Blood Vessel Lecture Notes

Flashcards covering key vocabulary and concepts related to blood vessel structure, function, and fetal circulation.

Tunica Interna/Intima

The innermost layer of a blood vessel, consisting of simple squamous epithelium that lines the lumen.

Tunica Media

The middle layer of a blood vessel, composed of smooth muscle and elastic tissue.

Tunica Adventitia/Externa

The outermost layer of a blood vessel, consisting of dense irregular connective tissue.

Elastic Arteries

Arteries with a high concentration of elastic tissue in their tunica media, allowing them to withstand high blood pressure.

Muscular Arteries

Arteries with an increased amount of smooth muscle in their tunica media, providing greater autonomic control over blood flow.

Capillaries

The site of gas and nutrient exchange between blood and tissues; characterized by porous and leaky walls.

Venules

Small veins that drain blood from capillaries.

Endothelium

The simple squamous epithelium that lines blood vessels.

Venous Valves

Folds of the tunica intima in veins that prevent backflow of blood.

Skeletal Muscle Pump

Contractions of skeletal muscles that help pump blood back to the heart.

Abdominal Thoracic/Respiratory Pump

Changes in pressure within the thoracic and abdominal cavities due to breathing, aiding in venous return.

Continuous Capillaries

Capillaries with the least porosity, primarily for gas and nutrient exchange in tissues like skin and muscle.

Fenestrated Capillaries

Capillaries with pores (fenestrations) for greater fluid exchange, found in organs like the kidneys and small intestines.

Sinusoidal Capillaries

The most porous capillaries with large openings for cell exchange, found in bone marrow, liver, and spleen.

Metarterioles

Blood vessel that regulate entry into capillaries with precapillary sphincters

Precapillary Sphincter

A muscle that controls blood flow into true capillaries.

Vascular Shunt

Direct connection between metarteriole and venule that always remains open.

Anastomosis

Network of blood vessels that come together.

Arteriovenous Anastomoses

arteries connected to veins next to capillary beds.

Systolic Blood Pressure

Pressure when heart is contracting.

Diastolic Blood Pressure

Pressure when heart is at rest.

Foramen Ovale

Hole within the interatrial septum that connects the right atrium to the left atrium.

Ductus Arteriosus

Connects the pulmonary trunk to the aorta.

Ductus Venosus

Goes directly into inferior vena cava.