HEENT physio test Flashcards
What does visual perception require?
Eye to focus visual image and neural pathways and brain to process the image.
There is a small range of visible light we can see on what spectrum?
Electromagnetic.
What is refraction?
Bending of light. Light passing obliquely through one medium and another.
Refraction to focus on the retina requires what?
The cornea and the lens. The lens to do fine tuning with the convex and concave
Why does the lens need to convex?
thicker at the center and converges light rays to accomodate for hyperopia
Images in the brain get turned how?
upside down, reversed, and inverted
Why does the lens need to concave?
thinner at the center and diverges light rays to prevent focusing to accomodate for myopia
What is the pathway of light entering the eye?
Cornea- aqueous humor- lens (entrance and leaving)- vitreous humor- entire neural layer of the retina- photoreceptors and pigmented layer of the retina.
The lens shape is a _______ disc.
Biconcave.
Refraction to focus on the retina via changes in lens shape is determined by what structures?
Zonular fibers/ciliary zonules attached to ciliary muscles.
The lens _______ for distant vision.
Flattens. Sympathetic input relaxes the ciliary muscle and this tightens the ciliary zonule and flattens the lens.
In distant vision the sight rays are nearly ___________.
parallel
In close vision the sight rays are _________.
divergent, but get accommodated for by the ciliary muscles.
The lens ________ for close vision.
Bulges. Parasympathetic input contracts the ciliary muscle. This loosens the ciliary zonule and allows the lens to bulge.
How do signals spread from photoreceptors to bipolar cells to ganglion cells?
Mediated by glutamate neurotransmitter.
Myopia vs. hyperopia
Myopia (nearsightedness) is difficulty seeing distant objects clearly, while hyperopia (farsightedness) is difficulty seeing close objects clearly.
Rods vs. Cones
Rods: noncolor vision (one visual pigment), high sensitivity, function in dim light, low acuity, many, peripheral retina.
Cones: color vision (three pigments), low sensitivity, function in bright light, high acuity, fewer, central retina.
What is rhodopsin?
Retinal (light absorbing molecule) + opsin.
Retinal is synthesized from what vitamin?
Vitamin A.
What are the 3 types of color blindness?
- Protanomaly: reduced sensitivity to red light.
- Deuteranomaly: reduced sensitivity to green light, which is the most common form of color blindness.
- Tritanomaly: reduced sensitivity to blue light, which is extremely rare and not X-linked, as it affects a different chromosome.
Medial vs. lateral nerve fibers
Medial nerve fibers= cross over at the optic chiasm and carry visual information from temporal/lateral visual field.
Lateral nerve fibers= DO NOT cross over at the optic chiasm and carry visual info from medial visual field.
Where do the medial and lateral nerve fiber travel to?
genticulate nuclei then the primary visual cortex in the brain to be made 3-D and turned right side up.
What are the two muscles of the iris?
Sphincter pupillae and dilator pupillae.
If there was an injury in the optic nerve before the chasm, what would happen?
total blindness in that one eye. (anopia)
What is the sphincter pupillae?
Muscle contracts and the pupil constricts so the size decreases. It is part of the parasympathetic nervous system and is helpful for close vision and bright light.
If there is any injury in the optic nerve at the chasm, what would happen?
temporal visual field loss (bitemporal hemianopia)
If there is an injury in the optic nerve after the chasm (but before the geniculate nuclei), what would happen?
contralateral homonymous hemianopia
If there was an injury in the macula, what would happen?
central vision loss
If there was a constrcited visual field (intact macular but damage in other areas of the eye), what would happen?
tunnel vision
What is the dilator pupillae?
Muscle contracts, pupil dilates and size increases. It pulls the pupils open. This is a part of the sympathetic nervous system.
What are the two muscles of the iris?
sphincter pupillae and dilator pupillae
What is the sphincter pupillae?
muscle contracts and the pupil constricts so the size decreases. It is part of the parasympathetic nervous system and is helpful for close vision and bright light.
In the Edinger-Westphal nucelus of the midbrain, what cranial nerves are responsible for the afferent and efferent signals?
Afferent: CN II sends signals to midbrain
Efferent: CN III causes parasympathetic constriction of both pupils
What are pupillary light reflexes?
There is * Direct response: * Consensual response: * Multiple pathways/reflex arc that passes through the Edinger-Westphal nucleus (signal processing) in the midbrain.
How do sound waves travel?
