Neuroanatomy Dr. EstradaCerebral cortex forms the complete covering over cereberal hemispheresMade up of gray matter1.5 4.5 mm in thicknessFunctional areas:Frontal LobePrecentral area divided into 2 regions:1. Posterior region motor area / primary motor area / broadmann area 4Found in precentral gyrus extending to the anterior part of the paracentral lobule medially*lateral aspect imageFxn: stimulation produces movements on the opposite side of the body (contralateral)Exceptions: bilateral movements: extraoccular muscles and muscles of the upper part of the face, tongue, jaw, larynx and pharynx*parts of the body in primary motor area imageUpper part of body lateral sideLateral medial sideMotor homunculusArea of face, hand, and fingers larger than other body parts = representation related to skill of the movement not to the muscle massMore neurons are involved in motor movements2. Anterior region premotor area / secondary motor arean / BM area 6Loc: Anterior part of precentral gyrus, posterior parts of sup, middle, inferior frontal gyri*image lat view of brainFxn: stores programs of motor activity related to past experiences, programs activity of primary motor area3. Supplementary motor areaFound anterior to the paracentral lobuleFxn: contralateral movements of the limbsAblation og this structure = No effect on limb movement (as long as primary motor area is intact)4. Frontal eyefield / BM area 8Located in middle frontal gyrusFxn: voluntary scanning movements of the eyes independent of visual stimuli, eyes can moves even without stimulus5. Motor speech area/ Brocas area/ BM area 44, 45Located inferior frontal gyrusBm 44 pars obercularisBm 45 pars triangularisLeft dominant individuals (right handed): brocas area is in left cerebral hemisphereRight dominant: brocas area right cmAblation of non-dominant part: no effect on speechFxn: motor movements employed in speech / ability to speak6. Prefrontal area / BM areas 9, 10, 11, 12 part of frontal lobe anterior to precentral area occupies sup, middle, inf frontal gyri, orbital gyrus (inferior part of frontal lobe near olfactory bulbs), ant of cingulate gyrusfxn: personality resides, determines judgment and initiative, regulates depth of feeling/ emotions*hypothalamus where emotions generate, amygdala strengthens emotion, prefrontal regulatesParietal lobe1. primary somesthetic area / bm 3, 1, 2loc: post central gyrus extending to the post part of paracentral lobulefxn: reception of general sensations (pain, touch, temp)receive afferents from ventral posterolateral and vpmedial of thalamussenasations from opposite of body go to primary somesthetic areaexceptions: laryx, pharynx, perineum (bilateral)representation: same as motor homunculus ---- sensory homunculusrelated to functional significance not to size of body parttwo-point discrimination test, face: easily determined, thigh: X2. somesthetic assoc area / bm areas 5 & 7loc: superior parietal lobulefxn: integrates different sensory modalitiesstereognosis testing: facing familiar objects in hand without vision. Identifying objects without seeing it. Differentiating through feeling/touchrelates it past experiences object can be interpreted and recognizedOccipital lobe1. primary visual area / bm 17loc: lies on the bank of calcarine sulcus/fissurefxn: reception of visual input (vision)2. secondary visual area / bm 18 & 19loc: surrounds primary visual areafxn: relates visual input received by primary visual are to past experiences ( what is seen is recognized and appreciated)ie: binigyan ka ng flower, na-appreciate mo, kinilig ka behoccipital eye field within secondary visua areafxn: movement of eyeballs when following an objectTemporal lobe1. primary auditory area / bm 41, 42 / gyrus of heschelloc: inner aspect of sup temporal gyrus,need to move lateral fissure of sylvius to appreciate itfxn: reception of soundsant part: receptions of sounds low intensity/frequencypost part: reception of sounds of high intensity/frequency2. secondary auditory / bm 22loc: just posterior to the primary auditory areafxn: interprets sounds, association of sounds with other sensory modalities3. sensory speech area of Wernicke/ wernickes area/ in other books: bm 22, pero in discussion Xloc: post primary auditory extending to the parietal lobe, encompasses sup temporal gyrusrelated to brocas area via the arcuate fasciculusreceived input from visual and auditory areasfxn: comprehension of written and spoken languagedefects in brocas and wernickes:brocas: speech is labored and difficult (cannot speak well) but can comprehendwernickes: cannot understand what is being spoken and reading, produces meaningless speech (word salad) parang yung ibang students pag nag recite, word salad4. taste area/ BM 43loc: inferior part of postcentral gyrus extending into the insulafxn: reception of tastefacial chorda tympani -> nucleus TS -> vpm thalamus -> bm 43clinical sig: electrical stimulationpatients undergoing electrical stimulation -> movements opposite of the body occurredfMRI: dye injected absorbed by brain cells -> when person raises his hand, neurons in motor activated (there are also activated in sensory area)~ for diagnosis

Ambidexterity plasticity of the brainFor example:Blind people: auditory area extends to the ___area9u