The Transport System and Cardiovascular Health Flashcards

Vocabulary flashcards covering transport systems, blood components, circulatory dynamics, cardiac cycle, vessel structures, cardiovascular pathology, epidemiology, and pharmacological interventions.

Diffusion

The free movement of particles in a liquid or gas down their concentration gradient from an area of high concentration to an area of low concentration.

Mass Transport System

An internal transport system consisting of the heart, blood vessels, and transport fluid that rapidly carries substances to every cell in large multicellular organisms.

Plasma

The fluid portion of blood making up $50\%$ of blood volume that transports nutrients, excretory products, hormones, and heat while acting as a buffer to regulate pH.

Erythrocytes

Biconcave red blood cells with no nucleus and a lifespan of $120\,\text{days}$ that contain haemoglobin to carry oxygen throughout the body.

Leucocytes

Nucleated white blood cells that defend the body against infections and can alter their shape to squeeze through narrow blood vessels.

Platelets

Tiny cell fragments derived from megakaryocytes in the bone marrow that play a primary role in blood clotting.

Haemoglobin

A protein consisting of four polypeptide chains, each with an iron-containing prosthetic group, capable of binding four oxygen molecules to form oxyhaemoglobin.

Partial Pressure of Oxygen

The specific pressure exerted solely by oxygen gas molecules within a gas mixture.

Bohr Effect

The reduction in haemoglobin's affinity for oxygen caused by high carbon dioxide levels in active tissues, promoting easier release of oxygen.

Fetal Haemoglobin

A form of haemoglobin found in a fetus that possesses a higher affinity for oxygen than adult haemoglobin, enabling oxygen extraction from maternal blood across the placenta.

Myoglobin

A respiratory pigment present in cardiac muscle cells with a higher affinity for oxygen than haemoglobin, serving as an oxygen store for continuous cardiac contraction.

Thromboplastin

An enzyme released by damaged blood vessels and broken platelets that catalyses the conversion of prothrombin into active thrombin during blood clotting.

Thrombin

An active enzyme converted from prothrombin that catalyses the transformation of soluble plasma fibrinogen into insoluble fibrin.

Fibrin

An insoluble protein formed from fibrinogen that creates a mesh of fibers to trap blood cells and platelets, forming a blood clot.

Chloride Shift

The movement of chloride ions ($\text{Cl}^-$) into erythrocytes as hydrogencarbonate ions ($\text{HCO}_3^-$) diffuse out into the plasma.

Open Circulatory System

A circulatory system found in invertebrates where blood is pumped into body cavity spaces called sinuses to directly bathe organs rather than remaining enclosed in vessels.

Closed Circulatory System

A circulatory system where blood remains enclosed within blood vessels and is pumped under high pressure throughout the body.

Single Circulation

A circulatory system where blood passes through the heart only once during a single complete circuit of the body, as found in fish.

Double Circulation

A circulatory system featuring two distinct circuits (pulmonary and systemic) where blood passes through the heart twice in one complete circuit.

Atrial Systole

The stage of the cardiac cycle in which the atria contract, forcing blood through the open atrioventricular valves into the ventricles.

Ventricular Systole

The stage of the cardiac cycle in which the ventricles contract, closing the atrioventricular valves and forcing blood through the semilunar valves into the major arteries.

Diastole

The relaxation phase of the cardiac cycle during which heart muscle relaxes and the heart chambers fill with blood.

Sinoatrial Node (SAN)

A specialized region of tissue in the right atrium that initiates waves of electrical depolarisation to trigger atrial systole and establish heart rate.

Atrioventricular Node (AVN)

A node of cardiac tissue that conducts electrical excitation from the atria to the ventricles via the bundle of His and Purkyne fibres.

Tunica Media

The middle layer of an artery or vein wall composed of smooth muscle and elastic fibers that provide elasticity and control lumen size.

Endothelium

The smooth, innermost cellular lining (tunica intima) of blood vessels that minimizes friction and resistance to blood flow.

Arterioles

The smallest branches of the arterial system whose smooth muscle walls contract or relax to regulate blood flow into capillaries.

Capillaries

Microscopic blood vessels with walls one cell thick that provide a large surface area and short diffusion distance for exchange of materials.

Veins

Blood vessels carrying blood back to the heart at low pressure, featuring thin walls, wide lumens, and semilunar valves to prevent backflow.

Atherosclerosis

A progressive disease characterized by the buildup of fatty cholesterol plaques (atheromas) inside arteries, leading to hardening and narrowing of the lumen.

Aneurysm

A weakened, bulging section of an artery wall caused by blood accumulating behind a blockage formed by plaques.

Angina

Chest pain experienced during exercise when plaque deposition in coronary arteries reduces oxygenated blood supply to cardiac muscle.

Myocardial Infarction

A heart attack occurring when a blood clot completely blocks a coronary artery, depriving heart muscle cells of oxygen and causing tissue death.

Epidemiology

The scientific study of the patterns, distribution, and causes of health conditions and diseases within specified populations.

Cohort Study

An epidemiological study following a large group of people over a long period to monitor disease development and identify risk factor correlations.

Case-Control Study

An epidemiological study comparing individuals with a specific condition (cases) to a similar group without it (controls) to identify past exposures.

Low Density Lipoproteins (LDLs)

Lipoproteins composed of saturated fats, cholesterol, and protein that transport lipids in blood and can cause plaque buildup when levels are elevated.

High Density Lipoproteins (HDLs)

Lipoproteins composed of unsaturated fats, cholesterol, and protein that collect cholesterol from tissues and transport it to the liver for breakdown.

Body Mass Index (BMI)

A measure used to assess healthy weight for height, calculated as $\text{BMI} = \frac{\text{weight in kg}}{(\text{height in m})^2}$.

Waist-to-Hip Ratio

A body measurement ratio used to assess fat distribution and predict cardiovascular disease risk by dividing waist circumference by hip circumference.

Antioxidants

Substances that neutralize free radicals by donating electrons, protecting cells from oxidative damage and reducing plaque formation in arteries.

Statins

A class of drugs that lower blood cholesterol levels by inhibiting the enzyme in the liver responsible for cholesterol synthesis.

Antihypertensives

Prescription medications, including diuretics, beta blockers, and ACE inhibitors, used to lower abnormally high blood pressure.

Warfarin

An anticoagulant medication that reduces blood clotting by interfering with the body's manufacture of prothrombin.