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Natural Selection, Species Isolation and Real World Example

By: HWC, Views: 7169

`Natural selection' is the process in which organisms with adaptive traits survive and breed in greater number than organisms without such traits. Eventually, almost all of the individuals in the population will have the same adaptive trait. This was the concept presented by Charles Darwin in ...

Methods that regulate pH

By: HWC, Views: 7895

• The blood flow redistributes fluids that have different pH values between body regions. • The regulation of the blood pH is important to maintain homeostasis. • Blood pH is regulated by: • Chemical buffers. • The respiratory system. • The urinary system. • All thes...

DNA fingerprinting Animation

By: HWC, Views: 4687

DNA fingerprinting enables a scientist to compare the DNA from two biological samples, such as a blood stain and a suspect's blood. A restriction enzyme is added to the samples to be compared. The enzyme cuts the DNA into smaller fragments. The DNA fragments are placed on an electrophor...

Glucagon (glycogenolysis and gluconeogenesis)

By: HWC, Views: 7605

• Exercise, or not having eaten recently, causes a decline in blood glucose concentration. • Low blood glucose stimulates alpha cells in the pancreatic islets to secrete glucagon. • Glucagon targets liver cells. • Glucagon causes liver cells to undergo: • Glycogenolysis, a proce...

Bulk flow - factors that influence bulk flow

By: HWC, Views: 7405

• Bulk flow helps regulate the relative volumes of blood and interstitial fluid. • Flow from blood to interstitium is called filtration. • Flow from interstitium to blood is called reabsorption. • Four factors determine the net direction of capillary exchange. • These factors in...

Phlebotomy

By: Administrator, Views: 10862

How blood is taken from a patient. Phlebotomy is the process of making an incision in a vein with a needle. The procedure itself is known as a venipuncture.

Atrial natriuretic peptide (vasodilation) & Aldosterone

By: HWC, Views: 7363

• Certain situations will cause the body's stress level to rise. • increased blood pressure will stretch the atria of the heart, stimulating the secretion of atria natriuretic peptide (MP). • ANP causes muscle cells in blood vessels to relax. • Blood pressure is lowered as a result ...

Introduction to Sickle Cell Anemia

By: Administrator, Views: 11168

Sickle cell anemia (sickle cell disease) is a disorder of the blood caused by an inherited abnormal hemoglobin (the oxygen-carrying protein within the red blood cells). The abnormal hemoglobin causes distorted (sickled appearing under a microscope) red blood cells.

Structures that affect circulation - kidneys and blood volume and skeletal muscle pumping

By: HWC, Views: 8307

• Kidneys regulate blood volume and blood osmolarity via salt and water reabsorption. • Increased reabsorption increases blood volume and venous return (and CO). • Decreased reabsorption Increases urine production, which decreases blood volume and venous return (and CO). • Systemi...