CH # 10: The Senses Flashcards
Mechanism that allows the eye to focus at various distances, primary achieved by changing the curvature of the lens
Accommodation
The eyeball
Bulbous oculi
A sensory receptor that detects the presence of chemicals; responsible 4 taste, smell and monitoring of the concentration of certain chemicals in body fluids
Stimulus: changes in chemical concentration of substances
Chemoreceptor
Spiral or snail-shaped portion of the inner ear
Encloses the organ of Corti which contain the receptors 4 sound
Cochlea
Receptor organ located w/in the ampulla of the semicircular canals; functions in dynamic equilibrium
Crista ampullaris
Senses that r located throughout the body; somatic senses
General senses
Sense of taste
Gustatory sense
The structures that produce and convey tears
Lacrimal apparatus
Yellowish depression on the retina
Macula lutea
Sensory receptors that respond 2 a bending or deformation of the cells; located throughout the skin
Examples: receptors 4 touch, pressure, hearing and equilibrium
Stimulus: changes in pressure or movement in fluids
3 types: free nerve endings, Meissner corpuscles and pacinian corpuscles
Mechanoreceptors
Sensory receptors that respond 2 tissue damage; pain receptors
Stimulus: tissue damage
These receptors do NOT adapt and may continue to send signals after the stimulus has been removed
Nociceptors
A type of chemoreceptor that gives us a sense of smell
They r concentrated on the superior region of the nasal cavity and have long cilia that extend 2 the surface and project in2 the nasal cavity. The cilia r considered 2 b the sensitive receptors
Stimulated by chemicals dissolved in liquids
Olfactory neurons
Little stones of calcium carbonate in the macular of the inner ear
Otoliths
Sensory receptors that sense light; located in the retina of the eye
Stimulus: light energy
Photoreceptors
The sense of body position and movements; responds 2 stimuli originating w/in an organism or muscle
Golgi tendon organs(the junction of a tendon w/a muscle) and muscle spindles(located in skeletal muscles) r impoprtant mechanoreceptors 4 this
Proprioception
The bending of light as it passes from 1 medium 2 another so they can focus the image on the retina(up side down)
When light hits a concave surface; they scatter or diverge
When light hits a convex surface; they get closer together or converge
The closer the object, the more the light rays have 2 bend 2 focus and the greater the curvature of the lens
Refraction
A photosensitive pigment in the rods; the greater the concentration-the greater the sensitivity 2 light
A substance that is very light sensitive. When light hits this, it is broken down in2 it’s components: opsin(a protein) and retinal(derivative of vitamin A)
Rhodopsin
Phenomenon in which some receptors responds when a stimulus is 1st applied but decreases w/prolonged stimulation
Sensory adaptation
Senses w/receptors localized in a particular area; taste, smell, vision and hearing
Special senses
Sensory receptors that detect changes in temperature and show rapid sensory adaption
Located immediately under the skin and r widely distributed throughout the body. Highest concentration is in the lips and least concentration is in the broad surfaces of the trunk
Stimulus: heat and cold (10X’s more cold receptors then heat receptors) extreme temperatures can stimulate pain receptors
Thermoreceptors
5 types; the basis 4 these types is the type of stimulus 2
which they r sensitive or have a low threshold
-chemoreceptor
-mechanoreceptors
-nociceptors
-thermoreceptors
-photoreceptors
Sense receptors
This only occurs after impulses have been interpreted by the brain
Steps involved:
1-there must b a stimulus
2-a receptor must detect a stimulus and create an action potential
3-the action potential(impulse) must b conducted 2 the CNS
4-w/in the CNS, the impulse must b translated in2 information
5-information must b interpreted in the CNS in2 an awareness or perception of the stimulus
Perceived sensation
1 of 3 types of mechanoreceptors
Referred 2 as lamellae corpuscles because several layers of connective tissue surround the nerve endings. Heavy pressure is needed 2 stimulation
Common in deeper dermis and subcutaneous tissues, tendons and ligaments
Pacinian corpuscles
A type of chemoreceptor localized in the mouth region, on the surface of the tongue and is considered the organ of taste
Made up of specialized epithelial cells called gustatory cells or taste cells interspersed w/supporting cells and nerve fibers
