Answer:
Alpha-1
Explanation:
Adrenergic receptors are the integral proteins present in the postsynaptic plasma membranes. These receptors are activated when the neurotransmitter norepinephrine and the hormones norepinephrine and epinephrine bind to them. The alpha 1 adrenergic receptors are found in the smooth muscle fibers of blood vessels that serve the salivary glands, skin, and kidneys. These receptors are also found in the radial muscle of iris of the eye as well as in the sphincter muscles of the stomach and urinary bladder.
They exert excitatory effect and lead to contraction of smooth muscles of the blood vessels, dilation of pupil, and closure of sphincters of the bladder.
Answer:
Water, carbon dioxide, and oxygen are among the few simple molecules that can cross the cell membrane by diffusion (or a type of diffusion known as osmosis ). Diffusion is one principle method of movement of substances within cells, as well as the method for essential small molecules to cross the cell membrane.
Skin remains red after a bad sun burn because:
inflammation causes increased blood flow.
Explanation:
When our skin is exposed to sun rays , the epidermal layer starts getting damaged. The damage to the cell caused by sun rays triggers the melanin secretion. Increased secretion of melanin results in darkening of the exposed region .
However, the damage and inflammation to the skin increases blood flow to the skin, this causes reddening of the skin.
It will can cause infertile offspring (the offspring can't have kids)
