QUESTIONS AND COMPLETE
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, Which of the following cell types provides a waterproofing function for the outer layers of skin?
A. Melanocytes
B. Keratinocytes
C. Merkel cells
D. Langerhans cells - Answer: B. Keratinocytes
Keratinocytes contain the protein keratin. They are produced in the epidermis and migrate upwards. The
tight junctions between cells prevent water entry. They eventually form a layer of dead cells on the skin
surface, which produces a waterproofing effect.
A person is suddenly frightened. Which of the following reactions occurs next?
A. Liver cells absorb glucose from the blood stream.
B. Blood vessels supplying skeletal muscles constrict.
C. Blood vessels supplying the intestines dilate.
D. Liver cells release glucose into the blood stream. - Answer: D. Liver cells release glucose into the
blood stream.
Epinephrine causes liver cells to break down glycogen, which causes an increase in sugar in the blood
stream.
Kidneys remove which of the following from the blood?
A. Platelets
B. Salts
C. Oxygen
D. Fat - Answer: B. Salts
Salts are removed by the kidneys.