Exercise 20
 Cerebrum
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Largest region of the brain
Divided into the cerebral hemispheres
Fold – “gyrus”
Groove – “sulcus”
 Diencephalon
 Thalamus
 Hyptothalamus
Brain stem
 Mesencephalon
 Pons
 Medulla Oblangata
 Most inferior
 Connects brain to spinal cord
 Cerebellum
 Dura mater*
 Arachnoid mater – forms smooth covering of the brain
 Pia mater – contains the blood vessels that supply the brain
 Endosteal layer – “outer” layer
 Meningeal layer – “inner” layer
 Stabilizing extensions
 Falx cerebri
 Tentorium cerebri
 Falx cerebelli
 Dural sinuses – drain the blood from cranial veins into jugular veins
 Superior / Inferior sagittal sinuses
 Transverse sinus
 4 chambers  ventricles
 Each ventricle has a choroid plexus
where CSF is produced
 2 “lateral” ventricles
 Divided by Septum pellucidum
 3rd ventricle
 In the diencephalon
 4th ventricle
 Between brain stem and cerebellum
 Cerebrum
 Diencephalon
 Mesencephalon
 Pons
 Medulla Oblangata
 Cerebellum
Central Sulcus
 Conscious thought, memory
processing/storage, reasoning
 Regional specializations:
 Central sulcus – separates the motor region
from sensory region
 Pre-central gyrus – contains the primary motor
cotex
 Post-central gyrus – contains primary sensory
cortex (touch is perceived)
 Association areas – interprets and integrates
information
 Premotor Cortex – somatic motor association
area
 Connects the cerebral hemispheres
 Relevance in epileptic episodes?
 Corpus calloscotomy – split brain?
 https://www.youtube.com/watch?v=Z
MLzP1VCANo
 Fornix is the inferior portion of the corpus
callosum that connects the structures of
the limbic system – “emotional” brain
Fornix
Anterior
Commissure
 Involved in automating
voluntary muscle
contractions
 Thalamus – sense of awareness
 Picks up on sensory impulses (except smell and
proprioception)
 Relays sensory information to proper sensory cortex
 Hypothalamus – links nervous system to endocrine
system
 Regulates hunger, thirst, fatigue, circadian rhythms,
body temperature
 Mamillary bodies – control eating reflexes
 Infundibulum attaches the pituitary gland to
hypothalamus
 Pituitary gland – major endocrine gland responsible
for growth and development
 Superior colliculi
 Visual reflec
 Keep an object centered on the
retina by moving eyeballs and head
 Inferior colliculi
 Auditory reflex
 Moves the head to follow sound
 Directs sensory information to the
thalamus and cerebellum
 Autonomic center for visceral functions
 Sensory information enters brain via ascending tracks, and motor information enters
spinal cord via descending tracts
 Nuclei in this region regulate cardiovascular, respiratory, and digestive acitivities
 Covered by the cerebral cortex
 Hemispheres are divided by vermis
 Anterior and posterior lobes (smaller) are
separated by primary fissure
 Coordination of somatic motor functions
 Stores muscle patterns (i.e. playing piano,
playing tennis)
Primary
Fissure
- Higlly branched white matter is
called arbor vitae
- Cerebellar nuclei function in the
regulation of involuntary skeletal
muscle contraction
- Purkinjie (large neurons) cells
branch extensively and synapse
with thousands of neuons!
 Olfactory nerve (I)
 Optic nerve (II)
 Oculomotor nerve (III)
 Trochlear nerve (IV)
 Trigeminal nerve (V)**
 Abducens nerve (VI)
 Facial nerve (VII)
 Vestibulocochlear nerve (VIII)
 Glossopharyngeal nerve (IX)
 Vagus nerve (X)
 Accessory nerve (XI)
 Hypoglossal nerve (12)