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2.1 Olfactory & Gustation - Coggle Diagram
2.1 Olfactory & Gustation
Smell
Concepts
the cerebral cortex is responsible for carrying out this intricate chemosensory process
chemical sensation of gaseous odorants colloquially referred to as the ability to smell.
couples to other complex functions such as gustation (taste) and involuntary memory formation.
Cranial nerve I coordinating with other neuroanatomical structures in the nasal passages
Pathophysiology
Dysosmias
- Distortions / alteration in smell sensation
Agnosia
- inability to distinguish odorants apart from one another
Phantosmias
- spontaneous experience of smell in the absence of an odorant stimulus
Anosmia
- a complete lack of smell due to damage to olfactory receptor
Hypersmia
: lack of smell due to :arrow_down: adrenal
Hyposmia
: :arrow_down:vitamin A
Pathway
2nd order: olfactory bulb - pathway (mitral & tufted cells)
3rd order: perpiriform area (area 28)
1st order: from epithelium to glomerulus
Transduction
stimulate adenylate cyclase
:arrow_up: intracellular cAMP
combine with receptors on cilia
opening of Na+ channels receptors
Molecules dissolve in mucus layer
potential action in olfactory
Olfactory bulb
Frontal cortex
Hypothalamus
Olfactory receptor neurons
Hippocampus
Taste
Concept
sensation produced when mouth react chemically to a substance with taste receptor
taste buds located on soft palate, tongue, inner surface of cheeks
Types of papillae
Fungiform: rounded with taste buds
Circumvallate: large papillae with taste buds
Filiform: sharp
Structure
Glossopharungeal nerve: posterior 1/3 of tongue
Vagus nerve: palate, pharynx, epiglottis
Facial nerve: anterior 2/3 of tongue
Pathway
2nd nerve: medial lumnicus to thalamus
3rd order: from thalamus to cerebral cortex
1st order: 3 cranial nerve
Sensation
Sour: H+, acids
Bitter: alkaloids
Sweet: sugars
Salty: salt, ions, metal
Umami: glutamate
Pathophysiology
Hypergeusia: :arrow_down: ardrenal
Hypogeusia: loss of taste due to captopril
Dysgeusia: disturbed taste
Aguesia: complete loss of taste
Cortices
Primary: insula, taste and identification intensity
Secondary: olfactory cortex - value of taste experience
Deglutition
Oral phase
tongue forces blous back towrds the pharynx
somatosensory activated
bolus descend from mouth to pharynx
5th, 9th, 10th, 12th cranial nerve transmit motor impuls to pharynx and upper esophagus
Phayngeal phase
soft palate prevents bolus enters nasopharynx
epiglottis closes URT
Bolus descend from pharynx to esophagus
upper esophageal sphincter relaxes and pones
Esophageal phase
bolus goes to pharynx, upper esophageal sphincter, esophagus
bolus descend from esophagus to stomach