FISIOLOGI PENGHIDU & PENCECAP

By Sawiji Amani

Mobile phone: 081 328 028333

E-mail: sawijiamani@gmail.com

Lecturer and Researcher

Nursing Basic Science Department

Muhammadiyah Gombong University

June 2009

Anatomy of the olfactory neural pathways, showing the distribution of olfactory receptors in the roof of the nasal cavity.

PENGHIDU

Anatomi Reseptor Olfactorius• Epithel olfactorius:

• Reseptor olfactorius (10 – 100 juta reseptor)

• Neuron orde pertama (neuron bipolar)/ n. olfactorius

• Transduksi stimulus potensial bertingkat di rambut

olfactorius

• Sel penyokong (supporting cells):

• sokongan fisik, nutrisi, & insulasi listrik bagi reseptor

• detoksifikasi zat kimia

• Sel basal sel punca (stem cell) reseptor baru

• Glandula olfactorius (Bowman)

• Produksi mukus di epithelium melarutkan odoran (bau)

• Nervus facialis (VII) sel penyokong

glandula olfactorius

• Stimulus bau (mis: merica) n VII glandula lacrimalis

glandula olfactorius

Jaras Olfactorius

Nervus olfactorius Neuron bulbus olfactorius (orde kedua)

tractus olfactorius (akson dari neuron orde kedua) ke:

1. Area olfactorius primer (area 28) di medial lobus

temporalis lobus frontalis

thalamus lobus frontalis

- area orbitofrontalis (area 11): identifikasi & diskriminasi bau

- area 11 hemispherium kanan lebih aktif

2. Sistem limbik & hipothalamus (memori & emosi)

Area 28 di medial & inferior lobus temporalis tidak terlihat dari lateral

Area orbitofrontal(identifikasi & diskriminasi bau)

Simplified diagram of cortical regions thought to be involved in the processing of olfactory information as it passes from the olfactory epithelium to the brain.

Fisiologi Penghidu

• Bau dan rasa stimulus kimiawi

• 10.000 macam bau aktivasi kombinasi reseptor pola

aktivitas otak

• Odoran reseptor potensial generator impuls

• Odoran protein G aktivasi adenilat siklase produksi

cAMP kanal Na+ terbuka Na+ masuk potensial

generatorodorants

odorants

odorants

Ambang & Adaptasi Bau

• Ambang rendah mudah terangsang (methyl mercaptan

1/25 biliun mg/ ml udara bau busuk)

• Adaptasi cepat (50% pada menit 1)

• Perempuan (tu ovulasi) lebih peka bau daripada laki-laki

Hyposmia

• Hyposmia = kemampuan membau turun

ortu > 65 tahun

trauma kepala, Alzheimer, Parkinson, antihistamin,

analgetika, steroid

• Rokok merusak sensasi bau & reseptor olfactorius

PENCECAPAnatomy Indra Pencecap (Taste Buds) & Papillae• 10.000 indra pencecap (lidah, palatum mole, pharynx,

epiglottis)

• Semakin tua, jumlah indra pencecap menurun

• Indra pencecap:

• Sel penyokong untuk 50 sel reseptor

• Sel reseptor gustatorius

• Rambut gustatorius pori “taste pore”

• Sinaps dengan neuron orde pertama

• Sel basal produksi sel penyokong sel reseptor

gustatorius (hidup 10 hari)

• Indra pencecap di dalam papillae:

• Papillae circumvalatae:

• bentuk “V” di lidah belakang

• 100 – 300 indra pencecap

• Papillae fungiformis seperti jamur (5 indra pencecap)

• Papillae foliatum tepi lidah hilang waktu kecil

• Papillae filiformis:

• seluruh permukaan lidah

• seperti benang (menonjol kecil-kecil, “threadlike”)

• reseptor taktil (tak ada indra pencecap)

A. General locations of the different papillae on the tongue. 

 B. Electron microscope image of various papillae.

A B

Jaras Pencecap

• Neuron orde pertama (nervus kranialis):

• Pencecap:

• Nervus VII (facialis) 2/3 lidah anterior

• Nervus IX (glossopharyngeus) 1/3 lidah posterior

• Nervus X (vagus) pharynx & epigottis

• Somatosensoris:

• Nervus V (trigeminus) seluruh lidah

• Neuron orde I medulla oblongata

sistem limbik

hipothalamus

thalamus area gustatorius I (area 43)

Anatomy of peripheral taste pathways. Multiple nerves, including cranial nerves VII, IX and X, transmit taste information from the mouth and pharynx to the brain via the brain stem.

Area gustatorius primer(Area 43)

Fisiologi Pencecap• Rasa (tastan/ “tastants”) sensasi kimiawi

• Penghidu lebih sensitif & beragam daripada pencecap

• Pilek/ alergi mengganggu

• 5 rasa primer: “sour” (asam), manis, pahit, asin, umami

• Umami gurih, “daging”, MSG (monosodium glutamat)

• Rasa: kombinasi dari 5 rasa primer + olfactorius + taktil

• Urutan ambang rasa (mulai yang terendah):

- pahit (fungsi protektif)

- asam

- asin = manis

• Adaptasi lengkap setelah stimulasi kontinyu 1-5 menit

(pada reseptor gustatorius, olfactorius, & jaras gustatorius)

Dulu

a, Taste buds (left) are composed of 50–150 TRCs (depending on the species), distributed across different papillae. Circumvallate papillae are found at the very back of the tongue and contain hundreds (mice) to thousands (human) of taste buds. Foliate papillae are present at the posterior lateral edge of the tongue and contain a dozen to hundreds of taste buds. Fungiform papillae contain one or a few taste buds and are found in the anterior two-thirds of the tongue. TRCs project microvillae to the apical surface of the taste bud, where they form the 'taste pore'; this is the site of interaction with tastants. b, Recent molecular and functional data have revealed that, contrary to popular belief, there is no tongue 'map': responsiveness to the five basic modalities — bitter, sour, sweet, salty and umami — is present in all areas of the tongue

Sekarang

• Tastan larut saliva membran

plasma rambut gustatorius

transduksi potensial reseptor

eksositosis vesikel sinaptik sel reseptor

neurotransmiter neuron I

• Asin: Na+ masuk via kanal Na+ sel

reseptor depolarisasi Ca2+ masuk

eksositosis vesikel

• Asam: H+ masuk via kanal H+

• Manis, pahit, umami protein G

“second messenger”

RUJUKAN

1. Tortora GJ & Derrickson B (2006). Principles of Anatomy and Physiology, 11th ed. Chapter 17, Hal: 575-579