Brain stem & Cerebellum. The brain Telencephalon Diencephalon Cerebellum Brain stem.
Brain Prosencephalon – embryonic forebrain – Telencephalon Rhinencephalon –Olfactory bulbs...
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Transcript of Brain Prosencephalon – embryonic forebrain – Telencephalon Rhinencephalon –Olfactory bulbs...
Brain
Prosencephalon – embryonic forebrain– Telencephalon
Rhinencephalon– Olfactory bulbs– Olfactory tract– Olfactory lobe
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)MemoryIntegration (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 CSFEnters from Lateral ventricle via the
interventricular foramenExits 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
Cranial Nerves – See Cr. N. Page
I. Olfactory Nerve – Sensory only for smellII. Optic Nerve – Sensory only for visionIII. 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