Topic 1 – Neuroanatomy Review. CNS Organization - Axes. Fig. 1-1: Leonard,
The Neuroscience of Human Movement, Mosby:Toronto, 1998. dorsal ventral.
Topic 1 – Neuroanatomy Review 1) Organization of the nervous system – axes and planes, CNS vs. PNS 2) Structure of spinal cord 3) Structure of brain 4) Neurons and glial cells
Topic 1 – Neuroanatomy Review 1) Organization of the nervous system – axes and planes, CNS vs. PNS 2) Structure of spinal cord 3) Structure of brain 4) Neurons and glial cells
CNS Organization - Axes dorsal
caudal
rostral
Alignment of quadruped brain and spine
ventral
Fig. 1-1: Leonard, The Neuroscience of Human Movement, Mosby:Toronto, 1998.
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CNS Organization - Axes
Superior (above) Lateral (to the side)
Rostral
Medial (middle)
Anterior (in front of; toward the front)
Alignment of human brain and spine
Caudal Posterior (behind; toward the back)
Inferior (below)
Caudal
Fig. 1-9: Purves et al. Neuroscience, Sinauer Associates Inc: Massachusetts, 2001.
CNS Organization - Planes Coronal
Sagittal (Parasagittal)
Horizontal or Axial
Fig. 1-9: Purves et al. Neuroscience, Sinauer Associates Inc: Massachusetts, 2001.
CNS and PNS • CNS – Central Nervous System Æ Consists of the brain and spinal cord.
• PNS – Peripheral Nervous System Æ Consists of the peripheral nerves and ganglia.
The CNS & PNS are separated anatomically but functionally interconnected.
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Afferent – carries info towards the CNS Efferent – carries info away from the CNS Source: Lundy-Ekman, Neuroscience: Fundamentals for Rehabilitation, Saunders, 2002
Topic 1 – Neuroanatomy Review 1) Organization of the nervous system – axes and planes, CNS vs. PNS 2) Structure of spinal cord 3) Structure of brain 4) Neurons and glial cells
Spinal Cord • Segmented – each segment has 1 pair of dorsal and ventral roots.
Source: Zigmond et al., Fundamental Neuroscience, Academic Press, 1999
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Dorsal Horn Sensory IN (afferent)
Motor OUT (efferent)
Ventral Horn Source: Zigmond et al., Fundamental Neuroscience, Academic Press, 1999
Gray matter – ÆDorsal horn – groups of afferent sensory neurons from periphery ÆVentral horn – groups of efferent motor neurons (cell bodies) Æ Also contains interneurons which modulate information flowing between the sensory and motor components Source: Lundy-Ekman, Neuroscience: Fundamentals for Rehabilitation, Saunders, 2002
White matter – Æ Bundles of ascending and descending axons for carrying information towards and away from the brain
Source: Lundy-Ekman, Neuroscience: Fundamentals for Rehabilitation, Saunders, 2002
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Topic 1 – Neuroanatomy Review 1) Organization of the nervous system – axes and planes, CNS vs. PNS 2) Structure of spinal cord 3) Structure of brain 4) Neurons and glial cells
Main regions of brain Cerebellum – important for balance and coordination of movements
Vermis
Cerebellar hemisphere
Source: MacKay, Neuro 101, Sefalotek Ltd., 1999 And Lundy-Ekman, Neuroscience: Fundamentals for Rehabilitation, Saunders, 2002
Main regions of brain Medulla – important role in regulation of critical cardiovascular and respiratory functions
Source: MacKay, Neuro 101, Sefalotek Ltd., 1999
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Main regions of brain Pons – conveys information about movement from the cerebral hemispheres to the cerebellum
Source: MacKay, Neuro 101, Sefalotek Ltd., 1999
Main regions of brain Midbrain – important for coordination of visual and auditory reflexes
Source: MacKay, Neuro 101, Sefalotek Ltd., 1999
Main regions of brain Diencephalon – consists of -Thalamus -Hypothalamus -Epithalamus -Subthalamus
Source: MacKay, Neuro 101, Sefalotek Ltd., 1999
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Main regions of brain Cerebral hemispheres
Dorsal View
Longitudinal fissure
Gyrus Sulcus Left hemisphere
Right hemisphere
Source: MacKay, Neuro 101, Sefalotek Ltd., 1999 and
Purves et al. Neuroscience, Sinauer Associates Inc: Massachusetts, 2001
Subdivisions of Cerebral Cortex
Frontal lobe
Parietal lobe
Occipital lobe
Frontal lobe
Parietal lobe Occipital lobe
Temporal lobe
Temporal lobe
Source: Lundy-Ekman, Neuroscience: Fundamentals for Rehabilitation, Saunders, 2002
Functional Divisions of the Cortex (a few examples) -
Source: Kandel et al., Principles of Neural Science, McGraw Hill, 2000
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Anatomical divisions of the cortex -
e.g. Brodmann areas
Brodmann areas are based on microscopic variations in neuronal architecture. e.g.
