18. The function of neurons is to
a. maintain a difference in electrical charge across the cell membrane
b. have specific ions cross the membrane through ion channels
c. maintain a membrane potential with charged ions on either side of the cell membrane
d. all of the above
D?
19. When an impulse moves down the axon,
a. sodium ions first rush out of the cell
b. a small part of the axon momentarily reverses its polarity
c. the resting potential of the cell does not change
d. potassium ions are pumped into the axon
Not sure...?
24. The brain stem is responsible for
a. directing information in the brain and secreting hormones
b. regulating vital functions and memory
c. motor processing and regulating homeostatic functions
d. sensory processing and regulating balance
I'm stuck between A and C
29. Thyroid hormones
a. stimulate cell metabolism and growth
b. slow growth of their target cells
c. stimulate synthesis of DNA
d. bind to receptor molecules on the target cell's surface
A?
-MC
24 a
29 a
19 b
18. I don't know. I don't like the question.
18. The function of neurons is to maintain a difference in electrical charge across the cell membrane, have specific ions cross the membrane through ion channels, and maintain a membrane potential with charged ions on either side of the cell membrane. These functions are essential for the transmission of electrical signals, known as action potentials, through the nervous system. The correct answer is d. all of the above.
To arrive at this answer, you can eliminate options based on your knowledge of neurons. Neurons play a crucial role in transmitting information throughout the nervous system, and maintaining a difference in electrical charge across the cell membrane is a fundamental characteristic of neurons. In addition, the movement of specific ions across the membrane through ion channels is required for generating action potentials. Lastly, the maintenance of a membrane potential with charged ions on either side of the cell membrane is necessary for neuronal signaling to occur. Therefore, the correct answer is d. all of the above.
19. When an impulse moves down the axon, a small part of the axon momentarily reverses its polarity. The correct answer is b. a small part of the axon momentarily reverses its polarity.
To deduce this answer, you should recall the process of action potential propagation in neurons. When an action potential is generated at the initial segment of the axon, it triggers a depolarization wave to propagate along the axon. This depolarization is followed by repolarization of the membrane. However, during the propagation of the action potential, there is a brief moment where a small part of the axon reverses its polarity, known as the refractory period. This allows the action potential to travel in one direction (from the axon hillock to the axon terminals). Therefore, the correct answer is b. a small part of the axon momentarily reverses its polarity.
24. The brain stem is responsible for motor processing and regulating homeostatic functions. The correct answer is c. motor processing and regulating homeostatic functions.
To determine the answer, you should be familiar with the functions of the brain stem. The brain stem is a vital part of the central nervous system, located at the base of the brain. It connects the brain to the spinal cord and controls essential functions such as breathing, heart rate, blood pressure, and digestion. Motor processing refers to the coordination of voluntary movements, and the brain stem plays a significant role in this process. Additionally, the brain stem helps regulate homeostatic functions, which ensure the body maintains a stable internal environment. Therefore, the correct answer is c. motor processing and regulating homeostatic functions.
29. Thyroid hormones stimulate cell metabolism and growth. The correct answer is a. stimulate cell metabolism and growth.
To arrive at this answer, you should recall the basic functions of thyroid hormones. The thyroid gland produces hormones that play a crucial role in regulating metabolism, growth, and development in the body. Thyroid hormones stimulate cell metabolism, which affects multiple processes, including energy production and utilization by cells. Additionally, thyroid hormones contribute to the growth and development of various tissues and organs in the body. Therefore, the correct answer is a. stimulate cell metabolism and growth.