Download MBBS (Bachelor of Medicine and Bachelor of Surgery) Latest Olfactory Nerve Lecture PPT
Introduction
? Almost all environmental chemicals necessary for life enter the body by nose and
mouth.
? The senses of smell (olfaction) and taste (gustation) monitor such chemicals
determine the flavor and palatability of foods and beverages and
warn of dangerous environmental conditions, including fire, air pollution,
leaking natural gas and bacteria-Iaden foodstuffs.
? These senses contribute significantly to quality of life and when dysfunctional can
have untoward physical and psychological consequences.
? A basic understanding of these senses in health and disease is critical for the
physician because thousands of patients present to doctors' offices each year
with complaints of chemosensory dysfunction.
? Among the more important recent developments in neurology is the discovery that
decreased smell function is among the first signs if not the first sign of such
neurodegenerative diseases as Parkinson's disease (PD) and Alzheimer's disease
(AD) signifying their "presymptomatic" phase
Olfactory nerve
? C N I
? Components - sensory ( SVA )
? Function - olfaction ( smell )
? Opening in skull through which it passes - cribriform plate of ethmoid
bone
The basic pathways for processing olfactory information.
Anatomy of the olfactory neural pathways showing the distribution of olfactory
receptors in the roof of the nasal cavity (Copyright Oavid Klemm, Faculty and
Curriculum Support [FACS] Georgetown University Medical Center )
Structure of olfactory epithelium
(ORNs ? olfactory receptor neurons )
Peripheral and central components of the primary olfactory pathway
Schematic representation
of olfactory bulb .
Each receptor type (red
green,blue) projects to a
common glomerulus.
The neural activity within
each glomerulus is modul-
ated by peri glomerular
cells.
The activity of the primary
projection cells,the mitral
and tufted cells, is
modulated by granule cells
,periglomerular ceIls, and
secondary dendrites from
adjacent mitral and
tufted cells
Central components and basic connections of the olfactory system.
The basic pathways for processing olfactory information.
This post was last modified on 30 November 2021