Andrea New A&P Module 11

Senses

Transduction

how the mechanical stimulus changes the cell membrane potential

Types of Structural Receptors (3)

1. Free Nerve Ending 2.Encapsulated Ending 3.Receptor Cell

Example of free nerve ending Neuron

Dermal pain and Temp receptors

LOCATION receptor types (3)

1. Exteroreceptor 2. Interoceptor 3. Proprioceptor

FUNCTIONAL Receptor types (6)

1. Chemoreceptor

2. Osmoreceptor

3. Nociceptor

4. Mechanoreceptor

5. Thermoreceptor

6. Photoreceptor

What is a General Sense? Give Example

Distributed throughout the body and has receptor cells WITHIN the structures of the other organs. Ex: Mechanoreceptors in the skin, muscles, or walls of blood vessels

What is a special sense? Give example

A sense devoted to a specific organ

Ex: Inner ear, Eye, Tongue, and nose

Special Senses MODALITY clusters (3)

1. Chemosensation (Gustation & Olfaction)

2. Mechanosensation (Audition & Equilibrium)

3. Photosensation (Vision)

What ion depolarizes taste receptors?

Calcium

What 2 ions depolarize the olfactory sensory neuron?

Calcium or Sodium

What ion influences Audition &Equilibrium?

Potassium

5 tastes

Sweet, salty, sour, bitter, and umami(savory)

What are papillae?

Raised bumps that contain structures for gustatory transduction

3 Papillae associated with taste

1. Circumvallate/Vallate

2. Foliate

3. Fungiform

Where are Vallate lingual papillae and what do they sense?

Posterior Tongue, BITTER substances

Where are fungiform lingual papillae and what do they sense?

Superficial surface, SWEET tastes

Where are Foliate lingual Fungiform?

Lateral edge, SOUR and SALTY

What are alkaloids?

Nitrogen containing molecules that are commonly found in bitter-tasting plant products.

EX: Coffee, hops(in beer), tannis(in wine), tea, and aspirin

What is Olfactory mucosa Epithelium?

found within the superior nasal cavity, contains bipolar sensory neurons that are initial sensory olfactory neurons

What are odorant molecules?

Airborne molecules that are inhaled through the nose and pass over the olfactory epithelial region to dissolve into the mucous

What is the olfactory bulb?

Where olfactory axons group in the frontal lobe and branch out to different areas of the brain

What ONE sensory modality does not connect to the thalamus prior to the cerebral cortex?

SMELL

What structures of the ear make up the external ear?

Auricle/Pinna, Auditory canal, and Tympanic membrane

What structures of the ear make up the middle ear?

Malleus, incus, and stapes

What structures of the ear make up the inner ear?

Cochlea, vestibule, and semicircular canals

The steps of “hearing” (10)

1. Sound waves are amplified by outer ear

2. Waves strike the tympanic membrane

3. waves travel through ossicles

4. waves vibrate oval window

5. More waves are produced in Perilymph of Scala vestibuli

6. Endolymph in cochlear duct is displaced

7. Basilar Membrane vibrates

8. Stereocilia of hair cells bend and potassium depolarizes cell

9. Postsynaptic sensory neuron sends info to CNS

10. Four orders of sensory neurons carry auditory to the temporal lobe

What is macula?

hair cells surrounded by support cells

What are otoliths?

Calcium carbonate crystals on top of otolithic membrane

What is the ampulla of the semicircular canals?

The base of each semi-circular canal that connects to the vestibule

What is the crista ampullaris?

contains hair cells that respond to rotational movement like saying “no” with your head or spinning.

What fluid permeates semicircular canals and ampullae?

Endolymph fluid

What is physiological nystagmus?

prolonged input from the semicircular canal

EX: Rapid eye-tracking after spinning

Palpebral Conjunctiva

thin inner membrane of eyelid

Lacrimal Gland

Beneath lateral edges of eye, produces tears

Lacrimal Duct

Tears flow through this to cover the conjunctiva and wash away foreign objects

Nasolacrimal Sac

Medial corner of the eye where tears flow through to the nasal cavity

What are the 6 Extraocular Muscles

1. Superior Rectus

2. Medial Rectus

3. Lateral Rectus

4. Inferior Rectus

5. Superior Oblique

6. Inferior Oblique

What extraocular muscles are innervated by the oculomotor nerve? (4)

Superior, Inferior, and Medial rectus AND Inferior Oblique

What nerve innervates the lateral rectus?

Abducens Nerve

What nerve innervated the superior oblique?

Trochlear Nerve

What 3 tissues compose the hollow sphere of the eye?

1. Tunica Fibrosa- outermost layer

2. Tunica Vasculosa- middle

3. Tunica Interna- inner

What is the Chorid?

In Tunica Vasculosa, layer of very vascular connective tissue that supplies blood to eye

What is the ciliary Body?

In Tunica Vasculosa, a muscular structure that is attached to the lens by suspensory ligaments

What fluid fills the anterior cavity of the eye?

Aqueous Humor

What fluid fills the posterior cavity of the eye?

Vitreous Body

What is the optic disk?

The “blind spot” in the retina where the optic nerve begins

What is the fovea centralis?

The exact center of the retina where visual acuity is the sharpest

What are the 2 types of photoreceptors, what pigment do they hold and what do they see?

1. Rod Photoreceptor contains rhodopsin, which sees grey

2. Cone photoreceptor contains opsins, which sees red, green, blue

What is a photon?

A single unit of light

What photoreceptor is sensitive to low or scotopic light?

Rods

What photoreceptor is sensitive to bright or photopic light?

Cones

What is the visual Pathway to the brain? (4 steps)

1. Axons of ganglion cell combine to form optic nerve

2. Optic nerve travels to optic chiasm

3. Axons hemidecussate and travel as optic tracts to thalamus relay station

4. Optic tracts travel to the visual cortex of the occipital lobe of the brain

What is a normal eye called?

Emmetropic

What nervous system relaxes the ciliary muscles and flattens the lens tor distant vision?

SNS

What nervous system decreases pupil size and tightens the ciliary muscles to round the lens?

ParaNS

What is Anosmia?

Loss of smell/olfaction

What is Aguesia?

Loss of taste/gustation

What is vertigo?

Abnormal sense of equilibrium

What is tinnitus?

Abnormal sound perception/ ringing of the ears

What is Otitis?

Inflammation of the ear

What is a cataract?

clouding of the lens

What is glaucoma?

death of retinal neurons

What is an astigmatism?

misshapen cornea

What is hyperopia?

Eyeball is too short, difficulty seeing objects close by “farsighted”

What is Myopia?

eyeball is too long, difficulty seeing objects far away “nearsighted”

What is presbyopia?

Decreased flexibility of the lens as we age