Cardiovascular System Flashcards
Describe the function of the atrioventricular valves in the heart
The atrioventricular valves (tricuspid and bicuspid/mitral) prevent backflow of blood from the ventricles into the atria during ventricular contraction.
Identify the role of the semilunar valves
The semilunar valves (pulmonary and aortic) prevent the backflow of blood into the ventricles after contraction.
Explain the importance of coronary arteries
Coronary arteries arise from the aorta and supply oxygen and glucose to the heart muscle, ensuring it has the energy for continuous pumping.
Define the term “chordae tendineas”
hordae tendineae, also called ‘heartstrings,’ are fibrous cords that anchor the atrioventricular valves to the heart muscles, preventing valve prolapse.
Describe the flow of blood through the heart starting from the vena cava
Deoxygenated blood enters the right atrium via the vena cava, passes through the tricuspid valve into the right ventricle, then through the pulmonary valve into the pulmonary artery to the lungs. Oxygenated blood returns via the pulmonary veins to the left atrium, passes through the bicuspid valve to the left ventricle, and is pumped through the aortic valve into the aorta.
Explain the significance of a double circulatory system in mammals
A double circulatory system allows blood to flow through the heart twice per circulation, separating pulmonary circulation (lungs) and systemic circulation (body). This maintains high pressure for efficient oxygen and nutrient delivery.
Compare the structure and function of arteries, veins, and capillaries
Arteries have thick walls and no valves, carrying high-pressure blood away from the heart. Veins have thin walls and valves, carrying low-pressure blood back to the heart. Capillaries are one cell thick, facilitating efficient diffusion of gases and nutrients.
Describe the cardiac cycle phases
The cardiac cycle includes:
Diastole: Heart relaxes, blood flows into atria and ventricles.
Atrial Systole: Atria contract, pushing blood into ventricles.
Ventricular Systole: Ventricles contract, pumping blood into the pulmonary artery and aorta.
Explain how the sinoatrial node (SAN) controls heart rhythm
The SAN, the heart’s pacemaker, generates electrical impulses that cause atrial contraction. These impulses travel to the atrioventricular node (AVN), then through the Bundle of His and Purkinje fibers, causing ventricular contraction.
Identify two factors that can influence heart rate and explain their effects
Exercise: Increases heart rate due to greater oxygen demand.
Caffeine: Stimulates the heart, increasing both the strength and frequency of contractions.
Describe the purpose of an artificial pacemaker
An artificial pacemaker regulates heart rhythm by sending electrical impulses to stimulate atrial or ventricular contraction when the heart’s conduction system is impaired.
Explain the difference between Tachycardia and Bradycardia
Tachycardia is a fast heart rate (>100 bpm), while bradycardia is a slow heart rate (<60 bpm). Both are abnormalities in heart rhythm.
Define systolic and diastolic blood pressure
Systolic pressure is the peak arterial pressure during heart contraction. Diastolic pressure is the lowest arterial pressure when the heart is relaxed.
Explain why capillaries are efficient for gas exchange
Capillaries have thin, one-cell-thick walls and a large surface area, allowing for efficient diffusion of oxygen, carbon dioxide, and nutrients between blood and tissues.
What is the role of the Bundle of His in the heart?
The Bundle of His transmits electrical impulses from the AVN to the Purkinje fibers, coordinating the contraction of the ventricles.
Describe the difference between single and double circulatory systems
In a single circulatory system, blood passes through the heart once per circulation (e.g., in fish). In a double circulatory system, blood passes through the heart twice (pulmonary and systemic circuits), which occurs in mammals.
Identify the layers of an artery wall and their functions
Tunica intima: Smooth lining to reduce friction.
Tunica media: Elastic fibers and smooth muscle for strength and elasticity.
Tunica externa: Connective tissue for structural support and protection.
Explain how veins prevent the backflow of blood
Veins have valves that close to prevent backflow, especially in areas where gravity opposes blood flow, such as the legs.
Define a normal sinus rhythm
A normal sinus rhythm is the regular rhythm of a healthy heart, initiated by the sinoatrial node (SAN), with a heart rate between 60-100 beats per minute.
Explain what an electrocardiogram (ECG/EKG) measures
An ECG records the electrical activity of the heart over time, used to assess rhythm, detect abnormalities, and monitor heart function.
