Exam III Study Guide PET3322 Anatomy Physiology Figeuroa PET3322 Exam III Study Guide Autonomic Nervous System ANS o Not controlled by brain involuntary o Sympathetic Parasympathetic o motor neurons innervate smooth cardiac and glands o most effectors are viscera o Differentiating ANS vs SNS Effectors remember effect exit from last exam ANS cardiac muscle smooth muscle and glands SNS skeletal muscles always excitatory Efferent pathways Target organ responses o Efferent Pathways 2 neuron chain Preganglionic first lightly myelinated axon Postganglionic second extends to an effector organ thinner than preganglionic unmeyelinated o Two Divisions Sympathetic more important Parasympathetic works with the sympathetic Counterbalance each other s activity yet are synchronized o Interactions of the Autonomic Divisions Most visceral organs innervated by sympathetic and parasympathetic fibers this allows dynamic antagonisms that have very tight control on visceral activity Sympathetic fibers think fight or flight Increase heart and respiratory rates Inhibit digestion and elimination o Responsible for things such as rapid beating heart deep breathing dry mouth cold sweaty skin etc Parasympathetic fibers think resting and digesting Decrease heart and respiratory rates Allow for digestion and elimination of wastes o Keeps body E use as low as possible and directs house keeping activities such as elimination of body wastes o Neurotransmitters and Receptors ACh and NE are the 2 major NT of the ANS ACh released by all preganglionic and parasympathetic postganglionic axons Cholinergenic fibers release ACh stimulatory stimulates activity o ACh Receptors In ACh receptors on all effector cells stimulated by postganglionic cholinergic fibers Effect of binding can be or dependent on the receptor type of the target organ Ex ACh on heart inhibitory while ACh on abdominal organs is excitatory o Tissues with Cholinergic Receptors Exam III Study Guide PET3322 Anatomy Physiology Figeuroa General rule of thumb Above heart inhibitory Diaphragm separates two o Neurotransmitters and Receptors SNS Adrenergic fibers sympathetic axons that release NE Like others are or dependent on the receptor type Adrenergic Receptors o Two types and do not worry about their subclasses other than what s listed o Effects of NE binding to generally blood vessels everywhere generally adipose GI Tissues with adrenergic receptors In the ANS o Preganglionic fibers release ACh o Postganglionic fibers release NE sympathetic or ACh parasympathetic o Effect dependent on NT released and receptor type of the effector Notes from this slide In the sympathetic division ACh can act on adrenal medulla to release NE and E into blood hormone In the PS division ACh is released pre and post ACh and Catecholamines have opposite effects Ex ACh on GI Cat on GI Upper stimulatory Lower inhibitory Sympathetic Outflow o Spinal T1 L2 Exam III Study Guide PET3322 Anatomy Physiology Figeuroa o Preganglionic fibers synapse in the chain paravertebral ganglia o Fibers from T5 L2 form splanchnic nerves abdomen and synapse w collateral ganglia o Postganglionic fibers innervate numerous organs in the body o o The paravertebral ganglia form part of the sympathetic trunk chain o 33 ganglia 3C 11T 4L 1C o Notes o Catecholamines released by adrenal glands in response to stress part of SNS Stimulate heart o ACh stimulates hollow tubules and organs in the abdomen digestion etc Thus inhibits heart activity parasympathetic o Lot of SNS activity vasoconstriction o Sympathetic promotes metabolic effects that can t be reversed by parasympathetic Increased MR of cells raises bg mobilizes fat as E source Sympathetic Chain Ganglia o Located on both sides of vertebral column o Control effectors in body wall thoracic cavity and limbs o Innervates visceral organs in thoracic cavity via sympathetic nerves o Innervates visceral effectors via spinal nerves Exam III Study Guide PET3322 Anatomy Physiology Figeuroa Adrenal Medulla o Fibers of the thoracic splanchnic nerve pass directly to the adrenal medulla o A misplaced sympathetic ganglion o PS has no effect Upon stimulation medullary cells secrete norepinephrine NE and epinephrine EPI into the blood hormone blood Exam III Study Guide PET3322 Anatomy Physiology Figeuroa o reflexes Visceral Reflexes Same components as somatic Receptor sensory neuron o integration center motor neuron effector Two neurons in its motor o component Cell bodies of visceral sensory o neurons are located in dorsal root ganglia sensory ganglia of cranial nerves or autonomic ganglia Visceral afferents are found in o spinal nerves and in virtually all autonomic nerves They are always occurring and regulating within the body unlike motor Role of the Sympathetic Division o fight flight system o E activities exercise excitement embarrassment emergency o Think Stress Unique roles of the Sympathetic Division o Regulates many functions not subject to PS influence glands o Includes activity of the adrenal medulla sweat Kidneys and most blood vessels o See above sections on bg regulation fat Metabolic Effects of SNS mobilization etc o Catecholamines NE 80 E 20 more metabolic effect Role of PS division o D activities o Illustrated in a person who relaxes after a meal Decreased HR BP and RR GI tract activity high Skin warm pupils constricted Think after lunch nap Exam III Study Guide PET3322 Anatomy Physiology Figeuroa Parasympathetic Tone o Slows the heart o Stimulates the activity levels of the digestive and urinary systems o The sympathetic division can override these effects during times of stress Exam III Study Guide PET3322 Anatomy Physiology Figeuroa Endocrine System Overview o Acts w nervous system to coordinate and integrate the activity of body cells o Influences metabolic activities by means of hormones Hormones transported in the blood o Responses occur more slowly but tend to last longer than those of the nervous system o Endocrine glands pituitary thyroid parathyroid adrenal and pineal glands o Some organs produce both hormones and exocrine products Ex pancreas and gonads o The hypothalamus has both neural and endocrine functions o Other tissues and organs that produce hormones include adipose cells thymus cells in the walls of the small intestine stomach kidneys and heart o focus on hypothalamus pit gland adrenal gland and pancreas know briefly thyroid and parathyroid Exam III Study Guide PET3322 Anatomy Physiology Figeuroa Hormones o Chemical substances
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