A&P Nervous System PDF

REVIEW OUTLINE The Neuron 1. Key Structures a. Soma b. Dendrites c. Axon i. Axon Terminals ii. Axon Hillock iii. Myelin Sheath 1. Olig...

REVIEW OUTLINE The Neuron 1. Key Structures a. Soma b. Dendrites c. Axon i. Axon Terminals ii. Axon Hillock iii. Myelin Sheath 1. Oligodendrocytes vs Schwann cells iv. Nodes of Ranvier 1. Saltatory Conduction  The Neuron Bootcamp.com Key Structures Neuron: Functional unit of the nervous system Soma: Neuron cell body, nucleated region Dendrites: Processes for receiving signals from neighboring neurons Axon: Process for sending signals to neighboring neurons Axon Terminals: Site of synaptic signal transmission  The Neuron Bootcamp.com Key Structures Axon Hillock: Site of connection between the soma and the axon Myelin Sheath: Fatty, insulation of the axon, accelerates action potential propagation Oligodendrocytes vs Schwann Cells Nodes of Ranvier: ‘Gaps’ in the myelin sheath, action potential can jump from gap to gap Saltatory conduction The Neuron Bootcamp.com Key Structures The Neuron Bootcamp.com Mini Quiz! Which of the following neuron structures allows for ion exchange to occur via saltatory conduction? A) Dendrites B) Axon Hillock C) Nodes of Ranvier D) Myelin Sheath REVIEW OUTLINE The Neuron 1. The neuron is the functional unit of the nervous system 2. The three main sections of the neuron are the soma, dendrites and axons 3. The myelin sheath is a fatty insulation that covers most of the axon and prevents ion exchange 4. Myelin sheath cells are made by oligodendrocytes in the CNS and by schwann cells in the PNS 5. Nodes of ranvier are gaps in the myelin sheath where ion exchange may occur 6. Action potentials can be accelerated down the axon by jumping from node to node REVIEW OUTLINE Action 1. 2. What is an action potential? Resting State Potentials: a. Resting potential Part 1 b. Na+/K+ pumping via ATPases 3. Depolarization K+ a. Stimulus b. Voltage-gated Na+ channels Na+  Action Potentials: Part 1 Bootcamp.com What is an Action Potential? An action potential is a rapid change in the membrane potential that exists across a membrane Governed by relative ion ratios in the intracellular and extracellular spaces Neuron Action Potential: Na+ / K+ ALL OR NOTHING Action Potentials: Part 1 Bootcamp.com Steps of an Action Potential 1. Resting State 2. Depolarization 3. Repolarization 4. Hyperpolarization 5. Return to resting state Action Potentials: Part 1 Bootcamp.com Resting State - prior to the firing of the action potential Resting potential is maintained around ~ -70 mV by Na+/K+ ATPases Voltage is more negative inside the cell than outside Active transport of ion UP their concentration gradient Requires ATP cleavage Sodium/ Potassium ATPase Pump Outside the cell Inside the cell Action Potentials: Part 1 Bootcamp.com Resting State - prior to the firing of the action potential “SALTED BANANAS” Pump 3 Na+ OUT of the cell for every 2 K+ pumped INTO the cell Sodium/ Potassium ATPase Pump Outside the cell Inside the cell Action Potentials: Part 1 Bootcamp.com Depolarization Out Stimulated neurons depolarize IF threshold potential is reached Neuron threshold potential is -55 mv In Stimulus causes some Na+ to flow back into the cell Action Potentials: Part 1 Bootcamp.com Depolarization Depolarization is achieved if -55 mv is reached -55 mv result in voltage-gated Na+ channels opening, allowing a large influx of Na+ into the cell K+ channels close at this time Voltage-Gated Sodium Channel Voltage-Gated Potassium Channel (Depolarization) Outside the cell Sodium/ Potassium ATPase Pump Inside the cell Action Potentials: Part 1 Bootcamp.com Mini Quiz! Which of the following correlates with the opening of voltage-gated sodium channels? A) Maintenance of resting potential B) Stimuli from another neuron C) Arrival at threshold potential D) Hyperpolarization of membrane potential REVIEW OUTLINE Action 1. An action potential is a rapid change in the membrane potential that exists across a Potentials: 2. membrane Resting potential for a neuron is ~ -70 mV Part 1 3. Resting potential is maintained by active transport of Na+ and K+ 4. Action potentials are triggered in neurons by + K stimuli 5. If the stimuli brings the action potential to the