The spinal cord is ¾ of an inch wide and 42-45 centimeters in length. It extends inferiorly from the medulla oblongata to the inferior border of the L1 vertebrae. The spinal cord is divided into 5 parts that house the 31 pairs of spinal nerves. The cervical part is the superior part of the spinal cord. It contains neurons whose axons contribute to the 8 pairs of cervical spinal nerves. The thoracic part lies inferior to the cervical part. It houses the neurons for the 12 pairs of thoracic spinal nerves. The lumbar part contains the neurons for the 5 pairs of lumbar spinal nerves. The sacral part contains neurons for the 5 pairs of sacral spinal nerves. The coccygeal part is the most inferior tip of the spinal cord. It contains one pair of coccygeal
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The white matter is external to the gray matter in the spinal cord. The three parts of white matter are the funiculus. The anterior, lateral, and posterior funiculus. The anterior funiculus is between the anterior horns. It contains the anterior median fissure and interconnected by the white commissure. To the lateral of the gray horns lies the lateral funiculus and to the posterior of the gray horns lies the posterior funiculus. The axons within the white matter have small structural units called tracts and bundles of tracts are fasciculi. The tracts serves to conduct either sensory nerve signals (ascending tracts from the spinal cord to the brain) or the motor nerve signals (descending tracts from the brain to the spinal cord). The anterior and lateral funiculus have both ascending and descending tracts. Whereas the posterior funiculi contain only ascending tracts. The sensory pathways use a series of two or three neurons to transmit nerve signals from the body to the brain. The three are primary, secondary, and tertiary neuron. Whereas the motor pathways have only upper and lower motor neuron that go from the brain to the spinal cord that control …show more content…
There is the somatic sensory receptors and the visceral sensory receptors. The somatic sensory receptors are tactile receptors housed within both skin and mucous membranes. They monitor stimuli including texture on object, pressure, vibration, temperature, and pain. Also within the joints, muscles, and tendons. Visceral sensory receptors are located with the internal organs and blood vessels. Special senses receptors are located in the head. The five special senses are olfaction (smell), gustation (taste), vision (sight), hearing (audition), and equilibrium (head position and acceleration). Sensory receptors can also be classified by modality of stimulus. The five are chemoreceptors, thermoreceptors, photoreceptors, mechanoreceptors, and nociceptors. The chemoreceptors detect chemical, either molecules or ions dissolved in fluid. That can be inhaled air to food or drink ingested. Also located in some of humans blood vessels that help monitor the concentration of carbon dioxide in the blood. Therefore influencing our respiratory rate. Thermoreceptors respond to changes in temperature. They are present in the skin and the hypothalamus. Photoreceptors are located in the eye. They detect changes in light intensity, color, and movement. Mechanoreceptors respond to touch, pressure, vibration, and stretch. Nociceptors respond to painful stimuli. Somatic nociceptors detect damage done to the body
The white matter is external to the gray matter in the spinal cord. The three parts of white matter are the funiculus. The anterior, lateral, and posterior funiculus. The anterior funiculus is between the anterior horns. It contains the anterior median fissure and interconnected by the white commissure. To the lateral of the gray horns lies the lateral funiculus and to the posterior of the gray horns lies the posterior funiculus. The axons within the white matter have small structural units called tracts and bundles of tracts are fasciculi. The tracts serves to conduct either sensory nerve signals (ascending tracts from the spinal cord to the brain) or the motor nerve signals (descending tracts from the brain to the spinal cord). The anterior and lateral funiculus have both ascending and descending tracts. Whereas the posterior funiculi contain only ascending tracts. The sensory pathways use a series of two or three neurons to transmit nerve signals from the body to the brain. The three are primary, secondary, and tertiary neuron. Whereas the motor pathways have only upper and lower motor neuron that go from the brain to the spinal cord that control …show more content…
There is the somatic sensory receptors and the visceral sensory receptors. The somatic sensory receptors are tactile receptors housed within both skin and mucous membranes. They monitor stimuli including texture on object, pressure, vibration, temperature, and pain. Also within the joints, muscles, and tendons. Visceral sensory receptors are located with the internal organs and blood vessels. Special senses receptors are located in the head. The five special senses are olfaction (smell), gustation (taste), vision (sight), hearing (audition), and equilibrium (head position and acceleration). Sensory receptors can also be classified by modality of stimulus. The five are chemoreceptors, thermoreceptors, photoreceptors, mechanoreceptors, and nociceptors. The chemoreceptors detect chemical, either molecules or ions dissolved in fluid. That can be inhaled air to food or drink ingested. Also located in some of humans blood vessels that help monitor the concentration of carbon dioxide in the blood. Therefore influencing our respiratory rate. Thermoreceptors respond to changes in temperature. They are present in the skin and the hypothalamus. Photoreceptors are located in the eye. They detect changes in light intensity, color, and movement. Mechanoreceptors respond to touch, pressure, vibration, and stretch. Nociceptors respond to painful stimuli. Somatic nociceptors detect damage done to the body