olfaction and pathway
TRANSCRIPT
OLFACTION AND ITS PATHWAY
OLFACTION ANDITS PATHWAYDr.R.Ram ShankarM.S.Post graduate StudentUIORL,MMC&RGGGH,Chennai
OLFACTORY SYSTEMADD QUALITY OF LIFE
PERCEPTION OF ODOUR DEPEND ONANATOMICAL STATE OF NASAL EPITHELIUMSTATUS OF PERIPHERAL AND CENTRAL NERVOUS SYSTEMFOR OLFACTION CRANIAL NERVES 1,5,9,10 ARE INVOLVED
ODORANT SUBSTANCES REACH OLFACTORY CLEFT BYDIFFUSION
ORTHONASAL FLOW
RETRONASAL FLOW
AMOUNT OF AIR FLOW50% AIR FLOW THROUGH MIDDLE MEATUS
35% AIR FLOW THROUGH INFERIOR MEATUS
15% AIRFLOW THROUGH OLFACTORY CLEFT
MUCOSAL LAYER OF OLFACTORY EPITHELIUMPRODUCED BY BOWMANS GLANDS DEEP IN LAMINA PROPRIA AND RESPIRATORY GOBLET CELLS
NECESSARY FOR CONCENTRATION OF ODORANT SUBSTANCES
FOR SUBSTANCE TO PRODUCE ODOUR IT MUST BE LIPID SOLUBLE AND VOLATILE
OLFACTORY EPITHELIUMLOCATION-POSTEROSUPERIOR PART OF NOSE
AREA OF OLFACTORY EPITHELIUM-5 SQ.CM
PSEUDOSTRATIFIED COLUMNAR EPITHELIUM
4 TYPES OF CELLS-CILIATED OLFACTORY RECEPTOR,MICROVILLI CELLS,SUSTENTACULAR CELLS,BASAL CELLS
BASAL CELLSHORIZONTAL BASAL CELL
GLOBOSE BASAL CELL-STEM CELL
OLFACTORY PATHWAYCILIATED OLFACTORY RECEPTORAXONS CONDENSE TOFORM OLFACTORY NERVE10-15 FORAMINA IN CRIBRIFORM PLATEOF ETHMOID CONVERGE ON MITRAL CELLS OF GLOMERULI IN OLFACTORY BULBOLFACTORY TRACT PASS CROSSING OPTIC NERVEAND OPTIC CHIASMA END IN PYRIFORM CORTEX
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OLFACTORY CORTEXPRIMARY OLFACTORY CORTEX
SECONDARY OLFACTORY CORTEX
TERTIARY OLFACTORY CORTEX
VOMERONASAL ORGAN OF JACOBSONGROOVE IN ANTEROINFERIOR PART OF NASAL SEPTUM
PHERMONES
DO NOT DISTURB UNLESS NECESSARY IN SEPTAL SURGERY
ODOUR TRANSDUCTION AND PROCESSING
RECOGNITION AND DISCRIMINATION OF ODOURS
ODOUR MAPS
HUMANS HAVE RECEPTOR GLOMERULUS RATIO OF 1:16
IDENTIFICATION TESTPHENYL ETHYL ALCOHOL
PYRIDINE
1-BUTANOL
TESTS4 ODORANTS AT GIVEN CONCENTRATION
2 ALTERNATIVE FORCED CHOICE PROCEDURE
SCREENING TEST USING ALCOHOL PAD
ELECTROPHYSIOLOGICAL TESTSELECTROOLFACTOGRAM
BRAIN EVOKED POTENTIALS *EXCITATION OF TRIGEMINAL NERVE *EXCITATION OF OLFACTORY NERVE
CONTINGENT NEGATIVE VARIATION
UPSITUNIVERSITY OF PENNSYLVANIA SMELL IDENTIFICATION TEST
MOST WIDELY USED
40 POINT CARD TEST
6 CATEGORIES
CLINICAL CONDITIONSANOSMIA
HYPOSMIA
PAROSMIA
PHANTOSMIA
HYPEROSMIAHETEROSMIA
PRESBYOSMIA
OSMOPHOBIA
OLFACTORY AGNOSIA
DISEASES AFFECTING OLFACTION
OBSTRUCTIVE NASAL AND SINUS DISEASEMEDIAL AND ANTERIOR TO LOWER PART OF MIDDLE TURBINATE
1-2 WEEKS OF STEROIDS
AFTER URILAST FOR 1-3 DAYS
DECREASED NUMBER OF OLFACTORY RECEPTORS
HEAD TRAUMA5-10%
ANOSMIA COMMON ONSET IMMEDIATE
MC IN FRONTAL BLOWS
AGEINCREASED AGE CAUSE DECREASE IN MITRAL CELLS OF OLFACTORY BULB
CONGENITALRECOGNISE NEARING AGE OF 8
KALLMAN SYNDROME
TOXINSFORMALINE
POLLUTANTS
CONDITION IS PROGRESSIVE
NEOPLASMSINTRANASAL TUMOURS
INTRACRANIAL TUMOURS
MEDICATIONSMETROCLORFIBRATECPMAMPHOTERICIN BAMPI,TETRACYCLINE, STREPTOMYCINDOXORUBICIN,AZAPTU,CARBIMAZOLEALLOPURINOLCAPTOPRILGLIPIZIDECOEDINEMORPHINECARBAMAZEPINE, LITHIUM,PHENYTOIN
HIV
EPILEPSY
PSYCHAITRIC DISTURBANCES
SURGERIESNOW RARE DUE TO FESS
MORE COMMON IN CRANIAL AND SKULL BASE SX
LESS WITH ENDOSCOPIC PITUITARY SX
MANAGEMENTTREAT THE CAUSE
MEDICATIONS TRIED-STEROIDS VITAMIN A
THANK YOU