Answer:
A heart attack occurs when the flow of blood that carries oxygen to the heart is blocked. The myocardium is deprived of oxygen and begins to die.
A person who has a heart attack may have some of these symptoms, or all of them:
Uncomfortable pressure, inflammation or oppressive pain in the center of the chest
Discomfort or pain that spreads beyond the chest to the shoulders, back, neck, jaw, teeth, one or both arms, and sometimes the upper abdomen
Shortness of breath
Stun, dizziness and fainting
Sweating
Sickness
Usually, a heart attack causes chest pain for more than 15 minutes, but it also may not show any symptoms. It is important to know that other symptoms may occur in addition to chest pain, such as indigestion or persistent pain in the neck or jaw.
Many people who have a heart attack have warning signs in advance of hours, days or weeks.
The correct answer are valves. As lymphnodes become larger and deeper they turn into lymph vessels that develop one-way valves. These valves prevent the back flow of blood throughout the vessel and ensure that the lymph only flows in one direction.
Glycogen is a polysaccharide that is often referred to as animal starch (however this is not correct). It is the storage form of glucose in animal cells.
Glycerol is a compound consisting of a simple molecule. Used during the preparation of prescription drugs.
(hope this helps somewhat, let me know if you need me to explain)
What happens is the sun emits millions of waves of UV radiation, which is light particles to us. A wave of this UV radiation or light, takes about 8 minutes to get from the sun to earth, when the UV rays finally gets to earth, it is then filtered through our atmosphere, some light waves get in, but many bounce off.
jumping forward a few steps,
this light or UV radiation, penetrates our skin cells, about a couple inches or so.
the skin cells absorb the light, a similar process is seen by plants as photosynthesis,
and that's how we get a tan....
I hope this helps:)