threshold potential then depolarization may occur + 6. Threshold potential for a neuron is -55 mV Na 7. Depolarization is the beginning of an action potential where Na+ ions flow back into the cell 8. K+ channels are closed during depolarization REVIEW OUTLINE Action 1. Repolarization a. Voltage-gated K+ channels Potentials: 2. Hyperpolarization Part 2 a. Absolute vs relative refractory periods K+ 3. Return to resting potential 4. A new way to think of the action potential Na+ Action Potentials: Part 2 Bootcamp.com Repolarization Transition from a more positive “depolarized” membrane potential back to a more negative “re-polarized” membrane potential Voltage-gated K+ channels open to allow K+ out of the cell Na+ channels close and are inactive Voltage-Gated Potassium Channel Outside the cell Sodium/ Voltage-Gated Potassium ATPase Sodium Channel Pump Inside the cell Action Potentials: Part 2 Bootcamp.com Hyperpolarization Hyperpolarization A membrane potential even more negative than the resting potential Refractory Period A phase where if is either very difficult or impossible to trigger another action potential Voltage-Gated Potassium Channel Outside the cell Sodium/ Voltage-Gated Potassium ATPase Sodium Channel Pump Inside the cell  Action Potentials: Part 2 Bootcamp.com Refractory Absolute Refractory Period Impossible to trigger a second action potential Na+ channels are inactivated as K+ channels continue to re-polarize the membrane Relative Refractory Period Very difficult to trigger a second action potential Membrane potential drops below -70 mv and Na+ channels are closed but not inactivated Action Potentials: Part 2 Bootcamp.com Action Potentials: Part 2 Bootcamp.com Climax But it ’s a st ory ar c….. Fall n actio ing Act g Risin ion Exposition Resolution Conflict Action Potentials: Part 2 Bootcamp.com Outside the cell Resting Potential Inside the cell Outside the cell Depolarization Inside the cell Outside the cell Repolarization Inside the cell Action Potentials: Part 2 Bootcamp.com Mini Quiz! Which of the following is responsible for hyperpolarization? A) K+ continuing to flow out of the cell even after -70 mV is reached B) K+ continuing to flow into the cell even after -70 mV is reached C) Na+ flowing into the cell as a response to a stimulus D) Na+ flowing against its concentration gradient REVIEW OUTLINE Repolarization occurs when K+ channels open to Action 1. pump K+ out of the cell and Na+ channels Potentials: 2. inactivate Repolarization causes the membrane potential to Part 2 become more negative and re-approach -70 mV 3. K+ channels stay open past the return to -70 mV causing hyperpolarization K+ 4. Na+/K+ ATPases reset the membrane potential 5. The absolute refractory period lasts from depolarization through repolarization a. No new action potential can be triggered + 6. The relative refractory period exists beyond Na repolarization a. It is very difficult to trigger a new action potential here but it is possible REVIEW OUTLINE Synaptic 1. 2. What is synaptic transmission The synapse Transmission 3. Release of Neurotransmitters 4. Neurotransmitters and the postsynaptic neuron a. Excitatory postsynaptic potential vs. inhibitory postsynaptic potential 5. Determining if an action potential will fire a. Summation of EPSPs and IPSPs 6. Neurotransmitters a. Excitatory vs Inhibitory Synaptic Transmission Bootcamp.com The transmission of chemical signals from one neuron to another across an interneuron space called a synapse Chemical signals, or neurotransmitters (NTs), are generated in the presynaptic neuron and received at the postsynaptic neuron Synaptic Transmission Bootcamp.com The Synapse Synapse: The space between two neurons, including the Presynaptic presynaptic and postsynaptic neurons Neuron (Axon Terminal) Presynaptic Neuron: Responsible for sending the signal and releasing NTs into the synaptic cleft Axon terminal Synaptic Synaptic Cleft: The zone that exists between Cleft two neurons, not including either neuron { Postsynaptic Neuron (Dendrite) Synaptic Transmission Bootcamp.com The Synapse Synaptic Vesicles: Responsible for the transport of Presynaptic NTs from the axon to the synaptic cleft Neuron (Axon Terminal) Postsynaptic Neuron: Responsible for signal Synaptic