Which of the following statements is correct?
A) Myelin sheaths form an insulating layer around the axons of neurons in the central and peripheral nervous systems. These structures function to slow the transmission of impulses along the axon.
B) Myelin sheaths form an insulating layer around the axons of neurons in the central and peripheral nervous systems. These structures function to speed up the transmission of impulses along the axon.
C) Myelin sheaths form an insulating layer around the axons of neurons only in the peripheral nervous system. These structures function to speed up the transmission of impulses along the axon.
D) Myelin sheaths form an insulating layer around the cell bodies of neurons in the central and peripheral nervous systems. These structures function to speed up the transmission of impulses along the axon.
B
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The most important factor determining the extent of evaporation of sweat is the ____________________ of the air
Fill in the blank(s) with correct word
Which correctly describes the composition of the glomerular filtrate?
A. It is identical to urine, but has a much larger flow rate. B. It is similar to plasma, except it does not contain glucose. C. It is similar to plasma, except it does not contain plasma proteins. D. It is identical to urine, but has a much smaller flow rate. E. It is identical to blood plasma, except it lacks red blood cells.
In mammals, heart size tends to be proportional to body weight while heart rate is inversely proportional to body weight. What is the most probable explanation for pygmy shrews having unusually large hearts but an unusually slow heart rate?
A) Pygmy shrews are very active so they need large hearts. B) It is possible that the heart rate of shrews has reached its absolute limitation, so a large heart can pump more blood with each beat. C) Since pygmy shrews are tiny, their heart size differs from other mammals and their heart rate is slow when they are at rest. D) The heart size of pygmy shrews varies depending on latitude.
Match each of the terms with its definition or description.
a. digestion b. absorption c. amylase d. bile e. maltase f. lipase g. pepsin h. monosaccharides i. glycerol j. amino acids k. mastication l. lactase m. hydrochloric acid n. trypsin o. deglutition p. sucrase 1. _____ Causes the emulsification of fats 2. _____ Enzyme that reduces complex carbohydrates to maltose 3. _____ This and fatty acids are the end products of fat digestion 4. _____ Enzyme that converts maltose to simple sugars 5. _____ Enzyme that is responsible for the chemical digestion of fats 6. _____ Movement of digested food from the digestive system to the blood or lymph 7. _____ End product of carbohydrate digestion 8. _____ A protein enzyme that must be activated by hydrochloric acid in the stomach 9. _____ End product of protein digestion 10. _____ Physical and chemical changes in food that prepare it for movement into the blood or lymph 11. _____ Another word for swallowing 12. _____ Enzyme that digests cane sugar 13. _____ Substance needed to convert pepsinogen to pepsin 14. _____ Another word for chewing 15. _____ Protein-digesting enzyme in pancreatic juice 16. _____ Enzyme that digests milk sugar