2017-09-05 14:43:29

Prelude

Today's Topics

  • Web resources
  • Wrap up on the forebrain
  • White matter tracts
  • The peripheral nervous system

Web resources

Organization of the brain

Major division Ventricular Landmark Embryonic Division Structure
Forebrain Lateral Telencephalon Cerebral cortex
Basal ganglia
Hippocampus, amygdala
Third Diencephalon Thalamus
Hypothalamus
Midbrain Cerebral Aqueduct Mesencephalon Tectum, tegmentum

Organization of the brain

Major division Ventricular Landmark Embryonic Division Structure
Hindbrain 4th Metencephalon Cerebellum, pons
– Mylencephalon Medulla oblongata

Hippocampus

  • Immediately lateral to lateral ventricles
  • Memories of specific facts or events
  • Fornix projects to hypothalamus
  • Mammillary bodies

Hippocampus

Amygdala (“almond”)

  • Physiological state, behavioral readiness, affect
  • NOT the fear center! (LeDoux 2015).

Amygdala

Cerebral Cortex

Cerebral hemispheres

Groove (sulcus or sulci)

Bumps (gyrus or gyri)

Grey vs.white matter

Lobes

Cortical Gyri – Lateral

Cortical Gyri – Medial

Gray vs. White Matter

Lobes of the cerebral cortex

Frontal

Temporal

Parietal

Occipital

Bones of the skull

Lobes

Landmarks of the cortex

Lateral sulcus/fissure

Central sulcus

Frontal lobe

Where is it?

  • Anterior to central sulcus
  • Superior to lateral fissure
  • Dorsal to temporal lobe

Lobes of the Cerebral Cortex

Frontal lobe

What does it do?

  • Primary motor cortex (M1)
    • Supplementary motor cortex
    • Frontal eye fields (FEF)
  • Prefrontal cortex
    • Planning, problem solving, working memory…?

Frontal lobe

What does it do?

  • Basal forebrain
    • Nucleus accumbens
  • Anterior cingulate cortex (ACC)
  • Primary olfactory cortex

Cingulate Gyrus

Inferior Frontal Gyrus (IFG)

Middle Frontal Gyrus (MFG)

Temporal lobe

Where is it?

  • Ventral to frontal, parietal lobes
  • Inferior to lateral fissure

Temporal lobe

What does it do?

  • Primary auditory cortex
  • Object, face recognition
  • Storage of memories about events, objects
  • Amygdala, hippocampus

Inferior Temporal Gyrus (ITG)

Entorhinal Cortex (ER)

Parietal lobe

Where is it?

  • Caudal to frontal lobe
  • Dorsal to temporal lobe
  • Posterior to central sulcus

What does it do?

  • Primary somatosensory cortex
  • Perception of spatial relations, action planning

Inferior Parietal Lobule

Superior Parietal Lobule

Occipital lobe

Where is it?

  • Caudal to parietal & temporal lobes

What does it do?

  • Primary visual cortex (V1)

Visual Cortex

Insular cortex (insula)

Where is it?

  • medial to temporal lobe
  • deep inside lateral fissure

Insula

Insula

What does it do?

  • Primary gustatory cortex
  • self-awareness, interpersonal experiences, motor control

Brodmann Areas

Brodmann Areas

Brodmann Areas

Spinal cord

Rostral/Caudal axis

  • Spinal column w/ vertebrae
  • Cervical (8), thoracic (12), lumbar (5), sacral (5), coccygeal (1)
  • Spinal segments & 31 nerve pairs
  • Cauda equina

Spinal cord

Spinal cord

Organization of the spinal cord

  • Dorsal/Ventral
    • Dorsal root (sensory)
    • Ventral root (mostly motor)
  • Grey (interior) vs. white matter (exterior)

Organization of the PNS

Somatic division

Autonomic

Cranial nerves

Spinal nerves

Cranial nerves

  • Afferents (input), efferents (output), or mixed
  • Innervate head and neck
  • Olfactory (I), optic (II), (VIII) auditory, vagus (X), etc.
  • Spinal nerves

Cranial nerves

Major white matter pathways

Brainstem

Projection fibers

Association fibers

Commissural fibers

Brainstem projections

  • Corticospinal tract (descending/efferent)
  • Dorsal column/medial lemniscus (ascending/afferent)
  • Superior/inferior cerebellar peduncles (from/to cerebellum)

Projection fiber tracts

  • Internal capsule
    • Thalamic radiation
    • Cortico-{pontine, bulbar, reticular} tracts

Cortical white matter tracts

  • Superior/inferior longitudinal fasciculus
  • Superior/inferior fronto-occipital fasciculus
  • Cingulum, fornix (hyp-hip), stria terminalis (hyp-amyg)

Commissural fibers

  • Corpus callosum
  • Anterior commissure (AC)
  • Posterior commissure (PC)

Anterior, Posterior Commissures

Autonomic nervous system

  • CNS & PNS components
  • Controls “vegetative functions”
    • Limited voluntary control
  • Two divisions
    • Sympathetic
    • Parasympathetic

ANS

Sympathetic division

  • Prepares body for action
  • “Fight or flight”
  • Spinal cord
    • ganglion chain along spinal column to End organs
  • NTs
    • Preganglionic: ACh
    • Post: NE

Parasympathetic division

  • “Around” sympathetic
  • Restorative function
  • “Rest & digest”
  • Spinal cord (or Vagus n.) -> ganglia near end organs -> end organ
    • NT: ACh

Next time

  • Neuroanatomy lab

References