reception and interacting with NTs Transport Vesicles Synaptic Cleft { Postsynaptic Neuron (Dendrite) Synaptic Transmission Bootcamp.com The Synapse Neurotransmitters (NTs): Messenger molecules Presynaptic that are released by the presynaptic neuron and Neuron (Axon received by the postsynaptic neuron Terminal) Synaptic Postsynaptic Ligand-Gated Ion Channels: Directly Transport responsible for binding of free NTs at the Vesicles postsynaptic neuron Synaptic Cleft { Neurotransmitters Postsynaptic Postsynaptic Neuron Ligand-Gated Ion (Dendrite) Channels Synaptic Transmission Bootcamp.com Releasing Neurotransmitters Ca2+ Action potential finishes at the axon terminal Voltage-Gated Calcium Presynaptic neuron Channels Depolarization of the membrane potential causes voltage-gated calcium channels to open Synaptic Ca2+ enters the cell Transport Vesicles Large influx in Ca2+ triggers exocytosis of NTs Synaptic vesicles housing NTs bind to the plasma membrane to initiate exocytosis Postsynaptic Neuron (Dendrite) Synaptic Transmission Bootcamp.com Receiving Neurotransmitters Released NTs cross the synapse and are received at ligand-gated ion channels of the postsynaptic neuron Graded potentials are produced at the postsynaptic membrane Excitatory - Depolarization Inhibitory - Hyperpolarization Postsynaptic Ligand-Gated Ion Channels Synaptic Transmission Bootcamp.com Excitatory Postsynaptic Potentials (EPSPs) Graded potential that depolarizes the membrane Opens Na+ channels Inhibitory Postsynaptic Potentials (IPSPs) Graded potential that hyperpolarizes the membrane Opens K+ channels  Synaptic Transmission Bootcamp.com Summation of Graded Potentials (EPSPs + IPSPs) Graded potentials are created at all dendrites of a given postsynaptic neuron Both EPSPs and IPSPs All graded potentials will summate at the axon hillock If the total graded potential exceeds the neuron threshold potential a new action potential is generated If threshold is not reached there is no new action potential Synaptic Transmission Bootcamp.com Neurotransmitters The chemical messengers passed between a neuron and a target cell (neuron, muscle, etc.) EPSPs IPSPs  Synaptic Transmission Bootcamp.com Excitatory Neurotransmitters (ENTs) Neurotransmitters that invoke an ‘excitatory’ response at the postsynaptic membrane A neuron dendrite that receives ENTs will depolarize at its synaptic membrane and pass on the action potential signal Glutamate: The main ENT of the central nervous system Dopamine: Involved in reward motivated behavior Catecholamine Epinephrine and Norepinephrine: Involved in the ‘fight or flight’ response Both postsynaptic ENTs of the sympathetic nervous system Reroute blood toward the most critical parts of your body Catecholamines Acetylcholine: Most common NT in the muscular system Signals to muscle fibers by binding to ligand-gated sodium channels Postsynaptic Neuron (Dendrite) Synaptic Transmission Bootcamp.com Inhibitory Neurotransmitters (INTs) Neurotransmitters that invoke an ‘inhibitory’ response at the postsynaptic membrane A neuron dendrite that receives INTs will hyperpolarize at its synaptic membrane and refrain from passing down the action potential Gamma-aminobutyric acid (GABA): Main INT of the central nervous system Glycine: Another INT of the central nervous system Serotonin: INT of the brain Postsynaptic Neuron (Dendrite) Synaptic Transmission Bootcamp.com Mini Quiz! The opening of what channel is responsible for the exocytosis of neurotransmitters into the synaptic cleft? A) Voltage-gated Na+ channels B) Voltage-gated K+ channels C) Voltage-gated Ca2+ channels D) Ligand-gated ion channels REVIEW OUTLINE 1. Synaptic transmission begins with the conclusion of Synaptic the action potential at the axon terminal 2. Presynaptic membrane depolarization opens Transmission voltage-gated calcium channels, allowing large amounts of Ca2+ into the presynaptic cell 3. The high concentration of Ca2+ in the cell causes the exocytosis of NTs via synaptic vesicles 4. The NTs cross the synaptic cleft, binding to ligand-gated ion channels on the postsynaptic membrane 5. Either an excitatory or inhibitory postsynaptic graded potential results from this interaction 6. All newly formed graded potentials will summate at the