Endorphins are natural opiates released in response to pain and exercise. drugs and other chemicals affect brain chemistry at synapses. agonists
Nitrogen.
Plants cannot use atmospheric nitrogen directly. Nitrogen from the air must be converted into the different form so plants can absorb it. Thus plants need nitrogen-fixing bacteria to convert atmospheric nitrogen into ammonium, which is available for plants to absorb it.
Sebaceous gland, small oil-producinggland present in the skin of mammals.Sebaceous glands are usuallyattached to hair follicles and release a fatty substance, sebum, into the follicular duct and thence to the surface of the skin. ... Section through human skin and underlying structures
b hfdfcvyghfxdsgyuihgfhfdrsfghjgfdsafghjkhgftdrsfghjkhgf hjkhgfdg
