SENSEBy. Dr Khairun NisaBagian Ilmu FaalPSPD

SENSESejarah penghidu, pengecap, penglihatan, pendengaran dan sentuhanSekarang 2 kelompok dasar :1. Indera Umum ; reseptor tersebar merata di seluruh tubuha. Indera tubuh/somatik informasi/stimulus sensoris mengenai ubuh dan lingkunganb. Visceral senses informasi/stimulus mengenai organ internal, terdiri dari nyeri primer dan tekanan2. Indera Khusus ; struktur lebih spesifik dan lokasinya juga di bagian tertentu tubuh penghidu, pengecap, penglihatan, pendengaran dan keseimbangan

SENSEJalur Indera/Sense:Sensasi / persepsi ( rc sensoris) mengatur aksi potensial yang diteruskan menuju medula spinalis dan otak (ex. Thalamus dalam sensasi nyeri) respon akan dihasilkan biila potensial aksi mencapai kortek serebri.Receptor (stimuli) MS brain (cerebral cortex) effector (respon)

SENSEGate control theory (Teori Pengaturan Gerbang) :Ini menjelaskan menjelaskan dasar fisiologi untuk beberapa tehnik yang digunakan untuk menurunkan intensitas nyeri.Ini menjelaskan mengapa getaran yang kuat di area tempat sumber nyeri dapat menurunkan intensitas nyeri.Nyeri terlihat menurun intensitasnya pada seseorang ketika ia fokus terhadap sesuatu yang membutuhkan konsentrasi mentalProgram Latihan, komponen penting dalam penatalaksanaan klinik untuk nyeri kronik seperti pasien kanker stadium lanjutProsedur Akupuntur atau akupresure menurunkan sensai nyeri dengan menstimulasi neuron desending columna dorsalis, yang menghambat aksi potensial di neuron traktus spinothalamicus lateralis.

GENERAL SENSESRcs ; Mechanorc (bending, streching), chemorc(chemical, odor mol), photorc (light), thermorc (temp,changes), nocicp (pain).OUTER (Skin) : * Free nerve ending (dendrite) painfull stim, temperature (12oC 47oC), itch, movement* Merkels disks (light touch and superficial pressure)* Hair follicle rc (light touch)* Meissners corpuscles (fine, discriminative touch)* Ruffinis end organs (continuous touch or pressure)* Pacinian corpuscle (detect deep pressure, vibration, and position) INNER (tendo, ligament,musclesPhantom pain appendages amputated

20,000 times more sensitive than tasteTo taste quinine need 1 part in 2.000.000 To smell mercaptan need 1 part in 30.000.000.000.000 (30 billion)Adult can sense up to 10.000; children can do better

PersyarafanInervasi N. ophthalmicus (N. V1) N. Etmoidalis antN. Maxillaris (N. V2) N. Nasopaltinus Deteksi bahaya (noxious) dan stimulus nyeriN. olfactorius (N. I)

OLFACTIONStimuli (odorants) dissolved in fluidMucus keep the nasal epithelium keep moist, trap and dissolves airborne molecules, facilitates removal of molecules and particles from it.Neuronal Pathway:sensory rc (axons of olfactory neuron from olfactory nerves) olfactory bulb olfc tracts --. Olfactory cortex (temporal and frontal lobe)This feedback, plus the temporary decreases sensitivity at the level of the rcs, result ADAPTATION TO A GIVEN ODOR

OLFACTIONKlasifikasi sensasi Bau :1. Camphoraceous2. Musky3. flora4. Pepperminty5. Sangat samar (ethereal)5. Bau tajam (pungent)6. Busuk (Putrid)

STRUCTURE OF OLFACTORY RECEPTORSRoof of nasal cavityOlfactory epitheliumEpithelium consist 3 type of cells: > (1) receptor cell> (2) sustentacular cell> (3) basal cell30 days lifetime25 million cells (dog: 220 million)

HOW ODORS ARE PERCEIVED

Glomeruli are the critical sites of the processed odors.Neural mechanism still known unclearThe odors to be sensed must be volatile and solubleOdor molecules open the sodium channel generator potential

NEURAL PATHWAYSReceptor-silia epitel receptor olfactorius (molekul odoran)N. Olfactorius melalui lempeng cribriformisBulbus olfactoriusTractus olfactoriusPrimary olfactory cortex (temporal lobe)

OLFACTIONTractrus Olfactorius* Medialis Nuklei Septum (Hippotaloamus, sistem limbik)* Lateralis korteks prefirimformis dan korteks piriformis, kortikal nuklei amigdaloid paleokorteks (regio anteromedial lobus temporalis)* Baru: melalui dorsomedial nuklesu thalamik kuadran lateroposterior korteks orbitofrontalis.

