Special Senses Organs Flashcards
The Ear
3 non-communicating segments:
1) ? ear 2) ? ear 3) ? ear
External ear
Captures air ? and directs them towards the ? membrane
Parts:
* Auricle (pinna)– ?
shaped
* ?
* ? part
* ? part
The Ear
3 non-communicating segments:
1) External ear 2) middle ear 3) inner ear
External ear
Captures air vibrations and directs them towards the tympanic membrane
Parts:
* Auricle (pinna)– funnel
shaped
* ear canal
* vertical part
* horizontal part
Middle Ear
- Functions: sound ?
- Located in the ** ? part ** of the temporal bone of skull
- Tympanic membrane (aka ?) is connected to oval window by ** ? which include ?, ? and ?**
- Communicates with the pharynx via the “ ? “ to ensure ? inside the middle ear is equal to outside air pressure.
Middle Ear
- Functions: sound modulation
- Located in the ** TYMPANIC part ** of the temporal bone of skull
Middle Ear
- Functions: sound modulation
- Located in the ** TYMPANIC part ** of the temporal bone of skull
- Tympanic membrane (aka EAR DRUM) is connected to oval window by ** 3 auditory vesicles which include malleus, incus and stapes**
- Communicates with the pharynx via the “ auditory tube “ to ensure air pressure inside the middle ear is equal to outside air pressure.
Inner Ear
* Housed deep inside the ? bone (24)
- ? nerve (cranial nerve VIII) (21) – cochlear nerve (hearing) and vestibular nerve (balance)
- Comprises:
- Organ for ? (? – 16 )
- Organs for ? (? apparatus)
? – 13
? – 14
? – 15
23 – brain
22 – meninges
7 – auditory tube
21 – vestibulocochlear nerve
4 – tympanic membrane
Inner Ear
* Housed deep inside the temporal bone (24)
- Vestibulocochlear nerve (cranial nerve VIII) (21) – cochlear nerve (hearing) and vestibular nerve (balance)
- Comprises:
- Organ for hearing (cochlea – 16 )
- Organs for balance (vestibular apparatus)
semicircular canals – 13
utricle – 14 (also for balance)
saccule – 15
23 – brain
22 – meninges
7 – auditory tube
21 – vestibulocochlear nerve
4 – tympanic membrane
EYE BULB - has #? layers? (tunics)
Fibrous tunic
1.? -> allows for structural integrity and is opaque
2. ? -> Allows light to enter the eye and is transparent
Vascular tunic
1. ? -> Modulates the amount of light
2. ? -> Modulates vision focus
3. ? -> Provides blood supply and innervation
Nervous tunic: both below react to ? stimuli and outputs ? impulses for the brain, to be interpreted as ?
1. pigmented layer
2. neural layer
EYE BULB - has 3 layers? (tunics)
NVF (innermost to outer.)
Fibrous tunic
1.sclera -> allows for structural integrity
2. cornea -> Allows light to enter the eye
Vascular tunic
1. iris -> Modulates the amount of light
2. ciliary body -> Modulates vision focus
3. choroid -> Provides blood supply and innervation
Nervous tunic: both below react to light stimuli and outputs nervous impulses for the brain, to be interpreted as images
1. pigmented layer
2. neural layer
VASCULAR TUNIC
1.Choroid (14)
- Dense network of ? in heavily pigmented ? tissue
- Tapetum lucidum – dorsal or ventral? part, ? reflecting area, avascular or vascular?, when light hits reflects in iridescence (nocturnal adaptation)
2.Ciliary body (4)
- ? of choroid
- Has ciliary muscles attached to ? (3) to focus
- Iris (7)
* Suspended between ? and ?
* Opening in the center is the ?
* Smooth muscle constrict and dilate pupil to regulate amount of light reaching the ?.
VASCULAR TUNIC
1.Choroid (14)
- Dense network of blood vessels in heavily pigmented connective tissue
- Tapetum lucidum – dorsal part, light reflecting area, avascular, when light hits reflects in iridescence (nocturnal adaptation)
2.Ciliary body (4)
- thickening of choroid
- Has ciliary muscles attached to lens (3) to focus
- Iris (7)
* Suspended between cornea and lens
* Opening in the center is the pupil
* Smooth muscle constricts and dilate the pupil to regulate the amount of light reaching the retina.
Nervous Tunic (Retina)
- ? part is the thinner pigmented layer – has no ?
- ? part is the thicker layer of the retina contains photoreceptors and connects to the ? nerve (cranial nerve II)
- The optic ? is the region where axons emerge from the eye bulb. This creates a “ ? ”
Nervous Tunic (Retina)
- anterior part is the thinner pigmented layer – has no photoreceptors
- posterior part is the thicker layer of the retina contains photoreceptors and connects to the optic nerve (cranial nerve II)
- The optic disk is the region where axons emerge from the eye bulb. This creates a “ blind spot ” (see image)
Intrinsic Muscles of the Eye
- Are under involuntary control
- Ciliary muscles
– Changes the shape of the ? for
?.
– ? developed in domestic animals. - Pupillary muscles (in the iris)
– ? pupillae (shape?
fibers)
– ? pupillae (shape?, radial fibers)
– Regulate the amount of ?