4 different sensation types: salty, sweet, sour and bitter
When the microvilli(taste hairs) r stimulated, an impulse is triggered on a nearby nerve fiber. Impulses from the anterior 2/3 of the tongue travel along the facial nerve; impulses from the posterior 1/3 travel along the glossopharyngeal nerve
Taste buds
Olfactory neurons pass through the foramina in the ethmoid bone and enter the olfactory bulb of the olfactory nerve (cranial nerve 1). Here they synapse w/association neurons that conduct the impulses to this area in the temporal lobe where they r interpreted
Olfactory cortex
Inflammation of the eye’s sebaceous glands
Stye
Functions: they moisten, lubricate and cleanse the anterior surface of the eye and contain an enzyme(lysozyme) that helps destroy bacteria and prevent infections
They r produced by the lacrimal glands and flow through lacrimal ducts and across the surface of the eye 2 the medial side, where they drain in2 2 small lacrimal canals. They then flow in2 the lacrimal sac and then in2 the nasolacrimal duct, which opens in2 the nasal cavity
Tears
The white part of the eye
Covers the posterior 5/6th’s of the eyeball and the muscles that move the eye r attached 2 it
Sclera
Refers 2 when the suspensory ligaments relax and the lens bulges(becomes more convex) 2 allow focusing 4 close
vision
When this is relaxed, the suspensory ligaments r taut and the lens is flat allowing 4 distance vision
Ciliary muscle contractions
A type of photoreceptor cells located in a layer of the retina
They r thin cells w/slender, rodlike projections and r sensitive 2 dim light
They r more numerous than the other type of photoreceptor in the eye but they r absent in the fovea centralis and their number increases proportionately 2 the distance away from the fovea centralis.
Many of them synapse w/a single sensory fiber which causes them 2 lack fine detail. They also function 2 c black and white, dim vision and night vision
They contain a substance called rhodopsin
Rods
Where the optic nerve penetrates and passes through the retina layers
It does NOT contain photoreceptors so it is referred 2 as the blind spot of the eye1
Optic disk
A type of photoreceptor cells that control visual acuity and color vision and r located in the fovea centralis of the retina
They r thicker cells w/short blunt projections that converge less than the other type of photoreceptor in the eye so they provide color and sharp images w/fine detail
3 types each w/a different type of pigment: all these pigments contain retinal but the protein portion is different
- green light
- blue light
- red light
Perceived color depends on the quantity and the combinations of light receptors stimulated. If all colors r stimulated-u c white; if no colors r stimulated-u c black
Cones
A waxy substance produced in the ears which help prevent foreign objects from reaching the eardrum
Cerumen
5 types; the basis 4 these types is the type of stimulus 2
which they r sensitive or have a low threshold
-chemoreceptor
-mechanoreceptors
-nociceptors
-thermoreceptors
-photoreceptors
Sense receptors
This only occurs after impulses have been interpreted by the brain
Steps involved:
1-there must b a stimulus
2-a receptor must detect a stimulus and create an action potential
3-the action potential(impulse) must b conducted 2 the CNS
4-w/in the CNS, the impulse must b translated in2 information
5-information must b interpreted in the CNS in2 an awareness or perception of the stimulus
Perceived sensation
1 of 3 types of mechanoreceptors
Referred 2 as lamellae corpuscles because several layers of connective tissue surround the nerve endings. Heavy pressure is needed 2 stimulation
Common in deeper dermis and subcutaneous tissues, tendons and ligaments
Pacinian corpuscles
A type of chemoreceptor localized in the mouth region, on the surface of the tongue and is considered the organ of taste
Made up of specialized epithelial cells called gustatory cells or taste cells interspersed w/supporting cells and nerve fibers
4 different sensation types: salty, sweet, sour and bitter
When the microvilli(taste hairs) r stimulated, an impulse is triggered on a nearby nerve fiber. Impulses from the anterior 2/3 of the tongue travel along the facial nerve; impulses from the posterior 1/3 travel along the glossopharyngeal nerve
Taste buds
Olfactory neurons pass through the foramina in the ethmoid bone and enter the olfactory bulb of the olfactory nerve (cranial nerve 1). Here they synapse w/association neurons that conduct the impulses to this area in the temporal lobe where they r interpreted
