when you stimulate the dorsal column tract

WHEN YOU STIMULATE THE DORSAL COLUMN TRACT SKIN

The withdrawal reflex has more components, such as inhibiting the opposing muscle and balancing posture while the arm is forcefully withdrawn, which will be further explored at the end of this chapter. That neuron sends a signal along its axon to excite the biceps brachii, causing contraction of the muscle and flexion of the forearm at the elbow to withdraw the hand from the hot stove.

This triggers an action potential, which travels along the sensory fiber from the skin, through the dorsal spinal root to the spinal cord, and directly activates a ventral horn motor neuron.

WHEN YOU STIMULATE THE DORSAL COLUMN TRACT SKIN

Sensory receptors in the skin sense extreme temperature and the early signs of tissue damage. When you touch a hot stove, you pull your hand away. The distinction between the structures (i.e., anatomy) of the peripheral and central nervous systems and functions (i.e., physiology) of the somatic and autonomic systems can most easily be demonstrated through a simple reflex action. Peripheral sensory neurons receive input from environmental stimuli, but the neurons that produce motor responses originate in the central nervous system. The somatic nervous system is responsible for our conscious perception of the environment and for our voluntary responses to that perception by means of skeletal muscles. However, this misses an important point: somatic refers to a functional division, whereas peripheral refers to an anatomic division. The somatic nervous system is traditionally considered a division within the peripheral nervous system.

Explain the stimulus-response motor pathway.

Describe regions of the central nervous system that contribute to somatic functions.

Distinguish between general and special senses.

Name the modalities and submodalities of the sensory systems.

Describe the components of the somatic nervous system.

After studying this chapter, you will be able to

When you stimulate the dorsal column tract