Explain how to lift the leg. Begin with the pre-central gyrus and end with the l

Question

Explain how to lift the leg. Begin with the pre-central gyrus and end with the leg lifting away from my death grasp. The message from the brain is sent by neurons. How does a neuron send a message from axon hillock to axon terminal? And once it gets to the axon terminal, how does it pass the message on to the next neuron on the line? From the last axon to the muscle cell at the neuromuscular junction, how does the impulse result in the shortening of a myofiber. And how to get all those puny muscle cells to give the leg a good yank(summation and recruitment)? By the way, which muscles are using for this action? And since muscles act on bones at their joints, must include a discussion of bones and joints- the structure of a long bone and the structure of knee joint that moving.

Explanation / Answer

The remainder of the thoracic spinal nerves, T3 through T12, do little recombining. They form the intercostal nerves, so named because they run between the ribs. For points of reference, the 7th intercostal nerve terminates at the lower end of the sternum, also known as the xyphoid process. The 10th intercostal nerve terminates at the umbilicus, or the belly button. The somatic nervous system is that part of the peripheral nervous system associated with the voluntary control of body movements through the action of skeletal muscles, and also reception of external stimuli. The somatic nervous system consists of afferent fibers that receive information from external sources, and efferent fibers that are responsible for muscle contraction. The somatic system includes the pathways from the skin and skeletal muscles to the Central Nervous System. It is also described as involved with activities that involve consciousness. The basic route of the efferent somatic nervous system includes a two neuron sequence. The first is the upper motor neuron, whose cell body is located in the precentral gyrus (Brodman Area 4) of the brain. It receives stimuli from this area to control skeletal (voluntary) muscle. The upper motor neuron carries this stimulus down the corticospinal tract and synapses in the ventral horn of the spinal cord with the alpha motor neuron, a lower motor neuron. The upper motor neuron releases acetylcholine from its axon terminal knobs and these are received by nicotinic receptors on the alpha motor neuron. The alpha motor neurons cell body sends the stimulus down its axon via the ventral root of the spinal cord and proceeds to its neuromuscular junction of its skeletal muscle. There, it releases acetylcholine from its axon terminal knobs to the muscles nicotinic receptors, resulting in stimulus to contract the muscle. The somatic system includes all the neurons connected with the muscles, sense organs and skin. It deals with sensory information and controls the movement of the body.

Related Questions

Navigate

• Browse (All)
• Browse E
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.