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Brain & Cranial Nerves.

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Presentation on theme: "Brain & Cranial Nerves."— Presentation transcript:

1 Brain & Cranial Nerves

2 Major Regions Brain stem Cerebrum Diencephalon Mesencephalon Pons
Largest region of the brain Divided into the cerebral hemispheres Fold – “gyrus” Groove – “sulcus” Diencephalon Thalamus Hyptothalamus Mesencephalon Pons Medulla Oblangata Most inferior Connects brain to spinal cord Cerebellum Brain stem

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4 Cranial Meninges and Ventricles of the Brain
Dura mater* Arachnoid mater – forms smooth covering of the brain Pia mater – contains the blood vessels that supply the brain

5 Dura Mater – 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

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7 Ventricles 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

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10 Regions of the Brain Cerebrum Diencephalon Mesencephalon Pons
Medulla Oblangata Cerebellum

11 CEREBRUM Conscious thought, memory processing/storage, reasoning
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

12 Corpus Callosum Connects the cerebral hemispheres
Relevance in epileptic episodes? Corpus calloscotomy – split brain?

13 Fornix / Anterior Commissure
Fornix is the inferior portion of the corpus callosum that connects the structures of the limbic system – “emotional” brain Fornix Anterior Commissure

14 Basal Nuclei Involved in automating voluntary muscle contractions

15 DIENCEPHALON 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

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17 MESENCEPHALON (MIDBRAIN)
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

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21 PONS Directs sensory information to the thalamus and cerebellum

22 MEDULLA OBLONGATA 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 activities

23 CEREBELLUM 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)

24 Primary Fissure

25 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 neurons!

26 CRANIAL NERVES Olfactory nerve (I)  receptors in the nose
Optic nerve (II)  transmit signals from retina Oculomotor nerve (III)  enables movement of the eye and eyelid Trochlear nerve (IV)  innervates trochlea of the eye Trigeminal nerve (V)**  muscles of mastication / largest nerve Abducens nerve (VI)  controls lateral recturs muscles of eye Facial nerve (VII)  muscles of facial expression / taste sensation from 2/3 front of tongue Vestibulocochlear nerve (VIII)  conducts information about hearing and balance Glossopharyngeal nerve (IX)  receives sensory information from tongue Vagus nerve (X)  parasympathetic control of heart, lungs, and digestive organs Accessory nerve (XI)  supplies sternocleidomastoid and trapezius muscles Hypoglossal nerve (XII)  innervates extrinsic and intrinsic muscles of tongue (except palatoglossus)

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