The Human Brain Lectures
Master Watermark Image: http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gifDr.Haythem Ali Alsayigh University Of Babylon College Of Medicine MB.CH.B. F.I.M.B.S.
Part I:
Lobes, the Cerebral Cortex, and Cortical Regions of the BrainObjectives:
Students will be able to describe the general structure of the Cerebrum and Cerebral Cortex.Students will be able to identify the Cerebrum, the Lobes of the Brain, the Cerebral Cortex, and its major regions/divisions.
Students will be able to describe the primary functions of the Lobes and the Cortical Regions of the Brain.
The cerebral hemispheres occupy the greater part of the cranial cavity-above the floors of the anterior and middle cranial fossae, and above the tentorium cerebelli. One hemisphere, usually the left in right-handed people,is slightiy larger than the other and constitutes the dominant hemispher
Cerebrum -The largest division of the brain. It is divided into two hemispheres, each of which is divided into four lobes.
Cerebrum
Cerebrum
Cerebellum
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Cerebral Cortex
Cerebral CortexCerebral Cortex - The outermost layer of gray matter making up the superficial aspect of the cerebrum.
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Cerebrum
The medial surface of each hemisphere is flat and lies against the falx cerebri; below the falx the two hemispheres are joined by the corpus callosum. The undersurface of the hemisphere is more irregular than the medial surface; the orbital surface of the frontal lobe is slightly concave from the impression of the anterior cranial fossa, the temporal pole is boldly convex in conformity with the middle cranial fossa while the undersurface of the occipital lobe slopes downwards and outwards to conform with the shape of the tentorium cerebelli. The superolateral surface of the hemispheres is boldly convex in conformity with the shape of the skull.Cerebral Features:
Sulci – Small grooves dividing the gyri Central Sulcus – Divides the Frontal Lobe from the Parietal Lobe Fissures – Deep grooves, generally dividing large regions/lobes of the brain Longitudinal Fissure – Divides the two Cerebral Hemispheres Transverse Fissure – Separates the Cerebrum from the Cerebellum Sylvian/Lateral Fissure – Divides the Temporal Lobe from the Frontal and Parietal Lobes Gyri – Elevated ridges “winding” around the brain.Gyri (ridge)
Fissure (deep groove)Sulci (groove)
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Longitudinal Fissure
Transverse FissureSylvian/Lateral Fissure
Central Sulcus
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http://www.dalbsoutss.eq.edu.au/Sheepbrains_Me/human_brain.gif
Specific Sulci/Fissures:
Lobes of the Brain (4)
