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BBio 351: Principles of Anatomy & Physiology I
Fall 2015
Worksheet for Lab 7: sheep brain & cranial nerves – KEY
Grading: 10 points total – 0.5 points for general participation and 9.5 points for the specific questions
marked below.
Superficial structures of the sheep brain
1. On the diagram below (from your textbook), clearly label the four lobes of the cerebral cortex and list
one sensory modality processed by each. Also label the ventricles (lateral, third, fourth).
Note: taste is a tricky one. At least some of it is localized to the frontal lobe, but some is in the insular
lobe, an area where the frontal, parietal, and temporal lobes converge.
2. On the diagram below (from http://faculty.alverno.edu/bowneps/, which got it from
http://msjensen.cehd.umn.edu/webanatomy/, which got it from P. Cull’s Sourcebook of Medical
Illustration), clearly label the precentral gyrus and postcentral gyrus (you can color them different colors,
shade them, etc.) and list the type of information processed by each. Also label the medulla, pons, and
cerebellum and list a function of each.
(The figure is not completely unambiguous with respect to the gyri. You look for the central sulcus; the
gyri are on either side of it. Below is one possibility.)
3. Where are the superior colliculi and inferior colliculi located? List a function of each. [3 pts. – 1 per
bullet]
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BBio 351: Principles of Anatomy & Physiology I
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They are located in the midbrain / in the brainstem / anterior to the cerebellum / etc.
The superior colliculus processes visual information.
The inferior colliculus processes auditory information.
4. What is the pupillary light reflex? In this reflex, which cranial nerve carries the sensory input, and which
carries the motor (muscular) output?
 This reflex adjusts the size of the pupil in response to the intensity of incoming light.
 Cranial nerve II (optic nerve) carries the sensory input.
 Cranial nerve III (oculomotor nerve) carries the motor output.
Internal structures of the sheep brain
5. Label the following structures in the diagram below (from E.N. Marieb et al., Human Anatomy &
Physiology Laboratory Manual):
 Cingulate gyrus
● Medulla and pons
 Corpus callosum, genu, splenium
● Pineal gland
 Fornix
● Pituitary gland
 Hippocampus
● Septum pellucidum
 Hypothalamus
● Thalamus
 Inferior and superior colliculi
Some structures might not have a label line, and you will not use all label lines.
6. Name a substance produced by the pineal gland, and a function of this substance. [1 pt.]
 Melatonin – regulates GnRH release according to day length.
7. List two important general functions of the hypothalamus.
 Secretes tropic hormones that control release of anterior pituitary hormones.
 Regulates many physiological variables (temperature, osmolarity, etc.) via negative feedback.
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BBio 351: Principles of Anatomy & Physiology I
Fall 2015
8. What is the overall function of the thalamus? [1 pt.]
 Relays and processes most sensory information on its way to the cerebral cortex.
9. What is the overall function of the hippocampus?
 Helps create and store new memories
10. Instructor’s initials for check of internal sheep brain structures: _[1 pt.]_
Cranial nerves
11. Label cranial nerves I, II, III, V, and VI on the diagram of a ventral view of a sheep brain (taken from
E.N. Marieb et al., Human Anatomy & Physiology Laboratory Manual). [2.5 points: 0.5 points for each
correct answer.]
12. Fill in the cranial nerve table below.
#
Name of cranial
nerve
I
II
III
IV
V
Olfactory
Optic
Oculomotor
Trochlear
Trigeminal
Sensory,
Motor, or
Both?
Sensory
Sensory
Motor
Motor
Both
Function (brief)
Hole(s) in cranium
Smell
Vision
Control of eye muscles
Control of eye muscles
Facial senses, chewing
Cribriform foramina
Optic canal
Superior orbital fissure
Superior orbital fissure
Superior orbital fissure (ophthalmic
branch), foramen rotundum
(maxillary branch), foramen ovale
(mandibular branch) – weren’t
expected to name the branches
13. Instructor’s initials, verifying completion of pipe cleaner exercise: _[1 pt.]_
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