Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
senses
| Term | Definition |
|---|---|
| Sensory receptors | detect changes in the environment and stimulate neurons to send nerve impulses to the brain. |
| sensation | are feelings that occur when the brain interprets sensory impulses. |
| types of Sensory receptors | Somatic senses and Special senses |
| Somatic senses | widely distributed and structurally simple |
| Special senses | complex specialized sensory organs, smell, taste, hearing, equilibrium, and sight |
| 5 type of receptors | chemoreceptors,Pain receptors , Thermoreceptors, Mechanoreceptors, and Photoreceptors |
| chemoreceptors | Receptors sensitive to changes in chemical concentration |
| Pain receptors | detect tissue damage. |
| Thermoreceptors | respond to temperature differences |
| Mechanoreceptors | respond to changes in pressure or movement. |
| Photoreceptors | in the eyes respond to light energy |
| projection | sends the sensation back to its point of origin so the person can pinpoint the area of stimulation. |
| Sensory Adaptation | sensory impulses are sent at decreasing rates until receptors fail to send impulses unless there is a change in strength of the stimulus. |
| Touch and Pressure Senses | Free nerve endings, Tactile (Meissner's) corpuscles, and Lamellated (Pacinian) corpuscles |
| Free nerve endings | sensory nerve fibers in the epithelial tissues are associated with touch and pressure. |
| Tactile (Meissner's) corpuscles, | are flattened connective tissue sheaths surrounding two or more nerve fibers and are abundant in hairless areas that are very sensitive to touch, like the lips. |
| Lamellated (Pacinian) | are large structures of connective tissue and cells that resemble an onion. They function to detect deep pressure. |
| Temperature Senses | warm and cold receptors, both work best within a range of temperatures. |
| warm receprtors | Temperatures near 45o C stimulate pain receptors |
| cold receptors | temperatures below 10o C also stimulate pain receptors and produce a freezing sensation. |
| Visceral pain receptors | are the only receptors in the viscera that produce sensations. |
| Referred pain | occurs because of the common nerve pathways leading from skin and internal organs. |
| Pain Nerve Fibers | Fibers conducting pain impulses away from their source are either acute pain fibers or chronic pain fibers. |
| Acute pain | fibers are thin, myelinated fibers that carry impulses rapidly and cease when the stimulus stops |
| Chronic pain | fibers are thin, unmyelinated fibers that conduct impulses slowly and continue sending impulses after the stimulus stops. |
| where are Pain impulses are processed | in the gray matter of the dorsal horn of the spinal cord. |
| where are Pain impulses are conducted | to the thalamus, hypothalamus, and cerebral cortex. |
| sense of smell | Smell (Olfactory) receptors and taste receptors are chemoreceptors. The senses of smell and taste operate together to aid in food selection. |
| olfactory organs | contain the olfactory receptors plus epithelial supporting cells and are located in the upper nasal cavity. |
| olfactory receptor cells | bipolar neurons with hair-like cilia covering the dendrites. The cilia project into the nasal cavity. |
| cilia | To be detected, chemicals that enter the nasal cavity must first be dissolved in the watery fluid surrounding the cilia |
| olfactory bulbs | When olfactory receptors are stimulated, their fibers synapse with neurons in the olfactory bulbs lying on either side of the crista galli. |
| olfactory tracts | Sensory impulses are first analyzed in the olfactory bulbs, then travel along olfactory tracts to the limbic system, and lastly to the olfactory cortex within the temporal lobes. |
| sense of taste | Taste buds are the organs of taste and are located within papillae of the tongue and are scattered throughout the mouth and pharynx. |
| taste receptors | Taste cells(gustatory cells) are modified epithelial cells that function as receptors. |
| taste cells | Taste cells contain the taste hairs that are the portions sensitive to taste. These hairs protrude from openings called taste pores |
| Taste Sensations | sweet, sour, salt, bitter, umami receptors |
| taste buds | may be responsive to at least two taste sensations but one is likely to dominate. |
| sweet receptors | are plentiful near the tip of the tongue. |
| Sour receptors | occur along the lateral edges of the tongue |
| Salt receptors | are abundant in the tip and upper portion of the tongue |
| Bitter receptors | are at the back of the tongue. |
| Umami receptors | responds to certain amino acid derivatives such as monosodium glutamate |
| Taste Nerve Pathways | Taste impulses travel on the facial, glossopharyngeal, and vagus nerves to the medulla oblongata and then to the gustatory cortex of the cerebrum. |
| Sense of Hearing | The ear has external, middle, and inner sections and provides the senses of hearing and equilibrium. |
| Outer (External) Ear | The external ear consists of the auricle which collects the sound which then travels down the external acoustic meatus. |
| middle ear | The middle ear (tympanic cavity) begins with the tympanic membrane (eardrum), and is an air-filled space (tympanic cavity) housing the auditory ossicles. |
| Auditory Tube | The auditory (eustachian) tube connects the middle ear to the throat to help maintain equal air pressure on both sides of the eardrum. |
| inner ear | The inner ear is made up of a membranous labyrinth inside an osseous labyrinth. |
| Auditory Nerve Pathways | Nerve fibers carry impulses to the auditory cortices of the temporal lobes where they are interpreted. |
| Sense of Equilibrium | The sense of equilibrium consists of two parts: static and dynamic equilibrium. |
| static equilibrium. | help to maintain the position of the head when the head and body are still. |
| dynamic equilibrium | help to maintain balance when the head and body suddenly move and rotate. |
| sense of sight | Accessory organs, namely the lacrimal apparatus, eyelids, and extrinsic muscles, aid the eye in its function |
| Refraction | Light waves must bend to be focused, a phenomenon |
| Visual Receptors | elongated rods and blunt-shaped cones. |
| elongated rods | more sensitive to light and function in dim light; they produce colorless vision. |
| blunt shaped cones | provide sharp images in bright light and enable us to see in color. |
| Visual Pigments | The light-sensitive pigment in rods is rhodopsin (visual purple) |
| rhodopsin | which breaks down into a protein, opsin, and retinal (from vitamin A) in the presence of light. |
| optic nerves | The axons of ganglion cells leave the eyes |
| optic chiasma | Fibers from the medial half of the retina cross over |
| optic radiations | Impulses are transmitted to the thalamus, nerve pathways. the impulses are then transmitted to the visual cortex of the occipital lobe |
Created by:
gh337