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Unformatted text preview: Visceral Physiology Final Exam Material 4 Chambers of the Heart: • 2 Atria (right and left) • 2 Ventricles (right and left)- Cardiac muscle is unique because it has branching and gap junctions- Atrial tissue is separated by Ventricular Tissue by a non- conductile tissue 2 types of heart tissue: 1. Conductile- S.A. Node (right Atrium) A.V. Node (internodal tissue), Bundle of His, Purkinje Fibers specialized muscle tissue- LBB, RBB Interventricular Septum Purkinje Fibers Myocardial Tissue 2. Contractile- cannot generate an impulse Myocardial Tissue- functions as a syncitium: needs to be stimulated. SinoAtrial Node: fastest rate of generating impulses. 60-100 times/min. Pacemaker of the heart A.V. Node: 40-60 times/Min Purkinje Fibers: 20- 40 times/Min o Myocardium follows S.A. Node rhythm. o 60- 100 BPM: Average heart rate is 72 beats per minute o each impulse 1 contraction Normal Sinus Rhythm: when the S.A. node is the pacemaker of the heart (60-100 BPM) Nodal Rhythm : when the heart follows rhythm set by the A.V. node. - A.V. node takes over when there is damage to the S.A. node For muscle to contract: must depolarize In order to depolarize, impulse must come from Conductory tissue. Sympathetic Nervous System- Thoracolumbar- Thoracic Adjustments have the biggest impact on heart rate and respiration- T2-T4: repeatedly subluxated adjustment will dilate pupils and increase sweat activity. Parasympathetic Nervous System- CranioSacral Exocrine glands- use ducts to arrive at target tissue. stimulation of pre-cappilary arterioles increase blood pressure Vagus Nerve- parasympathetic : inhibits the S.A. node decrease heart rate Stimulate Sympathetic Nerve Fibers increase S.A. node increase heart rate Stimulate Parasympathetic (Vagus Nerve) inhibits S.A. node decrease heart rate • NO parasympathetic Nerve fibers innervate heart fibers. • Stimulate Myocardium increase S.V. increase Cardiac Output (contracts harder) 3 Ways to increase Heart Rate by Sympathetic Stimulation: 1. Pre-Capillary Arterioles- vascular tissues 2. Increase S.A. Node increase heart rate and stroke volume 3. Increase force of contraction Increase Sympathetic increase blood pressure Total Peripheral Vascular Resistance has biggest impact of increasing Systemic Blood Pressure- PCA’s- greatest resistance-under control of Sympathetic Nervous System- greatest effect of Peripheral Vascular Resistance Barcoreceptors- predominate in the head and heart- more beta than alpha and skeletal Sweat Glands : only exocrine gland under Sympathetic control - Post-ganglionic sympathetic fibers release Acetyl Choline- Sympathetic Cholinergic Control Only 2 way to increase total Peripheral Vascular Resistance is to: 1. constriction of pre-capillary arterioles 2. stimulation of Sympathetic Nervous System Blood vessel diameter is controlled EXCLUSIVELY by Sympathetic Nerves o only way to increase peripheral vascular resistance....
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This note was uploaded on 11/22/2011 for the course PHYS 1525 taught by Professor Lescane during the Winter '11 term at Life Chiropractic College West.
- Winter '11