axon hillock 7. If the summate reaches the neuron threshold potential then the action potential is passed along 8. Neurotransmitters can be excitatory or inhibitory REVIEW OUTLINE 1. Central nervous system vs peripheral nervous Central Nervous system 2. Embryonic development System: Part 1 a. Forebrain b. Midbrain c. Hindbrain Central Nervous System: Part 1 Bootcamp.com Central Nervous System vs Peripheral Nervous System Central Nervous System (CNS) Peripheral Nervous System (PNS) Brain and spinal cord Nerves branching off of the CNS  Central Nervous System: Part 1 Bootcamp.com Embryonic Development and the Brain Forebrain Telencephalon Diencephalon Midbrain Mesencephalon Hindbrain Metencephalon Myelincephalon 3-4 week 5 week embryo embryo  Central Nervous System: Part 1 Bootcamp.com Embryonic Development and the Brain Forebrain Telencephalon Cerebrum Diencephalon Thalamus, hypothalamus, pineal gland Midbrain Mesencephalon Midbrain Hindbrain Metencephalon Pons, cerebellum Myelencephalon Medulla oblongata Central Nervous System: Part 1 Bootcamp.com Central Nervous System: Part 1 Bootcamp.com Mini Quiz! What structure of the developing brain goes on to develop into the pons of the developed brain? A) Myelincephalon B) Metencephalon C) Mesencephalon D) Telencephalon REVIEW OUTLINE Central Nervous 1. The central nervous system (CNS) is comprised of the brain and the spinal cord System: Part 1 2. The peripheral nervous system (PNS) is comprised of accessory neurons that extend off of the CNS 3. During early development the brain can be distinguished in three main categories: the forebrain, the midbrain, and the hindbrain 4. The forebrain develops into the telencephalon and the diencephalon which further develops into the cerebrum, thalamus, hypothalamus, and pineal gland 5. The midbrain develops into the mesencephalon which further develops into the midbrain 6. The hindbrain develops into the metencephalon and myelencephalon which later develop into the pons, cerebellum, and medulla oblongata REVIEW OUTLINE 1. The developed brain cortex Central Nervous a. Frontal lobe b. Temporal lobe System: Part 2 c. Occipital lobe d. Parietal lobe 2. The cerebellum 3. The brainstem a. Midbrain b. Pons c. Medulla oblongata d. Reticular formations 4. Limbic system a. Thalamus, hypothalamus, hippocampus, and amygdala 5. Spinal cord 6. Meninges Central Nervous System: Part 2 Bootcamp.com Developed Brain Cortex Cerebral Cortex: The largest, outermost, deeply grooved portion of the brain Central Nervous System: Part 2 Bootcamp.com Developed Brain Cortex Four Main Lobes of the Developed Cortex Frontal Lobe: Higher level functioning; decision making, problem solving, attention and concentration Temporal Lobe: Responsible for speech and hearing Occipital Lobe: Responsible for vision Parietal Lobe: Responsible for spatial perception and sensation Central Nervous System: Part 2 Bootcamp.com Developed Brain Cortex https://commons. wikimedia.org/wik Four Main Lobes of the Developed Cortex i/File:Four_lobes. gif Frontal Lobe Parietal Lobe Occipital Lobe Temporal Lobe Central Nervous System: Part 2 Bootcamp.com Cerebellum Cerebellum: Responsible for the coordination of movement Structurally independent of the four lobes of the cerebral cortex Located between the occipital lobe and the brain stem Central Nervous System: Part 2 Bootcamp.com Brain Stem Brain Stem: Involved in the control of automatic functions (ex. heart rate and signal relay) Located between the cerebral cortex and the spinal cord Central Nervous System: Part 2 Bootcamp.com Brain Stem Main Components of the Brain Stem Midbrain: Responsible for the relay of senses to other parts of the brain Pons: Responsible for the relay of messages between the forebrain, cerebellum, and medulla Medulla Oblongata: Multi-functional part of the brain stem; responsible for controlling heart rate, breathing rate, blood pressure, and for sensing toxins Reticular Formations: Neurons that exist throughout the brainstem; responsible for cortical arousal and consciousness Central Nervous System: Part 2 Bootcamp.com Brain Stem Main Components of the Brain Stem Central Nervous System: Part 2 Bootcamp.com Limbic System Limbic System: Responsible for emotion, memory, learning, and motivation