BIOS-252 Week 3 Nervous System-Spinal cord, PNS, and reflexes – Lab Assignment (GRADED A+)

BIOS-252 Week 3 Nervous System-Spinal cord, PNS, and reflexes – Lab Assignment (GRADED A+) Week 4 Nervous System-Spinal cord, PNS, and reflexes Learning Objectives: • Locate and identify the regions and parts of the spinal cord. • Identify the spinal contributions to cervical, brachial, lumbar, sacral and coccygeal plexuses. • Locate and identify major peripheral nerves. • Identify the components of a reflex arc. Introduction: The spinal cord is a continuation from the medulla oblongata of the brain stem. It allows communication between the brain and the rest of the body. The spinal nerves contain both sensory and motor fibers. We will see that multiple spinal cord levels can contribute to the formation of a peripheral nerve as fibers pass through the various plexuses. The protective role of a reflex arc will be examined. Assignment: Part 1: Complete the following activities Anatomy.TV: Nervous System- Spinal cord, Spinal nerves, Reflexes To access Anatomy.TV: Resources tabLibraryLibrary Resources-Database A- ZAnatomy.TVTitles(default tab): Choose Nervous systemchoose assigned sections You will then work through the material and activities by scrolling down on the right. This will allow you to see and work through all activities for that section. Have the lab report with you as you complete the activities so you may record data. Part 2: Complete the lab report Week 3 Nervous System Lab Report 1. Describe the anatomy of the spinal cord by completing the following chart: (3 points) # of associated segments/spinal nerve pairs Spinal cord 31 Cervical region 8 Thoracic region 12 Lumbar region 5 Sacral region 5 Coccygeal 1 2. Define the following terms: (1 point each) Cauda equina The canal below the second lumbar vertebra. This bundle of nerve roots that resembles a horse's tail Conus medullaris At the level of the second lumbar vertebrae the spinal cord terminates by tapering. Reflex A rapid, involuntary sequence of actions occurring in response to a stimulus. Reflexes control actions with a lot of functions for example protection. 4. Describe a reflex arc including the 5 components. (5 points) A reflex arc is the most basic pathway in the nervous system. There are 5 components. Sensory receptor is a reflex that begins when sensory receptors are activated in response to a particular stimulus. Sensory neuron fires an action potential along a sensory neuron that travels with the dorsal root of a spinal nerve into the spinal cord. Synapses and interneurons are the sensory neuron that synapse directly with a motor neuron or interneurons .Motor neuron initiates an action potential which is then propagated along a motor neuron, in the ventral root of a spinal nerve to an effector, such as a skeletal muscle. Effector responds with a reflex action, such as contraction. 5. Describe the reflex response to a painful stimulus such as stepping on a nail. (2 points) An extensor reflex is begins by painful stimulus and happens at the same time as the flexor reflex. the Reflex contraction of the extensor muscles of the unharmed limb, allows the body to balance while the flexor reflex takes the harmed limb away from the stimulus. 6. Discuss why a person who has a spinal cord injury at C6 is spared from needing a ventilator. In order to answer you must consider what nerve innervates the diaphragm and which spinal cord segments contribute to this nerve. (2 points) The phrenic nerves diaphragm is above C6 but mostly in C3-C5 which allows breathing. The Injury at C3-C5 needs a ventilator. PART 1: LAB ACTIVITIES Grading Rubric for Lab Report Activity Deliverable Points Part 1 Complete lab activities 15 Part 2 Complete lab report 15 Total Complete all lab activities 30