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----begin mo chat-----
Yesteday we had the exam. Today we start the head. The heads are out 
there in ziploc baggies. Remove 2" strip of fur from nose all the way 
back, knock out the central incisors upper and lower w/hammer and chisel. 
Then he can split them. Also, you have to do that for the horse and rumen 
heads as well as the dogs.

Don't lose the ziploc bags. Daily, put dog heads in left cold box on the 
floor. keep all windows closed because they dry very fast.  
-----end mo chat------

dr orsini
lots of info int he head, every few millimeters is important!
We'll look at one side of the head for muscles and one side for vessels.
we're getting our practicals back after lab today.
p 269 start today (small miller). Dr dodson will lecture on the skull on 
monday.
Basically the dissection guide is like a cookbook. start at p 268 or 269. 
We'll first think about CN VII aka the Facial Nerve --->innervates 
muscles of facial expression. the names of the head muscles are long and 
confusing but they ARE named after the bones, so it's not too bad if you 
learn the underlying anatomy.
the laryngeal muscles are complex, it's a pretty sensitive region beause 
you have -[diagram]- and you have a food passageway and a nasal 
passageway and there's a criss cross of those pathways, known as the 
larynx, and it's heavily regulated by musculature etc to avoid food 
getting in airway etc.

so.

[diagram]
you have the base of the skull above the voicebox and it (the voicebox) 
is suspended by the bony hyoid apparatus

eg, the voicebox is suspended from base of skull by bony hyoid apparatus. 
the voicebox is made of the thyroid and crichoid cartilages, and the 
epiglottic cartilage cranially which flaps back and forth as needed to 
cover the airway as needed to prevent introduction of food. ALso the 
arytenoid cartilages.

so, a bolus of food enters the mouth and needs to get into stomach. the 
PHARYNX is where the esophagus passes by the hyoid apparatus. the 
PHARYNGEAL muscles connect to the cricoid cartilages and form a dome from 
one side tothe other, inserting on a median raphe dorsal to the 
esophagus. - CRICOPHARYNGEUS muscle. The one cranial to that starts at 
the thyroid cartilage and inserts dorsally, forming another dome. this is 
the THYROPHARYNGEUS muscle. there's another muscle of this group 
originating from last two bones of hyoid apparatus, and that's they 
HYOPHARYNGEUS. they are innervated such that the more cranial muscles 
contract first. They kind of blend into each other and you really need to 
look at the origin/insertion to determine which is which. they squeeze 
the phood into the esophagus :)

they are innervated by CN IX and X - glossopharyngeal and vagus.








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