Human Circulatory System and Cardiovascular Health

Flashcards covering the anatomy of the heart, blood circulation pathways, blood pressure, pulse, blood typing, and cardiovascular health principles.

Universal Donor

A person with blood group O who can donate blood to an individual with any blood type.

Blood Donation

A voluntary procedure where blood (normally a pint, or $420\,\text{mL}$) is drawn from a healthy individual to be administered to a patient requiring surgery or medical care.

Blood Bank

A specialised facility where donated blood is stored and preserved for future transfusion to recipients.

Obesity

Excessive body weight resulting from factors such as high sugar and high fat intake, acting as a major risk factor for heart diseases.

Pulse Rate at Rest

The average rate of rhythmic arterial throbbing in a healthy adult when resting, which is approximately $72$ times per minute.

Stethoscope

A diagnostic instrument that amplifies internal sounds, featuring a chest piece positioned to listen to heartbeats.

Blood Pressure

The force exerted by circulating blood against the walls of the arteries, with a normal healthy reading of $120/80\,\text{mm/Hg}$.

Sphygmomanometer

The medical instrument utilised to measure arterial blood pressure.

Hypertension

A clinical elevation of blood pressure exceeding $140/90\,\text{mm}$, commonly known as high blood pressure.

Hypotension

A condition characterised by blood pressure falling below normal baseline levels, commonly termed low blood pressure.

Karl Landsteiner

The scientist who identified the human ABO blood group system in the year $1900$ based on A and B antigens located on red blood cell membranes.

Universal Recipient

An individual possessing blood group AB whose red blood cells display both A and B antigens, enabling them to safely receive transfusions of any blood type.

Heartbeat

A distinct acoustic cycle produced each time circulating blood passes through and forces the heart valves to close, occurring at an average resting frequency of $72$ beats per minute.

Pulse

A palpable throbbing sensation in superficial arteries produced as their muscular, elastic walls expand when blood is driven into the aorta by left ventricular contraction.

Radial Artery

The superficial artery situated at the wrist along the side of the thumb where the pulse is most readily felt and counted.

Vena Cavae

The two primary systemic veins—the superior vena cava and inferior vena cava—that gather deoxygenated blood from all bodily tissues and deliver it into the right auricle.

Pulmonary Circulation

The circulatory pathway that transports deoxygenated blood from the right ventricle through the pulmonary artery to the lungs for gas exchange, returning oxygenated blood via pulmonary veins to the left auricle.

Systemic Circulation

The circulatory pathway that pumps oxygen-rich blood from the left ventricle through the aorta to the entire body and returns deoxygenated blood to the heart.

Pulmonary Artery

The blood vessel emerging from the right ventricle that carries deoxygenated blood to both lungs for oxygenation.

Pulmonary Veins

The vessels that collect newly oxygenated blood from the lungs and channel it directly into the left auricle of the heart.

Aorta

The body's largest artery, originating from the left ventricle to distribute oxygenated blood across all systemic body tissues via its arterial branches.

Artery

A deep-seated, thick-walled, and elastic vessel that transports blood away from the heart under high pressure and in distinct jerks, generally devoid of valves along its main length.

Vein

A superficial, thin-walled vessel that returns blood toward the heart under low pressure in a smooth stream, equipped with internal valves to halt retrograde backflow.

Capillaries

Microscopic blood vessels with single-cell-thick endothelial walls connecting arterial branches to veins, facilitating nutrient, gas, and metabolic waste exchange with tissues.

Cardiac Muscles

Specialised involuntary muscle tissues forming the heart walls that contract and relax tirelessly and without pause throughout an individual's lifetime.

Auricles (Atria)

The two smaller, superior receiving chambers of the heart that collect incoming blood brought back by veins.

Ventricles

The two larger, inferior pumping chambers of the heart responsible for discharging blood out through the pulmonary artery and the aorta.

Atrio-ventricular (AV) Valves

Internal fibrous valves positioned between the auricles and ventricles that open and close to direct unidirectional blood flow within the heart.

Septum

The central muscular partition or membrane dividing the heart internally into separate right and left halves.