Intrinsic Muscles of the Eye
- Are under involuntary control
- Ciliary muscles
– Changes the shape of the lens for
focusing
– poorly developed in domestic animals. - Pupillary muscles (in the iris)
– constrictor pupillae (circular
fibers)
– dilator pupillae (linear, radial fibers)
– Regulate the amount of light
Extrinsic muscles
- Are under ? control
- 4 ? (straight) muscles:
– ? rectus(1)
– ? rectus(3)
– ? rectus(2)
– ? rectus(4) - 2 ? (curved) muscles:
– ? oblique (6)
– ? oblique (5)
Extrinsic muscles
- Are under voluntary control
- 4 rectus (straight) muscles:
– dorsal rectus(1)
– ventral rectus(3)
– lateral rectus(2)
– medial rectus(4) - 2 oblique (curved) muscles:
– dorsal oblique (6)
– ventral oblique (5)
Compartments and Chambers of the Eye
The space between the ? and the ? is
divided by the iris in 2 CHAMBERS:
1) ? chamber from cornea to iris (3)
2) ? chamber from iris to lens (2)
* They communicate through the ?
* They contain ?
? (4) from lens to fundus
* Does not communicate with ?
compartment
* Contains ?
Compartments and Chambers of the Eye
The space between the cornea and the lens is
divided by the iris in 2 CHAMBERS:
1) Anterior chamber from cornea to iris (3)
2) Posterior chamber from iris to lens (2)
* They communicate through the pupils
* They contain aqueous humor
Vitreous chamber (4) from lens to fundus
* Does not communicate with anterior
compartment
* Contains vitreous (gelatin like) humor
Adnexa of the Eye
- The orbit is incomplete in
which animal? -> ? ligament (only specific to ?) - Eyelids (palpebrae)
bottom pic:
medial commisure
lateral commisure
superior palpebra
palpebral fissure
iinferior palpebra
Third eyelid (? semilunaris)
- Concave fold of palpebral ? that protrudes from the medial angle of the eye.
- Supported by a ?-shaped cartilage
- Contains the ? gland of the third eyelid
(label the numbers circled in pic)
Lacrimal gland
Lacrimal gland (9) located ? to eye, secretes ? fluid ->
Secretion flows over ? ->
Passes through lacrimal ? and into lacrimal ? (1, 5) ->
Drains into ? duct (3)
Third eyelid (plica semilunaris)
- Concave fold of palpebral conjunctiva that protrudes from the medial angle of the eye.
- Supported by a t-shaped cartilage
- Contains the superficial gland of the third eyelid
Lacrimal gland
Lacrimal gland (9) located dorsolateral to eye, secretes serous fluid ->
Secretion flows over cornea ->
Passes through lacrimal puncta and into lacrimal canaliculi (1, 5) ->
Drains into nasolacrimal duct (3)
Olfactory mucosa
The olfactory mucosa covers thin ? of bone belonging to the ? bone called “ ? “ (red arrow - pic). It is located in the ? region of the nasal cavity
> 250 million olfactory receptors in their noses
The olfactory nerve (cranial nerve I) - made up of numerous ? that arise in the olfactory ? and pass through the ? to the olfactory bulbs of the brain.
(in pic: cribiform plate of ethmoid bone with cut ends of olfactory nerves
olfactory nerves)
Olfactory mucosa
The olfactory mucosa covers thin mucosa of bone belonging to the ethmoid bone called “ ethmoid conchae “ (red arrow - pic). It is located in the caudal region of the nasal cavity
> 250 million olfactory receptors in their noses
The olfactory nerve (cranial nerve I) - is made up of numerous axons that arise in the olfactory bulb (found in frontal lobe of brain) and pass through the cribriform foramen to the olfactory bulbs of the brain.
(in pic: cribriform plate of ethmoid bone with cut ends of olfactory nerves
olfactory nerves)
The Tongue
- ?–picking up food
- ?–chewing the food
- ?–swallowing the food
- ?
- Heat loss (in panting) in ?
- ? sensation-taste
Taste buds and lingual papillae
* Taste buds have receptor cells that get stimulated by ? substances.
* There are taste buds on ?, ?, and fungiform papillae.
which is the ONLY papillae doesn’t have taste buds and where is it present on tongue? (top, body or tip)
The Tongue
- prehension–picking up food
- mastication–chewing the food
- deglutition–swallowing the food
- grooming
- Heat loss (in panting) in dogs
- gustatory sensation-taste
Taste buds and lingual papillae
* Taste buds have receptor cells that get stimulated by soluble substances.
* There are taste buds on vallate, foliate, and fungiform papillae (NOT on filiform - only mechanical purpose!!)
(valate papillae are located on the top part of tongue and fungiform is located on the middle/body of tongue and
filiform papillae is located on tip of the tongue
- FILIFORM PAPAILLAE HAVE NO TASTE BUDS on tip of tongue!
Taste vs Touch sensations – innervation
The lingual branch of the “ ** ? ** “n. (IX) is sensory or motor or both? (taste + touch) from the ? of the tongue.
The lingual nerve is sensory or motor or both? from the rostral ? of the tongue:
* Touch sensation is sent to the brain from the ? n. (V)
* Taste sensation is sent to the brain from a part of the ? n. (VII)
Taste vs Touch sensations – innervation
The lingual branch of the “ ** glossopharyngeal n. ** “. (IX) is sensory (taste + touch) from the caudal one of the tongue.
The lingual nerve is sensory from the rostral two thirds of the tongue:
* Touch sensation is sent to the brain from the trigeminal n. (V)
* Taste sensation is sent to the brain from a part of the facial n. (VII)
