Understanding Pulmonary and Systemic Circulation & Blood Disorders

Understanding Circulation and Blood Disorders

Pulmonary and Systemic Circulation

Pulmonary Circulation: Circulation through the lungs.

Systemic Circulation: Circulation to the rest of the body.

Vena Cava: Carries deoxygenated blood.

Coronary Heart Disease

Coronary Heart Disease: Refers to any disease that results in blockage of the coronary blood supply to part of the heart's muscular wall. The blockage causes partial deprivation of oxygen to the affected part and may result in the death of muscle cells.

Effects of Coronary Heart Disease

If a large part of the heart is affected, the person may die instantly. If a small region is affected, it may recuperate.

Atherosclerosis

Atherosclerosis: The most common form of hardening of the arteries. It begins with plaques of fatty material developing in the inner coat of the vessel wall. The more their presence restricts the flow of blood to an organ.

Angina

Angina: Refers to the crushing pain in the center of the chest, which tends to radiate out into the left arm and up to the neck and jaws.

Coronary Thrombosis

Coronary Thrombosis: Blockage of a coronary artery by a blood clot. It deprives part of the heart muscle of oxygen and leads to a heart attack.

Reducing the Risk of Coronary Thrombosis

• Avoid smoking.
• Avoid a stressful lifestyle.
• Avoid consumption of a diet high in cholesterol and saturated fat.
• Avoid being overweight.
• Engage in regular exercise.

Blood Cells and Plasma

Red Blood Cells: They are tiny, disk-like cells that do not have nuclei. In their cytoplasm is the red pigment called hemoglobin (protein + iron). They combine with oxygen to form oxyhemoglobin (an unstable compound). Blood contains both oxygenated and deoxygenated red blood cells. They are made in the bone marrow.

White Blood Cells: They have a nucleus. There is approximately 1 white blood cell for every 600 red blood cells. There are two types:

• Phagocytes: They move by flowing action of their cytoplasm and can escape from the blood capillaries into the tissues by squeezing between the cells of the capillary walls.
• Lymphocytes: Produce antibodies.

Platelets: Pieces of special blood cells budded off in the red bone marrow. They help to clot the blood at wounds and so stop the bleeding.

Plasma: The liquid part of the blood. It contains many substances, including food and hormones.

Genetic Disorders

Huntington's Disease: A disorder of the nervous system caused by a dominant allele and so it can be inherited from one parent who has the disease. If one parent is affected, there is a 50% chance of inheriting it. Symptoms are usually seen in people between 30 and 50 years old.

Cystic Fibrosis: Affects many organs of the body, particularly the lungs and the pancreas. Organs become clogged up by a very thick, sticky mucus, which stops them from working properly. Reproductive systems are also affected. Treatment includes physiotherapy and antibiotics to help keep the lungs clear of mucus and infections.

Sickle-Cell Disease: A genetic, lifelong blood disorder characterized by red blood cells that assume an abnormal rigid shape. This affects the cell's flexibility and can cause complications. The sickling occurs because of a mutation in the hemoglobin gene. Problems include a shortened life expectancy. It is usually presented in children.