A
B
A) prefrontal cortex B) primary visual cortex
Source: Mesulam M.-M., Principles of Behavioral and Cognitive Neurology, 2nd Ed. Oxford University Press, 2000
There can be up to 6 different types of layers in the cortex:
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Cerebrospinal Fluid System Ventricle
Source: Lundy-Ekman, Neuroscience: Fundamentals for Rehabilitation, Saunders, 2002
Topic 1 – Neuroanatomy Review 1) Organization of the nervous system – axes and planes, CNS vs. PNS 2) Structure of spinal cord 3) Structure of brain 4) Neurons and glial cells
The nervous system is made up of two main categories of cells – Æ Neurons (nerve cells)
Æ Glia (supporting cells)
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Neurons – the excitable cells responsible for transmission of information in the nervous system.
Axon Hillock
4 main anatomical regions – -Soma (cell body) -Dendrites -Axon
Presynaptic terminals
-Presynaptic terminals
Source: Kandel et al., Principles of Neural Science, McGraw Hill, 2000
4 common functional regions 1) Input 2) Integrative 3) Conductile 4) Output
Source: Kandel et al., Principles of Neural Science, McGraw Hill, 2000
Neurons come in many shapes and sizes…
Source: Purves et al. Neuroscience, Sinauer Associates Inc: Massachusetts, 2001.
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Sensory
Motor
Interneuron
Source: Kandel et al., Principles of Neural Science, McGraw Hill, 2000
Synaptic cleft
Neurotransmitters from the presynaptic terminal bind to receptors on a post-synaptic region
Source: Lundy-Ekman, Neuroscience: Fundamentals for Rehabilitation, Saunders, 2002
The nervous system is made up of two main categories of cells – Æ Neurons (nerve cells)
Æ Glia (supporting cells)
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Two main types of glial cells 1. Macroglia – large glial cells 2. Microglia – small glial cells
3 types of macroglia cells – 1. Astrocytes 2. Oligodendrocytes 3. Schwann cells
Astrocytes - only found in the CNS -main function is to maintain an appropriate chemical environment for neuronal signaling - take up extra K+ ions, remove and metabolize chemical transmitters from synaptic cleft, remove debris - important during development of CNS
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Astrocytes -Part of the bloodbrain barrier -Provide lactate (‘fuel’) for neurons
Source: Kandel et al., Principles of Neural Science, McGraw Hill, 2000
3 types of macroglia cells – 1. Astrocytes 2. Oligodendrocytes 3. Schwann cells
Oligodendrocytes and Schwann Cells
Oligodendrocytes (CNS only)
Schwann cells (PNS only)
Source: Kandel et al., Principles of Neural Science, McGraw Hill, 2000
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Two main types of glial cells 1. Macroglia – large glial cells 2. Microglia – small glial cells
Microglia -Scavenger cells that ingest foreign cells (e.g. bacteria) and old or injured cells. -Increase in number after injury or disease ÆProliferate from other microglia or from macrophages which migrate in from blood
End of Topic 1 – Neuroanatomy Review.
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