What stimulates the muscle fibers telling them to contract or relax?

What stimulates the muscle fibers telling them to contract or relax?

A Muscle Contraction Is Triggered When an Action Potential Travels Along the Nerves to the Muscles. Muscle contraction begins when the nervous system generates a signal. The signal, an impulse called an action potential, travels through a type of nerve cell called a motor neuron.

Which nervous system carries the response to the rest of the body?

The nervous system can be divided into two major subdivisions: the central nervous system (CNS) and the peripheral nervous system (PNS), shown in [link]. The CNS is comprised of the brain and spinal cord; the PNS connects the CNS to the rest of the body.

Do neuron transfers information in the form of an electrical impulse?

Your neurons carry messages in the form of electrical signals called nerve impulses. To create a nerve impulse, your neurons have to be excited. Stimuli such as light, sound or pressure all excite your neurons, but in most cases, chemicals released by other neurons will trigger a nerve impulse.

What stimulates smooth muscle contracts?

The triggers for smooth muscle contraction include hormones, neural stimulation by the ANS, and local factors. In certain locations, such as the walls of visceral organs, stretching the muscle can trigger its contraction (the stress-relaxation response).

What stimulates the activity of other endocrine glands?

Despite its small size, the pituitary is often called the “master gland.” The hormones it makes control many other endocrine glands.

What nervous system transmits information to voluntary muscles while?

The somatic nervous system, also called the somatomotor or somatic efferent nervous system, supplies motor impulses to the skeletal muscles. Because these nerves permit conscious control of the skeletal muscles, it is sometimes called the voluntary nervous system.

Which part of the neuron was stimulated?

Dendrites. Dendrites are tree-like extensions at the beginning of a neuron that help increase the surface area of the cell body. These tiny protrusions receive information from other neurons and transmit electrical stimulation to the soma.

Why are messages transmitted in neurons in the form of electrical impulses?

For communication between neurons to take place, an electrical impulse triggers the release of chemicals called neurotransmitters. Neurotransmitters are released into the space between the two neurons. Receptors receive and process the message, then send it on to the next neuron.

How does relaxation occur in the skeletal muscle?

Relaxing skeletal muscle fibers, and ultimately, the skeletal muscle, begins with the motor neuron, which stops releasing its chemical signal, ACh, into the synapse at the NMJ. The muscle fiber will repolarize, which closes the gates in the SR where Ca ++ was being released. ATP-driven pumps will move Ca ++ out of the sarcoplasm back into the SR.

How is the excitation of the muscle membrane coupled to SR?

The excitation of the muscle membrane is coupled to the SR release of calcium through invaginations in the sarcolemma called T-Tubules (“T” stands for “transverse”).

What happens when sodium ions enter the muscle fiber?

Sodium ions enter the muscle fiber, and an action potential rapidly spreads (or “fires”) along the entire membrane to initiate excitation-contraction coupling. Things happen very quickly in the world of excitable membranes (just think about how quickly you can snap your fingers as soon as you decide to do it).

Where does the energy for muscle contraction come from?

ATP supplies the energy for muscle contraction to take place. In addition to its direct role in the cross-bridge cycle, ATP also provides the energy for the active-transport Ca ++ pumps in the SR. Muscle contraction does not occur without sufficient amounts of ATP.