Central Nervous System: Part 2 Bootcamp.com Limbic System Main Components of the Limbic System Thalamus: The brain’s “relay center”; relays sensory and motor signals from the body to the brain Located between the cerebrum and the midbrain Hypothalamus: Responsible for the regulation of hormone secretion in the body Hippocampus: Responsible for the consolidation of memory Amygdala: Responsible for the emotional reaction to scents Central Nervous System: Part 2 Bootcamp.com Limbic System Main Components of the Limbic System Thalamus Hippocampus Hypothalamus Amygdala Central Nervous System: Part 2 Bootcamp.com Spinal Cord Spinal Cord: Nervous tissue that connects the brain to the body Sensory (afferent) neurons: Relay signals to the spinal cord and eventually the brain via dorsal roots Motor (efferent) neurons: Relay signals from the brain to the muscles via ventral roots Central Nervous System: Part 2 Bootcamp.com The Meninges Meninges: Membrane layers that serve to protect the central nervous system Three Protective Layers Dura Mater Arachnoid Pia Mater Mnemonic: D.A.P. Dura mater, Arachnoid, Pia mater Central Nervous System: Part 2 Bootcamp.com Mini Quiz! What structure of the developed brain is responsible for controlling heart rate, breathing rate, and blood pressure? A) Medulla Oblongata B) Parietal Lobe C) Hippocampus D) Cerebellum REVIEW OUTLINE Central Nervous 1. The cerebral cortex is responsible for ‘higher order functions’ and is comprised of the frontal lobe, System: Part 2 occipital lobe, temporal lobe, and parietal lobe 2. The cerebellum coordinates body movement 3. The brainstem is responsible for automatic functions and includes the midbrain, pons, medulla oblongata, and is supported by the reticular formation 4. The limbic system is responsible for emotion, memory, learning, and motivation 5. The limbic system is comprised of the thalamus, hypothalamus, amygdala, and hippocampus 6. The spinal cord connects that brain to the body 7. Afferent nerves relay signals from the to the brain via dorsal roots 8. Efferent nerves relay signal from the brain to the body via ventral roots 9. The meninges are three membranes that protect the CNS made of the dura mater, arachnoid, & pia mater REVIEW OUTLINE 1. Peripheral nervous system (PNS) Peripheral a. Somatic nervous system b. Autonomic nervous system Nervous System: 2. Sensory (afferent) neurons of the PNS a. Mechanoreceptors Part 1 b. Nociceptors c. Thermoreceptors d. Chemoreceptors e. Electromagnetic receptors Peripheral Nervous System: Part 1 Bootcamp.com Peripheral Nervous System Central Nervous System (CNS) Peripheral Nervous System (PNS) Brain and spinal cord Nerves branching off of the CNS Peripheral Nervous System: Part 1 Bootcamp.com PNS Motor (Efferent) Neurons Somatic Nervous System + Autonomic Nervous System Peripheral Nervous System: Part 1 Bootcamp.com Somatic Nervous System + Autonomic Nervous System Somatic Nervous System: Involved in voluntary motor action Skeletal muscles Autonomic Nervous System: Involved in involuntary actions Smooth muscles Cardiac muscle Effector organs Peripheral Nervous System: Part 1 Bootcamp.com PNS Sensory (Afferent) Neurons Mechanoreceptors: Responsible for reception of mechanical stimuli Nociceptors: Responsible for reception of pain stimuli Thermoreceptors: Responsible for reception of stimuli related to changes in temperature Chemoreceptors: Responsible for reception of chemical stimuli Electroreceptors: Responsible for reception of light, electrical, and magnetic stimuli Peripheral Nervous System: Part 1 Bootcamp.com Mini Quiz! Which of the following PNS sensory neurons is responsible for the reception of pain stimuli? A) Mechanoreceptors B) Thermoreceptors C) Nociceptors D) Chemoreceptors REVIEW OUTLINE Peripheral 1. The CNS consists of the brain and spinal cord 2. The PNS has both sensory (afferent) neurons and Nervous System: 3. motor (efferent) neurons The motor neurons of the PNS can be attributed to Part 1 4. either the somatic or autonomic nervous system The somatic nervous system carries out voluntary action by stimulating skeletal muscles 5. The autonomic nervous system carries out involuntary actions by stimulating smooth and cardiac muscle 6. Sensory neurons in the PNS receive