Nervous System

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(1)Nervous System Nerves serve the major function of sending messages in the body. They are one of two systems primarily responsible for sending messages in the body.  Nervous System – Sends signals QUICKLY throughout the body to respond to stimuli  Endocrine System – sends signals slowly through body to maintain homeostatic mechanisms.

(2) Paging Dr. You! . Nervous system sends signals quickly throughout the body using electrochemical signaling. . . Electro – using electricity, used to quickly relay signal over distances Chemical – using chemicals, used to transmit signals from one cell to another.

(3) nervous system.

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(5) Systems Use Cells . Neurons . . The main type of nervous tissue cell, performs the primary task of signal transduction Mature neurons do not divide, so loss of these nervous cells often cannot be replaced.

(6) Systems Use Cells . Neuroglia . . Associate cells, assist neurons in various ways Include: Astrocytes, Oligodendrocytes, Microglia, Ependyma, Schwann Cells, and Satellite Cells.

(7) Basic nerve cell structure.

(8) Neuron Structures .  . . Cell Body – the large part of the cell where the nucleus and cellular structures are housed Nucleus – control center of the cell Dendrites – small processes that receive input signal Axon – long process that outputs signals.

(9) Neuron Structures . . . Myelin Sheath – high lipid content covering for the axon, promotes faster signal transmission Schwann Cells – cells that myelinate the axon of a neuron Nodes of Ranvier – narrow gaps in the myelin sheath.

(10) Types of Neuron by Structure . . . Multipolar – many processes originate from body, one axon, rest dendrites Bipolar – two processes, one axon, one dendrite Unipolar – one process, splits into axon and dendrite.

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(12) Types of Neuron by function . . . Sensory – carry impulses toward brain cord Interneurons – forms links between other neurons, lie in the brain or spinal cord Motor – carry impulses away from the brain or spinal cord.

(13) 3 main types of nerve cells. Sensory neuron. Interneuron. Motor neuron.

(14) Sensory neurons. Carries impulses from receptors e.g pain receptors in skin to the CNS( brain or spinal cord).

(15) Relay neuron. Carries impulses from sensory nerves to motor nerves..

(16) Motor neuron. Carries impulses from CNS to effector e.g. muscle to bring about movement or gland to bring about secretion of hormone e.g ADH.

(17) Transmission of signals.

(18) Trasmitting along the neuron . . . . Electrical signals must be sent along the neurons membrane Charge of the membrane is typically controlled by gated ion channels Neuron membranes are negatively charged, and can be depolarized or hyperpolarized When membrane is depolarized to threshold potential, an action potential is formed.

(19) Action Potential . Membrane is typically at -70mV . . . This is achieved by pumping Na+ ions out and K+ ions in Sodium is pumped out faster than Potassium making the inside more negative and the outside more positive. By allowing Na+ to rush into the cell we can create an action potential.

(20) Figure 10.17 in book..

(21) Transmitting along the neuron . . Action potential is then propagated along the neuron to the synapse Another all-or-none response . If threshold potential is reached, the nerve will completely fire, if it is not reached, no AP will be created.

(22) Refractory Period . Once an impulse has been triggered, there is a brief (1/2,500th) pause where it can not be reactivated. . . This limits the amount of impulses that can be sent to about a maximum of 700 100 per second is more common.

(23) The Synapse.

(24) Synaptic transmission . . Presynaptic neurons transmit signals to postsynaptic neurons When the AP reaches the synaptic end bulb of the presynaptic neuron, synaptic vesicles release neurotransmitters into the synaptic cleft, which then diffuse across to the postsynaptic neuron.

(25) Synaptic transmission . . Diffused neurotransmitters can either cause the postsynaptic neuron to fire, called an excitatory postsynaptic potential (EPSP) or not fire, called an inhibatory postsynaptic potential (IPSP) Neurons can synapse with many types of cells, not just other neurons!.

(26) The Nervous System . . . Major division - Central vs. Peripheral Central or CNS- brain and spinal cord Peripheral- nerves connecting CNS to muscles and organs Central Nervous System. Peripheral Nervous System.

(27) Peripheral Nervous System . . . . 3 kinds of neurons connect CNS to the body  sensory  motor  interneurons Motor - CNS to muscles and organs Sensory - sensory receptors to CNS Interneurons: Connections Within CNS. Brain Spinal Cord. Nerves.

