The cardiovascular system is responsible for transporting nutrients and removing gaseous waste from the body. This system is comprised of the heart
and the circulatory system
. Structures of the cardiovascular system include the heart, blood vessels
, and blood
. The lymphatic system
is also closely associated with the cardiovascular system.
Structures of the Cardiovascular System
The heart is the organ that supplies blood and oxygen to all parts of the body. This amazing muscle produces electrical impulses through a process called cardiac conduction. These impulses cause the heart to contract and then relax, producing what is known as a heart beat. The beating of the heart drives the cardiac cycle which pumps blood to cells and tissues of the body.
- Blood Vessels
Blood vessels are intricate networks of hollow tubes that transport blood throughout the entire body. Blood travels from the heart via arteries to smaller arterioles, then to capillaries or sinusoids, to venules, to veins and back to the heart. Through the process of microcirculation, substances such as oxygen, carbon dioxide, nutrients, and wastes are exchanged between the blood and the fluid that surrounds cells.
The blood delivers nutrients to cells and removes wastes that are produced during cellular processes, such as cellular respiration. Blood is composed of red blood cells, white blood cells, platelets, and plasma. Red blood cells contain enormous amounts of a protein called hemoglobin. This iron containing molecule binds oxygen as oxygen molecules enter blood vessels in the lungs and transport them to various parts of the body. After depositing oxygen to tissue and cells, red blood cells pick up carbon dioxide (CO2) for transportation to the lungs where CO2 is expelled from the body.
The lymphatic system is a component of the immune system
and works closely with the cardiovascular system. The lymphatic system is a vascular network of tubules and ducts that collect, filter, and return lymph to blood circulation. Lymph is a clear fluid that comes from blood plasma, which exits blood vessels at capillary
beds. This fluid becomes the interstitial fluid that bathes tissues and helps to deliver nutrients and oxygen to cells
. In addition to returning lymph to circulation, lymphatic structures
also filter blood of microorganisms, such as bacteria
. Lymphatic structures also remove cellular debris, cancerous cells
, and waste from the blood. Once filtered, the blood is returned to the circulatory system.