SPECIAL SENSES Flashcards
Is the conscious or subconscious awareness of changes in the external or internal environment. Needs to satisfy the 4 conditions.
Sensation
It includes somatic and visceral senses.
General senses
sensations like touch, pressure, and vibration.
Tactile sensations
sensations like warm and cold
Thermal sensations
sensations like joint and muscle position movements
Proprioceptive sensations
4 sensations of the somatic senses
a. Tactile sensations
b. Thermal sensations
c. Pain sensations
d. Proprioceptive sensations
senses of the organs
VISCERAL SENSES
Include smell, taste, vision, hearing, and balance
SPECIAL SENSES
2 Types of senses
General & Special senses
4 CONDITIONS TO BE SATISFIED FOR A SENSATION TO OCCUR:
- Stimulus
- Sensory receptor
- Nerve impulses
- Region of the brain receiving and integrating nerve impulse
a change in the environment, capable of activating certain sensory neurons, must occur. Can be in a form of light, heat, pressure, mechanical or chemical energy.
Stimulus
must convert the stimulus to an electrical signal, which ultimately produces one or more nerve impulses if it is large enough.
Sensory receptor
must be conducted along a neural pathway from the sensory receptor to the brain.
Nerve impulses
must receive and integrate the nerve impulses into a sensation.
A Region of the brain
the conscious awareness and interpretation of sensations and is primarily a function of the cerebral cortex. Is more subjective.
PERCEPTION
a decrease in sensation during a prolonged stimulus. Some receptors are rapidly adapting; others are slowly adapting.
ADAPTATION
Rapidly adapting sensations
pressure, touch, smell
Slowly adapting sensations
pain, body position, chemical composition of blood
3 CLASSIFICATIONS OF SENSORY RECEPTORS BASED ON STRUCTURE:
- Free nerve endings
- Encapsulated nerve endings
- Separate cells
receptors for pain, temperature, tickle, itch, and some touch sensations.
Free nerve endings
for other somatic and visceral sensations such as touch, pressure, and vibration sensations.
Encapsulated nerve endings
specialized, separate cells that synapse with sensory neurons (e.g. hair cells in inner ear).
Separate cells
Bare dendrites associated with pain, thermal, tickle, itch, and some touch sensations.
Free nerve endings
Dendrites enclosed in a connective tissue capsule for pressure, vibration, and some touch sensations.
Encapsulated nerve endings
Receptor cell that synapses with first-order neuron; located in the retina of the eye (photoreceptors), inner ear (hair cells), and taste buds of the tongue (gustatory receptor cells)
Separate cells
Classification of sensory receptors are based on?
Structure and Function
6 CLASSIFICATIONS OF SENSORY RECEPTORS BASED ON FUNCTION:
- Mechanoreceptors
- Thermoreceptors
- Nociceptors
- Photoreceptors
- Chemoreceptors
- Osmoreceptors
Detect mechanical pressure; provide sensations of touch, pressure, vibrations, proprioception, and hearing and equilibrium; also monitor stretching of blood vessels and internal organs
Mechanoreceptors
Detect changes in temperature.
Thermoreceptors
Respond to painful stimuli resulting from physical or chemical damage to tissue.
Nociceptors
Detect light that strikes the retina of the eye.
Photoreceptors
Detect chemicals in mouth (taste), nose (Smell), and body fluids.
Chemoreceptors
Sense the osmotic pressure of body fluids.
Osmoreceptors
Arise from stimulation of sensory receptors in the skin, mucous membranes, muscles, tendons, and joints.
SOMATIC SENSATIONS
: Tactile receptors in skin and subcutaneous layer (Meissner corpuscles in the dermis)
: Cutaneous mechanoreceptors (in the epidermis and dermis)
Touch
: Deeper sensations (lamellated or pacinian corpuscles in the dermis)
: Internally around joints, tendons, muscles, external ganglia, etc.
Pressure
: detects high and low frequency sensations
Vibration Sensation
: Stimulation of free nerve endings (from chemicals or from touch)
Itch and tickle
Allow us to know where our head and limbs are located and how they are moving even if we are not looking at them.
PROPRIOCEPTIVE SENSATIONS
sensory receptors for pain that are located in the skeletal muscles, tendons, synovial joints, and inner ear (hair cells).
Proprioceptors
perception of body movements
KINESTHESIA
Receptors for the special senses: are housed in complex sensory organs such as the
eyes and ears.
5 special senses:
Smell Taste Sight Hearing Equilibrium
study of the eye and its disorders.
OPTHALMOLOGY
the science that deals with the ears, nose, and throat and their disorders.
OTORHINOLARYNGOLOGY
• The nose contains ___ for the sense of smell
10 – 100 million receptors
occupies the upper portion of the nasal cavity and consists of the 3 types of cells
OLFACTION EPITHELIUM
3 types of cells of the olfaction epithelium:
- Olfactory receptors
- Supporting cells
- Basal cells
sense of smell
olfaction
: Columnar epithelial cells of the mucous membrane lining of the nose.
