Sheep Brain Dissection BIOL241
Name:________________________________________
1. Please use the lab manual to guide you in the Sheep Brain Dissection. A few things to make note of before
beginning:
a. the brain most likely has meninges still present. Look at the meninges. Note the tough dura mater (may only
be visible in certain places) and the “saran wrap/cottony” arachnoid mater.
b. If you remove the dura mater from the ventral side you will likely REMOVE THE PITUITARY, TOO! This is ok,
but do try to observe the pituitary gland, before it is “yanked” from the brain.
c. you should be able to easily see and identify SOME of the cranial nerves, but you probably will not find all of
them, as many of them may be damaged/cut. Do your best, but please don’t use all of lab time trying to find the
cranial nerves! You will be tested MUCH MORE on the FUNCTION of the cranial nerves, not the exact location
on a brain!
2. Fill out list below to indicate what structures you were able to identify in your dissection. Write a brief
description of the function of the parts of the brain in the list. I will not be collecting this chart. See how many
cranial nerves you can identify on your sheep brain (Try to at least find: Olfactory, Optic, Occulomotor,
Trigeminal, Vagus). Use a memnonic to help you remember the nerves or make up your own “On Occasion,
Our Trusty Truck Acts Funny, Very Good Vehicle Any How” [It is okay if you don’t find every structure/nerve in
the dissected brain, but what you can’t find in the lab, you should locate in text or lab manual].
3. Please do Lab Review Sheet 19 questions #1-6, 8, 10, 11, 13-16 (13-16 all optional, highly recommended)
Dissection Website Help:
Good video for external features (up to minute 2:40). WATCH THIS VIDEO BEFORE CLASS, or at least after class, to review!!!
http://academic.uofs.edu/department/psych/sheep/
For internal structures http://www.youtube.com/watch?v=y7gEWzPqm94&NR=1http://
http://academic.scranton.edu/department/psych/sheep/newsheep/practice/welcome3.html (use college level) another very,
very, in depth guide (perhaps too in depth for some):
http://131.104.216.80/faculty/peters/labmanual/PrintSheepBrain.html .
REALLY good website to review sheep brain anatomy: http://www.gwc.maricopa.edu/class/bio201/brain/brshpx2.htm
and Cranial nerves (also p.502- 508 your text): http://www.gwc.maricopa.edu/class/bio201/cn/cranial.htm
Human brain structures: http://library.med.utah.edu/WebPath/HISTHTML/NEURANAT/NEURANCA.html#1
Check list for Sheep Brain Dissection
Structure
Check 
Meninges
Description / Function
Dura mater
Arachnoid
Pia mater
Right and left cerebral hemispheres
Longitudinal fissure
Frontal lobes
Temporal lobes
Occipital lobes
Parietal lobes
Cerebral peduncles
(posterior and lateral to
the mammillary body)
Basal nuclei (more easily
observed in illustrations
in lab manual or text).
Cerebellum
Cerebellum
Arbor vitae
4th ventricle (notice its
Location in relation to the
cerebellum)
Brain Stem
Midbrain (see separate section
below, for additional
Midbrain structures to
identify)
Pons
Medulla oblongata
Ventral surface of brain
Olfactory bulb
Optic nerves
Optic chiasm
Mammillary body
Midbrain
Corpora quadrigemina
Pineal body (look deep between cerebral
hemispheres)
Sagittal section of sheep brain
(internal structures)
Corpus callosum
Fornix
Septum pellucidum
Lateral ventricles +
Ventricles 3 and 4
Pituitary gland (may be
Missing at this point, look at Dura mater
remnant).
Hypothalamus
Thalamus