Nervous System - LYCEUM OF THE PHILIPPINES – DAVAO, PDF

LYCEUM OF THE PHILIPPINES – DAVAO Km 11, LPU Town Center, CP Garcia Highway, Buhangin District, Davao City JUNIOR COLLEGE Topic: Nervous System Names: Alicaya, Audbern Gem C. Eman, Leigh-Ann Alex C. Logronio, Lovely Mae M. Manacap, Beverly Nicole...

LYCEUM OF THE PHILIPPINES – DAVAO Km 11, LPU Town Center, CP Garcia Highway, Buhangin District, Davao City JUNIOR COLLEGE Topic: Nervous System Names: Alicaya, Audbern Gem C. Eman, Leigh-Ann Alex C. Logronio, Lovely Mae M. Manacap, Beverly Nicole A. I. Objectives By the end of the lesson, the learners will be able to: Identify the anatomy and physiology of each part of the nervous system Explain the processes of the nervous system And discuss its interaction with other organ systems. II. Introduction The nervous system is made up of the brain, spinal cord and nerves. It controls many aspects of what you think, how you feel and what your body does. It allows you to do things such as walk, speak, swallow, breathe and learn. It also controls how the body reacts in stressful situations. The nervous system interprets and responds to information gathered through the senses. The nervous system includes the central nervous system (CNS) and peripheral nervous system (PNS). The CNS is made up of the brain and spinal cord, whereas the PNS is made up of the somatic and autonomic nervous systems. Studying the nervous system is essential for understanding how these complex interactions and processes occur, diagnosing and treating neurological disorders, and advancing research in medicine and psychology. By exploring its functions, we gain insights into how to address conditions that affect mental and physical health, ultimately improving quality of life and fostering innovations in healthcare. III. Anatomy & Physiology 1. Central nervous system - The central nervous system consists of both the brain and the spinal cord. It is located in the dorsal body cavity wherein: (A) The brain is surrounded by the cranium (B) The spinal cord is protected by the vertebrae  LYCEUM OF THE PHILIPPINES – DAVAO Km 11, LPU Town Center, CP Garcia Highway, Buhangin District, Davao City JUNIOR COLLEGE (C) The brain is connected to the spinal cord at the foramen magnum–the opening in the base of the skull; Fig. 1.1: foramen magnum (D) The whole Central Nervous System is surrounded by connective tissue membranes–meninges– and by the cerebrospinal fluid. - It is responsible for receiving, processing, and responding to sensory information. - The Brain The brain is the most complex organ of the body. It also integrates sensory information and directs motor responses. it is divided into two hemispheres, the left and the right, responsible for different behaviors. The left and right hemispheres are dominant in various aspects of our brains, with the left hemisphere being more adept at logic and mathematical abilities and with the right being more dominant in creative and artistic abilities. Fig 1.2: The Brain Cerebrum: This is the largest part of your brain. It is divided into two hemispheres— left and right— this is called the cerebral  LYCEUM OF THE PHILIPPINES – DAVAO Km 11, LPU Town Center, CP Garcia Highway, Buhangin District, Davao City JUNIOR COLLEGE hemispheres. This controls muscle function, speech, thought, emotion, reading, writing, and learning. This is further divided into four lobes called collectively as the cerebral cortex. Cerebral Cortex: The outermost layer of your brain. Collectively, it is responsible for the higher-level processes of the human brain– language, memory, reasoning, thought, decision-making, emotion, initiates and regulates voluntary movements, intelligence and personality. It is divided into 4 lobes: (a) Frontal lobe: Responsible for voluntary motor function, problem-solving, attention, memory, and language. Contains the motor cortex and the Broca Area: - Motor cortex: for precise voluntary movements of our skeletal muscles. - Broca area: controls motor functions responsible for producing language. (b) Parietal lobe: responsible for processing sensory information and contains the somatosensory cortex. The neurons in the parietal lobe receive information from sensory receptors throughout the body, processes what to do and detects what is being touched based on previous experiences. (c) Occipital lobe: the visual processing center that contains the visual cortex, receives information from the retina and uses past visual experiences to interpret stimuli. (d) Temporal lobe: processes auditory stimuli through the auditory cortex. Sound energy activates mechanoreceptors, sending impulses to the auditory cortex. Fig. 1.3: The lobes of the cerebral cortex Cerebellum: responsible for smooth, coordinated voluntary movements. Communicates with the cerebral cortex, taking higher-level instructions about the brain's intentions, processing them through the cerebellar cortex, and sending it to the cerebral motor cortex to make voluntary muscle contractions.  