You go outside on a cold day, and blood flow to your skin is reduced, conserving body heat. You become angry, and your face turns red. Explain these changes
What will be an ideal response?
The blood vessels of the skin receive only sympathetic innervation. When you go outside into the cold, sympathetic neurons release NE and cause vasoconstriction of superficial blood vessels through stimulation of alpha receptors. When you get angry, sympathetic activation occurs, and large amounts of epinephrine enter the circulation. This stimulates beta receptors in the superficial blood vessels, dilating those vessels, and stimulates the heart, increasing blood pressure and blood flow. As a result, your skin — and most obviously your face — turns red.
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If the general interpretative area of the dominant hemisphere is damaged in a child, the
A. child will do very poorly in math. B. child will fail to learn language. C. corresponding region on the opposite side of the brain may take over the interpretative functions. D. child will have difficulty concentrating.
The respiratory surfaces of the nasal cavity are cleared by mucus produced in part by which of the following?
A) external nares B) paranasal sinuses C) soft palate D) nasal vestibule E) nasopharynx
Integrins
a. create a filamentous meshwork in the inner surface of the membrane. b. act as membrane-bounded enzymes. c. are used for cell recognition purposes. d. span the membrane, providing a mechanical link between the outer membrane and the cell's surrounding. e. none of these answers.
Choose the incorrect statement about white blood cells.
They carry oxygen to the body cells. They can leave the capillaries and move through body tissues. They can help the body defend against disease. They are formed in red bone marrow.