1. Cerebrum
Lundy-Ekman, Chapters 17, 18

2. Objectives
Explain the organization of cerebral cortex and subcortical structures
Identify the motor and cognitive functions of the basal ganglia, and the effects of injury on these functions
Recognize the cellular and structural organization of the cerebral cortex
Describe the anatomical and function meaning of Brodmann’s areas

3. For the different regions of cerebral cortex
Describe the functional significance of the following classifications of regions of cerebral cortex: Primary Sensory Areas, Sensory Association Areas, Primary Motor Areas, Motor Association Areas, and Heteromodal Association Areas
For the different regions of cerebral cortex
Identify the Brodmann’s area
Describe the function of the area
Describe the effects of injury on function

4. For higher cognitive and cerebral functions:
Describe the function
Identify the side and the region of the brain important for this function
Describe the effects of brain injury on the function
Identify regions of the brain important for attention and awareness
Differentiate between selective and sustained awareness

5. Identify anatomical structures and pathways important in the ARAS
Describe the different types of memory
Identify regions of the nervous system important for each type of memory

6. Cerebrum Diencephalon Thalamus Hypothalamus Epithalamus
Subthalamic nucleus
Telencephalon
Subcortical structures
White matter
Basal Ganglia
Cerebral Cortex

8. Intralaminar nuclei
Midline nuclei
Reticular nuclei

9. Thalamic nuclei Relay nuclei Association nuclei Non-specific nuclei
Relay information to cerebral cortex from?
Association nuclei
Emotional and some memory info
Integrate different types of sensation
Reciprocal connections with large areas of cortex
Non-specific nuclei
Multiple inputs, Output to large areas of cortex
Consciousness and arousal

10. Thalamic damage
To relay nuclei
Thalamic pain syndrome

11. Hypothalamus

12. Hypothalamus Homeostasis Body temperature Metabolic rate
Blood pressure
Water intake and excretion
Digestion

13. Epithalamus Pineal gland Regulate circadian rhythms
Regulate pituitary gland, adrenal gland, parathyroid gland and pancreas

14. Subthalamus

15. Organization of the Cerebral Cortex
Outer layer
Cells
Deeper layer
Basal Nuclei
Subcortical White Matter

16. Subcortical White Matter
Thalamus
Lenticular nucleus
Internal capsule

17. Subcortical White Matter
Projection fibers
Commissural fibers
Association fibers

19. Basal Ganglia Motor Functions Cognitive Functions Injury
Motor deficits
Behavioral deficits
Loss of initiative
Spontaneous thought
Emotional responses

20. Cerebral Cortex Divided into layers Neocortex – 6 layers
Layers differ between different regions of the cerebral cortex
Same 6 layers but they differ in thickness and appearance
p. 413

21. Brodmann’s areas Cytoarchitectural areas Korbinian Brodmann – 1909
Figure 17-8 (page 413)
Structure correlated with function

22.                                                
Brodmann’s areas

23. Overall organization of cerebral cortex
Primary Sensory Areas
Sensory Association Areas
Primary Motor Areas
Motor Association Areas
Heteromodal Association Areas

24. Primary Sensory Cortex
Receives input from thalamic regions
Only one type of sensation
Somatosensory
Auditory
Visual
Vestibular
Representation of sensation is topographically organized

26. Primary Somatosensory Cortex
Brodmann’s areas 3, 1, 2 (precentral gyrus)
Function
Location of stimuli
Discriminate among shapes, sizes and textures
Damage
Loss of discrimination – location and strenght
Crude awareness intact
Localization of pain intact

27. Primary Auditory Cortex
Brodmann’s area 41 (Superior Temporal Gyrus)
Pathway
Cochlea  Cochlear nucleus  inferior colliculus/medial geniculate body  CTX
Function
Conscious awareness of sound – bilateral
Not extremely well lateralized
Damage
Loss of localization

28. Primary Vestibular Cortex
Brodmann’s area 40 (Parietal-temporal-occipital association area)
Function
Information about head movement and position
Information also travels through thalamus
Damage
Loss of conscious awareness of head position and movement

