Cerbral cortex.


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Cerbral cortex.

  1. 1. • Dr.Zulcaif Ahmad• 03444737311• Hajvery University Lahore 12/28/2012 1
  2. 2. PhysiologyTopic Name:- Cerebral Cortex 12/28/2012 2
  3. 3. Cerebral Cortex Introduction:-• The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum(It is the part of the brain that controls thought, memory and the senses) of the mammalian brain. It covers the cerebrum and cerebellum(Help in maintaining bodys sense of balance.• Coordinates muscular movements with sensory information)• , and is divided into left and right 12/28/2012 3
  4. 4. • hemispheres. The cerebral cortex plays a key role in memory, attention, awareness, thought, language, and consciousness.• In human being , it has an area of 2.2 sq.m.• The human cerebral cortex is 2–4 mm (0.08–0.16 inches) thick. 12/28/2012 4
  5. 5. Grey MatterGrey matter (or gray matter) is a major component of the central nervous system, consisting of neuronal cell bodies, neuropil (den drites and unmyelinat ed axons), glial cells (astroglia and ol igodendrocytes) 12/28/2012 5
  6. 6. Sulcus• The surface of the cerebral cortex is folded in large mammals, such that more than two-thirds of it in the human brain is buried in the grooves, called "sulci“• depression in the surface of the brain called sulcus. 12/28/2012 6
  7. 7. Gyrus• A gyrus (pl. gyri) is a ridge on the cerebral cortex. It is generally surrounded by one or more sulci (depressions or furrows; sg. sulcus). 12/28/2012 7
  8. 8. 12/28/2012 8
  9. 9. Location of cerebral cortex 12/28/2012 9
  10. 10. Layers of Cerebral Cortex• Cerebral cortex consists of gray matter that surrounds the deeper white matter. It is formed by different types of nerve cells along with their processes and neuroglia.• Cerebral cortex is formed by six layers of structures. 12/28/2012 10
  11. 11. Layers1) Molecular or Plexiform layer2) External Granular Layer3) Outer Pyramidal Layer4) Internal Granular Layer5) Ganglionic Layer or Internal Pyramidal layer6) Fusiform Cell Layer 12/28/2012 11
  12. 12. 12/28/2012 12
  13. 13. Diffrence B/W Neocortex and Allocortex Neocortex AllocortexIt is the top layer of the • Remaining part of cerebral hemispheres, cerebral cortex has less 2-4 mm thick, and made than six layers of up of six layers, labelled structure. The part of I to VI (with VI being cortex is called the innermost and I allocortex. being the outermost) • It includes archicortex• Neocortex forms the and paleocortex that major portion of form the part of limbic cerebral cortex. system. 12/28/2012 13
  14. 14. 12/28/2012 14
  15. 15. Cerebral Dominance• Domaninance of one cerebral hemisphere over the other in the control of cerebral function. (the normal tendency for one half of th e brain, usually the left cerebral hemisphere in right- handed people, to exercise more control over certain functions (e.g. hand edness and language)than the other. 12/28/2012 15
  16. 16. Lobes Of Cerebral Cortex• In each hemisphere there are three surface lateral , medial and inferior surface. The neocortex of each cerebral hemisphere consists of four lobes. 12/28/2012 16
  17. 17. Lobes1)Frontal Lobe2)Parietal Lobe3)Occipital Lobe4)Temporal Lobe 12/28/2012 17
  18. 18. 1) Frontal Lobe of cerebral cortex• The frontal lobe forms one third of the cortical surface. It extend from frontal pole to the central sulcus and limited below by the leteral sulcus. 12/28/2012 18
  19. 19. The frontal lobe of cerebralcortex is divided in to two parts.1) Precentral cortex (which is situated) posteriorly.2) Prefrontal cortex (which is situated anteriorly.) 12/28/2012 19