- Sound waves vibrate TM 2. Auditory ossicles vibrate and pressure is amplified. 3. Pressure waves created by the stapes pushing on the oval window move through fluid in the scala vestibule. 4. A. Sounds with frequencies below the hearing range travel through the helicotrema and do not excite hair cells. B. Sounds in the hearing range go through the cochlear duct, vibrating the basilar membrane and deflecting hair on inner hair cells.
What is the spiral organ (organ of corti)?
Within the scala media. Basilar membrane and hair cells with stereocilia (hair cells which sit against tectorial membrane) + tectorial membrane. The movement of hair cells causes depolarization to tectorial membrane and basilar membrane vibrates and impulses will be sent back to cochlear nerve.
What is the pathway for nerve impulses from cochlear bipolar cells to the auditory cortex?
Spiral ganglion- cochlear nuclei (medulla)- superior olivary nucleus (pons-medulla)- lateral lemniscus (tract)- inferior colliculus (midbrain auditory reflex center)- medial geniculate nucleus (thalamus)- primary auditory cortex of temporal lobe.
What are the structures of the vestibular apparatus?
It is made up by the semicircular canals, vestibule with hairs and otoliths with otolith membrane. It is important for balance.
What are the functions of the semicircular canals?
Cupula-rotational movements of body, fluids move it back and forth and sends info to cerebellum.
What is the function of the vestibule?
Utricle- horizontal and saccule- up and down like on an elevator- both deal with linear movement.
What is the otolith membrane?
Gelatin with crystals- crystals in membranes move and cause depolarization.
Vestibular info is used to?
Control eye muscles, maintain upright posture and balance, provide awareness of body position and acceleration as well as spatial info.
What do vestibular nerve fibers do?
Vestibular nerve fibers transmit info through the brainstem and thalamus to the vestibular centers in the parietal lobe of the cerebral cortex.
Vestibular information is integrated with sensory information coing from ___________
proprioceptors
Smell is conducted by what structures?
Olfaction, cribiform plate + CN I. Odorants dissolve in nasal mucus.
Taste is conducted by what structures?
Gustation, taste buds (papillae)- folate, fungiform, and vallate.
What structures of the brain deal with taste and smell?
Olfactory cortex- thalamus=conscious interpretation of smell.
Limbic system-hypothalamus- pituitary= perception, association with emotion
What structures make up the taste bud papillae?
Folate, fungiform, and vallate. Taste pore= hollow area where dissolved food molecules. Basal cells= divide and differentiate to replace damaged taste buds.
What are the 5 types of taste?
- Sweet- sugars, saccharin, alcohol, some amino acids, some lead salts. 2. Sour- hydrogen ions solution. 3. Salty- metal ions (inorganic salts), sodium chloride is saltiest. 4. Bitter- alkaloids such as quinine and nicotine, caffeine, and nonalkaloids like aspirin. 5. Umami- amino acids glutamate and aspartate, example: beef (meat) or cheese taste and monosodium glutamate.
What are the important nerves of HEENT?
Facial nerve (VII)- carries impulses from anterior two-thirds of tongue. Glossopharyngeal (IX)- carries impulses from posterior one-third and pharynx. Vagus Nerve (X)- transmits from epiglottis and lower pharynx.
Myopia or nearsightedness is best described by
Eyeball is too long, image falls in front of retina
The process of other accommodation attempts to change the shape of the lens to focus, scattered light rays for near vision by:
Contracting ciliary muscles, loosening, ciliary fibers, bulging lenses
What is the proper direction of light through the eye?
Cornea, iris, vitreous, humor, and retina
What is the proper direction of light through the eye?
Cornea, iris, vitreous, humor, and retina
The main purpose of rods is
Dim vision
The light absorbing molecule combines with rhodopsin and changes shape when it absorbs light to send electrical signals
Retinal
A sex linked disorder, which is explained by reduce sensitivity, the green light is known as
Deuteranomaly
Night blindness is often a function of issues with
Rods
Vision loss at the optic chasm can be seen clinically during exam by
Loss of peripheral vision
Movement of visual information throughout the neurologic system in the correct order
Optic chiasm, lateral geniculate nuclei, primary visual cortex
Movement of sound waves throughout the ear
External acoustic mediators to the membrane, malleus, incus, stapes, oval window, cochlea, cochlear nerve
Origin of hearing
Spiral organ
Neural transduction of hearing through the brain in the correct order
Spiral organ, medulla, midbrain, and primary auditory cortex of the temporal lobe
Linear acceleration, such as in a car is sensed by
Utricle
Vertical acceleration, such as an an elevator is sensed by
Saccule
Rotational acceleration, such as figure skating as sensed by
Semicircular canals
Sending equilibrium is done by the vestibular nerve and cooperation with what two structures
Brainstorm (vestibular nuclei)
Cerebellum
Ansomnia or permanent loss of smell in someone would likely be caused by
Cribriform plate fracture
Why do we associate smell with emotions?