(28) Peripheral Nervous System. Peripheral Nervous System Skeletal (Somatic). Autonomic. Sympathetic. Parasympathetic.

(29) Somatic System . . . . . Brain. Nerves to/from spinal cord control muscle movements somatosensory inputs. Both Voluntary and reflex movements Skeletal Reflexes . simplest is spinal reflex arc. Sensory Neuron. Skin receptors. Motor Neuro n Interneuron. Muscle.

(30) Autonomic System . Two divisions:  . . Control involuntary functions     . . sympathetic Parasympatheitic heartbeat blood pressure respiration perspiration digestion. Can be influenced by thought and emotion.

(31) Sympathetic CENTRAL NERVOUS SYSTEMSYMPATHETIC  . . . . “ Fight or flight” response Release adrenaline and noradrenaline Increases heart rate and blood pressure Increases blood flow to skeletal muscles Inhibits digestive functions. Brain. Dilates pupil Stimulates salivation Relaxes bronchi Spinal cord. Salivary glands Lungs. Accelerates heartbeat Inhibits activity. Stimulates glucose. Heart Stomach Pancre as Liver. Secretion of adrenaline, Adrenal gland nonadrenaline Kidney Relaxes bladder Sympathetic Stimulates ejaculation ganglia in male.

(32) Parasympathetic CENTRAL NERVOUS SYSTEMPARASYMPATHETIC Brain. . . . “ Rest and digest ” system Calms body to conserve and maintain energy Lowers heartbeat, breathing rate, blood pressure. Contracts pupil Stimulates salivation Spinal cord. Constricts bronchi. Slows heartbeat Stimulates activity. Stimulates gallbladder Gallbladder Contracts bladder Stimulates erection.

(33) Summary of autonomic differences Autonomic nervous system controls physiological arousal Sympathetic division (arousing). Parasympathetic division (calming). Pupils dilate. EYES. Pupils contract. Decreases. SALVATION. Increases. Perspires. SKIN. Dries. Increases. RESPERATION. Decreases. Accelerates. HEART. Slows. Inhibits. DIGESTION. Activates. Secrete stress hormones. ADRENAL GLANDS. Decrease secretion of stress hormones.

(34) Central Nervous System Brain. . Brain and Spinal Cord . Involved in processing information and making coordinated responses to surroundings. Spinal Cord.

(35) The Human Brain Master Watermark Image:. http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif.

(36) m u r b e r e C Th e Lobes, the Cerebral Cortex, and Cortical Regions of the Brain.

(37) Objectives: . •. •. Students will be able to describe the general structure of the Cerebrum and Cerebral Cortex. Students will be able to identify the Cerebrum, the Lobes of the Brain, the Cerebral Cortex, and its major regions/divisions.. Students will be able to describe the primary functions of the Lobes and the Cortical Regions of the Brain..

(38) Cerebrum -The largest division of the brain. It is divided into two hemispheres, each of which is divided into four lobes.. Cerebrum. Cerebru m. Cerebellum. http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif.

(39) Cerebral Cortex - The outermost layer of gray matter making up the superficial aspect of the cerebrum.. Cerebral. Cortex Cerebral. Cortex. http://www.bioon.com/book/biology/whole/image/1/1-6.tif.jpg.

(40) Cerebral Features: • Gyri – Elevated ridges “winding” around the brain. • Sulci – Small grooves dividing the gyri – Central Sulcus – Divides the Frontal Lobe from the Parietal Lobe. • Fissures – Deep grooves, generally dividing large regions/lobes of the brain – Longitudinal Fissure – Divides the two Cerebral Hemispheres – Transverse Fissure – Separates the Cerebrum from the Cerebellum – Sylvian/Lateral Fissure – Divides the Temporal Lobe from the Frontal and Parietal Lobes.

(41) Gyri (ridge). Sulci (groove). Fissure (deep groove). http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif.

(42) Specific Sulci/Fissures: Central Sulcus Longitudinal Fissure. Sylvian/Late ral Fissure Transverse Fissure http://www.bioon.com/book/biology/whole/image/1/1-8 .tif.jpg. http://www.dalbsoutss.eq.edu.au/Sheepbrains_Me/human_bra.

(43) Lobes of the Brain (4)  Frontal  Parietal  Occipital  Temporal. http://www.bioon.com/book/biology/whole/image/1/18.tif.jpg. * Note: Occasionally, the Insula is considered the fifth lobe. It is located deep to the Temporal Lobe..

