Name five essential components of a reflex arc

WEEK 3 ASSIGNMENT 1: REFLEXES Submission Instructions Please complete your answers to the lab questions on this form. Please complete your answers and SAVE the file in a location which you will be able to find again. Then, attach and submit the completed form to the Week 3 Laboratory Dropbox in the Ashford University classroom. Post-Lab Questions 1. What is the pupillary response of the right eye when a light was shone into the pupil? 2. What is the consensual response? (The response of the left eye). 3. What branch of the nervous system controls this response? 4. Can this response be inhibited? 5. Define what a reflex is. 6. Name five essential components of a reflex arc. © eScience Labs, 2013 WEEK 3 ASSIGNMENT 2: TESTING CRANIAL NERVE FUNCTIONS Result Tables Table 2: Cranial Nerve Function Testing Cranial Nerve Test Result Post-Lab Questions 1. What do your cranial nerve test results tell you? 2. When might these tests be used in a clinical setting? 3. What cranial nerve may not be functioning properly if a patient cannot detect taste on the anterior tongue? 4. What cranial nerve may not be functioning properly if a patient can move his/her eyes medial, superior, and inferior, but not lateral? © eScience Labs, 2013 WEEK 3 ASSIGNMENT 3: TESTING TOUCH, TEMPERATURE, AND PAIN Result Tables Table 3: Blind Coin Differentiation Coin Observation Guess Quarter Dime Nickel Penny Post-Lab Questions 1. Describe the difference between the four US coins. 2. Was the participant able to distinguish between these coins? 3. Which coin was the easiest to identify by touch? Which was the most difficult to distinguish by touch? 4. Why is the detection of temperature important to maintaining overall health? 5. Did the participant notice any difference between the amounts of pain reception in the different areas tested? © eScience Labs, 2013 Create An Account / My account Log out Cart is empty HOME PRODUCTS EDUCATOR STUDENT BLOG CONTACT HAVE A CODE? Search Home » Student » The Human Body, Health and Disease/HPR 205 » Week 3 Lab Exercise (Introduction) Week 3 Lab Exercise (Introduction) Introduction The nervous system carries a large responsibility for maintaining the homeostasis within the body. It is the master control and communication center of the body. The nervous system allows the body to interpret, integrate, and react to the surrounding environment as well as the internal stimuli occurring simultaneously throughout the body. Voluntary actions such as writing, reading, or running, as well as involuntary actions such as the heart pumping blood through the body, the pancreas releasing enzymes, or the gut digesting food are monitored by this complex system. The importance of a properly functioning nervous system can be realized simply by considering how well protected the brain and spinal cord are. Disruptions to the nervous system could result from structural abnormalities, biochemical imbalances, neuronal damage, and microbial infections. Figure 1: Neurons are located all across the body, and allow impulses to travel from receptor cells to the central nervous system. The three main responsibilities of the nervous system are sensory input (for stimuli inside and external to the body), integration of sensory input, and a motor response by activating e ector organs. To accomplish these substantial tasks, the nervous system is organized into two distinct sub-systems: the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS includes the brain and the spinal cord. Nervous tissue that resides outside of the brain and spinal cord are included in the PNS. The PNS carries neural impulses to and from the brain. Figure 2: The brain, superior view. Note the areas that correspond to hearing and vision in addition to language and writing. The right and left cerebral hemispheres are connected by the corpus callosum (visible in a sagittal view), allowing them to coordinate actions. The Brain The master control center for the nervous system is the brain. This organ enables voluntary movements, interpretation and integration of sensation, consciousness, and cognitive function. Anatomically, the brain can be divided into several di erent structures and areas which perform speci c functions (Figure 2 and Table 1). The brain is protected by the skull, a specialized covering called the meninges and cerebrospinal uid. The Spinal Cord The spinal cord is a two-way impulse conduction pathway and a re ex center. It serves two main functions: the transmission of nerve impulses and spinal re exes. It resides within the vertebral column and is protected by meninges and cerebrospinal uid. Spinal nerves emerge from the spinal cord in pairs, one extending from each side. Thirty-one pairs of spinal nerve roots can be identi ed along the length of the spinal cord. Virtual Learning: Re ex Arc When examining a cross-section of the spinal cord (Figure 3), the central gray matter of the spinal cord appears H-shaped surrounded by white matter. The anterior horns of this gray matter are composed mainly of somatic motor neurons while the posterior horns contain visceral motor neurons and posterior horns contain interneurons that synapse with sensory neurons. Two major roots, or branches of the spinal nerve that connect to the spinal cord, are present in the spinal cord: ventral and dorsal roots. Ventral roots enter the ventral side of the spinal cord, and contain motor nerve axons responsible for transmitting impulses to skeletal muscles. Dorsal roots enter the dorsal side of the spinal cord, and contain sensory nerve bers that relay impulses from peripheral regions of the body to the spinal cord. Dorsal root ganglions are clusters of sensory nerve cell bodies that reside on the dorsal root. Figure 3: The spinal cord. Virtual Learning: The 12 Cranial Nerves Neurons and Glial Cells There are two principle cell types within the nervous tissue. Neurons are the excitable cells that transmit electric impulses, while glial cells surround and wrap neurons to aid in their functionality. Neurons are the structural units of the nervous system. They are composed of a body containing the nucleus, an axon which arises from the axon hillock of the cell body, and dendrites and their plasma membrane function in electrical signaling. Neurons can be classi ed structurally into the following groups based on the number of processes that extend from the cell body: multipolar (the majority of neurons in the body), bipolar (sensory neurons found in the special senses), and unipolar (located in the CNS). Figure 4: Multipolar neuron. In addition to the above receptors, the nervous system also features many specialized functions which rely on organs and cells with precise locations and utility. These functions are often referred to as the ve senses, or specialized senses.