The Nervous System - Part 1 PDF

PSW 1222 1 THE NERVOUS SYSTEM Part 1: The Systems within the System PSW 1022  PSW 1022 2 What is the function of the nervous system? It is the rapid messenger system for the bod...

PSW 1222 1 THE NERVOUS SYSTEM Part 1: The Systems within the System PSW 1022  PSW 1022 2 What is the function of the nervous system? It is the rapid messenger system for the body It receives and sends messages for body activities to occur. PSW 1022 3 So let’s review… What cells make up nervous tissue? Neuroglia (Glial Cells): Specialized cells that help keep the nervous tissue together so that the tissue can perform the proper functions. They protect and support neurons. Neurons: Unique structure - cell body with many extensions or processes (nerve "fibers") which conduct impulses. They can be sensory, motor or interneurons. PSW 1022 4 Neurons There are two types of extensions that come off of the cell body of the neuron: Dendrites Form the receptive surfaces of neurons. Axon Conducts impulse away from the cell body. The axon is covered by a myelin sheath which helps send the impulse. PSW 1022 5 PSW 1022 6 How do the neurons pass information to each other? Neurons are connected by SYNAPSES. It is through synapses that the impulse passes from one neuron to another. Chemicals (called neurotransmitters) are released from the axon to help send the impulses. These chemicals can either EXCITE or CALM (inhibit) the neuron that receives the chemicals. PSW 1022 7 Organization of the Nervous System Nervous System Central Peripheral Nervous Nervous System (CNS) System (PNS) Nerves Brain and Outside of the Spinal Cord Spinal Cord  PSW 1022 8 The Functions of the Nervous System Sensory Gathers information about changes occurring within and around the body. Send signals (nerve impulses) to the CNS. The INPUT signal is sent via SENSORY NEURONS Processing and Information is "brought together," interpreted, to Interpreting create sensations, create thoughts, add to memory, make decisions, etc. Motor Is the response to the signals (impulses). The goal is usually to maintain stable conditions - >Homeostasis. The OUTPUT signal is sent via MOTOR NEURONS PSW 1022 9 Peripheral Nervous System This system is divided into two different branches Somatic Autonomic Nervous System Nervous System Controls skeletal Controls smooth muscles and muscle, cardiac voluntary muscle and movement some of the endocrine glands PSW 1022 10 The Somatic Nervous System The Somatic Nervous System is the Motor System and is part of the Peripheral Nervous System. This system consists of efferent nerves, which carry nerve impulses away from the central nervous system to effectors such as muscles or glands. Remember: This is the OUTPUT side of the nervous system. Motor neurons are what send the signals to MOVE! PSW 1022 11 The Autonomic Nervous System The Autonomic Nervous System (ANS) controls the motor function of internal organs and glands. It controls involuntary muscles, such as the smooth muscle of the blood vessels and the cardiac muscle of the heart. Glands that release hormones are also controlled by the autonomic nervous system. PSW 1022 12 The Branches of the ANS Autonomic Nervous System Parasympathetic Sympathetic Nervous System Nervous System Resting and Fight or Flight Digesting PSW 1022 13 Parasympathetic Nervous System The parasympathetic Parasympathetic effects nervous system controls include: normal body functioning. decreased heart rate, respiration, and blood pressure The parasympathetic increased digestive activity system is responsible for including salivation and everyday activities and stomach activity. daily maintenance of our bodies: “resting and digesting” This means that we will maintain homeostasis. PSW 1022 14 Sympathetic Nervous System The sympathetic nervous system controls the “fight or flight” response. This is also known as a stress response. The body does not know the difference between stress from being chased by tigers and stress from a mean boss. PSW 1022 15 References Wilk, M.J., Sorrentino, S. & Remmert, L.N.. (2022). Sorrentino's Canadian textbook for the Support Worker (5th Cdn ed.). Elsevier: Toronto Chapter 25 Chapter 32