Image by Maria Keller - http://www.mariakellerac.com/
Nursing CalculatorsA collection of calculators used in a variety of nursing tasks. Each calculator, along with examples and formulas, provides a unique way to review nursing math.
Cochrane Reviews Podcast
Audio summaries of selected reviews from the Cochrane Library
Anatomy Videos from MedlinePlus
Free animated videos from MedlinePlus showing the anatomy of body parts and organ systems and how various diseases and conditions affect them.
AllergiesAllergens like pollen are nothing more than foreign plant antigens. The stimulus for sneezing gets triggered when allergens first enter the nasal tissue. Pollen allergens encounter the plasma cells in the nose, which respond by producing antibodies. These antibodies attach to mast cells, which are white blood cells containing the chemical histamine. As more antibodies are produced, they cause the mast cells to release histamine. Histamine then produces allergy symptoms. A stuffy and runny nose, sneezing and watery eyes help to remove the invading pollen. Medications called antihistamines may be used to help alleviate severe allergy symptoms.
Blood FlowAs the heart pumps, the arteries carry oxygen-rich blood (shown in red) away from the heart and toward the body's tissues and vital organs. These include the brain, liver, kidneys, stomach, and muscles, including the heart muscle itself. At the same time, the veins carry oxygen-poor blood (shown in blue) from the tissues back toward the heart. From there, it passes to the lungs to receive more oxygen. This cycle repeats itself when oxygen-rich blood returns to the heart from the lungs, which pumps it throughout the body.
Feeling PainPain provides the body with a protective mechanism, alerting it to potential or actual damage to the body's tissues. In the example of a bee sting, the pain receptors in the skin detect tissue damage from the bee sting. Then, the peripheral nerves send a pain signal to the brain. The brain analyzes the pain signal. In turn, the brain delivers a message back to the muscles of the arm to react.
Heart Bypass SurgeryHeart bypass surgery begins with an incision made in the chest, with the breastbone cut exposing the heart. Next, a portion of the saphenous vein is harvested from the inside of the leg. Pieces of this great vein will be used to bypass the blocked arteries in the heart. The venous graft is sewn to the aorta and to the affected coronary artery past the blocked site. The internal mammary artery from the chest may also be used to bypass a clogged artery. Several arteries may be bypassed depending on the condition of the heart.
StrokeA stroke may occur if an embolism travels from another part of the body and lodges within an artery in the brain. When an internal arterial wall becomes damaged, various types of emboli can form, such as one derived from platlets, thrombotic, cholesterol, or mixed. In this example, an embolism is formed in the internal carotid artery, breaks loose, travels towards the brain and lodges in a cerebral artery. The blocked artery deprives the brain of oxygen, damaging the surrounding brain tissue. The result is a stroke.