The Heart and Circulatory System

Flashcards covering key concepts from the lecture on the heart and circulatory system.

What is the primary function of arteries in the circulatory system?

Arteries carry blood away from the heart and toward capillaries.

What is the largest artery in the body?

The aorta is the largest artery in the body.

What do capillaries do?

Capillaries carry blood from arterioles to venules and facilitate the exchange of nutrients and gases.

What is the role of the tunica intima in arteries?

The tunica intima is the inner layer of endothelial cells that prevents the accidental formation of blood clots.

How does the tunica media differ in arteries compared to veins?

The tunica media is thicker in arteries and important for blood pressure regulation, while it is thinner in veins.

What layer is the tunica externa made of?

The tunica externa is made of elastic tissue to prevent bursting under pressure.

What happens in the capillaries regarding substance exchange?

Substances such as glucose, oxygen, and wastes quickly pass through capillaries due to their thin tunica intima.

What prevents retrograde movement of blood in veins?

Valves in the tunica intima of veins prevent retrograde movement of blood.

What is an aneurysm?

An aneurysm is an abnormal widening of the arterial wall that promotes the formation of thrombi.

What is the significance of the hepatic portal circulation?

It is a specialized route that carries blood from the digestive organs to the liver for detoxification and regulation of blood glucose levels.

What are the three key differences in fetal circulation?

1. Umbilical vein carries oxygenated blood to the fetus. 2. Ductus arteriosus connects the aorta and pulmonary artery. 3. Foramen ovale bypasses pulmonary circulation.

What condition is characterized by enlarged veins with pooled blood?

Varicose veins (varices) are characterized by enlarged veins where blood pools.