Smell travels through the limbic system
Sensory of gag reflex is the responsibility of the _________ nerve and the motor is __________
IX, X
Sensory from the anterior 2/3 of the tongue
VII
Stimulation of beta 2 receptors by epinephrine cause
Bronchodilation
What does a papilledema look like on a fundoscopic exam?
Bulge. Decreased visual acuity, specifically in peripheral fields.
What are the branches of the facial nerves (CN VII)?
TO ZANZIBAR BY MOTOR CAR:
* Temporal
* Zygomatic
* Buccal
* Mandibular
* Cervical
Describe the sphenoid bone.
Wing-like structure at base of the skull, pituitary sits on it.
Damage to which structure or bone can cause a brain bleed and kill someone?
pterion
What is the main muscle of the eye?
Orbicularis oculi - closing eyelids, CN VII (temporal and zygomatic branches).
Which muscle holds food in the mouth, expels air from the mouth, and puffs the cheeks?
Buccinator.
Which CN is responsible for the muscles of the mouth?
CN VII.
What are the specific muscles innervated by CN VII?
- Orbicularis oris
- Zygomaticus major
- Depressor angularis oris
Describe the facial lymphatic drainage.
- Submental nodes - drain the chin.
- Submandibular nodes - drain the midface.
- Pre-auricular and parotid nodes - drain the upper face and cheek.
- Deep cervical nodes - receive all drainage from the head and neck.
Describe the lacrimal gland.
Sits lateral, tears are pushed medially, tears are pushed over the surface of the eye and some is inside nose mucous.
What is the nasolacrimal duct?
Tears pushed here and nose runs when crying.
What is ptosis?
Dropping of the eyelid.
The orbital septum is an extension of?
The periosteum.
What muscle is responsible for the opening of the eyelids?
Levator palpebrae superioris (CN III).
Which CN is responsible for sensory innervation to the face?
CN V.
What structure of the eye determines chambers?
Iris.
What muscles of the eye create a pulley system?
Trochlea and superior oblique.
What are the functions and cranial nerve innervation of the superior rectus?
Elevation, adduction, internal rotation of the eyeball; Oculomotor (CN III).
What are the functions and cranial nerve innervation of the inferior rectus?
Depression, adduction, external rotation of the eyeball; Oculomotor (CN III).
What are the functions and cranial nerve innervation of the lateral rectus?
Abduction of the eyeball; Abducent nerve (CN VI).
What are the functions and cranial nerve innervation of the medial rectus?
Adduction of the eyeball; Oculomotor (CN III).
What are the functions and cranial nerve innervation of the inferior oblique?
Elevation, abduction, external rotation of the eyeball; Oculomotor (CN III).
What are the functions and cranial nerve innervation of the superior oblique?
Depression, abduction, internal rotation of the eyeball; Trochlear nerve (CN IV).
Why is dysfunction of the cavernous sinus so worrisome?
This is how infections from the eye spread to the brain and can kill you.
What is the ophthalmic artery a branch of?
The internal carotid artery, specifically called the central retinal artery.
The optic nerve is an extension of what?
The brain.
What are the chambers of the eye?
- Anterior (aqueous humor - watery)
- Posterior (vitreous humor - yellowy fluid)
What are the layers of the eye?
- Fibrous (sclera/cornea)
- Vascular (choroid, ciliary body)
- Inner (retina)
What is the sclera?
The white part of the eye that travels anteriorly and eventually forms the cornea. The conjunctiva overlays it
What is the choroid?
Vascular layer for the retina and develops humor.
What are the two muscles of the iris?
- Sphincter pupillae
- Dilator pupillae
What does the sphincter pupillae do?
Contracts to constrict the pupil, decreasing size.
What does the dilator pupillae do?
Contracts to dilate the pupil, increasing size.
The retina has two layers; what are they?
- Pigmented layer
- Neural layer
What is the other name for the Eustachian tube?
Pharyngotympanic tube.
What are the structures of the auricle (pinna)?
