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assignment: describe in detail the process of swallowing. include a 
description of all musles, their innervation, and how they function as a 
unit. include references. minimum 2 pages, handwritten ok. due 12/6/96.
This assignment is for people who cut lab on the day of the biochem exam. 
PHEW. I was worried for a minute :)


today: move on w/head dissection,  move on and look at skull. know where 
nerves come out, etc. do we need to memorize names of all these holes and 
processes? no. but you need to see the hole, and know what nerve comes 
out of it.!!
think about origins and insertions of muscles on skull.

we're skipping the perineum for now. tomorrow we'll start goat/horse 
head.

other things about the skull/head we need to know.

membranes covering the brain:

attached to inner surface of bone, is the DURA MATER. you would have to 
peel it away from periosteum to see it. dura mater in spinal column is no 
longer adhered to bone - there is epidural fat in the epidural space. but 
in skull, it's on the bone. it's heavy and fibrous.

the next layer in is the ARACHNOID (spiderweb). between its trabecular 
layers,  is the subarachnoid space filled with CSF. then intimately 
attached to the brain is the PIA MATER.  the arachnoid and the pia are 
also closely associated.

in these specimens there is no "arachnoid space" per se.


venous drainage of the brain case....
maxillary vein, vertebral vein, internal jugular. also internal ventral 
vertebral vein ventral to spinal cord.

may see the dorsal sagittal vein.
w/in dura mater is dorsal sag vein. on sagittal section will see section 
of a transverse vein.- the transverse sagittal sinus. sinus=larger, non 
valve vein. also a cavernous sinus at the base of the brain.

next thing - more in horse skull....there's something we'll see called 
paranasal sinuses. these are air filled spaces in the skull...in the dog, 
you see the frontal paranasal sinus
also the maxillary sinus - not all that exciting in the dog. often it's 
just called the maxillary recess. 
note that it's a diverticulum of the nasal cavity as opposed to a fully 
qualified sinus. in dog, not filled w/air, but filled w/glandular tissue 
"lateral nasal gland" functions to moisten nasal cavity.

diagram- xsection nasal cavity
note septum, concha, vomer bone. (concha=turbinate)

concha: when air comes in nose, it's filtered through turbinates. 
important for temperature excchange - lots of vascular tissue over them.



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