: Provide physical support, nourishment, and electrical insulation for olfactory receptor cell.
: Help detoxify chemicals that come in contact w/ the olfactory epithelium.
Supporting cells
: Stem cells located between the bases of the supporting cells.
: Continually undergo cell division to produce new olfactory receptor cells
: Live only for a month before being replaced.
Basal cells
sense of taste
GUSTATION
5 primary tastes:
Sour Sweet Bitter Salty Umami (savory/ meaty)
\: Where taste receptors are found \: Located on tongue papillae \: 10,000 are found mostly on the tongue \: Some on the roof of the mouth, pharynx, epiglottis \: Lifespan: 10 days
Taste buds
of taste buds found in the tongue
10,000
Lifespan of taste buds
10 days
meaning bumps
papillae
What are the 4 papillae?
- Vallate Papillae
- Fungiform Papillae
- Foliate Papillae
- Filiform Papillae
Form an inverted V-shape row at the back of the tongue. About 12 that contain 100-300 taste buds.
Vallate Papillae
Mushroom-shaped elevations scattered over the tongue with about 5 taste buds each.
Fungiform Papillae
Located in lateral trenches of the tongue – most of their taste buds degenerate in early childhood.
Foliate 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
dissolved in the saliva and enter taste pores.
TASTANT
3 CRANIAL NERVES THAT INNERVATE THE TASTE BUDS
- Facial Nerve (VII)
- Glossopharyngeal Nerve (IX)
- Vagus Nerve (X)
Impulses for taste conduct to the:
- medulla oblongata
- limbic system
- hypothalamus
- thalamus
- primary gustatory area in the parietal lobe of the cerebral cortex
SENSE OF TASTE PATHWAY
- Release of neurotransmitter molecules from gustatory receptor cells
- First order neuron
- Gustatory receptors in taste buds
5 ACCESSORY STRUCTURES OF THE EYES
- Eyebrows
- Eyelashes
- Eyelids
- Extrinsic eye muscles
- Lacrimal apparatus
control eyelid movement
PALPEBRAL MUSCLES
responsible for moving the eyeball in all directions.
EXTRINSIC EYE MUSCLES
Provide the action and insertion of the extrinsic eye muscle:
Superior Rectus
Action: Upward & medially
Insertion: Superior and central part of eyeball
Provide the action and insertion of the extrinsic eye muscle:
Inferior rectus
Action: Downward & medially
Insertion: Inferior and central part of eyeball
Provide the action and insertion of the extrinsic eye muscle:
Lateral rectus
Action: Laterally
Insertion: Lateral side of eyeball
Provide the action and insertion of the extrinsic eye muscle:
Medial rectus
Action: Medially
Insertion: Medial side of eyeball
Provide the action and insertion of the extrinsic eye muscle:
Superior Oblique
Action: Downward & laterally; rotates medially
Insertion: Eyeball between superior and lateral recti; Trochlea
Provide the action and insertion of the extrinsic eye muscle:
Inferior Oblique
Action: Upward & laterally; rotates medially
Insertion: Eyeball between inferior and lateral recti
a thin, protective mucous membrane that lines the eyelids and covers the sclera.
CONJUCTIVA
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 tears:
lacrimal glands lacrimal ducts lacrimal puncta lacrimal canaliculi lacrimal sac nasolacrimal ducts (carry the tears into the nasal cavity) nasal cavity
3 LAYERS OF THE EYEBALL
- FIBROUS TUNIC
- VASCULAR TUNIC
- RETINA
outer coat of the eyeball (cornea and sclera)
FIBROUS TUNIC
middle layer of the eyeball (choroid, ciliary body, & iris)
VASCULAR TUNIC
inner layer of the eyeball
RETINA
2 layers of the retina
a) Neural Layer
b) Pigmented Layer
photoreceptor layer, bipolar cell layer, and ganglion cell layer.
Neural Layer
sheet of melanin-containing epithelial cells.
Pigmented Layer
2 cavities of the interior eyeball that is divided by the lens
Anterior cavity and Vitreous chamber
contains aqueous humor (produces intraocular pressure within the eye).
Anterior Cavity
contains the vitreous body (helps the eyeball from collapsing and hold retina)
Vitreous Chamber
Admits and refracts (bends) light.
Cornea
Provides shape and protects inner parts.
Sclera
Regulates the amount of light that enters eyeball.
Iris
Secretes aqueous humor and alters the shape of the lens for near or far vision (accommodation).
Ciliary Body
Provides blood supply and absorbs scattered light.
Choroid
Receives light and converts it into nerve impulses.
Provides output to brain via axons of ganglion cells, which form the optic (II) nerve.
Retina
Refracts light.
Lens
TRUE OR FALSE
For viewing close objects, the lens DECREASES its curvature (accommodation).
FALSE
For viewing close objects, the lens INCREASES its curvature (accommodation).
TRUE OR FALSE
For viewing close objects, the pupil constricts to ALLOW light rays from entering the eye through the periphery of the lens.
