### substance | blood:

Blood donation
* appears to help give men the iron lowering benefits enjoyed by women.
* are a vital part of the health care delivery system in our community
  - kept liquid using citric acid
* help save lives every day.
* is also involves a significant loss of iron
  - an essential part of biomedical services
  - one way a little effort can make a big difference
  - the process of giving blood willingly to help patients in hospitals
* remains one of the safest of all medical procedures.
+ Citric acid, Main uses: Acids :: Citrus

### substance | blood:

Blood flow
* More blood flow means increased oxygen availability to brain cells.
* can decrease from lack of exercise, dehydration, and thick blood.
* ceases and unless the heart rhythm is restarted, death follows swiftly.
* decreases to areas that are less important for basic survival, including the mouth.
* increases drastically.
* increases to the area to heal the wound, and blood vessels dilate and become red
  - brain and major muscles
* is blocked or slowed down by the narrow arteries and the heart gets less oxygen
  - constricted to the extremities
  - critical to healthy kidney function
  - critical, because it carries oxygen into the tissues and promotes natural healing
  - crucial to bring all of the elements for cell growth to the brain
  - directed towards muscle and away from the gut and skin
  - distributed differently to specific layers of the intestinal wall
  - due to contraction of the heart muscle assisted by artery muscle contraction
  - improved by vitamin E and it causes blood vessels to dilate or expand
  - increased to vital organs, or organs that have higher oxygen extraction ratios
  - known to be closely coupled to functional activation
  - life itself
  - maintained through small vessels
  - measured by assessing pulse and penile blood pressure
  - monitored to insure adequate reperfusion or restoration of blood flow
  - more about arousal
  - poor throughout the entire retina
  - proportional to the fourth power of the radius of the blood vessel
  - reduced when constriction occurs
  - thick and dark
  - thus impaired and death follows from lack of oxygen to the brain
* makes blood vessels readily apparent.
* nourishes the skin and keeps it healthy.
* occurs through a series of vessels with different characteristics.
* prime method of distributing heat evenly throughout the body.
* starts when the pressure in the cuff becomes lower than the pressure in the artery.
* stops in the macula pellucida or stigma.
* stops, veins collapse and eventually disappear.
* supplies the nutrients the brain needs to survive.
* tends to slow as fluid leaves the capillaries.
* very effective means of carrying heat away from tissue.

Blood group
* antigens react with proteins called antibodies.
* are blood
  - distinctive molecules, called antigens, on the surface of red blood cells
  - permanent
* is blood

Blood testing
* can help ascertain if additional estradiol is needed.
* does have certain advantages over skin testing.
* is an important tool for people who are regularly exposed to lead
  - in aiding a physician in making a diagnosis
  - done to detect the presence of any infectious diseases
  - the cornerstone of diagnosis during the secondary phase
* refers to laboratory analysis of blood, usually drawn from a patient's arm.

Blood thinner
* Some blood thinners are very powerful.
* are medicine
  - necessary to prevent clotting of the valve
* help prevent further TIAs or strokes.
* work by slowing the clotting action of the blood.
* works better than aspirin.