- Helix
- Lobule
- Tragus
- External acoustic meatus
What are the bones and functions of the tympanic membrane?
- Malleus
- Incus
- Stapes
- Transition sound waves into vibrations. The tensor tympani and stapedius muscles help stabilize hearing and input. Pts can get arthritic changes in these bones.
What are the bones, structures, and functions of the middle ear?
- Mastoid air cells - lighten the load of the head.
- Pharyngotympanic (Eustachian) tube.
What are the bones, structures, and functions of the inner ear?
Bony/membranous labyrinth that contains the semicircular canals and cochla. The bony labyrinth is fluid with perilymph and the membranous labyrinth (inside the bony labyrinth) is filled with endolymph. Balance and transition vibrations are maintained by these fluid waves and turned into neural signals.
What makes up the membranous labyrinth?
- Cochlear duct
- Utricle (verticle)
- Saccule (horizontal)
- Semicircular ducts
What makes up the bony labyrinth?
- Cochlea
- Vestibule
- Semicircular canals
What bones make up the cochlea and what are its functions?
- Scala vestibuli - oval window
- Scala media - spiral organ (organ of Corti)
- Scala tympani - round window. Basialr membrane separates media from tympai and vibrates based on sound frequencies.
What bones make up the nasal septum?
- Ethmoid bone (posterior)
- Cartilage (anterior, nasal septum)
- Vomer (inferior)
- Cribriform plate (CN I)
What bones make up the nasal cavity?
- Palatine bones (of the hard palate)
- Maxillary bones (lateral)
- Sphenoid bone (posterior)
What happens if you break the cribriform plate?
You lose your sense of smell.
What are the bony prominences of the nose called?
Nasal concha.
What are the large mucosa of the nose called?
Nasal turbinates.
What are the nasal sinuses?
- Frontal
- Maxillary
they purify air and help to lighten the head.
What are the bony/cartilaginous structures of the neck?
- Cervical vertebrae (C1-C7)
- Hyoid bone
- Thyroid cartilage
- Cricoid cartilage
What are the muscles of the pharynx?
- Constrictors (CN X) superior, middle, and inferior to aid in swallowing.
- Longitudinal muscles (CN X and IX), pull food down into the esophagus. Salpingopharyngeus (CN X). Palatopharyngeus (CN IX)- forms part of the palatine arch in the back of the oral cavity.
What are the muscles of mastication?
- Temporalis - elevation and retraction
- Masseter - elevation
- Lateral pterygoid - protrusion and side-to-side movements
- Medial pterygoid - elevation and side-to-side movements
What are the 4 types of tonsils?
- Pharyngeal
- Tubal
- Palatine
- Lingual
What are the 3 cavities of the pharynx and their functions?
- Nasopharynx - base of the skull to soft palate. Pharyngotympanic (Eustachian) tube opening and pharyngeal tonsils (Adenoids)
- Oropharynx - soft palate to upper border of epiglottis (level of hyoid bone), lingual, palatine tonsils, uvula, opening to the eustachian tube.
- Laryngopharynx - epiglottis to laryngeal inlet, continuous inferiorly with epiglottis, anterior is the trachea.
What are the major arteries of the neck?
- Common carotid
- Internal carotid
- External carotid
What are the branches of the external carotid artery?
- Superior thyroid
- Ascending pharyngeal
- Lingual
- Facial
- Occipital
- Posterior auricular
- Maxillary
- Superficial temporal
What are the major veins of the neck?
- Internal jugular
- External jugular
- Subclavian
What is the glossopharyngeal nerve’s function in the gag reflex?
Afferent (sensory) and posterior pharynx, tonsils, soft palate.
What is the vagus nerve’s function in the gag reflex?
Efferent (motor response) and pharyngeal muscles.
What are the structures and functions of the larynx?
Voice/sound production. Sits anterior to the laryngopharynx. The hyoid bone (connected via the thyrohyoid ligaments). 3 cartilages: cricoid, thyroid, epiglottis. Trachea as well.
What is the cartilage of the adams apple?
the laryngeal prominence is made up of thyroid cartilage
Where do vocal cords attach?
cricoid cartilage attaches to arytenoid cartilage which is important for vocal cord attachmet
What does adduction and abduction of the epiglottis help us to do?
- Adduction: helps us to speak and swallow
- Abduction: letting air through
What are the important surrounding structures when doing a thyroidectomy?
- Thyroid/parathyroid glands
- Recurrent laryngeal nerve (branch of CN X)
