Laboratory Exercise IX (part B)

SHEEP (Ovis) BRAIN:

Meninges and ventricles:

pia mater, dura mater, arachnoid, ventricles I & II, foramen of Monro, ventricle III, cerebral aqueduct, ventricle IV, *choroid plexus

External anatomy:

Telencephalon: *cerebral hemispheres, gyri, sulci, *olfacotry bulbs, laberal olfactory band, medial olfactory band, pyriform lobe

Diencephalon: *optic chiasma, *optic nerves (n. I)_, optic tract, infundibulum, *hypophysis

Mesencephalon: corpora quadrigemina (superior & inferior colliculi), cerebral peduncles, *oculomotor nerves (n. III), trochelear nerve (n. IV)

Metencephalon: pons, *cerebellum (vermis, hemispheres, folia)

Myelencephalon: *medulla oblongata, trigeminal nerve (n. V), abducens (n. VI), facial nerve (n. VII), *vestibulochchlear nerve (n. VIII), glossopharyngeal nerve (n. IX), *vagus nerve (n. X), spinal accessory nerve (n. XI), *hypoglossal nerve (n. XII) (n. VII- XI are difficult to identify individually)

Internal anatomy: sagittal section of brain:

Telencephalon: *corpus callosum, fornix, septum pellucidum, *lateral ventricles

Diencephalon: intermediate mass, *third ventricle, *foramen of Monro, thalamus, hypothalamus, epithalamus (pineal body)

Mesencephalon: *cerebral aqueduct, *corpora quadrigemina,

Metencephalon: pons, cerebellum, arbor vitae

Myelencephalon: *medulla oblongata, *fourth ventricle

Brainstem: review those structures already identified

Spinal cord:

Note information provided with the spinal cord model including the following: spinal meninges (*dura mater, arachnoid, *pia mater), spinal nerve (dorsal root, ventral root, spinal ganglion), sulci (dorsal fissure, ventral fissure), *central canal, gray matter, white matter

Review the cranial nerves: (Identify as many as practical; for all note whether it is motor and/or sensory)

                olfactory (N. I)

                optic nerve (N. II)

                oculomotor nerve (N. III)

                trochlear nerve (N. IV)

                trigeminal (N. V)

                abducens nerve (N. VI)

                facial nerve (N. VII)

                vestibulocochlear nerve (N. VIII)

                glossophyaryngeal nerve (N. IX)

                vagus nerve (N. X)

                spinal accessory nerve (N. XI)

                hypoglossal nerve (N. XII)

Cow eye:

                External structures: *optic nerve (n. I), *retractor bulbi

Internal strucutures: *vitreous humor, aqueous humor, fibrous coat (*sclera, cornea), choroid(iris, ciliary body), *nervous coat (retina), *tapetum lucidum, optic disk, *iris, pupil, *ciliary body, zonule fibers, ora serrata, lens

* Know function (use laboratory text as a guide).