CIRCULATION IN ANIMALS

• Stroke is a disruption of blood flow to the brain, leading to damage or death of brain cells
• Stroke can be caused by a thrombus (blood clot fixed within a blood vessel), embolus (wandering clot), or hemorrhage (sudden artery bursts)
• Cerebral hemorrhage occurs when a patient has atherosclerosis and high blood pressure
• Coronary Heart Disease is the inability of blood to reach the coronary arteries of the heart due to aging or atherosclerosis
• Reduced blood flow in Coronary Heart Disease causes a painful sensation in the chest and shoulder, called angina pectoris
• Hypertensive Heart Disease is caused by hypertension, or elevated blood pressure from narrowing arterioles (smallest arteries)
• Rheumatic Heart Disease usually occurs in children and begins with an untreated bacterial infection caused by Streptococcus pyogenes
• Hemophilia is a disorder where blood does not clot properly, leading to uncontrollable bleeding
• Anemia is a condition where the red blood cell count stays persistently low, affecting the ability to carry oxygen to the body's tissues
• Leukemia is characterized by an abnormal increase in the number of white blood cells, being one of the most dangerous blood disorders
• Atherosclerosis is associated with cholesterol build-up called plaque inside the walls of the arteries, leading to narrowed and hardened arteries
• Atherosclerosis can cause irreversible damage, bacterial infection, and death of leg tissues that may require amputation
• Prevention of atherosclerosis includes a low-cholesterol diet, avoiding smoking, weight control, and exercise
• In the open circulatory system, hemolymph is a circulatory fluid that contains various cells, nutrients, hormones, and waste products
• In the open circulatory system, diffusion allows the exchange of gases, nutrients, and waste products between cells and the circulating fluid
• Closed circulatory systems, found in vertebrates, annelid worms, and cephalopod mollusks, enclose blood within vessels to transport oxygen, nutrients, hormones, and waste products