Anatomy/Physiology Flashcards
(35 cards)
Identify the right answer and justify what’s wrong: Among domestic animals, two of them have an enclosed orbit, and two of them have an opened orbit…
1. Horse and pigs; dogs and goats
2. Sheep and goats; pigs and cattle
3. Cattle and pigs; dogs and cats
4. Sheep and goats; pigs and dogs
G
1 False wrong: pigs and goats.
2. False wrong: cattle.
3. False wrong: pigs.
4. Correct.
Canine orbit: Identify the bones
GELATT: ophthalmic anatomy p. 43
Frontal
Palatine
Sphenoid
Zigomatic
Maxillary
Lacrimal
Orbital bones of dogs, cats, ox and sheep?
GELATT ophthalmic anatomy p. 43
Lacrimal
Zygomatic
Frontal
Sphenoid
Palatine
Maxillary
Orbital bones of horse and rabbit?
GELATT: ophthalmic anatomy p. 43
Lacrimal
Zygomatic
Frontal
Sphenoid
Palatine (same as the others)
Temporal
Goat has less orbital bones, 5 in total.
identify them.
GELATT: ophthalmic anatomy p. 43
lacrimal, zygomatic, frontal, sphenoid, palatine.
Within the orbit, various foramina and fissures provide osseous pathways for blood vessels and nerves: identify them.
GELATT: ophthalmic anatomy p. 42
Rostral alar, ethmoidal, lacrimal, orbital, ovale, optic, rotundum, supraorbital, maxillary, caudal palatine, sphenopalatine
Orbital fissure and foramen rotundum are typically fused to form the foramen orbitorotundum in which specie?
GELATT: ophthalmic anatomy p. 42
Cattle
Identify the three anatomic components of orbital fascia
GELATT: ophthalmic anatomy p. 42
Periorbita
Tenon’s capsule (or fascia bulbi)
Extraocular muscle fascial sheaths
sheath = bainha
Only species that has ethmoid bone as an orbital bone
GELATT: ophthalmic anatomy p. 43
Pig and human
Name the extraocular muscles and its related nerves
GELATT: ophthalmic anatomy p. 44
Dorsal rectus = Oculomotor (CNIII)
Ventral rectus = Oculomotor (CNIII)
Medial rectus = Oculomotor (CNIII)
Ventral oblique = Oculomotor (CNIII)
Dorsal oblique = Trochlear (CNIV)
Lateral rectus = Abducens (CNVI)
Retractor oculli = Abducens (CNVI)
The distribution of globets cells in the conjunctiva is heterogeneous. Identify the highest densities of GC in dogs and cats.
GELATT: ophthalmic anatomy p. 48
Dog: Lower nasal and middle fornix; lower tarsal portion of the palpebral conjunctiva
Cat: anterior surface of nictitating membrane and conjunctival fornices
What are the two layers of the conjunctiva?
GELATT: ophthalmic anatomy p. 48
Superficial = adenoid layer with lymphatic follicles and glands
Deep = fibrous layer with conjunctival nerves and vessels
The cornea is innervated by the ____________________, which are derived from the ophthalmic branch of the trigeminal nerve.
Long ciliary nerves
“In general, the most superficial layers are primarily innervated with ____, whereas more ____ are found in the stroma. This explains why a superficial corneal injury is often more painful than a deeper wound.”
GELATT: ophthalmic anatomy p. 54
pain receptors
pressure receptors
a) Identify the types of collagen and glycans in the stroma
b) Considering collagen types, which one is the most prevalent?
GELATT: ophthalmic anatomy p. 58
a) I, III, V, VI, XII
chonroitin 6- and 4 sulfates, dermatan sulfate, keratan sulfate
b) Collagen type I
Principal support structure of the cornea?
GELATT: ophthalmic anatomy p. 58
Colaggen fibrils
Proteoglycans
GAGS (heparan sulfates, chondroitin 4 and 6 sulfates, keratan sulfates, dermatan sulfates)
glycoproteins
Most abundant GAG? keratan!
Considering Descemet’s membrane, judge the following statements as false or True. Justify what’s wrong!
a) PAS - positive, homogenous, cellular membrane
b) Descemet’s membrane ends at the apex of the trabecular meshwork in the limbal region
c) Basement membrane of the posterior endothelium
d) Descemet’s membrane and iridocorneal angle share the same collagen type: VII.
GELATT: ophthalmic anatomy p. 60
a=False: it’s acellular
b=True
c=True
d=False: Type VIII
Cite the collagen types of Descemet’s membrane
GELATT: ophthalmic anatomy p. 60
III, IV, V, VI, VIII
Who am I?
I) I’m a single layer of flattened cells
II) My regerative ability varies with species
III) My active mitosis occurs primarily in the immature animal
IV) In adults my cells are usually hexagonal shaped
V) I can change the overall corneal thickness
VI) In young dogs my density is greater than 3000 cells/² but it can decrease to between 500 and 800 cells/mm² within age
GELATT: ophthalmic anatomy p. 60
Yasss, I’m Endothelium
(and I rule!)
The cornea is an exquisitely sensitive tissue: upon stimulation of the cornea, involuntary blinking occurs via intermediate relay from the ophthalmic branch of the ____ to orbicularis oculi innervation from the ____ nerve. This reaction is well known as ____.
GELATT: ophthalmic anatomy p. 131
trigeminal nerve
facial nerve
corneal or blink reflex
Concomitant with the blink reflex is reflex tearing from____ innervation to the ___________.
GELATT: ophthalmic anatomy p. 131
parasympathetic
lacrimal gland
False or True? justify.
a) Cochet-Bonnet esthesiometer shows that corneal sensitivity in dogs was highest, intermediate and lowest in the dolichocephalic, mesatocephalic and brachycephalic skull types
b) Corneal sensitivity is greatest in the peripheral cornea and lower in the central cornea
c) Corneal nerves fibers are sensory in origin with small proportion of sympathetic or parasympathetic in origin
d) Corneal nerve fibers respond to mechanical, chemical and thermal stimuli via facial nerve, hence are known as polymodal nociceptors
e) Corneal nerves maintain corneal epithelial health through the secretion of trophic factors and maintenace of basal tear secretions
f) All mammalian corneas contain a dense limbal plexus, multiple radially directed stromal nerve bundles, dense anastomotic subepithelial plexus and poorly innervated epithelium
GELATT: ophthalmic anatomy p. 132, 133, 134
a)True
b)False: it’s greater in the central and lower in the peripheral
c)True
d)False: via ophthalmic branch of the trigeminal nerve
e)True
f)False: richly innervated epithelium
As we know, corneal nerves maintain corneal epithelial health through the secretion of trophic factors and maintenace of basal tear secretions. Cite these trophic factors:
GELATT: ophthalmic anatomy p. 134
Acetylcholine
Vasoactive intestinal peptide
Neurotensin
Substance P
Calcitonin gene-related protein
Even an isolated corneal lesion can cause clinical signs as conjunctival hyperemia and anterior uveitis (miosis, ocular hypotension, aqueous flare). Explain the physiopathologic events related with this condition.
GELATT: ophthalmic anatomy p. 134
