Question

the whole body works together to function every day. think about how it all connects using the example and questions below.

a dancer in the nutcracker ballet performance is standing on her tiptoes on her right foot on the stage

1. what is the movement at her foot called as she stands on ti[toe?

2. what muscle powers this movement?

3. where in the brain would the action potential (AP) for this muscle originate?

4. on what side of the brain would the APS originate?

5. what pathway carries the APS down the spinal cord for this movement?

6. what nerve carries the action potential to the muscle?

7. from what plecus did this nerve arise?

8. what neurotransmitter would attach to the membrane receptors on the muscle fibers to start action potential at the muscle?

Answer 1

1. Plantar flexion is the movement in which the top of foot points away from the leg. It is used to stand on toes or point toes.

2. The plantaris muscle starts behind the knee, just above the gastrocnemius. This muscle works with the Achilles tendon to flex both ankle and knee joints. It allows to stand on toes or point foot in plantar flexion. Another muscle is flexor hallucis longus. This three muscles are three deep muscles of the leg.

3. The plantaris muscle is innervated by the tibial nerve which is a branch of the sciatic nerve in the sacral plexus. Signaling for contraction begins in the frontal lobe of the brain with the pre- central gyrus.

4. The primary motor cortex on the left side controls the movement of the right side of the body and vice versa, the right side controls the left side of the body.

5. The response results from the nociceptive fibers in the S* dermatome detecting stimulation. Nociceptive input travels up the tibial and sciatic nerve to the S1 region of the spine and synapse with anterior horn cells. The motor response which leads to the plantar flexion is mediated through the S1 root and tibial nerve.

6. Tibial nerve from anterior rami of S1 - S2.

7. Tibial nerve is a branch of sciatic nerve and originates at the apex of the popliteal fossa. They commonly derives from the L4 - S2.

8. When the nervous system signal reaches the neuromuscular junction's chemical message is released by the motor neuron. The chemical message, a neurotransmitter called acetylcholine, binds to receptor on the out side of the muscle fiber.