Nervous System Peripheral Nervous System Objectives : Describe the mechanisms of the peripheral nervous system Describe receptor types and their functions Explain perception mechanisms for: • Pain Taste • Sight Smell • Hearing Describe the autonomic nervous system n Explain the effects of sympathetic and parasympathetic stimulation n Describe the mechanism of somatic stimulation Structure of the PNS Afferent: • Receptors • Sense organs Efferent: • Autonomic • Somatic Receptors • photo- osmo- • mechano- chemo- • thermo- pain (nociceptors) • electro Graded receptor potential Receptor potential Generator potential Adaptation: tonic receptors
Adaptation: phasic receptors
Acuity: Receptor endings of afferent neurons Teeth Muzzle Back
Acuity: lateral inhibition
Vision • Structure of the eye • Cornea • Aqueous humour • Iris • Lens • Vitreous humour • Retina: rods and cones • Optic nerve • Field of view: monocular / binocular Photoreceptors