Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
GENERAL SENSES Dr. Hj. Abdul Rashid Hj. Said. Consultant Psychiatrist Hospital Tuanku Fauziah, Kangar, Perlis. Introduction • Sense is the ability to perceive stimuli. • Sight, smell, taste, touch and hearing • General senses – distributed over a large part of the body eg. Pain, touch, temperature, vibration, itch and proprioception. # somatic # visceral • Special senses - localized to specific part of the body eg. Smell, taste, sight, hearing and balance. RECEPTORS • Sensory nerve endings or specialized cell capable of responding to stimuli by developing action potential. • Mechanoreceptors – respond to mechanical stimuli such as bending or stretching. • Chemoreceptors – respond to chemicals such as odour molecules RECEPTORS….. • Photoreceptors – respond to light. • Thermoreceptors – respond to temperature changes. • Nociceptors – respond to stimuli that result in sensation of pain PAIN • Two types of pain sensation. – 1. Sharp well localized, pricking or cutting pain. Faster action potential 2. Diffuse, dull, burning or aching pain. Slower action potential Referred Pain • A painful sensation perceived to originate in the region of the body that is not the source of the pain stimulus. Areas of referred pain Suppression of Pain. • Local anaesthesia - blocking the action potential by using chemical agents. • General anaesthesia – Pain sensation can also be suppressed if loss conciousness is produced. Chemical agent that block the reticular formations PHANTOM PAIN • Occurs in people with appendages amputated. • Perceive intense pain in the amputated structure as if it were still there. • Integration of cerebral cortex results in perception of pain that is projected to the site of sensory receptor for that pathway. SPECIAL SENSES • OLFACTORY (SENSE OF SMELL) • SENSE OF TASTE • SIGHT / VISION • HEARING AND EQUILIBRIUM Special Senses • SENSE of TASTE VISION. Lacrimal apparatus Lacrimal apparatus Neuronal Pathways for Vision • 1. Each visual field is divided into a temporal and nasal half. • 2. Light from each half of the a visual field projects to the opposite side of the retina. • 3. An optic nerve consists of axons extending from the retina to the optic chiasma. Neuronal Pathways for Vision • 4. In the optic chiasma axons from the nasal part of the retina cross and project to the opposite of the brain. Axons of the temporal part does not cross. • 5. An optic tract consists of axons that have passed through optic chiasma to the thalamus. Neuronal Pathways for Vision • 6. The axons synapse in the thalamus. Collateral branches of the axons in the optic tracts synapse in the superior colliculi. • 7. An optic radiation consists of axons from thalamic neurons that project to the visual cortex. • 8. The right part of each visual field projects to the left side of brain and vice versa. Eye Disoders • Myopia (Nearsightedness) – Rabun jauh. • Hyperopia (Farsightedness) – Rabun dekat Rabun jauh Rabun dekat Conjunctivitis • Infection of the conjunctiva HEARING AND BALANCE • The ear - External Ear - Middle Ear - Inner ear Hearing. Neuronal Pathways for Hearing • 1. Sound waves strike the tympanic membrane and cause it to vibrate. • 2. Vibration of the tympanic membrane causes the three bones of the middle ear to vibrate. • 3. The stapes vibrates in the oval window. • 4. Vibration of the stapes causes the perilymph in the scala vestibuli to vibrate Neuronal Pathways for Hearing • 5. Vibration of the perilymph passes through the vestibular membrane and causes vibration of the endolymph in the cochlear duct. • 6. Vibration of the endolymph causes displacement of the basillar membrane Neuronal Pathways for Hearing • 7. Vibration of the perilymph in the scala vestibuli and of the endolymph in the cochlear duct are transferred to the perilymph of the scala tympani. • Vibrations in the perilymph of the scala tympani are transferred to the round window, which is flexible and allows movement of the entire fluid column of the perilymph. Ear Disorders • Otitis Media – infection of the middle ear. Equilibrium • Static equilibrium – associated with the vestibule and is involved in evaluation the position of the head relative to the gravity. • Kinetic equilibrium – associated with semicircular canal and is involved in evaluating changes in the direction and rate of head movements. Semicircular Canal Effects of Aging on the Special Senses • Presbyacusis - As the age increasing, the number of hair cells in the cochlear decrease. The decline doesn’t occur equally in both ears. • Old people tends to fall due to decrease in number of hair cells in the saccule, utricle and ampullae. Example of Questionnaires • Multiple Choice Questionaires. • 1. Berikut adalah sel-sel sistem saraf pusat. A. Microglia T/F B. Limfosit T/F C. Neutrophil T/F D. Astrocytes T/F E. Ependymal cell T/F • 2. Berikut adalah perkara-perkara yang benar mengenai action potential selsel saraf. A. Resting membrane potential berlaku kerana perbezaan cas negetif dan positif. T/F B. Depolarization adalah proses permulaan impulse. T/F C. Action potential sel-sel saraf bergerak di kedua arah. T/F D. Pencetusan pergerakan action potential berdasarkan hukum “all in one law”. T/F E. Repolarization adalah proses permulaan impulse. T/F. Contoh soalan nota pendek. • 1. a. Nyatakan fungsi-fungsi utama sistem saraf pusat. (4 markah) b. Bagaimanakah sistem saraf periferi berintegrasi dengan sistem saraf pusat ( 3markah). c. Berikan contoh khusus untuk soalan 1b.