Peripheral Nervous System PDF

Peripheral Nervous System Ania Janus PhD Candidate [email protected] Overall Organization of the Vertebrate Nervous System Neural systems: Anatomical division: Sensory system,...

Peripheral Nervous System Ania Janus PhD Candidate [email protected] Overall Organization of the Vertebrate Nervous System Neural systems: Anatomical division: Sensory system, Central nervous system (CNS) Motor system. Peripheral nervous system Associational systems Central Nervous System vs Peripheral nervous system Nervous System Peripheral Central Nervous Nervous System System Motor Neurons Sensory Neurons Brain Spinal Cord Somatic Nervous Autonomic System Nervous System Sympathetic Parasympathetic Nervous System Nervous System Central Nervous System vs Peripheral nervous system Purves, D., Augustine, G. J., Fitzpatrick, D., Hall, W. C., LaMantia, A. -S., McNamara, J. O., & Williams, S. M. (Eds.). (2004). Neuroscience (3rd ed.). Peripheral nervous system Peripheral Nervous System Autonomic Nervous System Somatic Nervous System Involuntary Response Voluntary Response and Reflexes Cardiac muscle fibers control Contraction of skeletal muscles Smooth muscle fibers control Glandular tissue control Somatic Nervous System Involves afferent (ascending) and efferent (descending) pathways. Consists of myelinated axons, cells responsible for axon myelinization = Shwann cells. Specific and localized neuromuscular junctions. Target organs always stimulated into action. Purves, D., Augustine, G. J., Fitzpatrick, D., Hall, W. C., LaMantia, A. -S., McNamara, J. O., & Williams, S. M. (Eds.). (2004). Neuroscience (3rd ed.). Muscle control – somatic nervous system Purves, D., Augustine, G. J., Fitzpatrick, D., Hall, W. C., LaMantia, A. -S., McNamara, J. O., & Williams, S. M. (Eds.). (2004). Neuroscience (3rd ed.). Autonomic Nervous System Maintains homeostatic conditions in the body. Coordinates the body’s response to stress. Supports the endocrine system to regulate reproduction. Autonomic Nervous System Autonomic Nervous System Sympathetic Nervous System Parasympathetic Nervous System Fight or flight Rest or Digest Autonomic Nervous System Autonomic Nervous System Sympathetic Nervous System Parasympathetic Nervous System Adrenaline-like Acetylocholine-like actions actions  Autonomic Nervous System Autonomic Nervous System consists of a two-neuron efferent chain: Preganglionic neuron. Postganglionic neuron. Sympathetic vs Parasympathetic Nervous System Neurotransmitters involved in the function of Autonomic Nervous System: Cholinergic system Acetylocholine receptors: Nicotinic (ligand-gated cation channel). Muscarinic (G protein-coupled receptor). Both receptor types bind to acetylcholine and cause changes in the target cell.  Cholinergic system Nicotinic acetylocholine receptors in the peripheral nervous system: Nm neuromuscular junction. Nn autonomic ganglia. Muscarinic acetylocholine receptors in the peripheral nervous system: M1 (Gq; exocrine glands, CNS). M2 (Gi; heart). M3 (Gq; smooth muscles of the blood vessels, endocrine and exocrine glands, lungs, CNS). M4 (Gi; CNS). M5 (Gq; CNS)  Adrenaline Adrenergic receptors: 𝛂-Adrenergic, 𝛃-adrenergic Both receptor types bind to norepinephrine and cause changes in the target cell. Adrenaline Adrenergic receptors: 𝛂1 (𝛂1A, B, D; Gq; vascular smooth muscle, GIT smooth muscle, heart, eye, liver, brain), 𝛂2 (𝛂2A, B, C; Gi; vascular smooth muscle, platelets, adrenergic nerve terminals, GIT), 𝛃1 (Gs; heart), 𝛃2 (Gs; smooth muscle in: bronchi, blood vessels, bladder, spleen, uterus, heart) 𝛃3 (Gs; adipose tissue, skeletal muscle) Sympathetic Nervous System Sympathetic Nervous System prepares body for activity and mobilizes during extreme situations. Divergence  Parasympathetic Nervous System Parasympathetic Nervous System conserves body energy and controls routine maintenance functions. Purves, D., Augustine, G. J., Fitzpatrick, D., Hall, W. C., LaMantia, A. -S., McNamara, J. O., & Williams, S. M. (Eds.). (2004). Neuroscience (3rd ed.). Sympathetic and Parasympathetic Nervous Systems Dual innervation most effector targets receive innervation from both the sympathetic and parasympathetic nervous systems. antagonistic effects on the organs. exceptions: sweat glands, smooth muscle in blood vessels. Sympathetic and Parasympathetic Responses Pupil Parasympathetic Nervous System Constriction Sympathetic Nervous System Dilation Sympathetic and Parasympathetic Responses Lens Near focus Parasympathetic Nervous System (Increased curvature) Sympathetic Nervous System Far focus (Lower curvature) Sympathetic and Parasympathetic Responses Heart Lower rate and blood Parasympathetic Nervous System pressure Sympathetic Nervous System Increased rate and blood pressure Sympathetic and Parasympathetic Responses Salivary glands Parasympathetic Nervous System Serous Sympathetic Nervous System High in viscosity Sympathetic and Parasympathetic Responses Gastrointenstinal tract Increased motility Parasympathetic Nervous System Anal sphincters relaxation Decreased motility, Sympathetic Nervous System Anal sphincters contraction Sympathetic and Parasympathetic Responses Liver Increased glycogenolysis Parasympathetic Nervous System Increased gluconeogenesis Decreased glucose production Sympathetic Nervous System Increased glycogen production Sympathetic and Parasympathetic Responses Suprarenal gland Parasympathetic Nervous System No innervation. Increased release of Sympathetic Nervous System epinephrine into bloodstream. Sympathetic and Parasympathetic Responses Kidneys Parasympathetic Nervous System Increased filtration rate Sympathetic Nervous System Decreased filtration rate Sympathetic and Parasympathetic Responses Bladder Parasympathetic Nervous System Relaxation of bladder sphincter, Contraction of detrusor muscle Sympathetic Nervous System Contraction of bladder sphincter Sympathetic and Parasympathetic Responses Male genitalia Parasympathetic Nervous System Erection Sympathetic Nervous System Ejaculation Sympathetic and Parasympathetic Responses Vascular smooth muscle Parasympathetic Nervous System Relaxation Sympathetic Nervous System Variable, depending on the neurotransmiter. Sympathetic and Parasympathetic Responses Arteries to skeletal muscle Parasympathetic Nervous System No innervation Sympathetic Nervous System Dilation Sympathetic and Parasympathetic Responses Sweat glands Parasympathetic Nervous System No innervation Sympathetic Nervous System Increased activity Sympathetic and Parasympathetic Responses Veins Parasympathetic Nervous System No innervation Sympathetic Nervous System Variable, depending on the neurotransmiter. Sympathetic and Parasympathetic Responses Tonic activity Parasympathetic Nervous System + (70 beats/min) - (100 beats/min) Sympathetic Nervous System + (vasoconstriction) - (vasodilation) Thank You