*SMELLOur sense of smell, or olfaction, is perhaps as much as 20,000 times more sensitive than our sense of taste. We can taste taste quinine in a concentration of 1 part in 2 million, but we can smell mercaptan (the type of chemical released by skunk) in a concentration of 1 part in 3 billion. Adult can sense up to 10.000 different odors, and children can do better. Unfortunately, our sense of smell is perfect. Several poisonous gases, including carbon monoxide, are not detectable by our olfactory receptor.*Structure of olfactory receptorThe olfactory receptor are located high in the roof of the nasal cavity, in specialized area called olfactory epithelium, about 2.5 sq cm (about the size of thumbnail). The epithelium consist of three types of cells: (1) receptor cells, which actually are the olfactory neurons, (2) sustentacular (supporting) cells, and (3) a thin layer of small basal cells. These basal cells are capable of undergoing cell division and replacing degenerating receptor and sustentacular cells. Each receptor cell has a lifetime about 30 days. They are replaced by basal cells, which are continually differentiating into new olfactory neurons and forming new synaptic connections in the olfactory bulb.We have more than 25 million bipolar cells (a hunting dog has 220 million) each of which is surrounded by sustentacular cells. The receptor cell ends in the bulbous olfactory vesicle. From this swelling, 6 to 20 long cilia project through the mucuslike fluid that covers the surface epithelium. The fluid is secreted by the sustentacular cells and olfactory (Bowmans) gland. It important because odriferous substances nee to be dissolved before they can stimulate receptor site.The receptive site of the cilia are exposed to the molecules responsible for odors. The axons of bipolar receptive cells pass through the basal lamina and join other axons to form fascicles of olfactory nerve (cranial nerve I). These unmyelinated olfactory fibers are among the smallest and slowest-conducting fibers of the nervous system. They pass through the foramina in the cribriform plate of the ethmoid bone an their way to the olfactory bulbs. The olfactory bulbs are specialized structure of gray matter, stemlike extensions of the olfactory region in the brain.In the olfactory bulb the terminal axons form a complex synapses called olfactory glomeruli that receives impulses from about 26,000 receptor cell axons. These impulses are conveyed along the olfactory tract posteriorly to the olfactory cortex in the temporal lobe of the cerebrum. Olfaction is the only sense that does not project fibers into the thalamus before reaching the cerebral cortex. (Do not pass through the thalamus).*How odors are perceivedOlfactory impulses are sorted in the glomeruli before being relayed to the cortex. It is believed that the glomeruli are the critical sites where odors are first processed. The olfactory cortex is initially involved is distinguishing and determining the intensities of odors. Actually, little is known about the neural mechanism of olfaction. We do know that in order for substances to be sensed, they must be volatile and soluble. Without these qualities, the odoriferous particles could not be carried into the nostril by air currents, dissolve in the mucuslike coating on the olfactory epithelium, and penetrate the lipid barrier surrounding the olfactory receptor cell.Many theories have been purposed to explain how we perceive odors. A likely suggestion is that odor molecules have a physical interaction with protein receptor sites on a plasma membrane. This binding opens channels, and depolarize it, causing a generator potential. The generator potential produces action potential in the nerve fibers that synapse wit neuron in olfactory bulb. According to this theory, the discrimination of different odors result from simultaneous but varying stimulation of receptor cells.*Neural Pathways for OlfactionMitral cells in the olfactory bulb project axonal branches through the olfactory tract to the primary olfactory cortex. The primary olfactory cortex is composed of the cortex of the uncus and adjacent areas, located in temporal lobe of cerebral cortex.