various stimuli 7. The types of sensory neurons in the PNS are mechanoreceptors, nociceptors, thermoreceptors, chemoreceptors, and electroreceptors REVIEW OUTLINE 1. Autonomic nervous system Peripheral a. Sympathetic nervous system b. Parasympathetic nervous system Nervous System: 2. Ganglia a. Preganglionic neurons Part 2 b. Postganglionic neurons c. Ganglia of the sympathetic and parasympathetic nervous systems Peripheral Nervous System: Part 2 Bootcamp.com Autonomic Nervous System Autonomic Nervous System: Involved in involuntary actions Smooth muscles Cardiac muscle Effector organs Sympathetic Nervous System + Parasympathetic Nervous System Peripheral Nervous System: Part 2 Bootcamp.com Sympathetic Nervous System Sympathetic Nervous System: Responsible for aiding the “fight or flight response” Effects of an active sympathetic nervous system - Release of sugar into the blood (increased energy) Increased heart rate (increased oxygen delivery to the brain and to muscles) Vasodilation of skeletal blood vessels, vasoconstriction of the digestive system Dilation of bronchi and bronchioles (more oxygen into the lungs) Dilation of pupils (more light and visual information for the brain) Peripheral Nervous System: Part 2 Bootcamp.com Parasympathetic Nervous System Parasympathetic Nervous System: Responsible for relaxing the body out of a sympathetic state (rest and digest) Effects occur via the vagus nerve Effects of an active parasympathetic nervous system - Relaxation of muscles Decreased heart rate Maintenance of homeostasis Increase in gastrointestinal activity  Peripheral Nervous System: Part 2 Bootcamp.com Sympathetic and Parasympathetic Nervous System Sympathetic Nervous System: Release of sugar into the blood (increased Parasympathetic Nervous System: energy) Relaxation of muscles Increased heart rate Decreased heart rate (increased oxygen Maintenance of delivery to the brain and homeostasis to muscles) Increase in gastrointestinal Vasodilation of skeletal activity blood vessels, vasoconstriction of the digestive system Dilation of bronchi and bronchioles (more oxygen into the lungs) Dilation of pupils (more light and visual information for the brain) Peripheral Nervous System: Part 2 Bootcamp.com Ganglia Terminology Ganglion: A cluster of nerve cell bodies in the peripheral nervous system Cite of synapsing between the preganglionic and postganglionic neurons Preganglionic Neuron: Neuron coming from the CNS that enters the ganglia Postganglionic Neuron: Neuron coming from the ganglia and exiting to the effector organs Peripheral Nervous System: Part 2 Bootcamp.com Ganglia of the Autonomic NS Parasympathetic Nervous System: Long preganglionic neuron, short postganglionic neuron Acetylcholine as sole neurotransmitter Peripheral Nervous System: Part 2 Bootcamp.com Ganglia of the Autonomic NS Sympathetic Nervous System (Toward Effector Organ): Short preganglionic neuron, long postganglionic neuron Acetylcholine as NT from preganglionic neuron to postganglionic neuron Norepinephrine or epinephrine as NT from postganglionic neuron to effector organ Peripheral Nervous System: Part 2 Bootcamp.com Ganglia of the Autonomic NS Sympathetic Nervous System (Toward Blood Stream): Stimulates adrenal medulla to release norepinephrine or epinephrine into the bloodstream  Peripheral Nervous System: Part 2 Bootcamp.com Ganglia of the Autonomic NS Both the parasympathetic and sympathetic nervous systems use acetylcholine Acetylcholinesterase: An enzyme that is responsible for the rapid hydrolysis of acetylcholine to stop the propagation of a signal Peripheral Nervous System: Part 2 Bootcamp.com Mini Quiz! Which of the following accurately describes the organization of ganglionic neurons in the parasympathetic nervous system? A) Short preganglionic neuron, long postganglionic neuron B) Short preganglionic neuron, no postganglionic neuron C) Long preganglionic neuron, short postganglionic neuron D) Long preganglionic neuron, no postganglionic neuron REVIEW OUTLINE 1. The autonomic nervous system is comprised of the sympathetic and parasympathetic nervous systems Peripheral 2. The sympathetic nervous system induces functions that Nervous System: aid “fight or flight” response 3. The parasympathetic calms the