E109 Lecture 5: Nervous System III Fall 2024 PDF

E109 Lecture 5: Nervous System III Photo by: Sebastian Kaulitzki Chemical Synaptic Diversity Ionotropic Metabotropic T difference Variation in the Postsynaptic Response...

E109 Lecture 5: Nervous System III Photo by: Sebastian Kaulitzki Chemical Synaptic Diversity Ionotropic Metabotropic T difference Variation in the Postsynaptic Response Presynaptic axon terminal auseschange in termsof ions Slow synaptic potentials excitatory Rapid, short-acting fast synaptic potential Neurotransmitter and long-term effects inhibitory can alter Chemically G protein–coupled gated ion channel receptor existing channels Mickchange can inhibit membrane Inactive permeability Postsynaptic pathway cell Alters state of Activated second ion channels messenger pathway meta Ion channels close Modifies existing Ion channels open proteins or regulates synthesis of new proteins More More K+ Less K+ Less Na+ in out or out Na+ in Cl– in EPSP = IPSP = EPSP = Coordinated excitatory inhibitory excitatory intracellular depolarization hyperpolarization depolarization response Synaptic Transmission: possibilities for modulation Many neurotoxins target specific parts of a synapse and disrupt synaptic transmission Botulinum toxin (bacteria) : disrupts vesicle docking Bungarotoxin (sea snakes): binds to and blocks nicotinic ACh receptors Calcicludine (green mamba): blocks voltage gated Ca+2 channels Disruption of synaptic transmission is a symptom of many neurological disorders (depression, schizophrenia, Alzheimer’s, etc.) 7 lack or mutations associated with receptors insufficient neurotransmitter release getting a strongenough signaltothe cell Review Synapses are used for communication between a neuron and another cell cardiac cos everywhere Synapses can be electrical or chemical Chemical synapses covert electrical information to chemical information Chemical synapses can affect the post-synaptic cell through ionotropic or metabotropic pathways Synaptic transmission can be altered by neurotoxins or pharmacological agents Lecture 5 Learning Objectives Learn that the hypothalamus serves a critical function in maintaining homeostasis Understand that spinal reflexes are fast, involuntary actions without direct integration by brain Observe that homeostatic reflexes are slower often involve the autonomic nervous system Learn that the autonomic nervous system has two branches (parasympathetic and sympathetic) Understand that within the CNS, control of the two branches of are spatially segregated Observe that the two branches of the ANS affect the same target cells but interact with different cellular receptors Organization of the Nervous System CNS Architecture Cranium Cerebral hemispheres Cerebellum Cervical spinal nerves Thoracic spinal nerves Lumbar spinal nerves Sacral spinal nerves Coccygeal nerve From the “Bodies” Exhibit Gray & White Matter gray matter white matter White matter Myelinated axons Contains very few cell bodies Gray matter gray matter white matter Unmyelinated axons Cell bodies Dendrites Axon terminals Control Centers of the Brain understand hypothalamus is Parietal lobe rig center Somatic sensory cortex understand what each muscles a skin Frontal lobe section does Primary motor cortex Occipital lobe Visual cortex what yousee Hypothalamus regulation Thalamus sensory-motor Pituitary integration Hormone Secretion Temporal lobe Cerebellum Auditory cortex Movement coordination Olfactory cortex Pons Gustatory cortex Respiratory control Medulla oblongata taste sound Control of involuntary functions breathing coughing sneezing Hypothalamus Activates sympathetic nervous system Maintains body temperature Controls body osmolarity Controls reproductive functions Controls food intake Influences cardiovascular control center in medulla oblongata Regulates release of hormones from the pituitary gland Spinal Cord: Anatomy Visceral sensory nuclei Somatic sensory nuclei backside ecievesinfo interenty Dorsal root Dorsal ganglion horn gatheringofcellbodies Autonomic Lateral efferent horn Ventral nuclei horn Ventral root sendsinto out efferent Somatic motor nuclei Figure 9-7b Spinal Cord: Anatomy spiff coporba Descending tract takesintofromspinal chordto brain Ascending tract Figure 9-7 Response to Stimulus Reflex response Homeostatic response short fast doesnt need to rethe feedback feedback Sensory input Sensory input hypothalamic Somatic & visceral receptors sensory neurons Integration pons, medulla, hypothalamus Somatic Autonomic Endocrine response motor response response Spinal Cord: Integrating Center Sensory information goes to the brain Sensory input doesntneed totell the brain tomake the reflexhappen but lets the prain know after Integration Spinal Stimulus cord response Sensory information Integrating center Interneuron Command to muscles or glands Response Withdrawal Reflex Relay Sensory information to Brain efferent somatic motor neuron interneuron afferent aferent sensory neuron interneuron interent reflex Response to Stimulus Reflex response Homeostatic response feedback feedback Sensory input Sensory input hypothalamic Somatic & visceral receptors sensory neurons Integration pons, medulla, hypothalamus Somatic Autonomic Endocrine response motor response response Autonomic Division Hypothalamus, Reticular formation Ganglion Controls: Pons smooth & cardiac muscle Medulla exocrine & endocrine glands lymphoid & adipose tissue Vagus nerve Antagonistic branches Spinal cord Parasympathetic “Rest and digest” Restore body function Store nutrients/energy Sympathetic muchbroader Pelvic nerves “Fight or flight” Energetic action (burn fuels) KEY Parasympathetic Sympathetic Autonomic Pathways Somatic motor Parasympathetic Sympathetic Adrenal sympathetic pathway pathway pathways pathway CNS CNS CNS CNS Noganglion ACh Nicotinic receptor Adrenal cortex Adrenal medulla Ganglion E ACh Nicotinic Ganglion receptor strengthens receptor NE ACh signal Muscarinic receptor Autonomic effectors: Blood vessel Skeletal 1 receptor Smooth and cardiac muscles muscle ACh Some endocrine and exocrine E Nicotinic glands receptor Some adipose tissue 2 receptor onlyepinepin  Thermoregulation afferent sensory neuron interneuron ascending tract descending tract somatic motor neuron efferent autonomic neuron Hypothalamus skeletal muscle nicotinic receptor ACh tunica externa Smooth Muscle NE endothelium adrenergic receptor Review The hypothalamus serves a critical function in maintaining homeostasis Spinal reflex are fast involuntary actions without direct integration by brain Homeostatic reflexes are slower often involve the autonomic nervous system The autonomic nervous system has two branches (parasympathetic and sympathetic) Within the CNS control of the two branches of are spatially segregated The two branches of the ANS affect the same target cells but produce antagonistic effects by interacting with different receptors on the same cell E109 lecture 6: Intro to skeletal muscles Three Types of Muscle Skeletal Cardiac Smooth Attached to Skeleton Heart Internal organs/vessels Striated Striated Smooth Sarcomere Sarcomere Oblique Bundles Multinucleated Uninucleated Uninucleated Fastest Intermediate Slowest Somatic motor Autonomic Autonomic Fundamental Function Neural Information Mechanical Energy (force and displacement) Ultrastructure of Muscle Thin filaments Titin Troponin Nebulin Tropomyosin G-actin molecule Actin chain