Neuroanatomy

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Neuroanatomy

• The Human Brain

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I. Directional Terms

• Dorsal- toward the back.
• Ventral- towards the stomach or bottom.
• Anterior towards the front.
• Posterior- towards the rear or back.

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Terms contd.

• Rostral towards front nostrils.
• Caudal- towards the tail.
• Superior- top of head
• Inferior- bottom of head
• Lateral to the side
• Medial to the middle
• Ipsilateral same side
• Contralateral opposite side

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Anterior view of brain
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Posterior view of the brain
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Lateral view of Right side of brain
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Lateral view of Left Side of brain
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Dorsal (Superior) view
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Ventral (inferior) view
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II. Brain Slices

• 1. Coronal slices brain from front to back.
  Resembles a butterfly in most slices.

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Brain slices (contd)

• 2. Sagittal (midsagittal) slices the brain down
  the midline so you can see whats on each half.

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Brain slices

• 3. Horizontal slices the brain from top to
  bottom.

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III. Planes of brain
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IV. Cortical Landmarks

• 1. Gyrus (gyri) bulges on the brains surface.
• 2. Sulcus (sulci) a small ridge in the cortex.
• 3. Fissure (s) a large ridge in the cortex.

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A. Gyri

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B. Sulci-

• Central sulcus- separates frontal lobe from
  parietal lobe.

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C. Fissures-

• 1. Sylvian (Lateral Fissure)- Large ridge that
  separates temporal lobe from other lobes.

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Fissures (contd.)

• 2. Longitudinal fissure separates left right
  hemispheres.
• Left
  Right

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V. CNS PNS terms

• Nuclei cell bodies in the CNS.
• Ganglion cell bodies in the PNS
• Tracts Axon bundles in the CNS
• Nerves Axon bundles in the PNS

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Terms contd.

• White matter composed of axon bundles. Is white
  because of the myelin sheaths (white fatty
  tissue) that cover the axons.
• Gray matter composed of clusters of cell
  bodies, have dark gray appearance from cell body
  structures.

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VI. Three Divisions of the Brain

• 1. Hindbrain oldest part of brain, governs
  basic functions (breathing, regulates heart
  beat).
• 2. Midbrain involved in some perceptual
  motor functions.
• 3. Forebrain governs all higher-order level
  functions (problem solving, planning, emotion
  regulation, language).

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VII. The Hindbrain-

• consists of the medulla, pons, cerebellum.

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A. Medulla (oblongata)

• a structure just above spinal cord. Controls
  regulates vital reflexes for survival
  (respiration, HR, vomiting, salivation, coughing,
  sneezing).
• Damage to the
• Medulla is almost always
• fatal.

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B. Pons

• An enlarged protrusion anterior to the medulla.
  Both pons medulla form reticular formation
  raphe system.
• Plays a role in arousal dreaming.

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C. Cerebellum (means little brain)

• Large hindbrain structure that is posterior to
  the brainstem.
• Governs motor functions, motor memory.

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VIII. The Midbrain

• Most obvious feature is the tectum (roof).
• Two pairs of bumps on tectum
• Superior colliculi (vision)
• Inferior colliculi (audition)
• Substantia nigrapart of basal ganglia, involved
  in movement (Parkinsons disease).

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IX. The Forebrain

• Consists of subcortical and cortical structures.
• 1. Subcortical structures include the thalamus,
  hypothalamus, limbic system, basal ganglia.

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A. Thalamus-

• A large two-lobed structure that sits on top of
  the brainstem. Is brains sensory relay station.
• Several nuclei receive sensory input send that
  input to parts of the cortex.
• Nuclei Lateral geniculate nuceli (visual),
  medial geniculate nuceli (auditory) ventral
  posterior nuclei (somatosensory)

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Thalamus
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B. Hypothalamus

• Is ventral to the thalamus. Receives projections
  from the fornix in its mammilary bodies.
• Function regulation
• Of basic motivational
• Drives (sex, hunger,
• thirst, fighting).

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C. Limbic system

• Comprised of the fornix, hippocampus, amygdala,
  septum, cingulate gyrus.

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Limbic system

• Fornix (arch) is the major pathway of the
  limbic system projects in an arc from the
  hippocampus into mammilary bodies of the
  hypothalamus.
• Hippocampus seahorse is the structure that lies
  in between the cortex thalamus, rests in the
  temporal lobe plays a large role in LTM storage.

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Limbic system

• Amygdala almond lies anterior to the
  hippocampus, is involved in basic emotions (fear,
  anger).

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2. Cortical structures-

• Lobes of the brain

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Occipital lobe

• Most posterior portion of brain. Processes
  visual sensory information.
• Houses primary visual cortex (striate cortex).
• Damage to PVC can cause
• cortical blindness.

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B. Parietal lobe

• Is posterior to the frontal lobe dorsal to
  temporal lobe. Processes visual tactile
  sensory information.
• Houses primary
• Somatosensory cortex
• Which receives sensory
• Info from skin.

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C. Temporal lobe

• Processes auditory and visual information.
  Houses primary auditory cortexthe primary
  projection site for auditory stimuli.
• Language, face recognition,
• processing of sounds
• Occurs here.

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D. Frontal lobe

• Processes information for planning, executive
  control, fine movement, emotion regulation,
  higher-order cognitive functions.