29. Primary Visual Cortex Pathway Brodmann’s area 17 – occipital lobe
Retina  LGN  10 visual cortex
Brodmann’s area 17 – occipital lobe
Function is to distinguish
Light/dark
Various shapes
Location of objects
Movement of objects
Damage – contralateral homonymous hemianopsia

30. Sensory Association Areas
Contribute to the analysis on one type of sensation – unimodal
Usually located adjacent to primary sensory cortex for that modality
Input from both primary sensory cortical area and the thalamus
Damage – Agnosia – inability to identify something using one sensation

31. Projections Primarily to primary motor cortex
Also to Association areas
Important in formulating motor plans for complex movements

33. Somatosensory Association Cortex
Brodmann’s areas 5,7
Function
Integrate tactile and proprioceptive information
Stereognosis
Memory of tactile and spatial environment
Damage
Astereognosis
May avoid affected hand

34. Visual Association Cortex
Brodmann’s areas 18-21
Function
Analyzes colors and motion
Directs visual fixation
Damage
Visual agnosia is contralateral visual field

35. Auditory Association Cortex
Brodmann’s areas 22, 42
Function
Compares sounds with memories of other sounds
Categorizes sounds as music, language or noise
Damage – auditory agnosia
Left – unable to understand speech
Right – loss in interpretation of noises

36. Primary Motor and Motor Planning Areas
Primary motor cortex
Supplementary motor cortex
Premotor area
Broca’s area
Area corresponding to Broca’s area on the language non-dominant side of the brain

38. Primary motor cortex Brodmann’s area 4
Location – precentral gyrus, anterior part of paracentral lobule
Function
Source of many corticospinal neurons
Contralateral voluntary movements for lower face and extremities
Bilateral voluntary movements for upper face and back muscles

39. Damage to Primary Motor Cortex
Contralateral paresis – mostly in lower face and distal extremities
Loss – fractionation
Speech problems – spastic dysarthria
UMN disorder
Harsh, awkward speech

40. Motor Planning Areas Located anterior to primary motor cortex
Four regions
Supplementary Motor Cortex
Premotor Area
Both are in Brodmann’s area 6
Broca’s Area
Area on contralateral hemisphere corresponding to Broca’s

41. Supplementary Motor Cortex
Medial and superior area 6
Functions
Initiation of movement
Orientation of head and eyes
Planning bimanual and sequential movements

42. Premotor Area Lateral part of area 6 Functions
Controls trunk and girdle muscles
Medial activating systems

43. Broca’s Area Unilateral – Usually on L side Areas 44 and part of 45
Functions
Motor speech
Planning movements of mouth
Grammar
All the little word that help a sentence make sense

44. Area contralateral to Broca’s
Obviously, usually on R side
Functions
Similar to Broca’s area but for non-verbal communication
Plans nonverbal communication
Adjusts tone of voice

45. Inputs to primary motor cortex
Sensory input from thalamus and primary somatosensory cortex
Motor input from motor planning regions
Motor input from basal ganglia and cerebellum via the thalamus
Primary
Motor
Cortex Cb
Motor
Thalamus BG

46. Inputs to motor planning regions
Sensory information from sensory association areas
From BG and Cb – relayed by the thalamus

47. Cortical Motor Output Fibers Location of neuronal cell bodies
Corticospinal
Corticobulbar
Corticopontine
Cortical projections to putamen
Location of neuronal cell bodies
Primary motor cortex, motor planning areas, and primary somatosensory cortex

48. Damage to Motor Planning Areas
Apraxia
Inability to perform voluntary movements
Can perform involuntarily
Damage to PMA or SMC
Motor Preseveration
Uncontrollable repetition of a movement
Damage to SMC

49. Damage to area homologous to Broca’s area
Damage to Broca’s area
Broca’s aphasia
Difficulty producing verbal communication
Damage to area homologous to Broca’s area
Difficulty producing nonverbal communication