Somatic and Special Senses Flashcards
2 classification of general senses?
Somatic senses and visceral senses
- Conscious or subconscious awareness of changes
in the external or internal environment. - Must satisfy the four conditions.
Sensation
Conscious awareness and interpretation of sensations and is primarily a function of the cerebral cortex
Perception
4 conditions for sensations to occur
- stimulus
- nerve impulse
- brain
- interpreted as sensation
_______ - stimulus getting to the brain
_______ - how the cerebral cortex interprets the sensation
Sensation, perception
- Characteristic of MOST sensory receptors.
- Decrease in the strength of sensation during prolonged stimulus because of decrease in responsiveness of receptors.
- Perception of a sensation may fade or disappear even
though the stimulus persists
Adaptation
2 variation of adaptation
- rapidly adapting
- slowly adapting
Pressure, touch, and smell are what variant of adaptation?
Rapidly adapting
pain, body position, and chemical composition of the blood are what variant of adaptation?
Slowly adapting
2 classification of receptors are based on?
Structure, Function
3 sensory receptors classified by structure
- free nerve ending
- encapsulated nerve endings
- separate cells
6 sensory receptors based on function
- mechanoreceptor
- thermoreceptor
- nociceptor
- photoreceptor
- chemoreceptor
- osmoreceptor
Corpuscles of touch, hair root plexuses, and type I and type II cutaneous mechanoreceptors detect _____
Touch
Lamellated corpuscles detect _____
pressure and vibration
free nerve endings detect _____
tickle and itch sensations
Free nerve endings present in nearly everybody detects _____
pain
Free nerve endings in the epidermis and dermis have ______
thermoreceptors
_____ is detected by proprioceptors in the skeletal muscles, tendons, synovial joins, inner hair cells
proprioception
2 types of cutaneous mechanoreceptors
- Type I cutaneous mechanoreceptor
- Type II cutaneous mechanoreceptors
- Merkel discs/tactile discs
- Found on fingertips, hands, lips, and external genitalia
Type I cutaneous mechanoreceptor
- Ruffini corpuscle
- Found deep in the dermis, ligaments, and tendons, hands and soles
- Sensitive to stretching
Type II cutaneous mechanoreceptors
- Dermal papillae of the hairless skin
- Fingertips, hands, eyelids, tip of the tongue, lips, nipples, soles, clitoris, top of the penis
- Corpuscles of Touch (Meissner’s
Corpuscle)
Found in hairy skin
hair root plexuses
3 tactile receptors that detect pressure
- Corpuscles of touch
- Type I cutaneous
mechanoreceptors - Lamellated (PACINIAN) Corpuscle
2 tactile receptors that detect vibrations
- corpuscles of touch
- lamellated corpuscles
Corpuscles of touch detect ____ frequency vibration
lower
Lamellated corpuscles detect __ frequency vibration
higher
- stimulation of free nerve endings by chemicals
- Eg: bradykinin – local inflammatory response
itch
- free nerve endings
- Arises only when someone touches you and not when you touch yourself
tickle
Free nerve endings for detecting cold (108 and 408ºC) is in the _____ layer
Epidermis
Free nerve endings for detecting warm (328 and 488ºC) is in the _____ layer
dermis
- Extreme temperatures beyond 108C and 488C stimulate mainly ____, rather than thermoreceptors, producing painful sensations.
nociceptors
- Free nerve endings
- Found everywhere except the brain
- Pain may persist even after a pain-producing stimulus is removed because pain causing chemicals linger and because ______ exhibit very little adaptation.
nociceptors/pain receptors
2 classification of pain receptors
Fast pain, slow pain
(classification of nociceptor)
- Rapid (after 0.1 seconds)
- Acute, sharp or picking pain
- Needle puncture, knife cut to the skin
- Not felt in the deeper tissues of the body
fast pain
- (classification of nociceptor)
- A second or more after stimulus
- Increases in intensity over a period of several seconds or minutes.
- May be excruciating chronic, burning, aching, or throbbing pain.
- Can occur both in the skin and in deeper tissues or internal organs.
- Tooth ache
slow pain
- Allow us to know where our head and limbs are located and how they are moving even if we are not looking at them
- Allows us to walk, type, or dress without using our eyes
- Also allows us to estimate weight * Muscles, tendons, joints, inner ear
Proprioceptive sensations
- The _____ include smell, sight, taste, hearing, and equilibrium.
SPECIAL SENSES
- ______ – study of the eye and its disorders
Ophthalmology
the science that deals with the ears, nose, and throat and their disorders.
Otorhinolaryngology (ENT)
The olfactory epithelium in the upper portion of the nasal cavity contains:
- Olfactory receptors cells
- Supporting cells
- Basal cells
Adaptation occurs rapidly with what sense/sensory type?
olfaction
What is stronger, gustation or olfaction?
olfaction
The gustatory receptor cells are located in _____
taste buds
To be tasted, substances must be _______
dissolved in saliva
The five primary tastes are ?
salty, sweet, sour, bitter, and umami.
Taste receptors are located where?
taste buds
Taste buds are located on _______
tongue papillae
lifespan of taste on tongue
10 days
3 kinds of epithelial cell in each taste buds
(1) Supporting cells
(2) gustatory receptor cells
(3) basal cells
4 types of tongue/lingual papillae
- Vallate
- Fungiform
- Foliate
- Filiform*
Lingual papillae: about 12 that contain100–300 taste buds
Vallate papillae
Lingual papillae: scattered over the tongue with about 5 taste buds each
Fungiform papillae
Lingual papillae: located in lateral trenches of the tongue—most of their taste buds degenerate in early childhood
Follate papillae
______ cover the entire surface of the tongue.
- Contain tactile receptors but no taste buds.