body down from a Part 2 sympathetic state, inducing “rest and digest” 4. A ganglion is a cluster of PNS neuron cell bodies 5. Preganglionic neurons extend from the CNS to the ganglion 6. Postganglionic neurons extend from the ganglion to the effector organ 7. The parasympathetic nervous system has long preganglionic neurons and short postganglionic neurons 8. The sympathetic nervous system has short preganglionic neurons and long postganglionic neurons 9. The sympathetic nervous system can stimulate the adrenal medulla to release epinephrine or norepinephrine into the bloodstream 10. Acetylcholinesterase is an enzyme that hydrolyzes ACh REVIEW OUTLINE 1. The ear and audition (hearing) Special Senses: a. Outer ear b. Middle ear Audition + 2. c. Inner ear Gustation (taste) Gustation a. Taste receptor cells  Special Senses Bootcamp.com Audition (Hearing) and the Ear Outer Ear: Responsible for taking in sound waves Tympanic Membrane: Responsible for transferring sounds from the outer ear to the middle ear  Special Senses Bootcamp.com Audition (Hearing) and the Ear Middle Ear: Responsible for carrying sound waves from the outer ear to the inner ear Three bony ossicles: Malleus, incus, stapes Transfer and amplify vibrations through the middle ear Stapes: Responsible for transferring sound from the middle ear to the inner ear via the oval window  Special Senses Bootcamp.com Audition (Hearing) and the Ear Inner Ear: Begin the transformation of sound waves into electrical impulses Cochlea: Uses fluid and hairs to convert mechanical signals into neural signals; known as transduction Round Window: Membrane covered opening between the middle ear and inner ear Helps cochlear expand and vibrate Semicircular Canal: Uses fluid and hairs to convey information about a person’s movement  Special Senses Bootcamp.com Gustation (Taste) Taste Taste Buds Taste Cells The Five Taste Receptor Cells: Salty Taste information is sent the Sweet thalamus and eventually the Bitter gustatory cortex Sour Umami Special Senses Bootcamp.com Mini Quiz! What is the name of the structure in the ear that is responsible for transferring sounds from the outer ear to the middle ear? A) Round Window B) Tympanic Membrane C) Stapes D) Semicircular Canal REVIEW OUTLINE Special Senses: 1. The ear is the structure in humans that is responsible for audition (hearing) Audition and 2. The ear can be structurally compartmentalized into the outer ear, the middle ear, and the inner ear Gustation 3. The outer ear receives sounds and relays them to the middle ear 4. Bony ossicles of the middle ear transmit and amplify the sound vibrations from the outer eat to the inner ear 5. Fluid filled chambers of the inner ear help to pass on the sound and convert sound waves to electrical impulses 6. Taste buds are structures of the tongue papillae that contain taste cells 7. Taste cells contain receptors for 5 main tastes 8. 5 main tastes: salty, sweet, bitter, sour, and umami REVIEW OUTLINE 1. Vision and the eye Special Senses: 2. a. Structures of the eye Olfaction and the nose Vision + a. Olfactory receptor cells Olfaction  Special Senses Bootcamp.com Vision and the Eye Cornea: Responsible for focusing light and protecting the eye; transparent Iris: Controls the size of the pupil Pupil: Controls the amount of light that enters the rest of the eye Lens: Focuses the relevant image onto the retina  Special Senses Bootcamp.com Vision and the Eye Retina: Located at the back of the eye and contains photoreceptors Retinal photoreceptors can either be rods or cones Rods: Responsible for vision in low light (greyscale) Cones: Responsible for color perception in high light environments Fovea: Retinal region with the highest concentration of photoreceptors Responsible for high acuity vision  Special Senses Bootcamp.com Vision and the Eye Amacrine and Bipolar Cells: Transmits the information from the retinal rods and cones to ganglion cells of the optic nerve fibers Optic Nerve: A bundle of axons that transmits visual information to the brain Optic Disk: The eye’s blind spot; the site of passage for the optic nerve heading toward the brain No photoreceptors present  Special Senses Bootcamp.com Vision and the Eye Sclera: Protective connective tissue that surrounds the