BIOL 201 Lecture Notes - Lamellar Corpuscle, Depolarization, Threshold Potential
Document Summary
Stimulus: environmental change of an organism change in energy. Transduce ( convert) a stimulus into a nerve impulse: stimulus above threshold, detected by receptors, changes its membrane potential, causes generator potential, action potential along sensory neurone. Found in dermis of skin, joints, tendons, external genitalia, internal organs. Structure: layers (maellae) of connective tissue surround, myelinated sensory neurone (nerve fibre ending) that have, stretch-mediated na+ channels. Round pacinian corpuscle has a resting potential. Stretch-mediated sodium channels restrict movement of ions. Causes depolarisation / membrane potential / generator potential. Threshold potential reached: slight pressure / small generator potential / no depolarisation, great pressure / more channels open / larger generator potential. Table 16-8-1: the structure and function of the mammalian eye. Pigment prevents light reflection within the eyeball by absorbing light. Optic nerve (sensory nerve fibres) leave the eyeball. Transmissive and refractive properties of the eye in.
