BIO 20 - Circulatory System

Agglutination of Blood

Agglutination occurs when someone receives the wrong blood type. The immune system recognizes the foreign blood type as an invader, producing antibodies against the antigens on the donor blood’s red blood cells. This leads to clumping (agglutination) of the blood, causing blockages and severe reactions.

Aorta

The main artery that carries oxygenated blood from the left ventricle to the rest of the body. It is the largest artery in the body and is responsible for delivering oxygen-rich blood to various organs and tissues.

Aortic Valve

A valve located between the left ventricle and the aorta. It regulates blood flow from the left ventricle to the aorta, ensuring that oxygenated blood flows in one direction.

Artery

A blood vessel that carries oxygenated blood away from the heart, except for the pulmonary artery, which carries deoxygenated blood to the lungs. Arteries are thick-walled and muscular to withstand high pressure.

Atrium

The upper chamber of the heart. The right atrium receives deoxygenated blood from the body, and the left atrium receives oxygenated blood from the lungs.

AV Node (Atrioventricular Node)

A part of the heart’s conduction system located between the atria and ventricles. It slows down the electrical signal from the SA node before it reaches the ventricles, ensuring the atria contract before the ventricles.

Blood Clot

A gel-like mass of blood formed by platelets and fibrin, preventing excessive bleeding from injuries. It is an essential part of the body’s defense against hemorrhages.

Blood Pressure

The force of blood against the walls of the arteries as the heart pumps blood. It is measured in millimeters of mercury (mmHg) and is expressed as two numbers

Capillary

The smallest blood vessels in the body where the exchange of oxygen, nutrients, and waste products occurs between the blood and tissues. Capillaries connect arterioles and venules.

Cardiac Output

The volume of blood pumped by the heart per minute. It is a measure of the heart’s efficiency and is calculated by multiplying stroke volume by heart rate.

Cardiovascular System

The system in the body responsible for transporting blood, nutrients, oxygen, and hormones throughout the body. It consists of the heart, blood vessels, and blood.

Coronary Arteries

The arteries that supply oxygen-rich blood to the heart muscle. Blockages in these arteries can lead to heart attacks.

Deoxygenated Blood

Blood that has a low oxygen content and high carbon dioxide content. It returns from the body to the right side of the heart before being pumped to the lungs for oxygenation.

Diastolic Pressure

The pressure in the arteries when the heart is at rest between beats. It is the lower number in a blood pressure reading.

Fibrin

A protein that is essential for blood clotting. It forms a mesh that traps blood cells to create a clot.

Fibrinogen

A soluble plasma protein that is converted into fibrin during the clotting process.

Foramen Ovale

A small hole between the right and left atria in a fetal heart that allows blood to bypass the lungs, which are not yet in use for oxygen exchange.

Heart

The muscular organ that pumps blood throughout the body, supplying oxygen and nutrients to tissues and removing waste products.

Heart Rate

The number of times the heart beats per minute. It is an indicator of the body’s demand for oxygen and nutrients.

Hemoglobin

A protein in red blood cells responsible for carrying oxygen throughout the body. It binds to oxygen in the lungs and releases it in tissues that need it.

Hypertension

A condition where blood pressure is consistently elevated, putting strain on the heart and blood vessels. It can lead to serious health problems like heart disease and stroke.

Inferior Vena Cava

A large vein that carries deoxygenated blood from the lower half of the body to the right atrium of the heart.

Lymphatic System

A network of tissues and organs that help rid the body of toxins, waste, and other unwanted materials. It is essential for immune function and fluid balance.

Lymphatic Vessels

Vessels that transport lymph, a fluid containing white blood cells, throughout the lymphatic system.

Left Atrium

The chamber of the heart that receives oxygenated blood from the lungs through the pulmonary veins.

Left Ventricle

The chamber of the heart that pumps oxygenated blood into the aorta, which distributes it throughout the body.

Lungs

The organs responsible for gas exchange, where oxygen is taken into the blood, and carbon dioxide is removed.

Myocardium

The muscular tissue of the heart, responsible for contraction and pumping blood.

Oxygenated Blood

Blood that is rich in oxygen and has low carbon dioxide levels. It is pumped from the lungs to the left side of the heart and then to the rest of the body.

Pacemaker (SA Node)

A group of cells located in the right atrium that initiates electrical impulses, setting the pace for the heart rate.

Platelets

Small cell fragments in the blood that play a key role in clotting by forming plugs at injury sites and triggering clotting pathways.

Pulmonary Artery

The artery that carries deoxygenated blood from the right ventricle to the lungs for oxygenation.

Pulmonary Vein

The vein that carries oxygenated blood from the lungs to the left atrium of the heart.

Right Atrium

The chamber of the heart that receives deoxygenated blood from the body through the superior and inferior vena cava.

Right Ventricle

The chamber of the heart that pumps deoxygenated blood into the pulmonary artery, leading to the lungs.

Systolic Pressure

The pressure in the arteries when the heart contracts and pumps blood. It is the higher number in a blood pressure reading.

Superior Vena Cava

A large vein that carries deoxygenated blood from the upper body to the right atrium of the heart.

Systemic Circulation

The part of the circulatory system that carries oxygenated blood from the heart to the rest of the body and returns deoxygenated blood back to the heart.

Tricuspid Valve

The valve between the right atrium and the right ventricle that prevents blood from flowing back into the atrium when the ventricle contracts.

Vein

A blood vessel that carries deoxygenated blood back to the heart. Veins are equipped with valves to prevent the backflow of blood.

Venule

A small vein that collects deoxygenated blood from capillaries and channels it into larger veins.

Ventricles

The lower chambers of the heart that pump blood to the lungs and the rest of the body. The left ventricle pumps oxygenated blood to the body, and the right ventricle pumps deoxygenated blood to the lungs.

Venous Valves

Valves located within veins that prevent the backflow of blood, helping blood move toward the heart against gravity.

White Blood Cells (Leukocytes)

Cells in the blood that are part of the immune system, responsible for fighting infections and protecting the body against foreign invaders.

Valve

A structure in the heart or veins that ensures blood flows in one direction, preventing backflow.

Vasoconstriction

The narrowing of blood vessels, which increases blood pressure and reduces blood flow to certain areas of the body.

Vasodilation

The widening of blood vessels, which decreases blood pressure and increases blood flow to certain areas of the body.

Venous Return

The return of blood to the heart via the veins, influenced by muscle contractions and respiratory movements.