  20. 20. Precental cortex• The posterior part of frontal lobe is called precentral lobe cortex.• Precentral cortex is further divided in three functional areas.1) Primary motor area2) Pre motor area3) Supplementary motor area 12/28/2012 20
  21. 21. 12/28/2012 21
  22. 22. Function of primary motor area• Primary motor area is concerned with initiation of voluntry movements and speech. Function of premotor areaThe posterior part of the premotor cortex sends its signals either directly to the primary motor cortex to excite specific muscle. 12/28/2012 22
  23. 23. Function of Supplementary motor area• The exact function of this area is not understood clearly.• It is suggested that it is concern with the co-ordinated skilled movements. 12/28/2012 23
  24. 24. Prefrontal cortex• It is the anterior part of frontal lobe of central cortex, in front of area 8 and 44. 12/28/2012 24
  25. 25. Function of Prefrontal cortex• It forms the center for the higher functions like emotion , learning , memory , and social behavior. short term memory are register here.• This area is the seat of intelligence so it is also called the organ of mind.• It is responsible for personality of the individual and various autonomic changes during emotional condition. 12/28/2012 25
  26. 26. Frontal lobe syndrome• The injury or ablation of prefrontal cortex leads to a condition called frontal lobe syndrome.• Features:-• Emotional instability• Lack of concentration• Lack of initiation and difficulty in planning any course of actions.• Hyperphagia (increased food intake) 12/28/2012 26
  27. 27. 2-PARIETAL LOBE• Parietal lobe extends from central sulcus and merges with occipital lobe behind the temporal lobe below 12/28/2012 27
  28. 28. Parietal lobe are further divided into three functional areas1) Somesthetic area I2) Somesthetic area II3) Somesthetic association area 12/28/2012 28
  29. 29. 1) Somesthetic area IIt is also called somatosensory area I or primary sensory area. It is present in the posterior lip of central sulcus. Function of Somesthetic area I. Discriminative(diffrence krna) function:-In addition to perception of cutaneous and kinesthetic(detects bodily position) sensation , this area is also responsible for recognization the discimitive features of sensation. 12/28/2012 29
  30. 30. • This area sends sensory feedback to the premotor area. It is also concerned with the movement of head and eyeballs.• It receives sensory impulses from cutaneous receptor (touch, pressure , pain and temperature ). 12/28/2012 30
  31. 31. 2) Somesthetic area II• It is situated in postcentral gyrus below the area of face of somesthetic area I . 12/28/2012 31
  32. 32. Function of Somesthetic area II• This area receives sensory impulses from somesthetic area I and from Thalamus directly. Though exact role of this area is not clear , it is concerned with preception( ) of sensation. 12/28/2012 32
  33. 33. 3) Somesthetic Association Area• This area is situated posterior gyrus , above the auditory cortex and in front of visual cortex.• Function of Somesthetic Association Area:-• It is concerned with the synthesis of various sensation perceived by 12/28/2012 33
  34. 34. somesthetic area I. thus the somesthetic association areaforms the center for combined sensation like stereognosis (understanding the form andnature of objects by the sense of touch. The lesion of thisarea causes astereognosis (Theinability to determine the form of an object by touch.) 12/28/2012 34
  35. 35. Parietal lobe syndrome• Lesion or ablation of parietal lobe(sensory cortex) results in the following disturbances1) Contralateral disturbance of cutaneous sensation.2) Disturbances in kinesthetic sensation.3) Loss of tactile(the ability to identify, without looking) localization and discrimination (understanding diffrence b/w one thing 12/28/2012 35 and another).