FALSE
For viewing close objects, the pupil constricts to PREVENT light rays from entering the eye through the periphery of the lens.
near-sightedness
Myopia
farsightedness
Hyperopia
irregular curvature of the cornea or lens
Astigmatism
specialized cells in the photo pigment that begin the process by which light rays are converted into nerve impulses.
PHOTORECEPTORS
allows us to see shades of gray in dim light, such as moonlight.
Rods
stimulated by bright light; gives color vision.
Cones
Two types of photoreceptors
- Rods
2. Cones
substance that can absorb light and undergo a change in structure.
PHOTOPIGMENT (VISUAL PIGMENT)
photopigment in rods (non-functional in daylight)
Rhodopsin
collects sound waves and channels them inward.
EXTERNAL (OUTER) EAR
conveys sound vibrations to the oval window.
MIDDLE EAR
houses the receptors for hearing and equilibrium
INTERNAL (INNER) EAR
3 main regions of the ear
- EXTERNAL (OUTER) EAR
- MIDDLE EAR
- INTERNAL (INNER) EAR
Components of the external ear
- Auricle
- External Auditory Canal
- Eardrum
Components of the middle ear
- Auditory (eustaschian) tube
- Auditory Ossicles
- Oval Window
Components of the inner ear
- Bony Labyrinth
- Membranous Labyrinth
- Spiral Organ (organ of Corti): organ of hearing
Auditory Pathway
- Sensory neurons in the cochlear branch of the vestibulocochlear
- Medulla Oblongata
- Midbrain
- Thalamus
- Temporal Lobes
orientation of the body relative to the pull of gravity. (utricle and saccule)
STATIC EQUILIBRIUM
the maintenance of body position in response to rotational acceleration and deceleration.
DYNAMIC EQUILIBRIUM
Equilibrium pathways
- Vestibular branch axons of vestibulocochlear (VII) nerve
- Brain stem
- Medulla or Cerebellum, & pons
- Synapse with the next neurons in the equilibrium pathways
- Cranial nerves for eye, head, and neck movements
structure of the external ear that collects sound wave
Auricle
Directs sound waves to the eardrum
External Auditory Canal
Sound waves cause it to vibrate, which in turn causes the malleus to vibrate
Eardrum
Transmit and amplify vibrations from tympanic membrane to oval window
Auditory Ossicles
Equalizes air pressure on both sides of tympanic membrane
Auditory Tube
Contains a series of fluids, channels, and membranes that transmits vibrations to the spiral organ (organ of Corti); Hair organs in spiral organ trigger nerve impulses in the cochlear branch of the vestibulocochlear (VIII) nerve
Cochlea
Generate nerve impulses in that propagate along the vestibular branch of the vestibulocochlear (VIII) nerve
Vestibular Apparatus
Contain cristae, sites of hair cells for dynamic equilibrium
Semicircular ducts
Contains macula, site of hair cells for static equilibrium
Utricle and Saccule
System where
Sympathetic nerves of the autonomic nervous system (ANS) control contraction of smooth muscles attached to hair follicles and secretion of perspiration from sweat glands.
INTEGUMENTARY SYSTEM
System where
Pain receptors in bone tissue warn of bone trauma or damage.
SKELETAL SYSTEM
System where
Somatic motor neurons receive instructions from motor areas of the brain and stimulate contraction of skeletal muscles to bring about body movements.
Basal nuclei and reticular formation level of muscle tone.
Cerebellum coordinates skilled movements.
MUSCULAR SYSTEM
System where
Hypothalamus regulates secretion of hormones from anterior and posterior pituitary.
ANS regulates secretion of hormones from adrenal medulla and pancreas.
ENDOCRINE SYSTEM
System where
Cardiovascular center in the medulla oblongata provides nerve impulses to ANS that govern heart rate and the forcefulness of the heartbeat.
Nerve impulses from ANS also regulate blood pressure and blood flow through blood vessels.
CARDIOVASCULAR SYSTEM
System where
Certain neurotransmitters help regulate immune responses.
Activity in nervous system may increase or decrease immune responses.
LYMPHATIC SYSTEM AND IMMUNITY
System where
Respiratory areas in brain stem control breathing rate and depth.
ANS help regulate diameter of airways.
RESPIRATORY SYSTEM
System where
Enteric division of the ANS helps regulate digestion.
Parasympathetic division of ANS stimulates many digestive processes.
DIGESTIVE SYSTEM
ANS helps regulate blood flow to kidneys, thereby influencing the rate of urine formation.
Brain and spinal cord centers govern emptying of urinary bladder.
URINARY SYSTEM
System where
Hypothalamus and limbic system govern a variety of sexual behaviors.
ANS brings about erection of penis in males and clitoris in females and ejaculation of semen in males.
Hypothalamus regulates release of pituitary hormones that control gonads (ovaries and testes).
Nerve impulses elicited by touch stimuli from suckling infant cause release of oxytocin and milk ejaculation in nursing mothers
REPRODUCTIVE SYSTEMS