Frontal Parietal Occipital Temporal* Note: Occasionally, the Insula is considered the fifth lobe. It is located deep to the Temporal Lobe.
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Lobes of the Brain - Frontal
The Frontal Lobe of the brain is located deep to the Frontal Bone of the skull.(anterior cranial fossa)(Investigation: Phineas Gage)
It plays an integral role in the following functions/actions:
- Memory Formation
- Emotions
- Decision Making/Reasoning
- Personality
Investigation (Phineas Gage)
Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
The frontal lobe
The frontal lobe is located at the front of the brain and is 1-associated with reasoning, 2- motor skills, 3-higher level cognition, and 4-expressive language. 5-At the back of the frontal lobe, near the central sulcus, lies the motor cortex. 6-This area of the brain receives information from various lobes of the brain and utilizes this information to carry out body movements.ᯉ(ƔȠăpǯЂ戈ⓙЃ攰‚늘ѓ攰„攰…‡€їǿ́琂̿쎀οعنوان 3Аȿᕟΐlц怟Ꙉ�श墙�瓞⸿ૢ朞￦⏱垩槛㌔뙅⧞⺸ါ들혷혾앏ࠝ踌釞ᶂ갱쮚窋⋄ᶻᠫ勷Ẳ䉨紮霠鴯钑읬ⱘᮺ낤�䑈䎉㡲�䔌粍糼ꖖ쩤䪥ᅲ훐⚳尥禄袔胫몾�ꐻ楄∦ނ雴飼쿳讎⪾ᨈ픋ȯ턺ᨷ鰪賰枩셹峢䱦哣㝞줊᜕榚鐌趥덶큹壈먉팒ㅑꚔ블ຜ䤥肢叮堢ↆ翧Ｐ﹫섧ퟡ⿹�㽾揿ﯾ追㿷㚑呭嵍యඬ商뇼싿寙社欁䩟껌٥塨櫦Ծ㓘ᚃꈓˮ淺鋦䁙캣䇑綯귔㨚鲰늨易姽댬特頻ᱹఓ�ꄴ寄�儎쾬驧蚄횵힠⒥䔄疷㫘ᑰ윍鶉掦�ṙ髝揖ꄜ꜖修✗䳬ᝃ벹播겐舲铣⾤ᇨ٘�璞붺丶櫤磍䚵�鹹☐倚㗏탎찺芳臩ᔘ↡猴ꐩ埒ힳᙌᓄ࣑禲辙갦雠䶀䨇蔛튯隚婼㳪㑎玉䞡䬡齡醮橸뤆凤ᨙ༓Ⱘⅼ❚팿ꩇ䣴ꛟ뇼뒲굊᫉技☳랸♢문튴ꝋ⼐Ȣʹ垺끓䰳褩籸웅‣됎뭒鰶쐍벙낍济㆓䙓戂㵙퀚阛쐢䴠ҫ䴫黃숪ꡡ铉䴙鄛荚溆⥖磎퍜뭨爰䒧냴㾬疍奍嫷ࡷꪺ屶Ꞟ㝀㜆賾쓣짵Ⴢ灲Юꢠ용셮⇣ꆌ�벸쓀뺉砭䋌쩘챫磒Ֆ䖗☊蕲ႋ뭹닙�콦兽牰닁㔤虈ณ䰧ส壹杯읇笕ꀹ볿�峁놳帳蟖늇掲곣�菽澾Ⳋቯ鶫⠏笗䚯敐㈄閶ꠌﮀꄷ♀怷嬣䮆㠓퇠멀㐢쎀茥阙眦⯼橻鿴☦�ꆺ雘䒣챪圔ꙕ叏탎浩蘉酵鍦ꬊ㲛≍訽돒䥚镪잊༱犠긠ᙦꕇꛩ嬪峛�餗䯘�՚깧吢ᕫ㊡뀕꼤ࡏ漡ߜ揠숚䵌첆㴔귘垢㳁惴醷菊臝荭廀뵡㱂裱蟛귯�䐋᳛긽긽긽ٷ�宒⸦�涁ᶐ疽麲몷穗샳滣纉呶렯굧ᇺ∸㘾ⷺ뼫땥嬓ୖ筸ﭐ桽྿⎽탻䘾쟻﹊튱㴮牖䨷绞뷡뽯Ῑמּ�ꌳ㉠毢钟翓꓂떜购⟃륉ꦄ퐧鶃ᕂା滛⠬䃬铹퓜䳍屹憬頽ꉽ侄�䓪얉�쮏�弧盧ⰵ੶☶�㪇坐尯걽鷃囸䤶㸛戮䣨䗇搴啝嫿�ﯛ幟嵋�悿╪�Ｆ럨韉쩮뽭钁慻孼∟捜㼕判㛿訇㢪៹䭐Ѓ!댢�Цщ牤⽳潤湷敲浸䑬䮏썋ᑀﾂ롡鮂❢푚㬒∭䑈뺐럷�❳䳎琮㡹ⷰ荖䑩칇陗�ช㦻Ἀ㖐阶셉Ṉ쭖꯫ꘅꖼᝮᄊ呓虐ꛐ禍Ⓖ纃孪�궝ᠳ瑢풅㜈粍鉈椧僸䭢╯拮䰔�潜⾲㷷縻�뇾沛몔ᦽ彞р숚ﭘ伱쫾푟嚇̰칱鏆紖꜠먠퍅२沈Ͽ倀ŋⴂ᐀ࠀ℀諷ﶻ怟Ꙉ�श墙�瓞⸿ૢ朞￦⏱垩槛㌔뙅⧞⺸ါ들혷혾앏ࠝ踌釞ᶂ갱쮚窋⋄ᶻᠫ勷Ẳ䉨紮霠鴯쪦�鐱䈬侌䁑䈕犛诮㒊駺쥭鵬⮣犹䟘溸⋸ṉ욹쓚ઇ穛ꢭᲸ媯즔폫켥ﷳ�᜴牢氷聟ᨅￂ⭸⻥羗䷪堉㬂띧圯Ϋ䃺䁎譴톦ߺ䭐ȁ-!뮊эǢ Damage to the frontal lobe can lead to
1-changes in sexual habits, 2-socialization, 3-attention as well as 4-increased risk-akingBehavior Abstract thought processes ,5-Problem solving ,6-Attention , 7-Creative thought 8-Some emotion ,9-Intellect ادراك, Reflection 10-Judgment 11-Initiative ابداع,12- Inhibition ردع 13-Coordination of movements 14-Generalized and mass movements , 15-Some eye movements , 16-Sense of smell , 17-Muscle movements , 18-Skilled movements , 19-Some motor skills,Physical reaction, 20-Libido (sexual urges)
Frontal Lobe - Cortical Regions
Orbitofrontal Cortex – Site of Frontal Lobotomies Primary Motor Cortex (Precentral Gyrus) – Cortical site involved with controlling movements of the body. Broca’s Area – Controls facial neurons, speech, and language comprehension. Located on Left Frontal Lobe. Broca’s Aphasia – Results in the ability to comprehend speech, but the decreased motor ability (or inability) to speak and form words. Olfactory Bulb - Cranial Nerve I, Responsible for sensation of Smell* Desired Effects:1-- Diminished Rageحماسه 2- Decreased Aggressionالعدوانيه 3- Poor Emotional Responses * Possible Side Effects:- Epilepsy- Poor Emotional Responses- Perseveration (Uncontrolled, repetitive((تكراري actions, gestures(ايماء), or words)
