The Circulatory System

The Body’s Delivery System Your body’s way to continuously supply oxygen and nutrients and a away to remove wastes. Cardiovascular system includes the heart, kilometers of blood vessels and blood.

The Heart Heart is made up of cardiac muscle. Is located between the lungs and behind the sternum. Has four chambers. The two upper chambers are called the right and left atriums. The two lower chambers are called the right and left ventricles.

The Heart cont. The right side of the heart receives blood from the body and pumps it to the lungs. The left side of the heart does the exact opposite: It receives blood from the lungs and pumps it out to the body.

The Heart cont. A one-way valve separates each atrium from the ventricle below it. The blood flows from an atrium to a ventricle, and then from a ventricle into a blood vessel. A wall, called the septum, between the two atriums or the two ventricles keeps blood rich in oxygen separate from blood low in oxygen.

Blood Vessels Arteries– are blood vessels that carry blood away from the heart. Arteries have thick, elastic walls made of connective tissue and smooth muscle tissue.

Blood vessels cont. Veins- the blood vessels that carry blood back to the heart are called veins. Veins have one-way valves that keep blood moving toward the heart. When skeletal muscles contract, this action squeezes veins and helps blood move toward the heart.

Blood vessels cont. Capillaries- the walls of capillaries are only one cell thick. Nutrients and oxygen diffuse into the body cells from capillaries. Waste materials and carbon dioxide diffuse from body cells into the capillaries.

Functions of Blood Blood carries oxygen from your lungs to all your body cells. Carbon dioxide diffuses from your body cells into your blood. Your blood carries carbon dioxide to your lungs to be exhaled. Blood carries waste products from your cells to your kidneys to be removed. Blood transports nutrients and other substances to your body cells. Cells and molecules in blood fight infections and help heal wounds.

Parts of the blood Blood is a tissue made of plasma, red and white blood cells, and platelets. Blood makes up about 8% of your body’s total mass. Each part of the blood have different densities, and will separate into four different and distinct layers if centrifuged.

Plasma Plasma- the liquid part of the blood which is made mostly of water. Makes up more than half the volume of blood. Nutrients, minerals, and oxygen are dissolved in plasma so that they can be carried to body cells. Wastes from body cells are also carried in plasma.

Red Blood Cells White Blood Cells Disk-shaped Don’t have a nuclei when mature. Contain hemoglobin- carries oxygen and carbon dioxide Life span of about 120 days. Fights bacteria, viruses and other invaders of your body. Life span varies to a few days to many months Blood Cells

Platelets Irregularly shaped cell fragments that help clot blood. Life span of 5-9 days. When blood is exposed to air, platelets become sticky and form internal and external “scabs” to catch the blood cells and plasma, thereby stopping bleeding.

Lymphatic System The lymphatic system is part of the circulatory system, comprising a network of conduits called lymphatic vessels that carry a clear fluid called lymph directionally towards the heart. Lymph is essentially recycled blood plasma. Lymph contains water, dissolved substances, and lymphocytes ( a type of white blood cell). Lymphocytes help your body defend itself against disease-causing organisms.

Functions of the Lymphatic System The lymphatic system has multiple interrelated functions: It is responsible for the removal of interstitial fluid from tissues It absorbs and transports fatty acids and fats as chyle from the digestive system It transports white blood cells to and from the lymph nodes into the bones The lymph transports antigen-presenting cells (APCs), such as dendritic cells, to the lymph nodes where an immune response is stimulated.

Immunity Your skin and respiratory, digestive and circulatory systems are the first-line of defenses against pathogens. Your second-line defenses are specific and work against specific pathogens.

Second-line of defense White blood cells Inflammation Specific Immunity Memory B Cells Active Immunity Vaccination Passive Immunity

Diseases and disorders Hypertension, or high blood pressure, occurs when a high force of blood presses against the artery walls over time. Heart disease, or coronary artery disease, occurs when the blood vessels that supply oxygen to the heart narrow and stiffen. Varicose veins are another common disease of the circulatory system that happens when veins in the legs twist, swell, and become painful

Careers Cardiologists monitor, diagnose and treat heart conditions through a variety of non-surgical means, including medications and management of lifestyle factors. Echocardiography technicians perform ultrasounds of the heart and are trained to read the images. Exercise physiologists look at the body's physical response to exercise, and in the field of cardiology they may work in a rehab program or in a cardiac catheterization lab. They perform stress test and EKG’s.