(44) Lobes of the Brain - Frontal . •. The Frontal Lobe of the brain is located deep to the Frontal Bone of the skull.. It plays an integral role in the following functions/actions: - Memory Formation - Emotions - Decision Making/Reasoning - Personality. (Investigation: Phineas Gage)Gage) Investigation (Phineas Modified from:.

(45) Frontal Lobe - Cortical Regions • Primary Motor Cortex (Precentral Gyrus) – Cortical site involved with controlling movements of the body. • Broca’s Area – Controls facial neurons, speech, and language comprehension. Located on Left Frontal Lobe.. – Broca’s Aphasia – Results in the ability to comprehend speech, but the decreased motor ability (or inability) to speak and form words. . Orbitofrontal Cortex – Site of Frontal Lobotomies * Possible Side Effects: * Desired Effects: - Diminished Rage - Decreased Aggression - Poor Emotional Responses. - Epilepsy - Poor Emotional Responses - Perseveration (Uncontrolled, repetitive actions, gestures, or words). • Olfactory Bulb - Cranial Nerve I, Responsible for sensation of Smell.

(46) Investigation (Phineas Gage). Primary Motor Cortex/ Precentral Gyrus Broca’s Area Orbitofrontal Cortex Olfactory Bulb. Regions Modified from:.

(47) Lobes of the Brain - Parietal Lobe . The Parietal Lobe of the brain is located deep to the Parietal Bone of the skull.. • It plays a major role in the following functions/actions: - Senses and integrates sensation(s). - Spatial awareness and perception (Proprioception - Awareness of body/ body parts in space and in relation to each other). Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg.

(48) Parietal Lobe - Cortical Regions . Primary Somatosensory Cortex (Postcentral Gyrus) – Site involved with processing of tactile and proprioceptive information.. • Somatosensory Association Cortex - Assists with the integration and interpretation of sensations relative to body position and orientation in space. May assist with visuo-motor coordination.. •. Primary Gustatory Cortex – Primary site involved with the interpretation of the sensation of Taste..

(49) Primary Somatosensory Cortex/ Postcentral Gyrus. Somatosensory Association Cortex. Primary Gustatory Cortex. Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg. Regions.

(50) Lobes of the Brain – Occipital Lobe . •. The Occipital Lobe of the Brain is located deep to the Occipital Bone of the Skull.. Its primary function is the processing, integration, interpretation, etc. of VISION and visual stimuli.. Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg.

(51) Occipital Lobe – Cortical Regions . Primary Visual Cortex – This is the primary area of the brain responsible for sight -recognition of size, color, light, motion, dimensions, etc.. • Visual Association Area – Interprets information acquired through the primary visual cortex..

(52) Primary Visual Cortex. Visual Association Area. Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg. Regions.

(53) . •. Lobes of the Brain – Temporal Lobe. The Temporal Lobes are located on the sides of the brain, deep to the Temporal Bones of the skull. They play an integral role in the following functions: - Hearing. - Organization and Comprehension of language. - Information Retrieval (Memory and Memory Formation) Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg.

(54) Temporal Lobe – Cortical Regions Primary Auditory Cortex – Responsible for hearing Primary Olfactory Cortex – Interprets the sense of smell once it reaches the cortex via the olfactory bulbs. (Not visible on. . •. the superficial cortex). • Wernicke’s Area – Language comprehension. Located on the Left Temporal Lobe. Aphasia – Language - Wernicke’s comprehension is inhibited. Words and sentences are not clearly understood, and sentence formation may be inhibited or non-.

(55) Primary Auditory Cortex. Wernike’s Area. Primary Olfactory Cortex (Deep) Conducted from Olfactory Bulb. Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg. Regions.

(56) Arcuate Fasciculus - A white matter tract that connects Broca’s Area and Wernicke’s Area through the Temporal, Parietal and Frontal Lobes. Allows for coordinated, comprehensible speech. Damage may result in: - Conduction Aphasia - Where auditory comprehension and speech articulation are preserved, but people find it difficult to repeat heard speech. Arcuate Fasciculus •. Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg.

(57) Click the Region to see its Name. Korbinian Broadmann - Learn about the man who divided the Cerebral Cortex into 52 distinct regions: http://en.wikipedia.org/wiki/Korbinian_Brodmann.

(58) B.. Lobes and Structures of the Brain A.. G.. F.. C.. E. D.. http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif.

