|
|
When blood is deoxygenated and flowing back to the heart through the veins, it is dark reddish-blue in color. Blood in the arteries that is oxygenated and flowing out to the body is bright red. Whereas arterial blood comes out in spurts, venous blood flows.
Vampire bats have a natural anticoagulant in their saliva that permits continuous bleeding after they painlessly open a wound with their incisors. This capillary blood does not cause any significant blood loss to their victims.
Autoimmune diseases occur when the immune system destroys its own healthy tissues. When this occurs, white blood cells cannot distinguish between pathogens and normal cells.
The training of an anesthesiologist typically requires four years of college, 4 years of medical school, 1 year of internship, and 3 years of residency.
The average older adult in the United States takes five prescription drugs per day. Half of these drugs contain a sedative. Alcohol should therefore be avoided by most senior citizens because of the dangerous interactions between alcohol and sedatives.