After Quiz 6 Flashcards
Cornea
Transparent & circular front part of the eye that covers the: iris, pupil, & anterior chamber
Provides most of eye’s optical power
Light hits the cornea, bends (refracts) incoming light onto the lens
Sclera
Opaque, fibrous, & collagenous protective layer of the eye
Helps maintain rigidity
Limbus
Corneoscleral junction
Where cornea meets sclera
Uvea
Deep to sclera
Consists of choroid, ciliary body, & iris (contains the pupil)
Choroid
Vascular layer of the eye, located between the retina & the sclera
Ciliary body
Located between iris & choroids
Contains many muscle bundles that regulate the shape of the lens
Iris
Overlays the lens
Controls the amount of light that enters the eye (along with the pupil
Made of thin, elastic tissue with an opening (pupil) in the center; surrounded by a circular muscle (the sphincter)
It contains pigmented epithelium
Pupil
Controls the amount of light that enters the eye (along with the iris)
During low light = expands
During high light = contracts
Retina
Thin layer of neural cells along the back of the eyeball
Where light is converted into electrical impulses & sent along the optic nerve to the brain
Made of rods (dim light vision), cones (color vision), & photoreceptor cells
Zonule
Suspensory ligaments of the lens
Composed of zonular fibers
- Change tension via contraction & relaxation of the ciliary muscle to change the focusing power of the eye (contradictory)
Lens
Biconvex, transparent, & elastic structure that focuses the light coming in through the cornea & pupil
Loses its accommodation ability as the individual ages (called presbyopia)
Three parts:
- Lens capsule
- Lens epithelium
- Lens fibers
Lens capsule
Elastic & composed of collagen
Lens epithelium
Regulate most of the homeostatic functions of the lens
Lens fibers
Form the bulk of the lens
Vitreous humor
Clear, jelly-like aqueous solution that fills the space between the lens & retina
maintains the shape of the eyeball & provides clear path for light to travel to the retina
Aqueous humor
Fills the space between the cornea & the lens
Provides nutrients to the lens & corneal endothelium
Its pressure maintains the convex shape of the cornea
Anterior chamber
Fluid filled space between the cornea & iris
Posterior chamber
Narrow cavity between the iris & lens
Scleral sinus
Critical area for drainage of aqueous humor from the eyeball
*failure to drain = inc. intraocular pressure (glaucoma)
Tapetum lucidum
Light-colored, reflective area of choroid
Reflects light rays (improves vision in low-light conditions)
Found mostly in nocturnal animals
Nontapetal nigrum
Brown-black portion of interior of the eyeball
Optic disk
Entrance of optic nerve into posterior aspect of the eyeball
Contains no rods or cones (called the blind spot)
External jugular vein
Formed by meeting of linguofacial & maxillary veins
Linguofacial vein
Two major branches:
Lingual vein
Facial vein
Lingual vein
Drains blood from tongue larynx, & pharynx
Facial vein
Drains blood from the face
Maxillary vein
Drains blood from the ear, orbit, palate, nasal cavity, cheek, mandible, & cranial cavity
Facial nerve
Nerve VII
Supplies all superficial muscles of head & face, along with digastricus m (caudal belly) & platysma
Caudal thyroid artery
Supplies:
Trachea
Esophagus
Thyroid
Cranial thyroid artery
Supplies: Thyroid gland Parathyroid gland Pharynx-larynx mm. Sternocephalicus m. Cleidocephalicus m. (mastoid part)
Internal carotid artery
Major artery of head & neck
Supplies:
Brain
External carotid artery
Supplies structures within: Neck Face Scalp Maxilla Tongue
Occipital artery
Supplies caudal muscles of:
Skull
Meninges
Cranial laryngeal artery
Supplies larynx ___:
muscles
Mucous membrane
Glands
Lingual artery
Supplies:
Tongue
Tonsil
Facial artery
Supplies:
Lips
Nose
Caudal auricular artery
Supplies:
Ears
Superficial temporal artery
Supplies: Parotid gland Masseter m. Temporal m. Auricular m. Eyelids
Maxillary artery
Supplies:
Deep structures of the face
Alar canal
Inferior alveolar artery
Supplies:
Roots of lower jaw teeth
Skin (via mental branch)
Middle meningeal artery
Passes through oval foramen
Supplies:
Dura mater (via brain)
Infraorbital artery
Runs through maxilla bone -> under orbit of the eye
Supplies:
Some eye muscles
Cranial nerves
12
Emerge from or enter the brain through foramina of the skull
Sensory, motor, or mixed
Olfactory nerve
Cranial Nerve I
Supplies:
Olfactory bulbs
Vomeronasal organ
Optic nerve
Cranial Nerve II
Supplies:
Eyes (sight)
Oculomotor nerve
Cranial Nerve III
Supplies:
Muscles of the eyeball
Trochlear nerve
Cranial Nerve IV
Supplies:
Dorsal oblique muscle
Trigeminal nerve
Cranial Nerve V Three nerves: Opthalmic n. Maxillary n. Mandibular n.
Opthalmic nerve
Sensory nerve Supplies: Eyelids Eyeballs Nasal mucosa Skin of the nose
Maxillary nerve
Sensory nerve Supplies: Superior eyelid Nasal mucosa Superior teeth Superior lip Nose Lacrimal gland Nasal gland Palatine gland
Mandibular nerve
Sensory & motor nerve Supplies: Masseter m. Temporal m. Mucosa of the cheeks Lateral & medial pterygoid mm. Lower teeth Rostral/middle tongue Rostral belly of the digastricus m.
Abducent nerve
Cranial Nerve VI
Supplies:
Retractor bulbi m.
Lateral rectus m.
Facial nerve
Cranial Nerve VII Supplies: Platysma Buccinator Orbicularis oris Orbicularis oculi Levator nasolabialis Retractor anguli oculi lateralis Digastricus m. (caudal belly)
Vestibulocochlear nerve
Cranial Nerve VIII
Supplies:
Ears
Provides sense of hearing & balance
Glossopharyngeal nerve
Cranial Nerve IX Supplies: Tonsils of tongue Root of tongue Mucosa & muscles of pharynx
Vagus nerve
Cranial Nerve X Gives off R & L recurrent laryngeal nerves Supplies: Eyes Salivary glands Bronchi Esophagus Organs (Heart, stomach, liver, pancreas, kidneys, small intestines, colon)
L & R laryngeal nerves
Innervate:
trachea
Esophagus
Laryngeal mm.
Accessory nerve
Cranial Nerve XI Supplies: Trapezius Omotransversarius m. Sternocephalicus m. Cleidocephalicus m.
Hypoglossal nerve
Cranial Nerve XII Supplies: Motor to muscles of the tongue (intrinsic/extrinsic) Genihyoideus m. Thyrohoideus m.
