Search Results

Miller's reaction chamber experiment Animation

By: HWC, Views: 1320

A simple diagram of Stanley Miller and Harold Urey's experimental apparatus. The lower portion of the apparatus was filled with water. The upper portion was filled with a mixture of gases that simulated the earth's early atmosphere. Examples are methane, ammonia, hydrogen and carbon dioxide. ...

Cardiac Cycle (Part 4 of 4)

By: Administrator, Views: 10887

Diastole and systole are two phases of the cardiac cycle. They occur as the heart beats, pumping blood through a system of blood vessels that carry blood to every part of the body. Systole occurs when the heart contracts to pump blood out, and diastole occurs when the heart relaxes after contract...

Acid-base imbalances - compensation of respiratory acidosis and alkalosis

By: HWC, Views: 7862

• When one pH balancing system is affected then the other balancing system attempts to correct, or compensate for, the pH imbalance. - Respiratory acidosis: • Excessive CO2 is present so blood pH becomes acidic. • Compensation is increased secretion of H+ into urine and reabsorption ...

Structures that affect circulation - heart and systolic/diastolic BP

By: HWC, Views: 7660

• Heart generates blood pressure. • Arterioles produce resistance thereby regulating blood flow to tissues. • Veins store blood; kidneys regulate blood volume; both affect venous return and cardiac output. ■ Contractions of the ventricles determine blood pressure, which drives th...

Antidiuretic hormone (vasoconstriction, water reabsorption & sweat inhibition)

By: HWC, Views: 7616

• Dehydration, blood loss, and low amounts of water in the blood can cause blood volume and pressure to decrease. • Neurosecretoxy cells in the posterior pituitary release antidiuretic hormone(ADH). • ADH binds to smooth muscle cells in blood vessel walls, stimulating them to vasoconstr...

Glomerubular filtrate rate -pressures that affect GFR and net filtration pressure

By: HWC, Views: 8189

• The glomerular filtration rate is the amount of filtrate formed per minute within the renal corpuscle. • Once the filtrate is formed it moves down the tubule. • The production and movement of filtrate depends on three pressures: I. Glomerular blood hydrostatic pressure (GBHP) is pre...

Congenital Heart Defects Animation

By: Administrator, Views: 10922

Pulse, blood pressure, and respiration vary according to the child’s age. A newborn’s pulse rate is irregular and rapid, varying from 120 to 140 beats per minute. Blood pressure is low and can vary with the size of the cuff used. Average blood pressure at birth is 80/46. Respirations are ...

Red Blood Cells - Erythropoietin (EPO)

By: HWC, Views: 7725

• The endocrine system maintains many body conditions within normal limits with feedback loops. Each endocrine feedback loop maintains homeostasis using the following components: • Stimulus - a change in a body condition. • Production cell - an endocrine cell that produces a hormone aft...

Stroke volume - afterload definition & hypertension

By: HWC, Views: 7199

• Pressure (or other resisting force) that ventricles must overcome to push open semilunar valves and eject blood. ▪ Normally, the left ventricle blood pressure must overcome arterial pressure in the aorta. ▪ Abnormally high blood pressure, or hypertension, increases aortic pressure w...