1. CNS Basic Anatomy

2. SLP and Neuroscience Speech-Language Pathology
Study of developmental and acquired disorders of human cognition, language and speech
Complete neurolinguistic assessments and management

3. Neuroscience Neurology Neurosurgery Neuroanatomy Neuroradiology
Neuroembryology
Neurophysiology
Neuropathology

4. The Nervous System Central Nervous System (CNS)
Brain + Spinal Cord
Peripheral Nervous System(PNS)
Spinal Nerves
Cranial Nerves
All nerves to muscles and sensory reception sites

5. Terms for Fiber Tracts
Fiber tracts like the internet – sending information across distances
Bundle - a group of fibers
Column - a pillar of fibers
Fasciculus - a small bundle
Funiculus - a cord; a cord of nerve fibers in a nerve trunk
Lemniscus - a ribbon of fibers
Tract - a large group of fibers, a pathway

6. Organization CNS Relays incoming and outgoing messages
Integrates Information
Higher mental functions (language, cognition)
Regulates

7. The two hemispheres Bilateral Anatomical Symmetry
Connected by Corpus Callosum
Unilateral Functional Differences
Little lateralization of function at birth
Gradual development of specialization
Left hemisphere is dominant for language and handedness
Right hemisphere is dominant for music, emotion, and spatial processing

8. Laterality and Function
Sensory information projects to opposite hemisphere
Object felt in right hand, Information processed by left hemisphere
Pain felt in left foot, Information processed by right hemisphere
Motor functions are also contralateral
Motor
Functions
Sensory
Functions

9. Types of Brain Tissue
Gray Matter: The neurons or cells which have specialized neurologic functions (motor or sensory)
White Matter: Axons which form pathways for conducting different types of information.

10. Distinct Pathways
Connections are not random – specific. organization of connections.
Carry information from peripheral body parts to specific areas of the brain - project to particular cortex (outside bark) of the brain
Each peripheral body part has a receptive area of the brain responsible for processing or receiving input
Example: visual cortex

11. Plasticity of the Brain
Brain injury is permanent, but individuals can show recovery.
Plasticity refers to the brain’s ability to reorganize and modify functions and adapt to internal and external changes
Important for learning
Important for rehabilitation
Younger brains tend to be more plastic

12. How do we learn about brain function?
Classically, examine deficits following brain injury, infer that damaged brain area is required for task.
Today, most studies of brain function utilize neuroimaging techniques such as fMRI (functional Magnetic Resonance Imaging) or PET(Positron Emission Tomography) – These studies usually focus on normal brains

13. MRI scan
This image is in radiological orientation (left is shown on right).
Images can also be in neurological orientation (left on left)
These structural scans can show abnormalities and injury. L

14. CT Scans CT scans use X-Rays to see inside body. Excellent for bone
Often first scan in acute care (e.g. unconscious patient can not tell us if they have pacemaker, cochlear implant, or other contraindications to MRI).

15. PET/SPECT Images
Measures of blood flow can help determine brain metabolism. PET: Inject radioactively labeled glucose.
Note: reduced uptake in posterior region.

16. Combining anatomy and metabolism
Anatomical scans (T2 MRI) have excellent spatial resolution.
Metabolic scans can identify abnormalities (e.g. tumor).
Combining takes advantage of complementary strengths

17. Relative Coordinates
On the globe we talk about North, South, East and West.
Lets explore the coordinates for the brain.

18. Orientation Human anatomy described as if person is standing
If person is lying down, we would still say the head is superior to feet.

19. Orientation - animals Dorsal back Caudal tail Ventral belly
Rostral
Caudal
Ventral
Cranial head
Rostral beak
Caudal tail
Ventral belly

20. Coordinates – Dorsal Ventral
Human dorsal/ventral and rostral/caudal differ for brain and spine.
Head/Foot, Superior/Inferior, Anterior/Posterior not ambiguous.
Dorsal
Ventral
Dorsal
Ventral
Dorsal
Ventral

21. Coordinates – Human
Human dorsal/ventral and rostral/caudal differ for brain and spine.
Head/Foot, Superior/Inferior, Anterior/Posterior not ambiguous. C R R R C
Anterior
Posterior C

22. Anatomy – Relative Directions
lateral < medial > lateral
Posterior <> Anterior
Ventral/Dorsal
aka Inferior/Superior
aka Foot/Head
Ventral <> Dorsal
Anterior/Posterior
aka Rostral/Caudal
Posterior <> Anterior

23. Coordinates - Anatomy 3 Common Views of Brain: Coronal (head on)
sagittal
coronal
axial
3 Common Views of Brain:
Coronal (head on)
Sagittal (profile)
Axial (bird’s eye), aka Transverse. The book calls this ‘Horizontal’ but it is not horizontal when we are lying in a scanner.

24. Coronal
Corona: ‘crown’ a coronal plane is parallel to crown that passes from ear to ear
Coronal cut creates anterior, posterior portions

25. Transverse Transverse: perpendicular to the long axis
These cuts are also referred to as Axial.
Example: cucumber slices are transverse to long axis.

26. Sagittal Sagittal – ‘arrow like’
Sagittal cut divides object into left and right
sagittal suture looks like an arrow.
top view

27. Sagittal and Midsagittal
A Sagittal slice down the midline is called the ‘midsagittal’ view.
midsagittal
sagittal

28. Oblique Slices
Slices that are not cut parallel to an orthogonal plane are called ‘oblique’.
The oblique blue slice is neither Coronal nor Axial.
Cor
Oblique Ax

29. Distance from midline
Medial – near sagittal midline Optic chiasm C medial of eyes
Lateral – far from sag. Midline Eyes are lateral of optic chiasm
Ipsilateral – same side Damage to A will cause blindness in ipsilateral eye
Contralateral –different side Damage to D will lead to a contralateral field cut.
Note: after brain injury (lesions) we talk about contralesional and ipsilesional Damage to visual cortex G leads to problems with contralesional vision.