Primary Motor Cortex/ Precentral Gyrus
Broca’s Area Orbitofrontal CortexOlfactory Bulb
Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
Regions
Investigation (Phineas Gage)
Lobes of the Brain - Parietal Lobe
The Parietal Lobe of the brain is located deep to the Parietal Bone of the skull.It plays a major role in the following functions/actions:
- Senses and integrates sensation(s)
Spatial awareness and perceptionالقدره على الفهم) )(Proprioception - Awareness of body/ body parts in space and in relation to each other) Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
Parietal Lobe
The parietal lobe is located in the middle section of the brain and is associated with: processing tactile sensory information such as pressure, touch, and pain. A portion of the brain known as the somatosensory cortex is located in this lobe and is essential to the processing of the body's senses. Damage to the parietal lobe can result in problems with: verbal memory, an impaired ability to control eye gaze and problems with language among other ailmentsParietal Lobe
Sense of touch (tactile senstation) Appreciation of form through touch (stereognosis) Response to internal stimuli (proprioception) Sensory combination and comprehension Some language and reading functions Some visual functionsParietal Lobe - Cortical Regions
Primary Somatosensory Cortex (Postcentral Gyrus) – Site involved with processing of tactile and proprioceptive information. Somatosensory Association Cortex - Assists with the integration(توحيد and interpretation) يفسرof sensations relative to body position and orientation in space. May assist with visuo-motor coordination. Primary Gustatory Cortex – Primary site involved with the interpretation of the sensation of Taste.Primary Somatosensory Cortex/ Postcentral Gyrus
Primary Gustatory CortexSomatosensory Association Cortex
Regions
Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
Lobes of the Brain – Occipital Lobe The Occipital Lobe of the Brain is located deep to the Occipital Bone of the Skull.
Its primary function is the processing, integration, interpretation, etc. of VISION and visual stimuli.
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Occipital Lobe
The occipital lobe is located at the back portion of the brain and is associated with interpreting visual stimuli and information. The primary visual cortex, which receives and interprets information from the retinas of the eyes, is located in the occipital lobe.Vision Reading Damage to this lobe can cause visual problems such as difficulty recognizing objects, an inability to identify colors and trouble recognizing words.