LYCEUM OF THE PHILIPPINES – DAVAO Km 11, LPU Town Center, CP Garcia Highway, Buhangin District, Davao City JUNIOR COLLEGE Limbic System: responsible for processing and regulating emotion and memory. These are the different parts: - Basal Nuclei: responsible for muscle movements and coordination. - Thalamus: receives afferent impulses from sensory receptors throughout the body and processes the information for distribution to the appropriate cortical area. Also responsible for regulating consciousness and sleep. - Hypothalamus: It is vital for maintaining homeostasis.. Responsible for heart rate, blood pressure, appetite, thirst, temperature, and the release of various hormones. - Other parts of the limbic that is also vital: amygdala, hippocampus, and cingulate gyrus. Fig 1.4: Limbic system - Brain Stem: Connects your brain to your spinal cord, it includes the midbrain, pons, and medulla oblongata. Helps regulate vital body functions that you don't have to think about. Pons: responsible for relaying impulses from the motor cortex to the cerebellum, medulla, and thalamus. Medulla Oblongata: responsible for autonomic functions. It monitors the body's respiratory system through chemoreceptors that detect changes in blood chemistry. It can also regulate the body's blood pressure, pulse, and cardiac contractions based on the body's needs. Moreover, it controls reflexes like swallowing, vomiting, coughing, and sneezing. Midbrain: A relay system that processes visual and auditory signals.  LYCEUM OF THE PHILIPPINES – DAVAO Km 11, LPU Town Center, CP Garcia Highway, Buhangin District, Davao City JUNIOR COLLEGE - Spinal cord: it functions to send motor commands from the brain to the body, send sensory information from the body to the brain, and coordinate reflexes. Fig. 1.5: Labeled brain indicating the cerebrum, brainstem, the cerebellum, and spinal cord 2. Peripheral nervous system The peripheral nervous system is the part of the nervous system outside the brain and spinal cord. It has two main types: the cranial nerves and spinal nerves. a. Cranial Nerves - Are the set of 12 nerves that originate in the brain.It supplies sensory and motor information to the head and neck. a. olfactory nerve - transmits information regarding a person’s sense of smell to the brain. b. optic nerve - transmits information to the brain regarding a person’s vision. c. oculomotor nerve - helps control muscle movements of the eye. d. trochlear nerve - It powers the contralateral superior oblique muscle that allows the eye to point downward and inward. e. trigeminal nerve  LYCEUM OF THE PHILIPPINES – DAVAO Km 11, LPU Town Center, CP Garcia Highway, Buhangin District, Davao City JUNIOR COLLEGE - Its motor functions help a person to chew and clench their teeth. f. abducens nerve - It helps the lateral rectus muscle, one of the extraocular muscles, turn the gaze outward. g. facial nerve - Consists of both motor and sensory functions, it helps with the movement of muscles that create facial expressions, sensation of taste,and sensation of the external ear. h. vestibulocochlear nerve - helps with a person’s hearing. i. glossopharyngeal nerve - allows the throat to shorten and widen. j. vagus nerve - provides movement to the throat and soft palate. k. accessory nerve - It controls the sternocleidomastoid and trapezius muscles that allow a person to rotate, extend, and flex the neck and shoulders. l. hypoglossal nerve - motor nerve that supplies the tongue muscle. b. Spinal Nerves They are the structures through which the central nervous system (CNS) receives sensory information from the periphery, and through which the activity of the trunk and the limbs is regulated.There are 31 pairs: eight cervical, twelve thoracic, five lumbar, five sacral, and one coccygeal. Receive sensory information from the periphery and pass them to the CNS. Receive motor information from the CNS and pass them to the periphery. Functionally the PNS can be divided