30. Relative positions Distance From Body Distance from Surface
Proximal, Central: near center of body
Think ‘proximity’
Shoulders are proximal parts of arms
Distal,peripheral: away from body
Think distant
Fingers are distal parts of the arms
Distance from Surface
Superficial, external: near surface
The bump bruised superficial tissue.
Profound, deep: far from surface
The car crash injured deep organs.

31. Movements
Flexion
Supination
Pronation
Extension
Abduction
Adduction

32. Types of cells in the brain
Neuron: Cell which is responsible for receiving, transmitting and synthesizing information
cell body: contains organelles for metabolism and a nucleus
Glial Cells: Support cells for Neurons (CNS: oligodendrocytes, astrocytes, ependymal cells, radial glial; PNS : Satellite and Schwann cells)

33. Neuron Types
Neurons come in different types – some only communicate locally, while others have very long axons that communicate with distant regions.

34. Glial Cells
Glial cells have crucial functions
Repair, maintenance and cleaning. They produce new myelin when it become damaged, lay down scar tissue, and remove dead cells and other debris.
Physical support. They have hairlike filaments which hold the neurons in place and allow the central nervous system to retain its structural integrity.
CNS development. Help migration of neurons.
Chemical regulation. Supply chemicals such as potassium and calcium and regulate neurotransmitter levels.
Ten times as many glial cells as neurons
Glial cells involved with many tumours (gliomas)

35. The Central Nervous System
Telencephalon (Cerebrum)
Cortex
Basal Ganglia
Diencephalon
Thalamus
Hypothalamus)
Mesencephalon (Midbrain)
Rhombencephalon
Cerebellum
Pons
Medulla

36. Deep Structures Basal Ganglia – Initiates movements
Caudate nucleus, Putamen,Globus pallidus
Diencephalon
Thalamus: Relay from body to cortex
Hypothalamus and pituitary gland: Regulation (e.g. hormone secretion)

37. Deep Structures Basal Ganglia – Initiates movements
Caudate nucleus(red)
Putamen (green)
Globus pallidus (blue)
Diencephalon
Thalamus: (yellow)
Hypothalamus: (not shown)

38. Brain Stem Pons Midbrain Medulla Oblongata CN III and IV emerge
Early auditory/visual processing
Dopamine for movement control
CN III and IV emerge
Pons
CN V, VI, VII VIII
Medulla Oblongata
Pyramidal decussation: nerves from left cross to right side and vise versa
CN IX, X, XI, XII

39. The cortex Cortex – ‘Bark’ shell of brain – mostly gray matter
~80% of human brain
~20% of squirrel brain

40. Cortical folding Cortical folding increases surface area.
Ridges are called Gyri (singular = Gyrus)
Greek gyros = circle, hence a coil of brain cortex
Valleys are called Sulci (singular = Sulcus).
Latin = a groove.
Gyri
Sulci

41. Gray and White Matter
The outer surface of the cortex is gray matter: lots of interconnected neurons (like cities)
Underneath is the white matter – the highways connecting regions.

42. Functional Classifications
Some neurons transmit general information
Pain and Temperature
Originate in surface structures
Other neurons transmit specialized information
Specialized receptors
Hearing and vision
Somatic: Skeletal muscles
Visceral: Refer to internal vital body organs
Can be either
Afferent: Sensory
Efferent: Motor

43. Cortical layers Neurons are in six layers Functions I. Molecular layer
II. External granular layer
III. External pyramidal layer
IV. Internal granular layer
V.Internal pyramidal layer
VI. Fusiform layer
Functions
Superficial layers (I-III): inter-cortical connections
IV: input from thalamus
V,VI: outputs to leave cortex

44. The big folds
The folds of your brain are like a fingerprint – there are a few general patterns, with individual variability.
Two main folds
Central Sulcus Fissure of Rolando Rolandic sulcus
Lateral sulcus Sylvian fissure

45. Describing cortex location
Brodmann Areas (BAs, 1909)
Appearance of cortex under microscope
Not necessarily function
Arbitrary numbers are hard to remember
Some are crucial for a speech pathologist:
44 Broca’s Area
22 Wernicke’s Area

46. Brodmann Areas (medial slice)
Note that gray matter is located in the longitudinal fissure (between the two hemispheres)

47. Cortical Names
Much of cortex referred to by combination of coordinate+lobe+gyrus
E.G. Superior Temporal Gyrus (STG)
Middle Temporal Gyrus(MTG)
Lateral Occipital Gyrus (LOG)

48. Cortical names Tip of an object called a ‘pole’ Frontal Pole
Temporal Pole

49. Sulci names
Many of sulci referred to by combination of coordinate+lobe+sulcus
Superior temporal sulcus (STS)
Inferior frontal sulcus (IFS)
Precentral and postcentral sulci are just anterior and posterior to the central sulcus.

50. Brain function
Anatomy is interested with the structure of an organism.
Physiology is interested in the function of the structure.
We are still learning about brain function
Modern maps of brain function are primitive…

51. Brain function Much of the primate cortex devoted to vision.
In some monkeys, up to 50% of neocortex is devoted to vision.

52. Brain function Two striking features of human brain
Lots of cortex ‘left over’ (yellow) not devoted to specific task – we are flexible
Not much of the cortex is solely devoted to language.