Aortic = Aorta’s Weak Spot”
→ Aorta bulges and may rupture.
Dissecting Aneurysm
Definition:
A dissecting aneurysm occurs when the inner layers of the aorta separate, allowing high-pressure blood to flow between them, potentially leading to rupture.
Example: Severe pain in the chest or back, along with shock, may signal a dissecting aneurysm.
Mnemonic:
“Dissecting = Layers Tear”
→ Blood flows between layers of the aorta, risking rupture.
LVAD (Left Ventricular Assist Device)
Definition:
An LVAD is a mechanical pump used to assist a weakened left ventricle in pumping blood, often used in severe heart failure.
Example: LVADs are used for patients who have severe heart failure or after a heart attack to help the heart pump effectively.
Mnemonic:
“LVAD = Left Ventricular Aid”
→ Device helps the left ventricle pump blood