1. Brain Prosencephalon – embryonic forebrain Telencephalon
Rhinencephalon
Olfactory bulbs
Olfactory tract
Olfactory lobe

4. Key Points
Identify the meaning of rhin- and olfactory.

5. Brain - Prosencephalon
Telencephalon
Cerebral hemispheres
Paleostriatum – primary region in fish, primarily involved with olfactory reflexes
Neostriatum – beginning with reptiles, more complex and paleostriatum becomes buried
Hyperstriatum – primarily in birds responsible for stereotypical behavior such as migration, courting, nesting

7. Brain - Prosencephalon
Telencephalon
Cerebral hemispheres = Cerebrum
Corpus striatum = Basal nuclei – remnants of paleostriatum buried in mammalian brain, responsible for stereotyped & repetitive movements
Cortex – starting with reptiles, billions of neurons that must be folded to fit in skull in mammals

10. Cerebral Cortex Voluntary movement (motor)
Conscious sensations (sensory)
Memory
Integration (decisions)
4 lobes according to skull bones

12. Brain - Prosencephalon
Telencephalon
Lateral Ventricles
Cavities in brain that contain
Cerebrospinal fluid (CSF)
Formed from blood vessels called choroid plexus
Circulates around CNS providing cushion, protection, nutrients

14. Cerebrum Comparisons

18. Brain - Prosencephalon
Diencephalon
Epithalamus - Pineal body is light receptor in agnathans & endocrine in gnathostomes
Thalamus – intermediate mass/adhesion; sensory relay
Hypothalamus – optic chiasma, infundubular stalk for pituitary gland; functions as endocrine, regulates ANS, emotions, water balance, thermostat, hunger, satiety

23. Diencephalon Third Ventricle carries CSF
Enters from Lateral ventricle via the interventricular foramen
Exits to Fourth ventricle via the cerebral aqueduct

25. Brain Mesencephalon – embryonic midbrain, but term used in adult too
Optic lobes – especially well developed in birds
Auditory lobes – auditory reflexes
Corpora Quadrigemina
Cerebral Peduncles – motor tracts
Cerebral Aqueduct – for CSF

26. Key Points What does the term corpora quadrigemina mean?
What structures are included in the corpora quadrigemina that you learned in lab?

31. Brain Rhombencephalon Embryonic hindbrain Myelencephalon
Medulla oblongata
Pyramids – crossing of sensory & motor tracts
Vital reflexes such as breathing, connection between brain & spinal cord for ascending & descending pathways

35. Brain - Rhombencephalon
Metencephalon
Cerebellum – Coordination & balance, quite large in birds & mammals
Pons – “bridge” between parts of brain
Fourth Ventricle carries CSF

40. Key Points What is the root enceph?
Pro? Tel? Di? Mes? Met? Myel? Rhomb?

41. Cranial Nerves – See Cr. N. Page
I. Olfactory Nerve – Sensory only for smell
II. Optic Nerve – Sensory only for vision
III. Oculomotor Nerve – Motor to intrinsic & extrinsic eye muscles

46. Cranial Nerves IV. Trochlear Nerve – motor to extrinsic eye muscles
V. Trigeminal nerve – mixed nerve, motor to mastication & pharyngeal arch muscles, sensory to nose & mouth
VI. Abducens nerve – motor to extrinsic eye muscles

51. Cranial Nerves
VII. Facial Nerve – motor to facial muscles, salivation, lacrimation, taste
VIII. Acoustic = Vestibulocochlear Nerve – sensory only for hearing & equilibrium
IX. Glossopharangeal Nerve – Motor for swallowing, taste

55. Cranial Nerves
X. Vagus Nerve – Sensory for taste, motor to visceral of thorax & abdomen for the Parasympathetic Nervous System
XI. Accessory Nerve – amniotes only – Motor for swallowing, head movement
XII. Hypoglossal Nerve – Amniotes only, motor for tongue

60. Key Points Which cranial nerves are sensory only?
Which cranial nerve is the most important for internal homeostasis?
Which cranial nerves are missing in the shark?

61. Key Points Name the three parts of the embryonic brain.
Match these terms with the three parts listed above:
Hypothalamus
Pons
Cerebral peduncle
Cerebellum
Cerebrum

62. Key Points
Name the 12 cranial nerves in order.