into two: c. Autonomic Nervous System -Unconsciously, it controls the glands and smooth muscle of all internal organs (viscera). This is why it’s also called the visceral nervous system. The peripheral part is made up of autonomic fibers and ganglia of the PNS. -It is responsible for the relaxation of smooth muscle, relaxation of cardiac muscle and Increased gland secretion. Functionally the Autonomic Nervous System can be divided into two: i. Sympathetic Nervous System -The sympathetic nervous system is responsible for regulating the "fight-or-flight" response. When you encounter danger or stress, the sympathetic nervous system becomes activated, leading to various physiological responses in your body.  LYCEUM OF THE PHILIPPINES – DAVAO Km 11, LPU Town Center, CP Garcia Highway, Buhangin District, Davao City JUNIOR COLLEGE -It activates to speed up your heart rate, deliver more blood to areas of your body that need more oxygen or other responses. ii. Parasympathetic Nervous System -The parasympathetic nervous system is accountable for the body's rest and digestion response during periods of relaxation, rest, or feeding. The parasympathetic nervous system decreases respiration and heart rate and increases digestion. d. Somatic Nervous System -The somatic, voluntary, nervous system is responsible for providing sensory and motor innervation to skin, muscles and sensory organs. In other words, it carries sensations from the body (pain, touch, temperature, proprioception) and innervates skeletal muscles that are under conscious, or voluntary control. 3. Nervous Tissue - This is present in both the CNS and PNS that contains two basic types of cells: (a) Glial cell: one of a variety of cells that provides a framework of tissue that supports the neurons and their activities. Fig 3.1: Glial Cells (b) Neuron: nerve cells that send messages all over your body that allows you to do everything. - Soma: the cell body Process: extensions of the cell Axon: an important process that every neuron contains, the fiber that connects a neuron with its target. Dendrite: it receives most of the input from other neurons.  LYCEUM OF THE PHILIPPINES – DAVAO Km 11, LPU Town Center, CP Garcia Highway, Buhangin District, Davao City JUNIOR COLLEGE Fig 3.2: structure of a neuron Lastly, there are regions where cell bodies and regions that the cell bodies are dominant and regions that are largely composed of axons. These regions are referred to as: (a) Gray matter: the regions with many cell bodies and dendrites; processes and transmits information. (b) White matter: the regions with many axons; connect brain regions to help with learning, attention, and movement control. Fig 3.3: Gray and White Matter VI. Processes in each system How does the Nervous System work? The nervous system is made up of all the nerve cells in your body. It is through the nervous system that we communicate with the outside world and, at the same time, many mechanisms inside our body are controlled. The nervous system takes in information through our senses, processes the information and triggers reactions, such as making your muscles move or causing you to feel pain. Here are the key components and processes to consider: Sensory Input: The nervous system gathers information from all over your body using sensory receptors. These receptors send messages to your brain about what’s happening around you.  LYCEUM OF THE PHILIPPINES – DAVAO Km 11, LPU Town Center, CP Garcia Highway, Buhangin District, Davao City JUNIOR COLLEGE Signal Transmission: Sensory signals are transmitted along neurons to the central nervous system (CNS), which includes the brain and spinal cord. This involves the propagation of action potentials, electrical impulses that travel along the axon of the neuron. Reflex Actions: Reflexes are super-fast, automatic reactions your body has to certain stimuli, like pulling your hand away when you touch something hot. Reflexes don’t wait for your brain to respond—they happen in the spinal cord to save time. Feedback and Homeostasis: Your nervous system keeps track of important body conditions (like temperature, pH, and fluid levels) and makes adjustments to keep everything stable, which is called homeostasis. Higher Cognitive Functions: The brain’s higher functions include learning, memory, decision-making, and emotional responses. These processes involve complex interactions between different brain regions and are crucial for adapting behavior and thought processes. V. Interactions with other systems The nervous system uses neurons to signal different parts of the body—from sensory, motor, and interneurons. Interaction with Other Systems 1. Integumentary System - The nervous system monitors the body’s temperature and responses. 