L23 - Circulatory System

Flashcards on the human circulatory system, covering pulmonary and systemic circuits, blood vessels, heart anatomy, capillary action, and the lymphatic system.

Human Circulatory System

The system that drives blood around the body, supplying oxygen and nutrients to all tissues.

Endothelium

Composed of arteries and veins, it provides a non-thrombogenic layer for blood flow and controls substance movement in and out of the bloodstream.

Elastic Tissue Layer

Allows expansion and contraction to maintain blood pressure in arteries.

Smooth Muscle Cells

Structural components in arteries which can contract to restrict blood flow or relax to dilate the artery.

Arterioles

Located between arteries and veins, these can dilate or constrict based on the body's needs.

Capillaries

Blood vessels with only endothelium, thin enough for a red blood cell to pass through.

Veins

Vessels that return blood back to the heart, containing valve-like structures to ensure one-way flow.

Pulmonary Artery

Carries deoxygenated blood to the lungs.

Pulmonary Vein

Returns oxygenated blood from the lungs to the left side of the heart.

Aorta

The major artery carrying oxygenated blood from the heart to the body.

Portal Systems

Parts of the body where double filtration is needed for a specific application.

Blood

Connective tissue suspended in fluid (plasma).

Fibrinogen

Important for the clotting process.

White Blood Cells

Immune cells that provide the innate and adaptive immunity.

Platelets

Important for the clotting process.

Erythropoiesis

The process of making red blood cells.

Erythropoietin (EPO)

A glycoprotein that controls erythropoiesis.

Cardiac Muscles

The muscles of the heart, only found within the heart.

Atrial Ventricular Valve

Separates the atrium and the ventricles.

Tricuspid Valve

Valve with three leaflets separating the right atrium to the right ventricle.

Bicuspid Valve

Valve with two leaflets separating the left atrium to the left ventricle.

Pulmonic Valve

Controls blood flow through to the pulmonary artery.

Aortic Valve

Controls blood flow through to the aorta.

Pacemaker Cells

Specialized cells that depolarize spontaneously, creating electrical signals for heart contraction.

Autorhythmic Cells

Another name for pacemaker cells.

Sinoatrial Node (SA node)

The node containing the majority of pacemaker cells.

Atrial Ventricular Node (AV node)

Location where electrical conductance slows down to allow for atrium contraction.

Bundle of His

Bundle of nerves embedded within the septum.

Purkinje Fibers

End of the conductive pathway for electrical signals in the heart.

Diastole

The relaxation state of the heart.

Systole

The contraction of the heart.

Stroke Volume

What is ejected from the heart with each stroke.

Cardiac Output

A measure of heart work calculated by stroke volume times heart rate.

Postural Hypertension

Unique physiological response when enough blood is not being transported back to the heart.

Diffusion

Movement between endothelium.

Transcytosis

Where materials are packaged in microvesicles.

Bulk Flow

Things leaking across juctions of the cells.