Describe the cardiac events during ventricular systole
During ventricular systole, the ventricles contract, blood is pumped through the open semilunar valves into the pulmonary artery and aorta, and the atrioventricular valves (tricuspid and bicuspid) close to prevent backflow.
Identify and describe two common types of arrhythmias
Atrial fibrillation (AF): Irregular heartbeat with no clear waves before the QRS complex.
Ventricular fibrillation (VF): Chaotic electrical activity with no pulse; may require defibrillation.
Describe how blood pressure is measured and interpreted
Blood pressure is measured in mmHg using a sphygmomanometer. It includes systolic pressure (pressure during ventricular contraction) and diastolic pressure (pressure during relaxation). Normal is approximately 120/80 mmHg.
Explain what happens during atrial systole
During atrial systole, the sinoatrial node initiates a wave of depolarization, causing the atria to contract and push blood through the atrioventricular valves into the ventricles.
Identify the components of the cardiac conduction system
The cardiac conduction system includes the sinoatrial node (SAN), atrioventricular node (AVN), Bundle of His, and Purkinje fibers.
describe the role of the bundle of His in the cardiac cycle
The Bundle of His transmits electrical impulses from the AVN down the interventricular septum, ensuring coordinated ventricular contraction.
Explain why myocardial infarction are dangerous
Myocardial infarctions (heart attacks) damage heart muscle due to reduced blood flow and oxygen, potentially leading to heart failure, arrhythmias, or death.
Define tachycardia and its symptoms
Tachycardia is a rapid heart rate (greater than 100 bpm) at rest, which may cause dizziness, palpitations, or fainting.
What are the main components of a treatment plan for coronary heart disease (CHD)?
Lifestyle modifications: Healthy diet, regular exercise, smoking cessation.
Medications: Statins, antiplatelets, beta-blockers, ACE inhibitors.
Procedures: Coronary angioplasty, stent placement, coronary artery bypass graft (CABG).
Psychological support: Managing stress and mental health.
What are the key priorities in the treatment of a stroke?
Emergency care: Restoring blood flow or stopping bleeding.
Medications: Thrombolytics, anticoagulants, antiplatelets, antihypertensives.
Rehabilitation: Physiotherapy, occupational therapy, speech therapy.
Lifestyle changes: Diet, exercise, smoking cessation.
How are hemorrhagic strokes managed?
Emergency care: Restoring blood flow or stopping bleeding.
Medications: Thrombolytics, anticoagulants, antiplatelets, antihypertensives.
Rehabilitation: Physiotherapy, occupational therapy, speech therapy.
Lifestyle changes: Diet, exercise, smoking cessation.
What is Tachycardia?
A condition where the heart rate exceeds 100 beats per minute (bpm) in adults.
What are the types of tachycardia?
Supraventricular tachycardia (SVT): Originates above the ventricles.
Ventricular tachycardia: Originates in the ventricles; can be life-threatening.
Sinus tachycardia: Normal response to stress, fever, or exercise.
How is Tachycardia treated?
Lifestyle modifications: Reduce caffeine, stress, and smoking.
Medications: Beta-blockers, calcium channel blockers.
Cardioversion: Electric shock to restore normal rhythm.
Ablation therapy: Destroys faulty electrical pathways in the heart.
What is bradycardia?
A condition where the heart rate is below 60 beats per minute (bpm) in adults.
How is bradycardia treated?
Address underlying causes: Treat hypothyroidism or adjust medications.
Pacemaker: Used for severe cases to regulate heart rate.
Lifestyle changes: Managing contributing factors (e.g., electrolyte levels).
What is myocardial infarction (MI)?
A medical emergency where blood flow to a part of the heart muscle is blocked, causing tissue damage or death.
How is a myocardial infarction diagnosed?
ECG (Electrocardiogram): Detects heart damage.
Blood tests: Elevated cardiac markers (e.g., troponin).
Angiography: Identifies blocked coronary arteries.
What are the treatment steps for a myocardial infarction?
Immediate care:
Administer oxygen and aspirin.
Nitroglycerin for chest pain.
Thrombolytics to dissolve clots.
Medications:
Beta-blockers, ACE inhibitors, statins, antiplatelet drugs.
Procedures:
Angioplasty and stent placement.
Coronary artery bypass graft (CABG) in severe cases.
