Laboratory Exercise IV

Squalus acanthias

Nervous system:

Brain: the assignment with respect to cranial nerves is that you can list in order (0- X) the cranial nerves present in the shark (as an example of a primitive vertebrate).

Dorsal view:

Telencephalon: olfactory bulbs, *olfactory tract, *cerebral hemispheres, *olfactory sac

Diencephalon: epithalamus, *tela choroidea

Mesencephalon: *optic lobes

Metencephalon: *cerebellum, auricles

Myelencephalon: *medulla oblongata

Ventral (DO NOT DISSECT: use models): *optic nerves, *optic chiasma

Ventricles of the brain (use figures 12.8): ventricles I & II (lateral ventricles), ventricle III, aqueduct of Sylvius, ventricles IV

Cerebrospinal fluid circulation and meninges (see figure 12.8): *anterior choroid plexus, *posterior choroid plexus

The occipital nerves, hypobranchial nerve, spinal nerves and spinal cord: omit

Cervicobrachial and lumbosacral plexus: omit

Autonomic nervous system: omit

Sense organs:

Olfactory apparatus: incurrent opening, nostril, *olfactory epithelium, excurrent opening

Lateral line system: *lateral line, *ampullae of Lorenzini

Auditory and equilibrium apparatus: omit

Eye and extrinsic eye muscles:

External: *ventral oblique, *ventral rectus, *dorsal oblique, *dorsal rectus, *medial rectus, *lateral rectus

Internal: omit

Endocrine system:

Hypophysis or pituitary (use model): *pituitary (omit individual lobes), *infundibulum

Pineal gland (use model): *pineal gland

Thyroid gland: *thyroid gland

Thymus gland: omit

Adrenal gland: omit

Pancreas: *dorsal lobe, *ventral lobe

Ovaries: *ovaries

Testes: *testes

Other endocrine tissue: omit

* Know function (use Fishbeck et. al  text). For cranial nerves innervating intrinsic eye muscles, a complete "function" would include the muscle(s) it innervates.