Senses Flashcards
Specialized cells or multicellular structures that collect information from the environment
Sensory Receptors
Sensory receptors stimulate neurons to send impulses along:
sensory fibers to the brain
A feeling that occurs when brain become aware of a sensory impulse
Sensation
A persons view of the stimulus; the way the brian interprets the info
Perception
Respond to changes in chemical concentrations
Chemoreceptors
Respond to tissue damage
Pain Receptors (Nociceptors)
Respond to changes in temperatures
Thermoreceptors
Respond to mechanical forces
Mechanoreceptors
Respond to light
Photoreceptors
Process in which the brain projects the sensation back to the apparent sources
Projection
*Allows a person to pinpoint the region of stimulation
Senses associated with skin, muscles, joints, and viscera
General Senses
Three groups of General Senses:
- Exteroceptive
- Visceroceptive
- Proprioreceptive
- Common in epithelial tissues
- simplest receptors
- sense itching
Free Nerve Ending
- Abundant in hairless portions of skin; lips
- Detect fine touch; distinguish between two points on the skin
Meissner’s Corpulses
- Common in deeper subcutaneous tissues, tendons, and ligaments
- Detect heavy pressure and vibrations
Pacinian Corpulses
Send information to spinal cord and CNS about body position and length and tension of muscles
Proprioreceptors
Main kind of proprioreceptors:
- Pacinian Corpulses
- Muscle Spindles
- Golgi Tendon Organs
*Stretch Receptors
in joints
Pacinian Corpulses
In skeletal muscle
Muscle Spindles
in tendons
Golgi Tendon Organs
- Chemoreceptors
- Respond to chemicals dissolved in liquids
Olfactory Receptors
- Contain olfactory receptors and supporting epithelial cells
- Cover parts of nasal cavity, superior nasal conchae, and a portion of nasal septum
Olfactory Organs
Stimulated by carbohydrates
sweet
stimulated by acids
sour
stimulated by salts
salty
stimulated by organic compounds
bitter
stimulated by glutomate
umani
Spicy foods activate:
pain receptors
modified epithelial cells that function as receptors (chemo-receptors)
Taste cells
Microvilli that protrude from taste cells; sensitive parts of taste cells
Taste hairs
Located on the papillae of tongue, roof of mouth, linings of cheeks, and walls of pharynx
organs of taste
Once olfactory receptors are stimulated, nerve impulses travel through:
olfactory nerves–> olfactory bulbs–> olfactory tracts–> limbic system (for emotions)–> olfactory cortex (for interpretation)
Organ of hearing
Ear
Collects sound waves
Auricle
- lined with ceruminous glands
- carries sound to tympanic membrane
- terminates with tympanic membrane
External Acoustic Meatus
Virbrates in response to sound waves
Tympanic Membrane
Air filled space in temporal bone
Tympanic Cavity
- Vibrate in response to tympanic membrane
- Malleus, incus, and stapes
Auditory Ossicles
- Opening in wall of tympanic cavity
- stapes vibrate against it to move fluids in inner ear
Oval Window
- Connects middle ear to the throat
- helps maintain equal pressure on both sides of tympanic membrane
- usually closed by valve-like flaps in the throat
Eustacian Tube
Complex system of labyrinths
Inner Ear
- Bony canal in temporal bone
- Filled with perilymph
Osseous Labyrinth
- Tube within osseous labyrinth
- filled with endolymph
Membranous Labyrinth
Three parts of Labyrinths:
- Cochlea
- Semicircular Canals
- Vestibule
- Group of hearing receptor cells
- on upper surface of basilar membrane
- particular sound frequencies cause hairs of receptor cells to bend
- nerve impulses generated
Organ of Corti
- Vestible
- Sense position of head when body is not moving
Static Equillibrium
- Semicircular Canals
- Sense rotation and movement of head and body
Dynamic Equillibrium
Communicates with saccule and membraneous portion of semicircular canals
Utricle
communicates with cochlear duct
Saccule
Hair cells of utricle and saccule
Macula
Three canals at right angles
Semicircle Canals
Swelling of membraneous labyrinth that communicates with the vestibule
Ampulla
- Sensory organ of ampulla
- hair cells and supporting cells
- rapid turns of head or body stimulate hair cells
Crista Ampullaris
The most dominant sense is the ___
eye
___ of all sensory receptors are in the eye
-70%
responsible for producing tears
Lacrimal Apparatus
Prevents perspiration from getting into the eye
Eyebrow
Coarse hairs that overlie the supraorbital margins
Functions include:
- shading the eye
- Preventing perspiration from reaching the eye
Eyebrows
- Protect the eye anteriorly
- Palpebral Fissure
- Lacrimal Caruncle
Papebrae (Eyelids)
- Project from the free margin of each eyelid
- Initiate reflex blinking
Eyelashes
- Transparent membrane that lines the eyelids and covers the whites of the eyes
- Lubricates and protects the eye
Conjunctiva
Consists of the lacrimal gland and associated ducts
Lacrimal Apparatus
secrete tears
Lacrimal Apparatus
The structure of the eyeball
Slightly irregular hollow sphere
The wall is composed of three tunics:
- fibrous
- vascular
- sensory
The internal cavity of the eyeball is filled with fluids called:
humors
The ____ separates the intern; cavity
lens
Forms the outermost coat of the eye and is composed of opaque sclera and clear cornea
Fibrous Tunic
- -Protects the eye and anchors extrinsic muscles
- the cornea lets light enter the eye
Three regions of the Vascular Tunic
- Choroid
- Ciliary Body
- Iris
- A dark brown membrane
- supplies blood to all eye tunics
Choroid
- A thickened ring of tissue surrounding the lens
- Composed of smooth muscle bundles (ciliary muscles)
- Anchors the suspensory ligament that holds the lens in place
Ciliary Body
Central opening of the iris
Pupil
The outer layer of the retina that absorbs light and prevents its scattering
Pigmented Layer
Contains photoreceptors that transduce light energy, bipolar cells and ganglion cells, and amacrine and horizontal cells
Neural Layer of Retina
- Respond to dim light
- Are used for peripheral vision
Rods
- Respons to bright light
- Have high-acuity color vision
- Are concentrated in fovea capitis
Cones
Where are cones concentrated?
Fovea Capitis
____ separates the internal eye
Lens
- Transmits light
- Supports the posterior surface of the lens
- Holds the neural retina against the pigmented layer
Vitreous Humor
A plasma-like fluid that fills the anterior segment of the eye
Aqueous Humor
*Supports, nourishes, and removes wastes
Between the cornea and iris
Anterior
Between the iris and the lens
Posterior
A biconvex, transparent, flexible, avascular structure that:
- Allows precise focusing of light onto your retina
- Is composed of epithelium and lens fibers
Lens
With age, the lens becomes more compact and dense and loses its _____
elasticity
When a convex lens forms an image it is:
upside down and reversed right to left
Light is reflected three times:
- At the cornea
- Entering the lens
- Leaving the lens
The lens curvature and shape allow for:
Fine focusing of an image
Process by which the eye detects light energy
Photoreception
- Modify neurons
- Resemble tall epithelial cells
- Exist as: cones and rods
Photoreceptors