Occipital Lobe – Cortical Regions Primary Visual Cortex – This is the primary area of the brain responsible for sight -recognition of size, color, light, motion, dimensions, etc. Visual Association Area – Interprets information acquired through the primary visual cortex.
Primary Visual Cortex
Visual Association AreaRegions
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Lobes of the Brain – Temporal Lobe The Temporal Lobes are located on the sides of the brain, deep to the Temporal Bones of the skull.
They play an integral role in the following functions:
1 Hearing
2 Organization/Comprehension of language
Information Retrieval (Memory and Memory Formation)
Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
The temporal lobe
The temporal lobe is located on the bottom section of the brain. This lobe is also the location of the primary auditory cortex, which is important for interpreting sounds and the language we hear. The hippocampus is also located in the temporal lobe, which is why this portion of the brain is also heavily associated with the formation of memories. Damage to the temporal lobe can lead to problems with memory, speech perception and language skills.
Auditory memories Some hearing Visual memories Some vision pathways Other memory Music Fear Some language ,Some speech Some behavior amd emotions Sense of identity
Temporal Lobe – Cortical Regions Primary Auditory Cortex – Responsible for hearing Primary Olfactory Cortex – Interprets the sense of smell once it reaches the cortex via the olfactory bulbs. (Not visible on the superficial cortex) Wernicke’s Area – Language comprehension. Located on the Left Temporal Lobe. - Wernicke’s Aphasia – Language comprehension is inhibited. Words and sentences are not clearly understood, and sentence formation may be inhibited or non-sensical.
Primary Auditory Cortex
Wernike’s Area Primary Olfactory Cortex (Deep) Conducted from Olfactory BulbRegions
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Arcuate Fasciculus - A white matter tract that connects Broca’s Area and Wernicke’s Area through the Temporal, Parietal and Frontal Lobes. Allows for coordinated, comprehensible speech. Damage may result in: - Conduction Aphasia - Where auditory comprehension and speech articulation are preserved, but people find it difficult to repeat heard speech.
Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
Click the Region to see its Name
Korbinian Broadmann - Learn about the man who divided the Cerebral Cortex into 52 distinct regions: http://en.wikipedia.org/wiki/Korbinian_BrodmannModified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
Lobes and Structures of the Brain
B.
A.
C.
D.
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Lobes and Structures of the Brain
B.A. (groove)
C. (groove)
D.
E.
F.
G.
B. Frontal Lobe
G. Parietal Lobe
F. Occipital Lobe
D. Temporal Lobe
A. Central Sulcus
(groove)
E. Transverse Fissure
C. Sylvian/Lateral Fissure
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Cortical Regions
A.B.
C.
D.
E.
F.
G.
H.
I.
J.
K.
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Cortical Regions
A.B.
C.
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J.
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A. Primary Motor Cortex/ Precentral Gyrus
B. Broca’s Area C. Orbitofrontal Cortex
K. Primary Somatosensory Cortex/ Postcentral Gyrus
I. Primary Gustatory Cortex
J. Somatosensory Association Cortex
G. Primary Visual Cortex
H. Visual Association Area
E. Primary Auditory Cortex
F. Wernike’s Area D. Primary Olfactory Cortex (Deep)
http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif
A: Primary Motor Cortex
* This graphic representation of the regions of the Primary Motor Cortex and Primary Sensory Cortex is one example of a HOMUNCULUS:Homunculus
Brain
Right Hemisphere (the representational hemisphere) The right hemisphere controls the left side of the body Temporal and spatial relationships Analyzing nonverbal information Communicating emotionLeft Hemisphere (the categorical hemisphere) The left hemisphere controls the right side of the body Produce and understand language Corpus Callosum Communication between the left and right side of the brain
Brain