- Increase friction to make it easier for the tongue to move food within the mouth.
Filiform papillae
- ____is dissolved in the saliva and enter taste pores
Tastant
3 cranial nerve activated in the gustatory sensation
Facial (VII), glossopharyngeal (IX), and vagus (X).
- Impulses for taste conduct to the ______, _______, ______, ______, and the _________.
medulla oblongata, limbic system, hypothalamus, thalamus, primary gustatory area in the parietal lobe of the cerebral cortex
5 accessory structures of the eye
- eyebrows
- eyelids
- eyelashes
- lacrimal apparatus
- extrinsic eye muscles
control eyelid movement
palpebral muscle
responsible for moving the eyeball
extrinsic eye muscles
- is a thin, protective mucous membrane that lines the eyelids and covers the sclera
conjunctiva
- a fold of connective tissue that gives form to the eyelids
- Contains a row of sebaceous glands (tarsal glands/ Meibomian glands) that keeps the eyelids from sticking to each other.
tarsal plate
Produces and drains tears
lacrimal apparatus
pathway for the tears:
- lacrimal glands
- lacrimal ducts
- lacrimal puncta
- lacrimal canaliculi
- lacrimal sac
- nasolacrimal ducts
- nasal cavity
6 extrinsic eye muscles
- superior rectus
- inferior rectus
- lateral rectus
- medial rectus
- superior oblique
- inferior oblique
2 tunic (coats) of the eyeball
- fibrous tunic
- vascular tunic
Tunic that covers the cornea and sclera
fibrous tunic
tunic that covers the choroid, ciliary body, and iris
vascular tunic
- colored portion of the eyeball
- controls the size of the pupil based on autonomic reflexes
iris
the pupil _____ in response to bright light
constricts
the pupil _____ in response to dim light
dilates
- inner coat of the eyeball
- beginning of the visual pathway
- has 2 layers
retina
what are the 2 layers of retina
- pigmented
- neural layer
Retina layer
* Contains melanin
* Absorbs stray light
pigmented layer
retina layer
* Rods
* Cones
Photoreceptors
- shades of gray in dim light
- 120 million
- Absent in fovea, more numerous in the periphery of the retina
- 6-600 : 1 bipolar cell
rods
- stimulated by brighter light; highly acute color vision
- Blue, green, red cones
- 6 million
- Most dense in fovea centralis(area of highest visual acuity)
- 1:1 bipolar cell higher acuity
cones
2 cavity of the eye
- anterior cavity
- posterior cavity
- Divided into an anterior chamber and a posterior chamber by the iris (colored portion of the eyeball).
- Both chambers are filled with aqueous humor (a clear, watery liquid).
anterior cavity
- Aka vitreous chamber
- Filled with vitreous humor (a transparent, gelatinous substance)
Posterior cavity
– focus image on the retina
cornea and lens
focuses image on the retina
cornea and lens
- The ___ of the eye further refracts the light rays so that they come into exact focus on the retina.
lens
___ of the total refraction occurs at the cornea.
75%
- Images focused on the retina are ____ and ____ reversed due to refraction.
- The ___ corrects the image
- The ____ must accommodate to properly focus the object.
inverted, right-to-left, brain, lens
site of the sharpest vision
central fovea
- normal
- sufficiently refract light rays from an object 6 m (20 ft)
emmetropic eye
near sightedness
myopia
farsightedness
hyperopia
irregular curvature (of the eye)
astigmatism
- The _____ eye will refract light correctly and focus a clear image on the retina.
normal (emmetropic)
- Nearsightedness
- The eyeball is longer than it should be and the image converges (narrows down to a sharp focal point) in front of the retina.
- People see close objects better.
- A concave lens is used to correct the vision.
myopia
- Farsightedness, hypermetropia
- The eyeball is shorter than it should be and the image converges behind the retina.
- Individuals can see distant objects better
- A convex lens is used to correct this abnormality
hyperopia
- _____ is a condition where either the cornea or the lens (or both) has an irregular curve.
- This causes blurred or distorted vision.
astigmatism
contains Auricle, external auditory canal, and eardrum
external ear
contains Auditory (eustachian) tube, ossicles, and oval window
middle ear
- Bony labyrinth and membranous labyrinth.
- Contains the spiral organ (organ of Corti), the organ of hearing.
internal ear
The _____ captures sound
auricle
- The _____ transmits sound to the eardrum.
external auditory canal
____ secrete cerumen (earwax) to protect the canal and eardrum
Ceruminous glands
3 auditory ossicles
- malleus
- incus
- stapes
Sound vibrations are transmitted from the eardrum through these 3 bones to the ____ into which the stapes fits
oval window
- The ____ extends from the middle ear into the nasopharynx to regulate air pressure in the middle ear
eustachian tube
translates vibrations into neural impulses that the brain can
interpret as sound
cochlea
contains the utricle and saccule
vestibule
_____ works with the cerebellum for balance and equilibrium
semicircular canals
2 types of equilibrium
- static equilibrium
- dynamic equilibrium
- UTRICLE AND SACCULE
- Detects linear motion
static equilibrium
- SEMICIRCULAR CANALS
- Rotational acceleration or deceleration
dynamic equilibrium
detects linear horizontal motion
utricle
detects linear vertical motion
saccule
