Chapter 13 Assignment

6/24/2021 CH 13 Assignment CH 13 Assignment Due: 11:59pm on Wednesday, June 30, 2021 Item 1 Watch the video, then answer the questions below. Watch the Why This Matters video for chapter 13, and then complete the questions at the right. Part A Severe whiplash, or acceleration flexion-extension neck injury, may cause numbness, tingling, or weakness in an accident victim’s arms. Most injuries happen in the C_5 and C_6 region. Which nerve plexus would this injury most likely involve? ANSWER: sacral brachial cervical lumbar Correct Part B A Morton’s (plantar) neuroma is a foot condition due to swelling of the common plantar digital nerve. It can cause excruciating pain felt between the third and fourth metatarsal bones when walking. Which of the following would NOT be a factor responsible for this disorder? ANSWER: nerve injury nerve compression nerve thinning nerve irritation Correct Item 2 Label the levels of neural integration and structures in sensory systems. 1/12 6/24/2021 CH 13 Assignment Part A Drag the appropriate labels to their respective targets. ANSWER: Reset Help Perceptual level Somatosensory cortex Thalamus Reticular formation Circuit level Free nerve endings (pain, cold, warmth) Muscle spindle Joint kinesthetic receptor Receptor level Correct Item 3 Part A Drag the appropriate labels to their respective targets. ANSWER: 2/12 6/24/2021 CH 13 Assignment Reset Help Reset Help Axon Myelin sheath Endoneurium Perineurium Fascicle Epineurium Correct Item 4 Part A Drag the appropriate labels to their respective targets. ANSWER: Olfactory nerve (I) Optic nerve (II) Facial nerve (VII) Vestibulocochlear nerve (VIII) Oculomotor nerve (III) Trochlear nerve (IV) Correct Item 5 3/12 6/24/2021 CH 13 Assignment Part A Drag the appropriate labels to their respective targets. ANSWER: Reset Help Glossopharyngeal nerve (IX) Trigeminal nerve (V) Vagus nerve (X) Abducens nerve (VI) Accessory nerve (XI) Hypoglossal nerve (XII) Correct Item 6 Part A Drag the appropriate labels to their respective targets. ANSWER: Reset Help Cervical plexus Brachial plexus Cervical enlargement Intercostal nerves Lumbar enlargement Lumbar plexus Sacral plexus Cauda equina 4/12 6/24/2021 CH 13 Assignment Correct Item 7 Part A Drag the appropriate labels to their respective targets. ANSWER: Reset Help Gray matter White matter Dorsal root ganglion Dorsal ramus of spinal nerve Spinal nerve Ventral ramus of spinal nerve Rami communicantes Sympathetic trunk ganglion Correct Item 8 Part A Drag the appropriate labels to their respective targets. ANSWER: 5/12 6/24/2021 CH 13 Assignment Reset Help Reset Help Axillary nerve Radial nerve Musculocutaneous nerve Ulnar nerve Median nerve Correct Item 9 Part A Drag the appropriate labels to their respective targets. ANSWER: Iliohypogastric Ilioinguinal Lateral femoral cutaneous Anterior femoral cutaneous Femoral Obturator Saphenous Correct Item 10 6/12 6/24/2021 CH 13 Assignment Part A Drag the appropriate labels to their respective targets. ANSWER: Reset Help Reset Help Superior gluteal Pudendal Sciatic Posterior femoral cutaneous Common fibular Tibial Superficial fibular Sural Correct Item 11 Label the levels of hierarchy of motor control and associated structures. Part A Drag the appropriate labels to their respective targets. ANSWER: Precommand level Basal nuclei Cerebellum Projection level Primary motor cortex Brain stem nuclei Segmental level Spinal cord 7/12 6/24/2021 CH 13 Assignment Correct Item 12 Part A Drag the appropriate labels to their respective targets. ANSWER: Reset Help Receptor Sensory neuron Integration center Motor neuron Effector Correct Item 13 Stretched muscle spindles initiate a stretch reflex, causing contraction of the stretched muscle and inhibition of its antagonist.Click the link below and study the entire Focus Figure. Then complete the following questions and activities to better understand the stretch reflex. Read through Focus Figure 13.1, and then complete the activities and questions below. Part A - Structures Involved in the Stretch Reflex Click and drag the description to the appropriate label in the figure. Hint 1. Directional terminology Afferent is defined as "carrying to or toward a center." Efferent is defined as "carrying away or away from," especially a nerve fiber that carries impulses away from the central nervous system. Hint 2. Muscle tone For muscle tone, two muscle groups oppose each other in contraction. As one muscle contracts, resisting a stretch, the opposing antagonist muscle relaxes. The antagonist muscle relaxes, so it cannot counteract the contraction of the other muscle. ANSWER: 8/12 6/24/2021 CH 13 Assignment Reset Afferent sensory neuron Help Cell body of sensory neuron Efferent motor neuron Interneuron Muscle spindle Antagonist muscle Correct Part B - Afferent Messages from the Muscle Spindle Select the true statements (more than one) about the characteristics of sensory neurons in the stretch reflex. Hint 1. Directional terminology Fero means "to carry"; af- means "toward," and ef- means "away." Consider the direction of the signal in sensory neurons versus motor neurons. Which neuron type carries information toward the central nervous system? ANSWER: These sensory neurons transmit afferent impulses toward the spinal cord (CNS). These sensory neurons transmit activating impulses via interneurons. These sensory neurons typically transmit efferent impulses toward antagonist muscles. When a stretch activates the muscle spindle, these sensory neurons transmit impulses at a higher frequency. These sensory neurons transmit efferent impulses to antagonist muscles. Correct Part C - Spinal Cord Synapses in Stretch Reflex, Part I Which is the true statement about the synapses in the spinal cord in the stretch reflex? 