THE CEREBELLUM Balance Posture Cardiac, respiratory, and vasomotor centersTHE BRAIN STEM Motor and sensory pathway to body and face Vital centers: cardiac, respiratory, vasomotor
Brain
Hypothalamus Moods and motivation Sexual maturation Temperature regulation Hormonal body processes Optic Chiasm Vision and the optic nerve Pineal Body Unknown Ventricles and Cerebral Aqueduct Contains the cerebrospinal fluid that bathes the brain and spinal cordPituitary Gland Hormonal body processes Physical maturation Growth (height and form) Sexual maturation Sexual functioning Spinal Cord Conduit and source of sensation and movement
Lobes of the Cerebral Cortex (lateral surface)
Frontal lobe Parietal lobe Temporal Lobe Occipital lobe Limbic lobeLobes of the Cerebral Cortex (medial surface)
Frontal lobe Parietal lobe Temporal Lobe Occipital lobe Limbic lobeLobes of the Cerebral Cortex (basal surface)
Frontal lobe Parietal lobe Temporal Lobe Occipital lobe Limbic lobeLateral Surface Precentral Gyrus --- primary motor area Superior Frontal Gyrus Middle Frontal Gyrus Inferior Frontal Gyrus Pars Opercularis Pars Triangularis Pars Orbitalis Medial Surface Medial Frontal Gyrus Paracentral Lobule Basal Surface Rectus Gyrus Orbital Gyrus Inferior Frontal Gyrus
Gyri of the Frontal Lobe
] Broca’s area (dominant hemisphere)
Gyri of the Cerebral Cortex (Lateral Surface)
Gyri of the Cerebral Cortex (Lateral Surface)Broca’s area Pars Opercularis Pars Triangularis Pars Orbitalis
Motor Homunculus
Photograph of the brain of Broca’s patient called “Tan” (real name is Leborgne). Broca’s Area Pars triangularis and pars opercularis of the inferior frontal gyrus of dominant hemisphere.
Gyri of the Cerebral Cortex (Medial Surface)
Gyri of the Cerebral Cortex (basal surface)Gyri of the Parietal Lobe
Lateral Surface Postcentral Gyrus ---- primary somesthetic areaSuperior Parietal Lobule Inferior Parietal Lobule ---- Wernicke’s areaSupramarginal Gyrus Angular Gyrus Medial SurfaceParacentral LobulePrecuneusGyri of the Cerebral Cortex (Lateral Surface)
Gyri of the Cerebral Cortex (Medial Surface)Sensory Homunculus
Gyri of the Occipital Lobe
Lateral Surface Lateral Occipital Gyrus Superior Occipital Gyrus Inferior Occipital GyrusMedial Surface Cuneus Lingual Gyrus
Basal Surface Lingual Gyrus Occipitotemporal GyrusGyri of the Cerebral Cortex (Lateral Surface)
Gyri of the Cerebral Cortex (Medial Surface)Gyri of the Cerebral Cortex (basal surface)
Gyri of the Temporal LobeLateral Surface Superior Temporal Gyrus Middle Temporal Gyrus Inferior Temporal Gyrus
Basal Surface Lingual Gyrus Occipitotemporal Gyrus Medial Occipitotemporal Gyrus Lateral Occipitotemporal Gyrus
Gyri of the Cerebral Cortex (Lateral Surface)
Gyri of the Cerebral Cortex (basal surface)
Gyri of the Limbic LobeOuter Ring Cingulate Gyrus Isthmus of Cingulate Gyrus Parahippocampal Gyrus Uncus, Uncinate Gyrus
Inner Ring Hippocampal Formation Hippocampus, Ammon's Horn Dentate Gyrus Fasciolar Gyrus Indusium Griseum (Supracallosal Gyrus) Paraterminal Gyrus (Subcallosal Gyrus) Subcallosal Area (Parolfactory Area)
The Brain Stem The brain stem is comprised of the hindbrain and midbrain. The hindbrain contains structures including medulla, the pons and the reticular formation
The Midbrain
The midbrain is the smallest region of the brain that acts as a sort of relay station for auditory and visual information. The midbrain controls many important functions such as the visual and auditory systems as well as eye movement. Portions of the midbrain called the red nucleus and the substantia nigra are involved in the control of body movement. The darkly pigmented substantia nigra contains a large number of dopamine-producing neurons are located. The degeneration of neurons in the substantia nigra is associated with Parkinson’s disease.The Cerebellum
Sometimes referred to as the "little brain," the cerebellum lies on top of the pons, behind the brain stem. The cerebellum is comprised of small lobes and receives information from the balance system of the inner ear, sensory nerves, and the auditory and visual systems. It is involved in the coordination of motor movements as well as basic facets of memory and learning.The Thalamus