(59) Lobes and Structures of the Brain. A. Central Sulcus B. Frontal Lobe C. Sylvian/Lateral Fissure A. (groove) D. Temporal Lobe. G.. B. F.. E. Transverse Fissure F. Occipital Lobe G. Parietal Lobe. C. (groove) D.. E. (groove ). http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif.

(60) K.. A.. J.. Cortical Regions. I.. B.. H.. G.. C.. D. E.. F.. http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif.

(61) . Primary Motor Cortex/ Precentral Gyrus B. Broca’s Area C. Orbitofrontal Cortex. Cortical Regions. D. Primary Olfactory Cortex (Deep) E. Primary Auditory Cortex A.. F. Wernike’s Area. K. J. I.. G. Primary Visual Cortex B. H. Visual Association Area I. Primary Gustatory Cortex. H. G.. J. Somatosensory C. Association Cortex K. Primary Somatosensory Cortex/ Postcentral. D. E.. F.. http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif.

(62) Copyright: Gary Larson. Q: Assuming this comical situation was factually accurate, what Cortical Region of the brain would these doctors be.

(63) A: Primary Motor Cortex. * This graphic representation of the regions of the Primary Motor Cortex and Primary Sensory Cortex is one example of a Homunculus HOMUNCULUS:.

(64) * Note: Homunculus literally means “little person,” and may refer to one whose body shape is governed by the cortical area devoted to that body region.. Q: What do you notice about the proportions depicted in the aforementioned homunculus? A: They are not depicted in the same scale representative of the human body.. Q: What is meant by depicting these body parts in such outrageous proportions? A: These outrageous proportions depict the cortical area devoted to each structure. - Ex: Your hands require many intricate movements and sensations to function properly. This requires a great deal of cortical surface area to control these detailed actions. Your back is quite the opposite, requiring limited cortical area to carry out its actions and functions, or detect sensation.. Back-Hom..

(65) Further Investigation Phineas Gage: Phineas Gage was a railroad worker in the 19th century living in Cavendish, Vermont. One of his jobs was to set off explosive charges in large rock in order to break them into smaller pieces. On one of these instances, the detonation occurred prior to his expectations, resulting in a 42 inch long, 1.2 inch wide, metal rod to be blown right up through his skull and out the top. The rod entered his skull below his left cheek bone and exited after passing through the anterior frontal lobe of his brain.. Frontal.

(66) Remarkably, Gage never lost consciousness, or quickly regained it (there is still some debate), suffered little to no pain, and was awake and alert when he reached a doctor approximately 45 minutes later. He had a normal pulse and normal vision, and following a short period of rest, returned to work several days later. However, he was not unaffected by this accident.. http://www.sruweb.com/~walsh/gage5.jpg. Learn more about Phineas Gage: http://en.wikipedia.org/wiki/Phineas_Gage. Frontal.

(67) Q: Recalling what you have just learned regarding the frontal lobe, what possible problems or abnormalities may Gage have presented with subsequent to this type of injury (remember the precise location of the rod through his brain)? A: Gage’s personality, reasoning, and capacity to understand and follow social norms had been diminished or destroyed. He illustrated little to no interest in hobbies or other involvements that at one time he cared for greatly. ‘After the accident, Gage became a nasty, vulgar, irresponsible vagrant. His former employer, who regarded him as "the most efficient and capable foreman in their employ previous to his injury," refused to rehire him Q: It is suggested Gage’s injury inspired the because he was sothat different.’ development of what at one time was a widely used medical procedure. What might this procedure be, and how does it relate to Gage’s injury? A: The frontal lobotomy. This has been used with the intention to diminish aggression and rage in mental patients, but generally results in drastic personality changes, and an inability to relate socially. This procedure is largely frowned upon today, with the development of Frontal neurological drugs as treatments..

(68) Resources Images:      . http://www.dalbsoutss.eq.edu.au/Sheepbrains_Me/human_brain.gif http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg http://www.bioon.com/book/biology/whole/image/1/1-6.tif.jpg http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLHviaTWD.gif http://www.math.tu-dresden.de/~belov/brain/motorcor2.gif Larson, Gary. The Far Side.. Phineas Gage:    . http://www.sruweb.com/~walsh/gage5.jpg http://soma.npa.uiuc.edu/courses/bio303/Image7.jpg http://en.wikipedia.org/wiki/Phineas_Gage http://science-education.nih.gov/nihHTML/ose/snapshots/multimedia/ ritn/Gage/Broken_brain1.html.

