Organization of Nervous System: Comparison of Somatic vs. Autonomic: Nervous system. Peripheral nervous system (PNS) Central nervous system (CNS)

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NS Parasympathetic Somatic NS Organization of Nervous System: Nervous system Comparison of Somatic vs. : Cell body location NTs organs Marieb & Hoehn Figure 14.

Skeletal muscle = Acetylcholine + Stimulatory Brain Spinal cord Motor division Sensory division (Efferent) (Afferent) self governing (Involuntary; smooth & cardiac muscle) Motor output Stability of

(unmyelinated) (lightly myelinated) Ganglion Postic Preic axon axon (lightly myelinated) (unmyelinated) NE Smooth muscle, glands, cardiac muscle + Stimulatory or inhibitory (depends on NT and NT

division (Efferent) (Afferent) (Involuntary; smooth & cardiac muscle) Motor output Sensory input Somatic Nervous System (Voluntary; skeletal muscle) Divisions of (ANS): 1) Division: ( fight or flight

1 NS Parasympathetic Somatic NS Organization of Nervous System: Nervous system Comparison of Somatic vs. : Cell body location NTs organs Marieb & Hoehn Figure 14.2 Ganglion: A group of cell bodies located in the PNS Effect Integration Central nervous system () Peripheral nervous system (PNS) Single neuron from to effector organs Heavily myelinated axon Skeletal muscle = Acetylcholine + Stimulatory Brain Spinal cord Motor division Sensory division (Efferent) (Afferent) self governing (Involuntary; smooth & cardiac muscle) Motor output Stability of internal environment depends largely on this system Sensory input Somatic Nervous System (Voluntary; skeletal muscle) Two-neuron chain from to effector organs Ganglion Postic axon Preic axon (unmyelinated) (lightly myelinated) Ganglion Postic Preic axon axon (lightly myelinated) (unmyelinated) NE Smooth muscle, glands, cardiac muscle + Stimulatory or inhibitory (depends on NT and NT receptor Type) NE = Norepinephrine Organization of Nervous System: Integration Central nervous system () Nervous system Peripheral nervous system (PNS) Brain Spinal cord Motor division Sensory division (Efferent) (Afferent) (Involuntary; smooth & cardiac muscle) Motor output Sensory input Somatic Nervous System (Voluntary; skeletal muscle) Divisions of (ANS): 1) Division: ( fight or flight ) Readies body for stressful situations Heightens mental alertness heart rate / blood pressure metabolic rate respiratory rate / bronchiole dilation Activates energy reserves Activates sweat glands Dampens non-essentials (e.g., digestion) 2) Parasympathetic Division: ( rest and digest ) Conserves energy at rest metabolic rate digestive motility / blood flow heart rate / blood pressure Stimulates defecation / urination digestive gland secretions division Parasympathetic division Division Anatomy: T 1 division also called the thoracolumbar division pathways have short preic fibers and long postic fibers Preganlionic fibers originate in spinal cord between cord segments T1 L2 located close to spinal cord (arranged as sympathetic chain) 23 / chain ( 3 cervical, 11 thoracic, 4 lumbar, 4 sacral, 1 coccygeal) Division Anatomy: (unmyelinated axons) Gray ramus communicans Spinal nerve Lateral horn of spinal cord Pathways in sympathetic chain: 1) Terminate directly in sympathetic chain Postic axons exit out gray ramus communicans 2) Ascend / descend several segments before terminating L 2 Ventral root Marieb & Hoehn Figure 14.5 / 14.6 chain White ramus communicans (myelinated axons) Marieb & Hoehn Figure 14.5 chain (paravertebral ) Rami communicantes only associated with sympathetic division May ascend / descend to located outside T1 L2 Cervical : (fed via T 1 T 6) Serve head / thorax Sacral : (fed via T 10 L 2) Serve genitalia / urinary bladder 1

Division Anatomy: Cervical T 1 Celiac L 2 Sacral Mesenteric Spanchnic nerves Marieb & Hoehn Figure 14.5 / 14.

abdominal cavity Pass-through point for splanchnic nerve feeding adrenal medulla Mesenteric : Serve lower abdominal cavity Parasympathetic Division Anatomy: Vagus nerve Splanchnic nerves S 2 S 4

4 pathways have long preganlionic fibers and short postganlionic fibers 90% of PNS fibers Terminal located near effector tissue Preic fibers originate in brain stem and S 2 S 4 : Occulomotor Nerve