Located above the brainstem, the thalamus processes and relays movement and sensory information. It is essentially a relay station, taking in sensory information and then passing it on to the cerebral cortex. The cerebral cortex also sends information to the thalamus, which then sends this information to other systems.The Hypothalamus
The hypothalamus is a grouping of nuclei that lie along the base of the brain near the pituitary gland. The hypothalamus connects with many other regions of the brain and is responsible for controlling hunger, thirst, emotions, body temperature regulation, and circadian rhythms. The hypothalamus also controls the pituitary gland by secreting hormones, which gives the hypothalamus a great deal of control over many body functionsThe Limbic System
The amygdala is one of the major structures found in the limbic system. The limbic system is comprised of four main structures: the amygdala, the hippocampus, regions of the limbic cortex and the septal area. These structures form connections between the limbic system and the hypothalamus, thalamus and cerebral cortex. The hippocampus is important in memory and learning, while the limbic system itself is central in the control of emotional responses.The Basal Ganglia
The basal ganglia are masses of grey matter made of cell bodies lying deep inside the white matter of the cerebrum, and makes up part of the midbrain.BASAL GANGLIA
FUNCTIONSMajor folds:
Major gyri and sulci on the lateral surface of the cortex Although there are enough variations in the shape and placement of gyri and sulci (cortical folds) to make every brain unique, most human brains show sufficiently consistent patterns of folding that allow them to be named. Many of the gyri and sulci are named according to the location on the lobes or other major folds on the cortex. These include: Superior, Middle, Inferior frontal gyrus: in reference to the frontal lobe Precentral and Postcentral sulcus: in reference to the central sulcus Trans-occipital sulcus: in reference to the occipital lobe Deep folding features in the brain, such as the inter-hemispheric and lateral fissure, which divides the left and right brain, and the lateral sulcus, which "splits-off" the temporal lobe, are present in almost all normal subjectsFunctional divisions
Lectures
Brodmann areas were originally defined and numbered by the German anatomist Korbinian Brodmann based on the cytoarchitectural organization of neurons he observed in the cerebral cortex using the Nissl stain.Brodmann published his maps of cortical areas in humans, monkeys, and other species in 1909, along with many other findings and observations regarding the general cell types and laminar organization of the mammalian cortex.
(The same Brodmann area number in different species does not necessarily indicate homologous areas.) A similar, but more detailed cortical map was published by Constantin von Economo and Georg N. Koskinas in 1925
Brodmann areas have been discussed, debated, refined, and renamed exhaustively for nearly a century and remain the most widely known and frequently cited cytoarchitectural organization of the human cortex.
Many of the areas Brodmann defined based solely on their neuronal organization have since been correlated closely to diverse cortical functions. For example, Brodmann areas 1, 2 and 3 are the primary somatosensory cortex; area 4 is the primary motor cortex; area 17 is the primary visual cortex; and areas 41 and 42 correspond closely to primary auditory cortex. Higher order functions of the association cortical areas are also consistently localized to the same Brodmann areas by neurophysiological, functional imaging, and other methods (e.g., the consistent localization of Broca's speech and language area to the left Brodmann areas 44 and 45). However, functional imaging can only identify the approximate localization of brain activations in terms of Brodmann areas since their actual boundaries in any individual brain requires its histological examination
the 47 different areas of the cerebral cortex that are associated with specific neurologic functions and distinguished by different cellular components. They control movements of the lips and vocal cords as well as motor speech. Compare motor area. See also cerebral cortex.
