Key Points Identify the meaning of rhin- and olfactory.
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
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
Cerebral Cortex Voluntary movement (motor) Conscious sensations (sensory) Memory Integration (decisions) 4 lobes according to skull bones
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
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
Diencephalon Third Ventricle carries CSF Enters from Lateral ventricle via the interventricular foramen Exits to Fourth ventricle via the cerebral aqueduct
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
Key Points What does the term corpora quadrigemina mean? What structures are included in the corpora quadrigemina that you learned in lab?
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
Brain - Rhombencephalon Metencephalon – Cerebellum – Coordination & balance, quite large in birds & mammals – Pons – “bridge” between parts of brain – Fourth Ventricle carries CSF
Key Points What is the root enceph? Pro? Tel? Di? Mes? Met? Myel? Rhomb?
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
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
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
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
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?
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
Key Points Name the 12 cranial nerves in order.