Chp 9 senses Flashcards
Describe the purpose of a sensory receptor.
Sensory receptors are specialized structures that detect stimuli and generate action potentials, which are transmitted to the central nervous system (CNS). The CNS then interprets these signals and initiates an appropriate response.
Identify the general senses and the special senses.
General Senses: Include pain, touch, pressure, stretching, chemical changes, cold, and heat.
Special Senses: Consist of taste, smell, vision, hearing, and equilibrium.
Differentiate between sense, sensation, and perception.
Sense: The ability to detect stimuli through specialized sensory receptors.
Sensation: The process of generating action potentials in response to stimuli and sending them to the brain.
Perception: The conscious awareness and interpretation of sensations by the cerebral cortex.
Recall the five basic types of sensory receptors.
Thermoreceptors - Detect temperature changes (warm and cold receptors).
Mechanoreceptors - Detect mechanical forces like touch, pressure, and stretch.
Nociceptors - Detect pain and harmful stimuli.
Chemoreceptors - Detect chemical changes in body fluids.
Photoreceptors - Detect light and enable vision.
Compare the mechanisms of projection and adaptation of sensations.
Projection: The brain interprets action potentials as originating from specific body regions.
Adaptation: Sensory receptors decrease action potential formation with repetitive stimulation (e.g., touch and smell adapt quickly, pain receptors do not adapt).
Contrast the structures, locations, and functions of the sensory receptors involved in sensations of warm, cold, touch, pressure, stretch, chemical change, and pain.
Warm and Cold: Thermoreceptors in the dermis (warm deeper than cold).
Touch: Tactile corpuscles, free nerve endings, and tactile epithelial cells in the skin.
Pressure: Receptors in the deep dermis, tendons, and ligaments.
Stretch: Baroreceptors in internal organs, proprioceptors in muscles and tendons.
Chemical Change: Chemoreceptors monitoring body fluids.
Pain: Nociceptors, abundant in the skin and visceral organs.
Explain the mechanism of referred pain.
Referred pain occurs when pain from visceral organs is erroneously projected to body wall or limbs due to shared neural pathways.
Contrast the location, structure, and function of olfactory and taste receptors.
Olfactory Receptors: Located in the upper nasal cavity; airborne molecules must dissolve in mucus to stimulate them.
Taste Receptors: Located in taste buds on the tongue; chemicals must be in solution to be detected.
Recall the location, structure, and function of the sensory receptors involved in hearing.
Located in the cochlear duct within the internal ear.
Cochlear hair cells in the spiral organ detect vibrations.
Action potentials are carried via the vestibulocochlear nerve (CN VIII).
Distinguish the location, structure, and function of the sensory receptors involved in static equilibrium and dynamic equilibrium.
Static Equilibrium: Maculae in the saccule and utricle detect head position and linear acceleration. Not moving
Dynamic Equilibrium: Cristae ampullares in semicircular canals detect rotational movement. when you move
Identify the structures of the eye and the functions of these structures.
Fibrous Layer: Sclera (protection) and cornea (light entry).
Vascular Layer: Choroid (nourishment, light absorption), ciliary body (lens focusing), iris (controls light entry via pupil).
Inner Layer: Retina (photoreceptors for vision).
Fluids: Aqueous humor (maintains pressure), vitreous body (holds retina in place).
Describe the location, structure, and function of the sensory receptors involved in vision.
Photoreceptors: Rods (dim light, black and white vision), Cones (color vision, bright light).
Pathway: Light is refracted by cornea and lens, stimulating photoreceptors. Action potentials travel via the optic nerve (CN II) to the brain for interpretation.
Describe the common disorders of taste, smell, hearing, and vision.
Taste and Smell: Ageusia, hypogeusia, dysgeusia, anosmia, hyposmia, dysosmia, parosmia, phantosmia.
Hearing: Deafness, labyrinthine disease, motion sickness, otitis media.
Vision: Macular degeneration, astigmatism, blindness, cataracts, color blindness, conjunctivitis, farsightedness, nearsightedness, presbyopia, retinoblastoma, strabismus.