Areas 1, 2 & 3 - Primary Somatosensory Cortex (rostral to caudal is 3, 1, 2) -Homunculus representation: legs and trunk fold over midline; arms and hands (most tissue dedicated) are along middle of strip; face (with much tissue dedicated to lips) near bottom. Area 4 - Primary Motor Cortex - motor homunculus Area 5 - Somatosensory Association Cortex Area 6 - Pre-Motor and Supplementary Motor Cortex (may congtribute to planning of complex coordinated movements.)
Area 7 - Somatosensory Association Cortex (involved in locating objects in space; where vision and proprioception converge, enabling us to determine where objects are in relation to parts of the body. Generally, use in visuo-motor coordination such as in reaching to grasp an object).) Area 8 - Dorsolateral prefrontal cortex involved in management of uncertainty (increasing uncertainty increases activation here, fMRI). Hope occurs here, a high-order expectation positively correlated with uncertainty. This area also includes frontal eye fields where conscious control of eyes is believed to take place. Area 9 - Dorsolateral prefrontal cortex - sustaining attention and working memory. Lesions cause difficulty in inhibiting responses.
Area 10 - Frontopolar area (involved in strategic processes of memory retrieval and executive function) Area 11 - Orbitofrontal area (orbital and rectus gyri, plus part of the rostral part of the superior frontal gyrus). involved in planning, reasoning, and decision making. Perhaps the only cortical constraint of the hypothalamus. Area 12 - Orbitofrontal area (used to be part of BA 11) Area 13 - Insular cortex
Area 14 - Insular cortex Area 15 - Anterior Temporal Lobe Area 17 - Primary Visual Cortex (V1) - highly specialized for processing information about static and moving objects and is excellent in pattern recognition. Area 18 - Secondary visual Association Cortex (V2) - bulk of the volume of the occipital lobe. Area 19 - Tertiery visual association cortex (V3) - with area 18, involved in feature-extraction, shape recognition, and visual attention.
Area 20 - Inferior Temporal gyrus - high-level visual processes and recognition Area 21 - Middle Temporal gyrus - auditory processing and language, notably left side Area 22 - Superior Temporal Gyrus, includes Wernicke's area in its posterior. Left side involved in generation and understanding of words. Right side, melody, pitch, and sound intensity. Area 23 - Ventral posterior cingulate cortex Area 24 - Ventral anterior cingulate cortex - motivation, will Area 25 - Subgenual cortex Area 26 - Ectosplenial area Area 28 - Posterior Entorhinal Cortex Area 29 - Retrosplenial cingular cortex Area 30 - Part of cingular cortex
Area 31 - Dorsal Posterior cingular cortex Area 32 - Dorsal Anterior cingulate cortex Area 34 - Anterior Entorhinal Cortex (part of parahippocampal gyrus) Area 35 - Perirhinal cortex (part of parahippocampal gyrus) Area 36 - Parahippocampal cortex (part of parahippocampal gyrus) Area 37 - Fusiform gyrus Area 38 - Temporopolar area - important area in self representation, semantic (left) and autobiographic (right) Area 39 - Angular gyrus, part of Wernicke's area - reading, on left side grapheme-phoneme conversion; and general semantic involvement Area 40 - Supramarginal gyrus part of Wernicke's area Area 41 - Primary Auditory Cortex - conscious awareness of sound Area 42 - Secondary Auditory Cortex Area 43 - Subcentral area (between insula and post/precentral gyrus)
Area 44 - pars opercularis, part of Broca's area on left hemisphere Area 45 - pars triangularis, part of Broca's area on left hemisphere Area 46 - Dorsolateral prefrontal cortex Area 47 - Inferior prefrontal gyrus - involved in syntactical processing Area 48 - Retrosubicular area (a small part of the medial surface of the temporal lobe) Area 52 - Parainsular area (at the junction of the temporal lobe and the insula)
PET (positron emission tomography) scan
2Q: Assuming this comical situation was factually accurate, what Cortical Region of the brain would these doctors be stimulating?Copyright: Gary Larson
Q: What do you notice about the proportions depicted in the aforementioned homunculus?
Q: What is meant by depicting these body parts in such outrageous proportions?
A: They are not depicted in the same scale representative of the human body.