2 Division Anatomy: Cervical T 1 Celiac L 2 Sacral Mesenteric Spanchnic nerves Marieb & Hoehn Figure 14.5 / 14.6 Adrenal medulla Pathways in sympathetic chain: 3) Exit sympathetic chain before terminating in collateral (prevertebral) Collateral Form splanchnic nerves (fed via T 5 L 2) Celiac : Serves upper abdominal cavity Pass-through point for splanchnic nerve feeding adrenal medulla Mesenteric : Serve lower abdominal cavity Parasympathetic Division Anatomy: Vagus nerve Splanchnic nerves S 2 S 4 Marieb & Hoehn Figure 14.4 pathways have long preganlionic fibers and short postganlionic fibers 90% of PNS fibers Terminal located near effector tissue Preic fibers originate in brain stem and S 2 S 4 : Occulomotor Nerve (III) Facial Nerve (IIV) Glossopharyngeal Nerve (IX) Vagus Nerve (X) Sacral Segments (S 2 S 4): Paraympathetic division also called the craniosacral division Ciliary : Pupillary sphincters / ciliary muscles Pterygopalatine : Nasal / lacrimal glands Submandibular : Salivary glands Otic : Salivary gland Intramural : Visceral organs Intramural : Large intestine / bladder / genitalia Fiber Types: Cholinergic Fibers: Synthesize / secrete acetylcholine (NT) All preic fibers (sympathetic and parasympathetic divisions) Postic fibers of parasympathetic division Adrenergic Fibers: Synthesize / secrete norepinephrine (NT) Postic fibers of sympathetic division (sans sweat glands / piloerector muscles) Synthesis of Neurotransmitters: NTs synthesized / stored in varicosities of nerve fibers Neuroeffector Junction of ANS: nerve fiber Varicosities Postic neuron forms diffuse, branching networks at synapse NTs released from varicosities ( beads ) Innervation by multiple ANS fibers may occur Postsynaptic receptors spread across target Smooth muscle cells Precision strike vs. Saturation bombing Remember: Marieb & Hoehn Figure 9.27 Synaptic vesicles Neuromuscular junction Fiber Types: Cholinergic Fibers: Synthesize / secrete acetylcholine (NT) All preic fibers (sympathetic and parasympathetic divisions) Postic fibers of parasympathetic division Types: -linked Located on target tissues of sympathetic nervous system Adrenergic Fibers: Synthesize / secrete norepinephrine (NT) Postic fibers of sympathetic division (sans sweat glands / piloerector muscles) Synthesis of Neurotransmitters: NTs synthesized / stored in varicosities of nerve fibers Acetyl-CoA + Choline choline acetyltransferase Acetylcholine Catalyzed by acetylcholinesterase Choline recycled Tyrosine Dopa Dopamine hydroxylation decarboxylation hydroxylation Removal: 1) Reuptake (~ 80%) 2) Diffusion (~ 20%) 3) Destruction (> 1%) monoamine oxidase Norepinephrine 2

G protein Systems: s interact with G-proteins to trigger cellular event A.

s: Composed of three unique sub-units (,, ) No intrinsic enzymatic activity; activates enzymes Interact with various G-proteins depending on sequence of 3 rd intracellular loop Wolfe Figure 4.

effector and rejoin other subunits G protein Systems: s interact with G-proteins to trigger cellular event C. s: G protein Systems: s interact with G-proteins to trigger cellular event C.

20 G protein Systems: s interact with G-proteins to trigger cellular event C.

3 G protein Systems: s interact with G-proteins to trigger cellular event A. s: 7 trans-membrane segments (each segment = similar helix sequences) G protein Systems: s interact with G-proteins to trigger cellular event B. s: Composed of three unique sub-units (,, ) No intrinsic enzymatic activity; activates enzymes Interact with various G-proteins depending on sequence of 3 rd intracellular loop Wolfe Figure 4.3 Activation: 1) Ligand binds to receptor 2) / interact GDP ( -subunit) replaced by GTP; dissociation occurs 3) -subunit activates effector Hydrolysis of GTP to GDP causes subunit to dissociate from effector and rejoin other subunits G protein Systems: s interact with G-proteins to trigger cellular event C. s: G protein Systems: s interact with G-proteins to trigger cellular event C. s: Synthesizes camp from ATP Methylxanthines (e.g., caffeine) Inactivates camp Activated by G S proteins Inhibited by G I proteins Lodish Figure G protein Systems: s interact with G-proteins to trigger cellular event C. s: B) Phospholipase C (2 nd messengers IP 3 / DAG) IP 3 activates release of Ca ++ (ER) DAG activates protein kinase Diacylglycerol (DAG) Types: Located on target tissues of sympathetic NS Divided into two types: and β receptors (most common) 1 receptors -linked 2 receptors (-) Inhibitory (-) Phosphoinositol (PIP) Inositol triphosphate (IP 3) Phenylephrine ( 1 agonist) Vascular smooth muscle - skin (constricts blood vessels) Gastrointestinal tract / bladder (constricts sphincters) Iris of eye (dilates pupil of eye) Membrane of adrenergic axon terminals (inhibits NE release) Gastrointestinal tract (inhibits GI function) Pancreas (inhibits insulin secretion) coupled to phosphorylase C G I protein coupled to Wolfe Figure 6.6 / 6.9 3

