PLASMA, ERYTHROCYTES, LEUKOCYTES AND PLATELETS COMPOSITION AND FUNCTION OF BLOOD
FUNCTION OF BLOOD... Oxygen is carried to tissues Carbon dioxide is carried fro m tissues to lungs Glucose is carried from the GI tract to either the liver or muscle tissues Ammonia (NH3) is carried from tissues to liver to be processed into urea Defend body against pathogens Removes excess heat from metabolism Plasma contains albumin, fibrinogen and, globulins, salts, nutrients, wastes and hormones
RED BLOOD CELLS (ERYTHROCYTES) Red blood cells containing hemoglobin can carry 60 times more oxygen than plasma alone Red cells are made within the bone marrow (hematopoiesis) in the skull, ribs, spine, pelvis and at ends of long bones. Red cell production is stimulated by a hormone erythropoietin which is made by the kidneys Red cells live for 120 days and then are destroyed by the liver or spleen
WHITE BLOOD CELLS (LEUKOCYTES) WBC s increase in quantity to fight off an infection Types of WBC s a. Neutrophils - main phagocytic cell of blood b. Eosinophils- increase in allergies and parasitic infections of tissues c. Basophils- become mast cells important in allergic reactions d. Monocytes or Macrophages- big eaters e. Lymphocytes: 1. B cell- produce antibodies 2. T cell-directly destroy foreign invaders
BLOOD CLOTTING: When injury to a blood vessel takes place, clotting will take place to repair the hole and prevent blood loss 1. Blood vessels will constrict to reduce or stop the flow of blood. 2. Blood platelets will become activated when collagen enters bloodstream. Platelets will seal the hole and maintain the lining of the blood vessel. 3. Clotting proteins help strengthen the platelet plug by activating a series of enzymatic reactions that will eventually result in a clot
CLOTTING CASCADES: ** Exposure of blood to collagen, tissue thromboplastin or foreign substance triggers clotting cascade *Hemophiliacs don t produce factor 8 **In order for Factor X to become activated, Calcium MUST be present
CIRCULATION/ RESPIRATION IN ANIMALS
CIRCULATORY SYSTEM:
CIRCULATION AND GAS EXCHANGE: Our circulatory systems provide a mechanism that allows our cells to exchange gases (oxygen and carbon dioxide) which are essential for cellular respiration and bioenergetics Some invertebrates don t have need of a circulatory system Some animals with many cell layers utilize open circulatory systems. Blood, body fluids and interstitial fluids = hemolymph.
CLOSED CIRCULATORY SYSTEMS: Cardiovascular system: contains heart with one or two atria and ventricles, arteries, veins and capillaries
MAMMALIAN HEART: Composed of thick cardiac muscle tissue called myocardium Two sides of heart do not communicate directly with each other There are one way valves that connect the atria to ventricles (tricuspid and mitral) Heart sounds from atrioventricular valves closing (lub) and pulmonary and aortic semilunar valves closing (DUB)
ELECTRICAL ACTIVITY OF THE HEART: SA node will cause approx 70 beats/min all by itself Dual control from brain by inhibitory and stimulatory nerves Stimulatory: Exercise, excitement, stress Inhibitory: Vagus nerve, barbiturates Defibrillators: stop erratic contractions of heart by depolarizing myocardium (reset) and allow SA node to get things back on track
Tour through the heart MAMMALIAN CIRCULATION ** Aorta: First stop at coronary arteries, then head and arms, then abdominal area and legs.
CIRCULATORY SYSTEM SURFACES:
INSECT CIRCULATION AND RESPIRATION:
FISH CIRCULATION AND RESPIRATION: Counter current exchange
BIRD RESPIRATION: Avian Respiration The air sacs permit a unidirectional flow of air through the lungs. Unidirectional flow means that air moving through bird lungs is largely 'fresh' air & has a higher oxygen content. Opposite of mammals, which utilize bidirectional flow.
MAMMALIAN CIRCULATION AND RESPIRATION Respiration overview