(69) Suggested Supplementary Materials: 1.. Skeleton Outline for note-taking.. 2.. Multiple Diagrams of the Human Brain. * Students will label features/lobes * Students will color-code cortical regions. 3.. Worksheets (matching, short answer, etc.), centered around the functions of the lobes and regions of the cerebrum.. 4.. A more in depth article on Phineas Gage. Read and discuss as a class - time permitting.. Suggested Assessments: 1.. Class/individual questioning throughout (especially at the conclusion of) the presentation.. 2.. Homework worksheets - discussed or collected in class.. 3.. Students will take a test on the nervous system in which they will be responsible for the structures, lobes, regions, functions, etc..

(70) Massachusetts State Biology Standards. Broad Concept: There is a relationship between structure and function in organ systems of humans. 4.1 Explain how major organ systems in humans (e.g., kidney, muscle, lung) have functional units (e.g., nephron, sarcome, alveoli) with specific anatomy that perform the function of that organ system. 4.2 Describe how the function of individual systems within humans are integrated to maintain a homeostatic balance in the body.. * Note: This PowerPoint has been developed for Juniors and Seniors enrolled in Anatomy and Physiology Courses. Thus, the detail of the concepts and information contained herein is far greater than required by the state Biology standards listed above..

(71) National Standards: THE BEHAVIOR OF ORGANISMS:  Multicellular animals have nervous systems that generate behavior. Nervous systems are formed from specialized cells that conduct signals rapidly through the long cell extensions that make up nerves. The nerve cells communicate with each other by secreting specific excitatory and inhibitory molecules. In sense organs, specialized cells detect light, sound, and specific chemicals and enable animals to monitor what is going on in the world around them.  Organisms have behavioral responses to internal changes and to external stimuli. Responses to external stimuli can result from interactions with the organism's own species and others, as well as environmental changes; these responses either can be innate or learned. The broad patterns of behavior exhibited by animals have evolved to ensure reproductive success. Animals often live in unpredictable environments, and so their behavior must be flexible enough to deal with uncertainty and change. Plants also respond to stimuli.  Like other aspects of an organism's biology, behaviors have evolved through natural selection. Behaviors often have an adaptive logic when viewed in terms of evolutionary principles.  Behavioral biology has implications for humans, as it provides links to psychology, sociology, and anthropology..

(72) BRAINSTEM.

(73) BRAIN STEM. 3 Major Divisions (in descending order) •. •Midbrain •Pons •Medulla.

(74) MIDBRAIN. •Most. superior aspect of the brain stem •Located inferiorly to the Cerebellum and superiorly to the Pons •Functions in motor system pathways •Produces Dopamine •Helps relay information for hearing and vision.

(75) PONS •Located. inferiorly to the Midbrain •Lies anterior to the Cerebellum, connected by a pair of Cerebellar peduncles •Contains Pneumotaxic center, which is responsible for regulating breathing •Plays a role in generating dreams.

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(77) MEDULLA. •Inferior. to the Pons, continuous with spinal cord •Contains centers for: •Cardiac •Respiratory •Vomiting •Vasomotor.

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(79) Other Parts of the Brain •Additional. parts of the brain that contribute to healthy function including: Cerebellum, Thalamus, Hypothalamus, Corpus Callosum, Pituitary Gland.

(80) Cerebellum •Is important for coordination and error. checking during motor, perceptual, and cognitive functions •Is also involved in learning and remembering motor skills.

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(82) Corpus Callosum •Connected. white matter tracts on both hemispheres of the brain •Relays signals from light to left brain and vice versa •Surrounds large ventricles that contain cerebrospinal fluid.

(83) Thalamus •Is the main input center for sensory. information going to the cerebrum and the main output center for motor information leaving the cerebrum.

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(85) Hypothalamus •The. hypothalamus regulates • Homeostasis • Basic survival behaviors such as feeding, fighting, fleeing, and reproducing •The hypothalamus also regulates circadian rhythms • Such as the sleep/wake cycle • AKA Biological clock.

(86) Pituitary Gland •Pea. sized gland that extends down from the hypothalamus •Nervous + Endocrine systems •Dwells in the Sella Turcica •Controlled by the hypothalamus, secretes 9 hormones that regulate homeostasis.

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