circulatory and lymph

The primary function of the circulatory system is to transport blood, nutrients, oxygen, carbon dioxide, hormones, and waste products throughout the body.

Lymph is a clear fluid that circulates through the lymphatic system, helping to remove waste and toxins from tissues, and plays a crucial role in immune function.

Vasoconstriction is the contraction of the smooth muscle in the walls of blood vessels, which decreases their diameter and increases blood pressure.

Vasodilation is the relaxation of blood vessel walls, leading to an increase in their diameter and a decrease in blood pressure.

Approximately 50 to 60 percent of blood volume is made up of plasma.

Capillaries are the smallest blood vessels that connect arterioles and venules, facilitating the exchange of oxygen, carbon dioxide, nutrients, and waste between blood and tissues.

The thoracic duct is the largest lymphatic vessel in the body, responsible for draining lymph from the left side of the head, neck, chest, abdomen, and both legs into the bloodstream.

Arteries carry oxygenated blood away from the heart to the body, while veins carry deoxygenated blood back to the heart.

Blood is composed of red blood cells, white blood cells, platelets, and plasma.

Lymph nodes filter lymph fluid and are key components of the immune system, helping to identify and fight infections.