Sensory and Motor Tracts (Nursing)

00:00 Alright, so now let's switch gears and talk about the physiology of the spinal cord.

00:06 So the purpose of the spinal cord is to maintain homeostasis.

00:12 And in order to do that, it must propagate nerve impulses as well as integrate information.

00:20 So how does information travel in the spinal cord? So first, let's discuss the two main parts of the spinal cord.

00:28 You have white matter tracts which are going to conduct the nerve impulses to and from the brain.

00:36 And you have gray matter tracts which are going to receive and integrate the incoming and outgoing information to perform spinal reflexes.

00:47 So let's take a closer look at how sensory information is processed.

00:54 First, a sensory receptor is going to detect a sensory stimulus in a part of the body.

01:01 Then a nerve impulse from that sensory neuron is going to go into the spinal nerve via the posterior route.

01:10 From this point, it can take three pathways, two of them include sensory tracts.

01:17 In the first sensory tract, we will send directly into the white matter and then ascend to the brain.

01:24 The second sensory tract involves a synapse with an interneuron that then ascends into the brain.

01:33 A third pathway is to synapse with an interneuron that will then synapse with a motor neuron in a spinal reflex pathway.

01:44 We can also have axons that originate from higher brain centers and descend from the brain into the white matter and synapse into a somatic motor neuron.

01:59 These somatic motor neurons will then extend to the skeletal muscles.

02:06 Third, we have the autonomic pathway.

02:09 In an autonomic pathway, autonomic motor neurons are going to go to our cardiac muscles or smooth muscles and our glands.

02:19 These autonomic motor neurons will synapse with other autonomic motor neurons in these effectors.