Larynx + Brain Review Flashcards
3 functions of the larynx
- respiration
- protection (from food getting to respiratory)
- phonation (vocal cords)
What is the main clinical relevance of the larynx?
oxygen (need unrestricted airflow in all animals)
What are the 4 cartilages of the larynx? Which is paired?
- epiglottic cartilage
- thyroid cartilage
- arytenoid cartilage (paired)
- cricoid cartilage
The laryngeal cartilages are composed of _______ cartilage except _______ which is composed of _______.
elastic
cricoid cartilage
hyaline
Function of epiglottic cartilage
close laryngeal opening during swallow
The horse has a _______ process on the epiglottic cartilage.
cuneiform
The hyoepiglottic ligament is from the __________ to the rostral edge of the epiglottic cartilage.
basihyoid bone
The soft tissue which spans the space of the thyroid fissure creates the ________.
thyroid foramen
The thyroid foramen is where ____________ enters the larynx to innervate laryngeal mucosa.
internal branch of cranial laryngeal N
Equids have a ________ in the thyroid cartilage which allows access to internal larynx during surgery.
deep caudal thyroid notch
What are the processes of the arytenoid cartilages?
- corniculate
- vocal
- muscular
The cricoarytenoideus dorsalis and lateralis Mm attach to the ______ process of the arytenoid cartilages.
muscular
Which laryngeal cartilage is the most caudal?
cricoid
_______ is the area on the cricoid cartilage where the cricoarytenoideus dorsalis M attaches.
median crest
_________ ligament is between the first tracheal ring and the ventral lamina and cricoid cartilage, connecting the trachea to larynx.
cricotracheal ligament
_______ ligament is between the cricoid and thyroid cartilage.
cricothyroid ligament
________ ligament from the cuneiform process of the epiglottis to the arytenoid cartilages.
vestibular
_______ ligament is from the thyroid cartilage to the vocal process of the arytenoid cartilage.
vocal
What is the term for entrance into the larynx?
aditus laryngis
What is the most rostral cavity of the larynx itself called?
vestibule
Term for opening between vestibular folds.
rima vestibuli
Term for blind pocket between vestibular and vocal fold only in the horse.
laryngeal ventricle
What is the term for the vocal apparatus?
glottis
Of the glottis, the vocal folds cover the _______ M in the horse, and the ________ M in the ox.
vocalis
thyroarytenoideus
Term for opening between vocal folds and arytenoid cartilages.
rima glottidis
The most caudal cavity in the larynx is called:
infraglottic cavity
List the 5 extrinsic muscles of the larynx.
- hyoepiglotticus
- thyrohyoideus
- sternothyroideus
- thyropharyngeus
- cricopharyngeus
Contraction of the sternothyroideus M causes what? Which muscle does the oppposite?
larynx pulled caudally
thyrohyoideus (pulls rostrally)
List the 5 intrinsic muscles of the larynx.
- cricothyroideus
- cricoarytenoideus dorsalis
- cricoarytenoideus lateralis
- arytenoideus transversus
- thyroarytenoideus
The thyroarytenoideus M is split into which two muscles in the horse?
vocalis
ventricularis
Which nerve innervates all but one intrinsic muscle of the larynx? Which does it NOT innervate?
caudal laryngeal N
cricothyroideus M
What innervates the cricothyroideus M?
cranial laryngeal N
All but one intrinsic muscle of the larynx have the same action. What action is this? Which DOES NOT perform this action?
narrows glottis
cricoarytenoideus dorsalis M
Function of cricoarytenoideus dorsalis M.
enlarges glottis
Cranial laryngeal A. is branch of ________.
cranial thyroid A.
What are the 5 common clinical signs of laryngeal pathology?
- coughing
- abnormal breathing sounds (stridor or sturdor)
- exercise intolerance
- increase respiratory effort
- asymmetry
Match whether these disorders have infectious causes or exercise-induced:
- infectious bovine rhinotracheitis
- dorsal displacement of soft palate
- laryngeal hemiplegia
- arytenoid chondritis
- necrotic laryngitis
- epiglottic entrapment
Infectious: 1, 4, 5
Exercise: 2, 3, 6
What causes epiglottic entrapment?
hyperplasia (increased cells) of aryepiglottic fold
Laryngeal hemiplegia causes narrowing on one side of rima glottidis caused by damage to what two structures?
cricoarytenoideus dorsalis M
recurrent laryngeal N
The PSNS is ________ while the SNS is ________.
craniosacral
thoracolumbar
List the 5 regions of the brain.
telencephalon
diencephalon
mesencephalon
metencephalon
myelencephalon
What are the 3 layers of the meninges covering the CNS? Order from superficial to deep?
- dura mater (outmost/superficial)
- arachnoid (middle)
- pia mater (innermost/deepest)
Name the part of the dura mater matched to each location:
- projects to transverse cerebral fissure
- projections separate hypophysis from brainstem
- projects into longitudinal cerebral fissure
- tentorium cerebelli membranaceum
- diaphragma sellae
- falx cerebri
Match the region of the brain to its contents:
- thalamus, hypothalamus, geniculate nuclei, hypophysis
- tectum, tegmentum, crus cerebri
- cerebral hemispheres
- pons, cerebellum
- trapezoid bodies, medullary pyramids
- diencephalon
- mesencephalon
- telencephalon
- metencephalon
- myelencephalon
Which cranial nerve is in the telencephalon? Diencephalon?
CNI (olfactory)
CNII (optic)
Which cranial nerves are in the mesencephalon?
CN III (oculomotor)
CN VI (abducens)
Which cranial nerve is in the metencephalon?
CN V (trigeminal)
Which 3 cranial nerves originate in the rostral myelencephalon?
CN VI (abducens)
CN VII (facial)
CN VIII (vestibulocochlear)
Of the caudal myelencephalon, what cranial nerves originate from the dorsolateral sulcus? Ventrolateral sulcus?
dorsolateral:
CN IX: glossopharyngeal
CN X: vagus
CN XI: accessory
ventrolateral:
CN XII: hypoglossal
Where is CSF made?
lateral ventricles
Order of CSF flow in the brain.
lateral ventricle –> interventricular foramen –> third ventricle –> mesencephalic aqueduct –> fourth ventricle
The mesencephalic aqueduct is bordered by the _______ which is the “roof” and the _______ which is the “floor”.
tectum
tegmentum
The fourth ventricle is bordered by the _________ which is the “roof” and ______ which is the “floor”.
cerebellum
rhomboid fossa
Which arteries anastomose to form the Basilar A in equine?
vertebral Aa + ventral spinal Aa
Which two arteries feed into the cerebral arterial circle in the horse?
basilar A
internal carotid Aa
In the ruminant, the vertebral Aa and the ________ meet the _________.
condylar Aa
rete mirable epidurale
The rete mirable epidurale has ______ and ______ components which are within the cavernous sinus.
rostral
caudal
