Question

question 15 which of the following is true about skeletal muscle? sensory neurons stimulate muscles to contract. there are very few blood vessels in skeletal muscle. every muscle fiber receives a branch of an axon from the nerve. there are very few nerve fibers in a muscle. all of the choices are true. question 16 atrophy at the neuromuscular junction that naturally occurs with age would have what effect on muscles? it would stimulate the nervous system to increase the speed in which it sends action potentials to the muscle fiber. it would stimulate muscle cramps. it would decrease the number of action potentials sent to the muscle fiber. it would cause an increase in the amount of ach released by the neurons to compensate. it would have no effect on the muscles. question 17 lack of acetylcholinesterase in the synaptic cleft would result in a decrease in acetylcholine production by the motor neuron. continuous stimulation of the postsynaptic membrane. rapid degradation of acetylcholine. relaxation of the muscle. continuous stimulation of the presynaptic membrane.

Explanation:

• Question 15: Motor neurons, not sensory neurons, stimulate muscle contraction. Skeletal muscles have a rich blood - vessel and nerve - fiber supply. Each muscle fiber receives a branch of an axon from a motor nerve.
• Question 16: Atrophy at the neuromuscular junction with age reduces the efficiency of signal transmission, decreasing the number of action potentials sent to muscle fibers.
• Question 17: Acetylcholinesterase breaks down acetylcholine in the synaptic cleft. Without it, acetylcholine would continuously stimulate the postsynaptic membrane.

Answer:

• Question 15: Every muscle fiber receives a branch of an axon from the nerve.
• Question 16: It would decrease the number of action potentials sent to the muscle fiber.
• Question 17: continuous stimulation of the postsynaptic membrane.