Divisions of nervous syst

Divisions of nervous syst - Notes Notes Divisions of the...

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Unformatted text preview: Notes Notes Divisions of the Nervous System Nervous Chapter 35 Section 3 Lecture Outline – Divisions of the Nervous System PowerPoint Notes textbook questions Keys Keys Divisions of the Nervous System System Two main divisions I. Central Nervous System System Consists of: Brain Processes and Processes interprets incoming stimuli and information information Relays a message Relays or causes a response response Directs all bodily Directs functions functions Divisions of the Nervous System System Central Nervous System Also consists of: Spinal Cord Pathway to and Pathway from the brain from Located in the Located vertebral column vertebral Enables reflex Enables actions actions Divisions of the Nervous System System II. Peripheral Nervous II. System System Consists of: A. Sensory Division Contains sense organs and sensory neurons and Receive impulses from sense organs sense A. Motor Division Contains motor neurons Contains and muscles and glands Response to stimuli sent to muscle or gland gland Motor Division Motor Divided into: 1. Somatic Nervous System 1. Somatic Controls voluntary (skeletal) Controls muscle muscle Conscious functions Nerves active in reflexes Motor Division Motor 2. Autonomic Nervous 2. System System Controls involuntary Controls muscle associated with organ function with Unconscious Unconscious functions functions Visceral functions Autonomic Nervous System Autonomic Divided into two parts Divided with opposite effects: effects: 1. Sympathetic Sympathetic Nervous System Nervous Increases activity Active in times of stress Fight or flight Autonomic Nervous System Autonomic 2. Parasympathetic Parasympathetic Nervous System Nervous Decreases activityrelaxation conservation conservation of energy Interesting tidbits: How much does an average brain weigh? Approximately 3 lbs How many neurons are in the brain? How 100 billion What type are they? Mostly interneurons How much does the How brain eat? About 20% of the oxygen About and food from the blood and Regions of the Brain Regions I. II. III. IV. V. Cerebrum Cerebellum Brain stem Thalamus Hypothalamus I V IV III II Cerebrum – 80% of the mass of the brain of Function: Sensory and motor functions (voluntary) and higher Sensory mental processing mental 4 Lobes: 1. Frontal – concentration, problem solving, voluntary muscle movement, emotions muscle 2. Parietal – speech, pressure, temp., pain temp., 3. Occipital – bilateral vision 4. Temporal – memory and hearing hearing Cerebral lobes Cerebral Frontal lobe Parietal lobe Occipital lobe Temporal lobe Cerebellum Par i et al Par l obe Fr ont al Fr l obe Occi pi t al Occi l obe Cer ebel l um Tem al por Tem l obe Self-Quiz Self-Quiz Cerebral lobes Cerebral Frontal lobe Parietal lobe Occipital lobe Temporal lobe Cerebellum Cerebrum Cerebrum 2 layers: A. Cerebral cortex – thin, outer layer A. Cerebral Contains 75% of the cell bodies of the nervous Contains system system Cerebral cortex So what color is it? Cerebral medulla Grey (cell bodies are Grey grey matter) grey B. Cerebral medulla – B. Cerebral bundles of myelinated axons = white matter axons Cerebrum Cerebrum Cerebrum Corpus callosum Cerebellum Pons Medulla Cerebrum Cerebrum • Divided into 2 hemispheres Divided Connected by corpus callosum Folds and grooves greatly increase surface Folds area, and ability to do work. area, Which side of the body is Which controlled by the right side of the brain? of The left side and vice versa Cerebellum –the 2nd largest Cerebellum region Function: Coordination of Coordination muscle movement, balance, equilibrium, and posture and Brain Stem – connects brain and spinal cord and Function: Control center for Control visceral activity like breathing, heart rate, digestion, coughing, swallowing and other involuntary activities involuntary 2 Regions: 1. Pons 2. Medulla oblongata 1. 2. Thalamus Thalamus Relay station Relay between spinal cord and cerebrum and Receives sensory Receives impulses from receptors receptors Sorts and files Sorts information like a secretary secretary Hypothalamus Hypothalamus Key in homeostatic Key feedback mechanisms mechanisms Links nervous and Links endocrine systems endocrine Body temp., water Body balance, sleep/wake cycles, hunger cycles, Review of the Main Regions of the Brain Regions 1. Cerebrum 2. Corpus callosum 3. Cerebellum 4. Medulla oblongata 5. Spinal cord 6. Pons 7. Hypothalamus 8. Thalamus Label the Key Parts Label of the Brain of Lateral View of the Brain Parietal Lobe Corpus Callosum Frontal Lobe Occipital Lobe Hypothalamus Thalamus Temporal Lobe Pons Cerebellum Medulla Oblongata Spinal Cord The Reflex Arc The What is a reflex? A quick, automatic response to a quick, stimulus. (The simplest nerve pathway) Why is it important? 1. Allows organism to escape danger by Allows producing an immediate response. producing 2. Reduces severity of injury by producing Reduces specific responses to pain. Where does a reflex Where come from? A reflex is part of the… Somatic nervous system. This is a This part of the… part Motor neuron muscle Intermediate neuron Motor division, which is part of the… which Peripheral nervous Peripheral Spinal cord system system Skin Sensory neuron Reflex Arc What are the components of the reflex arc? the 1. Receptor – detects stimuli 2. Sensory neuron – sends impulse to spinal Sensory cord (Afferent neuron) cord 3. Interneuron – sends response to effector Interneuron and info to brain and 4. Motor neuron - sends impulse to effector (Efferent neuron) 5. Effector- (Muscle or gland) causes or some response to stimuli to stimuli (Sensory neuron) (Motor neuron) Reflex Arc: A No-Brainer Reflex A reflex arc is the pathway that reflex a nerve reflex, such as the knee jerk reflex, follows. jerk 1. A tap on the knee stimulates 1. sensory receptors, generating a nerve signal. 2. The signal travels along a nerve pathway to the spinal cord. 3. At the spinal cord, the signal is transmitted from the sensory nerve to a motor nerve. 4. The motor nerve sends the signal back to a muscle 4. in the thigh. 5. The muscle contracts, causing the lower leg to jerk 5. upward. The entire reflex occurs without involving the brain. Patellar (Knee-jerk) Reflex Patellar Other Examples Other Dilation of pupils Removing hand from Removing hot or sharp object hot Sneezing Coughing Gag reflex Blinking Flinching ...
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This note was uploaded on 11/09/2011 for the course BIO 110 taught by Professor Harmon during the Winter '11 term at BYU.

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