  36. 36. Temporal Lobe• Temporal lobe of cerebral cortex include three functional area.1) Primary Auditory area2) Auditopsychic area3) Area of equiblirium 12/28/2012 36
  37. 37. 12/28/2012 37
  38. 38. 1) Primary Auditory area• Primary auditory area includes.1) Area 412) Area 423) Wernicke’s areaArea 41 and 42 are situated in anterior transverse gyrus and leteral surface of superior temporal gyrus.Wernick’s area in upper part of superior temporal gyrus posterior to areas 41 and 42. 12/28/2012 38
  39. 39. Function of Primary Auditory area• Primary auditory area is concerned with perception of auditory impulses , analysis of pitch and determination of intensity and source of sound.• Area 41 and 42 are concerned only with perception of auditory impulses.• Wernicke’s area is responsible for the interpretation of sound. It carries out this function with the help of auditopsychic area (Area 22) 39 12/28/2012
  40. 40. 2) Auditopsychic area• It occupies the superior temporal gyrus .it is called area 22.• Functions:-• This area is concerned with interpretation of auditory sensation along with Wernicke’s area. 12/28/2012 40
  41. 41. 3) Area of equiblirium• This area is the posterior part of superior temporal gyrus.• Function:-• It is concerned with the maintenance of equilibrium of the body stimulation of this area causes dizziness, swaying (rhythmical movement) , falling and feeling of rotation. 12/28/2012 41
  42. 42. Temporal lobe Syndrome• It is observed in animal. It occurs in human being during bilateral lesions of these structure. The manifestation of this syndrome are :• Aphsia ( inability to understand)• Auditory disturbance• Disturbance in smell and taste• Dreamy states• Visual hallucination (real preception of some thing which is not present actually). 12/28/2012 42
  43. 43. Occipital Lobe• Occipital lobe is called the visual cortex.• Areas of Visual Cortex:-1) Primary visual area-area 172) Visual association area-area 183) Occipital eye field – area 19 12/28/2012 43
  44. 44. Function of Occipital Lobe• Primary area-area 17 is concerned with perception of visual impulses.• Visual association are-area 18 is concerned with interpretation of visual impulses.• Occipital eye field-area 19 is concerned with movement of eye. 12/28/2012 44
  45. 45. Occipital lobe syndrome• Lesion in the upper or lower part of visual cortex results in hemianopia.• Bilateral lesion leads to total blindness. 12/28/2012 45
  46. 46. Cerebral Cortex Lobes• Frontal Lobes -involved with decision- making, problem solving, and planning.• Occipital Lobes-involved with vision and color recognition.• Parietal Lobes - receives and processes sensory information.• Temporal Lobes - involved with emotional responses, memory, and speech 12/28/2012 46
  47. 47. 1.review.ca/I10-80-prefrontal.jpgwww.universe-review.ca2.8:30 AMGoogle Image Result forhttp://4.bp.blogspot.com/_aWjmeDtLYpk/TODVISxIYSI/AAAAAAAAAAg/i-Fo0Um9bCU/s1600/brain3.gif4.bp.blogspot.com3.8:29 AMparts of frontal lobe of cerebral cortex - Google Searchwww.google.com.pk4. • Morphonix - Brain - Cerebral Cortex: The Thinker • Virgil:Basic Neuroanatomy • Google Image Result for http://morphonix.com/software/education/science/brain/g ame/specimens/images/cerebral_cortex.gif • 12/28/2012 47
  48. 48. • uic.edu/classes/bios/bios100/lecturesf04am/lect22.htm• www.uic.edu• 7:37 AM• Google Image Result for http://www.uic.edu/classes/bios/bios100/lecturesf04am/ce rebrum_1.gif• www.uic.edu• 7:37 AM• Google Image Result for http://3.bp.blogspot.com/_G7la- BXebak/S94bOMmqHwI/AAAAAAAAC04/qo5jIaZsXto/s1 600/cerebral-cortex.jpg• 3.bp.blogspot.com• 7:36 AM• parts of cerebral cortex - Google Search• www.google.com.pk• 7:35 AM• Google Image Result for http://www.benbest.com/science/anatmind/FigV5.gif 12/28/2012 48• www.benbest.com
  49. 49. Thank You12/28/2012 So Much 49