Brain Development:

Primary vesicles Secondary vesicles Adult brain part

Proencephalon Diencephalon Thalamus & Hypothalamus

Telencephalon Cerebrum

Mesencephalon Mesencephalon Midbrain

RhombencephalonMyelencephalon Medulla Oblongata

Metencephalon Pons & Cerebellum

Cerebrospinal fluid (CSF) - formed in choroid plexes of 4 ventricles:2 lateral - one in each hemisphere3rd - interventricular foramen connect with 3rd w/ both lateral vent.4th - cerebral aqueduct connects 3rd and 4th vent. Three openings (apertures) from 4th into subarachnoid space:

2 lateral, 1 medianReturns to blood via arachnoid villa

Internal hydrocephallusExternal hydrocephallus

Blood-CSF barrierBlood brain barrier (BBB)

Medulla:Ascending and descending tractsInferior cerebellar peduncles - medulla to cerebellum Pyramids

Decussation of pyramidsReflex centers (nuclei)

Cardiac - CAC CICMedullary rhythmicity - respirationsVasomotor - blood vessel diameter

Cranial nerves VIII* - XII

Pons:Ascending and descending tracts

Middle cerebellar peduncles - pons to cerebellumNuclei:

Pneumotaxic - respirationApneustic "

Cranial nerves V – VIII*

Midbrain:Cerebral peduncles - connect upper brain w/ brain stem and SCSuperior cerebellar peduncles - midbrain to cerebelumCerebral aqueductCorpora Quadrigemina:

Superior colliculi – reflex center for eyes, head, neck in response to visual stimuli

Inferior colliculi – reflex center for head, trunk in response to auditory stimuli

Nuclei:Substantia Nigra – control subconscious myo activityRed Nuclei – coordinates myo activity w/ basal ganglia,

cerebellumCranial nerves III – IV

Reticular Formation:gray matter among white matter in medulla, pons, midbrainsensory and motor functionsRAS – consciousness and arousal

Hypothalamus:Involved with homeostasis, hunger, thirst, etc.Secondary controller of emotional behavior

Thalamus:Receives and interprets all sensory input (Cranial Nerve I -Olfactory). Relays information to sensory cortex of brain.

Thalamic Nuclei

Cerebrum:Outer layer - cerebral cortex (gray), gyriInner layer - whiteLongitudinal fissure - hemispheres (lobes), falx cerebri, corpus callosumCentral sulcus - separates frontal & parietalLateral cerebral sulcus - separates frontal & temporalParieto -occipital sulcus - separates parietal & occipitalTransverse fissure - separates cerebrum & cerebellumThree sets of fibers:

Association - w/i same hemiCommissural - between corresponding gyri in each hemiProjection - Ascending and descending tracts

Basal ganglia - paired masses of gray matter Corpus Striatum

Caudate Nucleus - controls large subconscious movementLentiform Nucleus

Putamen - same as CaudateGlobus Pallidus - regulates myo tone for specific

movementsLimbic system - gray matter, primary controller of emotions

Basal Ganglia

Limbic system

Cerebral cortex:Motor areas

Primary - controls groups of skeletal myoBroca's - control myo for speech

Sensory areasPrimary somesthetic - locate point of stimuli

Association areas Premotor - generates impulses to control complex, sequential learned movements (writing)Somesthetic association - integrates/interprets Wernicke's - comprehension written & spoken language.

Fibers connect w/ Broca'sCerebral asymetry

L hemi - verbal, math, analytical, etc.R hemi - non-verbal, music, spatial, etc.

Motor Areas of Cerebral Cortex

Sensory Areas of Cerebral Cortex

Association Areas of Cerebral Cortex

Cerebellum:Transverse fissure (Tentorium Cerebelli – cranial meninges in TF)Vermis - constricted portion, divides into hemi (falx cerebelli)Hemi divided into lobes

Anterior - controls large subconscious skeletal movementPosterior - sameFlocculonodular - equilibrium, posture

Three sets of fibersInferior cerebellar pedunclesMiddle " "Superior " "

Cerebellar Peduncles

Levels of Motor Control Low levels controlled by reflex arcs. Complex levels walking/swimming (FAPs)

Segmental - CPGsProjection - command nueronsProgram/instruction - Cerebellum and basal ganglia

Motor Areas of Cerebral Cortex