Types: Located on target tissues of sympathetic NS Divided into two types: and β receptors 1 receptors -linked 2 receptors (-) Inhibitory (-) Activated by Types: nicotines Activated by toxins from

4 Types: Located on target tissues of sympathetic NS Divided into two types: and β receptors 1 receptors -linked 2 receptors (-) Inhibitory (-) Activated by Types: nicotines Activated by toxins from toadstools B) Cholinoreceptors (bind ): Divided into two types: nicotinic & muscarinic Muscarinic Located on postic neurons / target tissues of parasympathetic NS Nicotinic atropine (muscarinic antagonist) & (-) Inhibitory (-) Predominately in the heart (increases contraction rate / strength) Kidney (triggers renin (hormone) release) Vascular smooth muscle - skeletal (dilates vessels) muscle Lungs (dilates bronchioles) Motor end plate skeletal muscle (contracts skeletal muscle) All postic neurons (activate postgangionic neurons) coupled to K + channel Parasympathetic organs sans heart (excites organ activity) Heart (inhibits heart rate) Propanolol (β-blocker) Albuterol ( 2 agonist) Gastrointestinal tract (relaxes GI tract) Chromaffin cells adrenal medulla (triggers release of E / NE) Sweat glands sympathetic NS (activates sweat glands) G S protein coupled to G S protein coupled to Ligand-gated ion channel coupled to phosphorylase C (Majority of locations) Parasympathetic Muscarinic receptors Visceral dffector cell Cholinergic fibers Nicotinic receptors Visceral effector cell Adrenergic fibers Adrenergic receptors (α / β) Costanzo Figure 2.1 Control of Functioning: Costanzo Figure 2.4 A) Brain stem / Spinal cord Vasomotor center (cardiovascular) Respiratory center Micturition center (urination) Swallowing / coughing / vomiting B) Hypothalamus Main integration center Body temperature Water balance Food intake Links emotion with ANS C) Cortical control Links emotional past with ANS Voluntary cortical ANS control possible Interactions of Divisions: A) Antagonistic Interactions: Pupil: Heart (sinoatrial node): Parasympathetic = Decrease heart rate = Increase heart rate B) Synergistic Interactions: * Tone: Parasympathetic = Constriction (circular fibers) = Dilation (meridional fibers) External genitalia = fight or flight Parasympathetic = rest and digest Systems do not compete with each other; coordinated by nervous system Parasympathetic = Vasodilation of blood vessels (erection of tissue) = Smooth muscle contraction (ejaculation / reflex contraction) Basal rate of activity present in a system Allows increase / decrease by single system Blood vessels under sympathetic tone Decrease output = vasodilation of vessel Increase output = vasoconstriction of vessel 4

Interactions of Divisions: C) Coordinated Function within Organ: Bladder: = fight or flight Parasympathetic = rest and digest Filling = Relaxed detrusor muscle; contracted internal sphincter Emptying

and norepinephrine (20%)) methylation Catecholamines transported via blood (= hormone) Delayed effect (3 5 sec.); prolonged effect (2 4 min.

5 Interactions of Divisions: C) Coordinated Function within Organ: Bladder: = fight or flight Parasympathetic = rest and digest Filling = Relaxed detrusor muscle; contracted internal sphincter Emptying = Contracted detrusor muscle; relaxed internal sphincter Parasympathetic Adrenal Medulla: Large sympathetic Cortex Medulla Postic cells = Chromaffin cells Releases catecholamines (epinephrine (80%) and norepinephrine (20%)) methylation Catecholamines transported via blood (= hormone) Delayed effect (3 5 sec.); prolonged effect (2 4 min. to clear from system) Stimulation of cardiovascular function / metabolic rate (helps deal with stress) Perceived purpose: 1) Safety factor (dual mechanism backs up sympathetic nervous system) Costanzo Figure 2.4 2) Stimulate structures not directly innervated (e.g., every cell of body ) 5

I. Neural Control of Involuntary Effectors. Chapter 9. Autonomic Motor Nerves. Autonomic Neurons. Autonomic Ganglia. Autonomic Neurons 9/19/11

Chapter 9 I. Neural Control of Involuntary Effectors The Autonomic Nervous System Lecture PowerPoint Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Autonomic