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Conduction of action potentials

By: HWC, Views: 6789

• Action potentials must be rapidly conducted over long distances in order for the nervous system to communicate with other cells. • Propagation of an action potential uses processes similar to those that generate the potential at the trigger zone. • a When a graded potential reaches ...

Types of Shock (Part 2 of 2)

By: Administrator, Views: 9612

Shock is a life-threatening condition in which delivery of oxygen to the organs is low, causing organ damage and sometimes death. Blood pressure is usually low.

DNA close up Animation

By: HWC, Views: 553

A section from a DNA double helix The backbone of each DNA strand consists of alternating deoxyribose sugars and phosphate groups. The two strands run in opposite directions. One runs from the 5' to 3' direction, the other in the 3' to 5' direction. Think of the deoxyribose units o...

Aneurysm

By: Administrator, Views: 9520

An aneurysm refers to a weakening of an artery wall that creates a bulge, or distention, of the artery. Most aneurysms do not show symptoms and are not dangerous. However, at their most severe stage, some can rupture, leading to life-threatening internal bleeding.

hGH, Thyroid hormones & Aldosterone

By: HWC, Views: 6721

Glycogenolysis and lipolysis • Stressors stimulate production of a hypothalamic releasing hormone (GHRH). • The releasing hormone stimulates somatotroph cells of anterior pituitary to secrete human growth hormone. • Human growth hormone targets liver cells and fat cells. hGH (glycog...

Phases of the ovarian cycle

By: HWC, Views: 7039

• The ovarian cycle is a monthly sequence of events, consisting of three phases: • Preovulatory • Ovulatory • Post ovulatory Preovulatory phase • prior to ovulation: Primary follicles develop into secondary follicles. • Follicular cells surrounding the primary oocyte In...

Heart sounds

By: HWC, Views: 6529

During a normal, healthy heartbeat, or what we call a cardiac cycle, the top two chambers of the heart, called the atria, contract simultaneously. Then, as they relax, the bottom two chambers, called the ventricles, contract. This explains what happens during a cardiac cycle, but what it doesn't ...

Introduction to Dysrhythmia

By: Administrator, Views: 9668

Cardiac dysrhythmias are a problem with the rate or rhythm of your heartbeat caused by changes in your heart’s normal sequence of electrical impulses. Your heart may beat too quickly, called tachycardia; too slowly, bradycardia; or with an irregular pattern. Dysrhythmias can range from complete...

Fermentation - When Oxygen Is Absent, Pyruvate to Lactate & Pyruvate to Ethanol

By: HWC, Views: 6201

Pyruvate is the end product of glycolysis. If oxygen is present, pyruvate enters the mitochondrion where further energy yielding reactions of the Krebs cycle will take place. However, if oxygen is not present, pyruvate will enter a pathway called fermentation. This pathway regenerates NAD+ fro...