### body part:

Valve
* Some valves are closed by muscles
  - force blood
* Some valves have metering rods- long stainless steel rods that move up and down in a small hole
  - teeth
  - leave ventricles
* Some valves use for locomotion
  - gases
  - valves that are opened with a straight-edge screwdriver
* allow blood to flow in one direction between the chambers of the heart
  - the blood to flow in only one direction, up or down
* also control the flow of blood between the heart and arteries.
* appear as knot-like bulges in the vein in some patients.
* are also present between the ventricles and the vessels leading from it
  - composed of both chitin and calcium carbonate and are hinged along the dorsal margin
  - devices
  - flap-like structures that allow blood to flow in one direction
  - mechanical devices that allow or impede the movement of a liquid or a gas
  - more likely to stick in hot summer weather than in cold winter months
  - most numerous in the veins of the extremities, and are absent in the smallest veins
  - one of the most used apparatuses within a refinery or chemical complex
* are part of brass
  - hearts
  - trumpets
  - portals
* are present in an otter's nose and ears which close automatically as the otter submerges
  - lymph vessels to prevent backflow
  - veins to prevent backflow of blood
  - shells
  - the doorways of the heart
  - usually the single largest source of fugitive emissions
* close the ostia when the heart contracts.
* connect guts.
* control the flow of blood between the atria and ventricles
  - from the atria to the ventricles
  - fluids and gasses and appear in several places in a paintgun system
* created by the lips and tongue keep food in the mouth and in place prior to swallowing.
* direct the flow of blood through the heart's chambers.
* guard the opercular clefts, preventing the backflow of water.
* have a natural tendency to twist in their respective casings.
* help buildups.
* includes corpi.
* keep blood flowing in the proper direction
  - the blood flowing in one direction
* prevent backflow of blood into the heart when the heart relaxes
  - backflow, keeping the blood flowing in one direction through the heart
  - backward flow of blood
* prevent blood backflow
  - or lymph from flowing backward
  - passing in the opposite direction from deep to surface veins
  - the backflow of blood
  - what is trapped within the lymph vessels to return to interstitial fluid
* regulate the flow of a liquid or gas
  - blood through the heart and to the pulmonary artery and the aorta
* stems can swell in their guides and also scuff or seize.
* tend to rotate under the action of the valve springs and by engine vibration.
* usually contain one to several short spines, perpendicular to the shell surface.
* vary in construction and size depending upon their function.

### body part | valve | cardiac valve:

Mitral valve
* cardiac valve
* is made of very heavy cusps and is located at the entrance of the left ventricle.

Semilunar valve
* begin to form in the heart.
* separate the ventricles from the outgoing blood vessels.

Heart valve
* Most heart valves are part of hearts.
* are body parts
  - implants
  - solid objects
* perform the vital job of maintaining the heart's blood flow in the correct direction.
* regulate the flow of blood from the heart's pumping chambers
  - inside the heart
* replace damaged valves in infants and adults with heart valve defects.

Inbal valve
* are a breakthrough in conceptual design of control valves.
* work with water and can operate efficiently with other fluids and gases.

Mechanical valve
* can cause all sorts of problems, such as breakdown of blood cells or infection
  - last indefinitely if proper blood thinning medications are always taken
* tend to last longer, but they are more prone to cause blood clots and strokes.

Stenotic valve
* are often a natural result of aging.
* hinder the forward flow of blood.