Olfactory cortex
Inflammation of the eye’s sebaceous glands
Stye
Functions: they moisten, lubricate and cleanse the anterior surface of the eye and contain an enzyme(lysozyme) that helps destroy bacteria and prevent infections
They r produced by the lacrimal glands and flow through lacrimal ducts and across the surface of the eye 2 the medial side, where they drain in2 2 small lacrimal canals. They then flow in2 the lacrimal sac and then in2 the nasolacrimal duct, which opens in2 the nasal cavity
Tears
The white part of the eye
Covers the posterior 5/6th’s of the eyeball and the muscles that move the eye r attached 2 it
Sclera
Refers 2 when the suspensory ligaments relax and the lens bulges(becomes more convex) 2 allow focusing 4 close
vision
When this is relaxed, the suspensory ligaments r taut and the lens is flat allowing 4 distance vision
Ciliary muscle contractions
A type of photoreceptor cells located in a layer of the retina
They r thin cells w/slender, rodlike projections and r sensitive 2 dim light
They r more numerous than the other type of photoreceptor in the eye but they r absent in the fovea centralis and their number increases proportionately 2 the distance away from the fovea centralis.
Many of them synapse w/a single sensory fiber which causes them 2 lack fine detail. They also function 2 c black and white, dim vision and night vision
They contain a substance called rhodopsin
Rods
Where the optic nerve penetrates and passes through the retina layers
It does NOT contain photoreceptors so it is referred 2 as the blind spot of the eye1
Optic disk
A type of photoreceptor cells that control visual acuity and color vision and r located in the fovea centralis of the retina
They r thicker cells w/short blunt projections that converge less than the other type of photoreceptor in the eye so they provide color and sharp images w/fine detail
3 types each w/a different type of pigment: all these pigments contain retinal but the protein portion is different
- green light
- blue light
- red light
Perceived color depends on the quantity and the combinations of light receptors stimulated. If all colors r stimulated-u c white; if no colors r stimulated-u c black
Cones
A waxy substance produced in the ears which help prevent foreign objects from reaching the eardrum
Cerumen
A structure of the ear consisting of an auricle and the external auditory canal which ends at the tympanic membrane
Auricle collects sound waves and conducts them towards the auditory canal
The skin that lines the auditory canal contains hairs and ceruminous glands; ceruminous gland secretes cerumen in order to protect the eardrum from foreign particles
External ear
A structure of the ear that is an air-filled cavity that contains the tympanic membrane, an auditory/Eustachian tube and the auditory ossicles
Middle ear
An air filled tube that is part of the middle ear
Connects the middle ear w/the throat
Purpose is 2 equalize the pressure from the outside air and the middle ear cavity
Eustachian tube
Auditory tube
A structure of the ear consisting of a series of interconnecting chambers in the temporal bone
It is divided in2 the vestibule, semicircular canals and the cochlea.
Inner ear
Detected by the organ of Corti that vibrates in response 2 the sound and sensitivity of the hair cells w/in the ear
Pitch
Determined by the intensity of the sound waves
Loudness
Sequence of events:
1) tympanic membrane vibrates in response 2 sound waves
2) the auditory ossicles, the malleus, incus and stapes, transfer
vibrations 2 the oval window membrane
3) movement in the oval window causes starts up oscillations in the
cochlea
4) cochlea movement causes hair on hair cells to bend and rub
against the tectorial membrane
5) bending of hairs stimulates impulses
6) impulses r transmitted 2 the auditory cortex of the temporal
lobe by the cochlear branch of cranial nerve VIII;
vestibulocochlear nerve
Initiation of auditory impulses
A type of equilibrium that is involved in evaluating the position of the head in relation 2 gravity; occurs when the head is motionless or moving in a straight line
Contains otoliths
Static equilibrium
A type of equilibrium that is involved in evaluating the position of the head in relation 2 gravity; occurs when the head is moving in a rotational or angular direction
Contains the crista ampullaris
Dynamic equilibrium