2. Skeletal System - Serves as a protection for the nervous system and its stems 3. Muscular System - The nervous system controls the muscle through the spinal motor neurons. In terms of these neurons, they are used in the neuromuscular system by controlling the body’s movements and functions. 4. Cardiovascular System - Regulates the cardiovascular system with the following: Baroreceptors - Relayed information derived from blood pressure. Chemoreceptors - Detects changes and sends information to the brain to regulate cardiovascular functions. 5. Respiratory System - Controls breathing with its autonomic/involuntary nervous system. 6. Digestive System - Interrelates digestion, secretion, and motility for adequate nutrient absorption with the enteric nervous system. 7. Urinary System - Works with the muscles of the system to hold and release urine. 8. Endocrine System - Uses the pathway of the nervous system to provide instructions to the brain for chemical messengers. 9. Female Reproductive System - directs the system to ensure fertilization in a female’s body.  LYCEUM OF THE PHILIPPINES – DAVAO Km 11, LPU Town Center, CP Garcia Highway, Buhangin District, Davao City JUNIOR COLLEGE 10. Male Reproductive System - uses the autonomic nervous system to regulate muscle activity, glandular secretions, and the blood flow. also provides assistance in erection, ejaculation, and rhythmic contraction. Each system of the body typically works together in general. Without the different systems, the body would be dysfunctional. VI. Trivia and facts Signals and Chemicals Chemical changes take plan in the nerve fiber. Once this reaches the end of it, they release neurotransmittters. These chemicals then move across a microscopic gap where they can hit the receptors of a different cell, triggering these cells with chemical changes. The brain’s structure is constantly changing as we learn, as new neuronal connections are made which increases the density of the brain. VII. References Betts, J. G., Young, K. A., Wise, J. A., Johnson, E., Poe, B., Kruse, D. H., Korol, O., Johnson, J. E., Womble, M., & DeSaix, P. (2022, April 20). 12.1 Basic Structure and Function of the Nervous System - Anatomy and Physiology 2e | OpenStax. https://openstax.org/books/anatomy-and-physiology-2e/pages/12-1-basic-structure-and-f unction-of-the-nervous-system Brain basics: Know your brain. (n.d.). National Institute of Neurological Disorders and Stroke. https://www.ninds.nih.gov/health-information/public-education/brain-basics/brain-basics-k now-your-brain Cleveland Clinic. “Sympathetic Nervous System (SNS).” Cleveland Clinic, 6 June 2022, my.clevelandclinic.org/health/body/23262-sympathetic-nervous-system-sns-fight-or-fligh t. Institute for Quality and Efficiency in Health Care (IQWiG). (2023, May 4). In brief: How does the nervous system work? InformedHealth.org - NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK279390/#:~:text=The%20nervous%20system% 20takes%20in,pain%20signals%20to%20your%20brain  LYCEUM OF THE PHILIPPINES – DAVAO Km 11, LPU Town Center, CP Garcia Highway, Buhangin District, Davao City JUNIOR COLLEGE Kenhub. “Autonomic Nervous System.” Kenhub, Kenhub, 15 Apr. 2019, www.kenhub.com/en/library/anatomy/autonomic-nervous-system. MSD Manuals. (2024, May 9). Overview of the nervous system [Video]. MSD Manual Consumer Professional, C. C. M. (2024, September 17). Nervous system. Cleveland Clinic. https://my.clevelandclinic.org/health/body/21202-nervous-system Version.https://www.msdmanuals.com/home/quick-facts-brain-spinal-cord-and-nerve-dis orders/biology-of-the-nervous-system/overview-of-the-nervous-system Noyes, Frank, and Sue Barber-Westin. “Parasympathetic Nervous System - an Overview | ScienceDirect Topics.” Www.sciencedirect.com, 2017, www.sciencedirect.com/topics/neuroscience/parasympathetic-nervous-system#:~:text=Th e%20parasympathetic%20nervous%20system%20is%20responsible%20for%20the%20b ody. Professional, C. C. M. (2024, July 2). Brainstem. Cleveland Clinic. https://my.clevelandclinic.org/health/body/21598-brainstem Thau, L., Reddy, V., & Singh, P. (2022, October 10). Anatomy, central nervous system. StatPearls - NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK542179/