Cardiac Physiology Quiz

Cardiac muscle fibers are shorter, branched, and interconnected via gap junctions called intercalated disks, which enable electrical impulses to travel from cell to cell.

The sarcomere is the basic functional unit of striated muscle, consisting of organized myosin and actin filaments that slide past each other during contraction.

The conducting system of the heart ensures rhythmic heartbeats by generating and conducting electrical impulses through specialized cardiac cells.

The SA (sinoatrial) node, located in the right atrium, acts as the heart's natural pacemaker. It generates electrical impulses that trigger heart contractions.

The heart's conducting system ensures coordinated contraction of the heart chambers, starting with the atria and followed by the ventricles.

The cardiac muscle's action potential is longer than the skeletal muscle's, preventing tetanic contractions and ensuring a rhythmic heartbeat.

The influx of calcium ions plays a crucial role in triggering the release of additional calcium from intracellular stores, leading to a more powerful myocardial contraction.

The autonomic nervous system regulates heartbeat through sympathetic (speeds it up) and parasympathetic (slows it down) innervation of the heart.

The electrocardiogram (ECG) is a noninvasive diagnostic tool that records the electrical activity of the heart. It displays a pattern of waves that reflect the heart's electrical events.

The Cardiac cycle comprises systole (contraction) and diastole (relaxation). The period of ventricular contraction corresponds to the ejection of blood into the aorta, while the period of relaxation allows for filling of the ventricles.

A condition where the blood's ability to carry oxygen is reduced, usually due to insufficient red blood cells.

Iron deficiency anemia occurs when the body doesn't have enough iron to produce hemoglobin, the protein in red blood cells that carries oxygen.

This type of anemia occurs when the bone marrow, responsible for producing blood cells, is damaged by toxins or cancer.

Hemorrhagic anemia is caused by excessive blood loss, leading to a shortage of red blood cells.

Renal anemia arises from the kidneys' inability to produce enough erythropoietin, a hormone crucial for red blood cell production.

This anemia is caused by an increased destruction of red blood cells, like in sickle cell disease.

White blood cells, also known as leukocytes, are responsible for defending the body against infections and diseases.

Platelets, tiny cell fragments, play a critical role in blood clotting, preventing excessive bleeding after injury.

A standard limb lead records electrical activity between the right arm and left arm.

A standard limb lead records electrical activity between the right arm and left leg.

A standard limb lead records electrical activity between the left arm and left leg.

A precordial lead records electrical activity from the chest.

The process of a small amount of calcium entering the cell through L-type calcium channels triggers the release of a larger amount of calcium from the sarcoplasmic reticulum, leading to muscle contraction.

A complete heart beat cycle is divided into two phases: systole, the contraction phase when blood is ejected, and diastole, the relaxation phase when the heart refills with blood.

The duration of a typical cardiac cycle is approximately 0.8 seconds, with 0.3 seconds in systole and 0.5 seconds in diastole.

Ventricular contraction and blood ejection is called systole.

Ventricular relaxation and blood filling is called diastole.

The narrowing of the aortic valve, which is the main valve that exits the heart. This narrowing makes it harder for the heart to pump blood out to the body.

The difference between systolic blood pressure (highest pressure) and diastolic blood pressure (lowest pressure). It's like a car's speed gauge - the difference between the highest and lowest readings.

The amount of blood pumped out by the heart in one minute. Imagine a water pump, its output is how much water it pumps per minute.

Sensors in the blood vessels that detect blood pressure changes and send signals to the brain to adjust heart rate and blood vessel diameter. Imagine your car's cruise control, it senses speed and adjusts accordingly.

The increased thickening of the heart muscle, often due to increased workload or stress. Imagine going to the gym regularly, your muscles get bigger.

Fluid buildup in the tissues, often due to poor circulation, causing swelling. Imagine your body as a sponge, too much water makes it swell.

A feeling of breathlessness or difficulty breathing, often a sign of heart failure or other conditions that limit oxygen intake. Imagine running a marathon - your lungs need to work harder to get oxygen.

The state of heart failure, where the heart can't pump enough blood efficiently to meet the body's needs. Imagine a pump struggling to fill a swimming pool, it can't keep up.

The relationship between blood flow (F), pressure difference (ΔP), and resistance (R). It states that blood flow is directly proportional to the pressure difference and inversely proportional to the resistance.

The constriction of blood vessels, mainly arterioles, leading to decreased blood flow.

The dilation of blood vessels, mainly arterioles, leading to increased blood flow.

Increased blood flow to a tissue or organ due to increased metabolic activity.

The automatic adjustment of blood flow to a tissue despite changes in pressure, ensuring adequate blood flow based on the tissue's needs.

A temporary, significant increase in blood flow to an organ following release of a complete blood flow occlusion.

Chemicals released by injured cells or found in the blood that cause vasodilation of blood vessels in the injured area.

Endothelial cells release nitric oxide (NO), a paracrine agent, continuously, contributing to arteriolar vasodilation.

The medullary cardiovascular control center, found in the medulla oblongata, is the central hub for integrating and coordinating the baroreceptor reflexes.

Baroreceptors detect changes in blood pressure and send signals to the medulla cardiovascular center.

The cardiovascular control center in the medulla receives information from baroreceptors and controls the sympathetic and parasympathetic nervous systems to adjust blood pressure.

The Vagus Nerve is a parasympathetic nerve that slows down heart rate, while the sympathetic nervous system speeds it up and constricts blood vessels.

Hormones like ADH (Antidiuretic Hormone) and Angiotensin II also play a role in blood pressure regulation by constricting blood vessels.

Baroreceptors in the veins, pulmonary vessels, and heart walls contribute to a 'feedforward' mechanism, anticipating and adjusting blood pressure before major changes occur.

Low blood pressure (hypotension) can be caused by blood loss, decreased cardiac contractility, strong emotions, or allergic reactions.

Hypertension is a chronic condition of high blood pressure (above 140/90 mmHg). It can be primary (unknown cause) or secondary (with identifiable causes).