eye; ‘whites’ of the eyes Choroid: Vascular connective tissue that exists between the sclera and the retina  Special Senses Bootcamp.com Olfaction (Smell) Olfactory Receptor Cells: Sense ‘smell’ molecules Send signals to olfactory cortex Thalamus Orbitofrontal cortex Special Senses Bootcamp.com Mini Quiz! What is the function of the retina in the eye? A) Reception of light at the back of the eye B) Being responsible for high acuity vision C) Transmitting visual information to the brain D) Focusing light and protecting the eye REVIEW OUTLINE Special Senses: 1. The cornea focuses light and protects the eye 2. The iris controls the size of the pupil Vision and 3. The pupil controls the amount of light allowed into the eye Olfaction 4. 5. The lens focuses images onto the retina The retina contains photoreceptors that are either rods or cones 6. The fovea is responsible for high acuity vision 7. Amacrine and bipolar cells transmit signals from the retina to the optic nerve 8. The optic nerve transmits visual information to the brain 9. The optic disk is the eye’s blind spot 10. The sclera is a protective connective tissue surrounding the eye and the choroid is a vascular connective tissue between the sclera and retina 11. Olfactory receptor cells receive ‘smell’ molecules and transmit signals to the olfactory cortex of the brain  Nervous System Bootcamp.com References Slide 1,6, Doctor Jana, CC BY 4.0, via Wikimedia Commons Slide 4, Sanu N, CC BY-SA 4.0, via Wikimedia Commons Slides 8,9,10,11,12,13, “Action Potential”: Created with BioRender.com Slides 10,11, “Resting Potential”: Created with BioRender.com Slides 12,13, “Depolarization”: Created with BioRender.com Slides 17,18,20, “Action Potential”: Created with BioRender.com Slide 17, “Repolarization”: Created with BioRender.com Slide 18, “Hyperpolarization”: Created with BioRender.com Slide 21, “Action Potential Story Arc”: Created with BioRender.com Slide 22, “Resting Potential, Repolarization, and Depolarization”: Created with BioRender.com  Nervous System Bootcamp.com References Slides 25,38, “Synaptic Transmission Logo”: Created with BioRender.com Slides 27, “Synapse”: Created with BioRender.com Slides 28, “Synapse with Vesicles”: Created with BioRender.com Slides 29, “Synapse with NTs”: Created with BioRender.com Slides 30, “Synapse with Calcium Channels”: Created with BioRender.com Slides 31,34,35, Synapse with ligand-gated channels: Created with BioRender.com Slides 32,33, “Action Potential”: Created with BioRender.com Slide 36, Another-anon-artist-234, CC0, via Wikimedia Commons  Nervous System Bootcamp.com References Slide 45,46,60, ‘The Brain’: Created with BioRender.com Slide 40,62, “The Nervous System with both the CNS and PNS”: Created with BioRender.com Slides 41,43, OpenStax, CC BY 4.0, via Wikimedia Commons Slide 42, “Human Brain Drawing”, https://freesvg.org/human-brain-drawing Slide 47, “The Cerebral Cortex 2 Ways”: Created with BioRender.com Slide 48, “The 4 Lobes of the Cerebral Cortex”: Created with BioRender.com Slide 49, Images are generated by Life Science Databases(LSDB)., CC BY-SA 2.1 JP, via Wikimedia Commons Slide 49, “Lobes of the brain clipart”, ArtsyBee on Pixabay, https://creazilla.com/nodes/77946-lobes-of-the-brain-clipart Slide 50, “The Cerebellum”: Created with BioRender.com Slide 51, “The Brain Stem”: Created with BioRender.com Slide 52, “The Brain Stem Zoomed In”: Created with BioRender.com Slide 53, “The Brain Stem 2 Ways and Labeled”: Created with BioRender.com Slide 54, “The Limbic System 1”: Created with BioRender.com Slide 55, “The Limbic System 2”: Created with BioRender.com  Nervous System Bootcamp.com References Slide 56, “The Limbic System Labeled”: Created with BioRender.com Slide 57, “The Spinal Cord”: Created with BioRender.com Slide 58, “The Meninges Labeled”: Created with BioRender.com Slide 61,67,68,79, “Peripheral Nervous System”: Created with BioRender.com Slide 80,86, “Ear and Mouth”: Created with BioRender.com Slide 85, “Mouth”: Created with BioRender.com Slide 87,94, “Nose and Eye”: Created with BioRender.com Slides 88,89,90,91, “Anatomical features of the eye”, Cenveo, https://www.coursehero.com/study-guides/austincc-ap1/special-senses-vision/ Slide 92, “Nose”: Created with BioRender.com