A: These outrageous proportions depict the cortical area devoted to each structure. - Ex: Your hands require many intricate movements and sensations to function properly. This requires a great deal of cortical surface area to control these detailed actions. Your back is quite the opposite, requiring limited cortical area to carry out its actions and functions, or detect sensation.
Back-Hom.
* Note: Homunculus literally means “little person,” and may refer to one whose body shape is governed by the cortical area devoted to that body region.
Further Investigation
Phineas Gage: Phineas Gage was a railroad worker in the 19th century living in Cavendish, Vermont. One of his jobs was to set off explosive charges in large rock in order to break them into smaller pieces. On one of these instances, the detonation occurred prior to his expectations, resulting in a 42 inch long, 1.2 inch wide, metal rod to be blown right up through his skull and out the top. The rod entered his skull below his left cheek bone and exited after passing through the anterior frontal lobe of his brain.Frontal
Remarkably, Gage never lost consciousness, or quickly regained it (there is still some debate), suffered little to no pain, and was awake and alert when he reached a doctor approximately 45 minutes later. He had a normal pulse and normal vision, and following a short period of rest, returned to work several days later. However, he was not unaffected by this accident.
Learn more about Phineas Gage: http://en.wikipedia.org/wiki/Phineas_Gage
Frontal
http://www.sruweb.com/~walsh/gage5.jpg
Q: Recalling what you have just learned regarding the frontal lobe, what possible problems or abnormalities may Gage have presented with subsequent to this type of injury (remember the precise location of the rod through his brain)?
A: Gage’s personality, reasoning, and capacity to understand and follow social norms had been diminished or destroyed. He illustrated little to no interest in hobbies or other involvements that at one time he cared for greatly. ‘After the accident, Gage became a nasty, vulgar, irresponsible vagrant. His former employer, who regarded him as "the most efficient and capable foreman in their employ previous to his injury," refused to rehire him because he was so different.’ Q: It is suggested that Gage’s injury inspired the development of what at one time was a widely used medical procedure. What might this procedure be, and how does it relate to Gage’s injury? A: The frontal lobotomy. This has been used with the intention to diminish aggression and rage in mental patients, but generally results in drastic personality changes, and an inability to relate socially. This procedure is largely frowned upon today, with the development of neurological drugs as treatments.
Frontal
Resources
Images: http://www.dalbsoutss.eq.edu.au/Sheepbrains_Me/human_brain.gif http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg http://www.bioon.com/book/biology/whole/image/1/1-6.tif.jpg http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif http://www.math.tu-dresden.de/~belov/brain/motorcor2.gif Larson, Gary. The Far Side. Phineas Gage: http://www.sruweb.com/~walsh/gage5.jpg http://soma.npa.uiuc.edu/courses/bio303/Image7.jpg http://en.wikipedia.org/wiki/Phineas_Gage http://science-education.nih.gov/nihHTML/ose/snapshots/multimedia/ritn/Gage/Broken_brain1.htmlSuggested Supplementary Materials: Skeleton Outline for note-taking. Multiple Diagrams of the Human Brain. * Students will label features/lobes * Students will color-code cortical regions 3. Worksheets (matching, short answer, etc.), centered around the functions of the lobes and regions of the cerebrum. 4. A more in depth article on Phineas Gage. Read and discuss as a class - time permitting.
Suggested Assessments: Class/individual questioning throughout (especially at the conclusion of) the presentation. Homework worksheets - discussed or collected in class. Students will take a test on the nervous system in which they will be responsible for the structures, lobes, regions, functions, etc.
Broad Concept: There is a relationship between structure and function in organ systems of humans. 4.1 Explain how major organ systems in humans (e.g., kidney, muscle, lung) have functional units (e.g., nephron, sarcome, alveoli) with specific anatomy that perform the function of that organ system. 4.2 Describe how the function of individual systems within humans are integrated to maintain a homeostatic balance in the body.
* Note: This PowerPoint has been developed for Juniors and Seniors enrolled in Anatomy and Physiology Courses. Thus, the detail of the concepts and information contained herein is far greater than required by the state Biology standards listed above.
Massachusetts State Biology Standards