9/12 6/24/2021 CH 13 Assignment Hint 1. Afferent neuron synapses Afferent neurons can synapse with alpha motor neurons as well as interneurons. Hint 2. Efferent neuron synapses Efferent neurons make multiple synapses to perform dual functions in the stretch reflex. Consider the patellar reflex: Efferent neurons must activate both quadriceps and inhibit the hamstrings simultaneously. ANSWER: Sensory neurons synapse with motor neuron interneurons to excite the extrafusal fibers of the stretched muscle. The antagonist muscle is activated by increased frequency stimuli. Polysynaptic interneurons first synapse with higher brain centers. Interneurons make inhibitory synapses with neurons that prevent contraction of the antagonist muscle. Correct Inhibitory signals to the muscle antagonistic to the stretched muscle will not counteract the stretching, reciprocal inhibition. Part D - Spinal Cord Synapses in Stretch Reflex, Part II Examine the cross section through the lumbar section of the spinal cord and the two patellar reflex pathways shown. Select the true statements (more than one) that identify these synapses. Hint 1. Stretch reflex versus reflex arc The stretch reflex itself occurs through a single synapse between sensory and motor neurons. The reflex arc that inhibits the motor neurons of the antagonist muscle has more than one synapse. ANSWER: Both pathways will activate muscles. Afferent impulses synapse with motor neurons and interneurons. Efferent impulses synapse with motor neurons and interneurons. Afferent impulses synapse twice with motor neurons. Pathways will activate one muscle and simultaneously inhibit its antagonist muscle. Both pathways will inhibit muscles. Efferent impulses synapse twice with motor neurons. Correct Part E - Efferent Messages of Stretch Reflex Examine and characterize the two motor pathways in the stretch patellar reflex. 10/12 6/24/2021 CH 13 Assignment Hint 1. Interneurons Are interneurons in the agonist pathway or the antagonist pathway? Note that agonist refers to the muscle that bears the major responsibility for effecting a particular movement, or prime mover. Hint 2. Agonist versus antagonist For muscle tone, two muscle groups oppose each other in contraction. As the agonist muscle contracts, the opposing antagonist muscle relaxes. This happens so that the antagonist will not oppose the contraction of the agonist. What would occur at the knee if the agonist and its antagonist both contracted during the patellar reflex? ANSWER: Interneurons excite alpha motor neurons, which in turn excite the muscle. Alpha motor neurons send efferent messages to the quadriceps, while parallel efferent messages to the hamstrings are reduced. Alpha motor neurons activate the quadriceps. Once the quadriceps have contracted, alpha motor neurons inhibit the hamstrings. Alpha motor neurons send efferent messages to excite the quadriceps, and the hamstrings are reduced. Correct Part F - Conclusion/Synthesis: Stretch Reflex, Part I Order the following terms as they would occur in a typical stretch reflex. Hint 1. Afferent neuron synapses Afferent neurons can synapse with alpha motor neurons as well as interneurons. Hint 2. Efferent neuron synapses Efferent neurons make multiple synapses to perform dual functions in the stretch reflex. Consider the patellar reflex: Efferent neurons must activate both quadriceps and inhibit the hamstrings simultaneously. ANSWER: 11/12 6/24/2021 CH 13 Assignment Reset  Muscle stretch Muscle spindles are activated    Sensory neurons transmit afferent impulses Help  Extrafusal fibers of the stretched muscle are excited and interneurons send inhibitory impulses to antagonistic motor neurons Efferent impulses to antagonistic muscles are reduced and efferent impulses cause the stretched muscle to contract Correct Part G - Conclusion/Synthesis: Stretch Reflex, Part II A patient sustains a ventral horn injury to the lumbar region of the spine. This injury has damaged the cell bodies of several afferent nerves within the region. Predict how the patient's patellar reflex might be affected. Hint 1. Afferent neuron synapses Afferent neurons can synapse with alpha motor neurons as well as interneurons. Hint 2. Efferent neuron synapses Efferent neurons make multiple synapses to perform dual functions in the stretch reflex. Consider the patellar reflex: Efferent neurons must activate both the quadriceps and inhibit the hamstrings simultaneously. ANSWER: The hamstring would relax, but the quadriceps would not contract. Both the quadriceps and the hamstring would contract. The patient's patellar reflex would be hyperactive. The quadriceps would contract, but the hamstring would not relax. The patient's patellar reflex would be absent or weak. Correct Score Summary: Your score on this assignment is 101%. You received 20.21 out of a possible total of 20 points. 12/12