Question

17. Which of the following statements are accurate?

A. Neurotransmitters can act as ligands.
B. Acetylcholine is a neurotransmitter. It can bind to an acetylcholine receptor on the surface of a cell. If this receptor is also a sodium channel, we would call acetylcholine a ligand and its receptor a ligand-gated receptor.
C. Neurotransmitters can act as chemical signals between two neurons.
D. Diffusion is a type of passive transport and does not require energy. Sodium channels are an example of a membrane-bound protein that allows diffusion of sodium within requiring energy (ATP).
E. Ion pumps do not require energy (e.g. ATP) in order to move molecules across the membrane

18. Which of the following statements are accurate?

A. Nerves typically collect sensory information such as light, touch, or blood pressure.
B. Motor neurons can interact (e.g. stimulate) with muscle cells or glands.
C. Interneurons are a type of sensory neuron.
D. The peripheral nervous system is able to carry information to and from the central nervous system.
E. Interneurons are responsible for analysis of stimuli and forming a circuit to respond to the stimuli

19. Which of the following statements are accurate?

A. At rest, excitable cells (e.g. neurons) have a negative charge.
B. Once a depolarization reaches threshold, an action potential will most likely occur, however, a strong repolarization or hyperpolarization event could prevent the action potential.
C. Repolarization of a neuron results from sodium diffusing out of the cell.
D. To reach threshold, cells at rest must hyperpolarize.
E. Sodium diffusing out of a neuron will cause depolarization

20. Which of the following statements are accurate?

A. Repolarization of a neuron results from potassium diffusing out of the cell.
B. At rest, excitable cells (e.g. neurons) have a negative charge.
C. Once a depolarization reaches threshold, an action potential will occur and can not be prevented.
D. To reach threshold, cells at rest must depolarize.
E. Sodium diffusing into a neuron will cause depolarization.

Answer 1

17. B

Acetylcholine is a neurotransmitter of parasympathetic nervous system. It acts on muscarinic (GPCR) and nitocinic (ion channel) receptors.

18. B

Motor neurons of the spinal cord are part of the central nervous system (CNS) and connect to muscles, glands and organs throughout the body. These neurons transmit impulses from the spinal cord to skeletal and smooth musclesand so directly control all of muscle movements.

19. A

The resting potential of electrically excitable cells lies in the range of −60 to −95 millivolts with the inside of the cell negatively charged.

20 A as well as B (B option is correct option in Ans 19 and 20)

Repolarization typically results from the movement of positively charged K+ ions out of the cell.