Circulatory System and Heart Anatomy

Comprehensive vocabulary flashcards covering the circulatory system, heart components, blood pressure, cardiac conditions, and blood composition based on the lecture notes.

Circulatory system

A mechanism for transport of nutrients, waste, and gas exchange.

Open circulatory system

A system found in arthropods and many molluscs where the heart pumps blood through open-ended vessels and cells are directly bathed in blood.

Closed circulatory system

A system found in vertebrates, earthworms, squids, and octopuses where blood stays confined to vessels and is pumped by a heart through arteries to capillaries.

Arteries

Vessels that carry blood from the heart to the capillaries.

Veins

Vessels that return blood to the heart.

Single circuit

A circulatory system with a two-chambered heart consisting of one ventricle and one atrium, found in organisms with gill capillaries.

Three-chambered heart

A heart structure with two atria and one ventricle, supporting a pulmocutaneous circuit and a systemic circuit.

Four-chambered heart

A heart structure with two atria and two ventricles, supporting separate pulmonary and systemic circuits.

Systolic pressure

The blood pressure during heart contraction, which is typically around $120$ in a standard reading.

Diastolic pressure

The blood pressure when the heart is relaxed, which is typically around $70$ in a standard reading.

Hypertension

A condition that causes the heart to work harder, leads to increased plaque formation and risk of blood clots, heart attacks, or strokes.

Cardiac output

The amount of blood pumped into the systemic circuit per minute.

Heart rate

The number of heart beats per minute.

Heart valves

Structures such as the Semilunar and Atrioventricular (AV) valves that prevent the backflow of blood.

Heart murmur

A defect in one or more heart valves.

Pacemaker (SA node)

The structure that sets the rate of heart contractions and generates electrical signals in the atria.

AV node

The structure that relays electrical signals from the pacemaker to the ventricles.

Heart attack

Damage to cardiac muscle, typically caused by a blocked coronary artery.

Stroke

The death of brain tissue resulting from blocked arteries in the head.

Atherosclerosis

A condition where plaques develop inside the inner walls of blood vessels, narrowing them and reducing blood flow.

Capillaries

Narrow blood vessels with thin walls consisting of a single layer of epithelial cells that serve as the site of gas and fluid exchange.

Precapillary sphincters

Smooth muscle structures that restrict blood flow through capillaries, typically allowing only about $5-10\%$ of capillaries to be open at once.

Plasma

The liquid constituent of blood, making up $55\%$ of its volume, acting as a solvent and maintaining osmotic balance and pH buffering.

Fibrinogen

A plasma protein specifically involved in the process of blood clotting.

Immunoglobulins

Plasma proteins also known as antibodies that function in defense and immunity.

Erythrocytes

Red blood cells that transport oxygen and carbon dioxide, numbering approximately $5-6\,million$ per $\mu L$ of blood.

Leukocytes

White blood cells, such as Basophils, Lymphocytes, Eosinophils, Neutrophils, and Monocytes, that function in defense and immunity.

Platelets

Cellular elements in the blood responsible for blood clotting, numbering $250,000-400,000$ per $\mu L$ of blood.

Anemia

A condition caused by abnormally low amounts of hemoglobin or red blood cells, resulting in fatigue due to oxygen lack in tissues.

Erythropoietin (EPO)

A hormone that regulates red blood cell production.