Cranial Fossa: Brain and Spinal Cord

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Cranial FossaBrain and Spinal Cord

• PA 544
• Tony Serino, Ph.D.
• Clinical Anatomy

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Central Nervous System (CNS)

• Gray vs. White matter
• Protection of CNS
• Meninges
• CSF flow
• Brain
• Development
• Selected structures
• Spinal cord
• Selected structures

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Cranial Fossa
Anterior
Middle
Posterior
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CNS (Central Nervous System)

• Brian and spinal cord
• Displays gray and white matter
• Gray matter are areas of CNS with many cell
  bodies of neurons present (little myelinated
  nerve fibers)
• White matter are area of CNS with few cell bodies
  but many myelinated nerve fibers
• Protected by bone and membranes

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Gray and White Matter

• Since the cerebrum and cerebellum outgrow their
  cores, gray matter ends up on outside of both
  structures.

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Meninges

• Dura Mater outermost tough, fibrous CT
• In brain, divided into two layers (periosteal and
  meningeal)
• In spine, only one layer with fat filled space
  above the layer called the epidural space
• Arachnoid middle web-like appearance
• Potential space between Dura and arachnoid is the
  subdural space
• Pia Mater innermost, delicate membrane fused
  with CNS surface
• Space between Pia and Arachnoid is the
  subarachnoid space

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Meninges of the Spinal Cord
Pia mater
Epidural space
Arachnoid
Meninges
Dura mater
Subdural space
Subarachnoid space
Dorsal Root Ganglion
Centrum
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Brain Meninges
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Extensions of Dura Materhold brain in cavity
Sellar diaphragm (not shown)
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Venous Sinuses of Cranium
Superior Sagittal
Inf. Sagittal
Straight
Cavernous
Transverse
Sigmoid
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Lateral Venous Lacunae
Arachnoid villi
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Middle Meningeal Artery
Middle Meningeal A.
Maxillary A.
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Brain Ventricles
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Choroid Plexus
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CSF (cerebral-spinal fluid) Flow
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Hydrocephalus

• Blockage of CSF flow can lead to severe brain
  and/or head enlargement.
• In an adult, such swelling would be fatal.

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Brain

• Development
• Structures
• Functional Areas

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Neural Tube forming
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Neural Tube
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Brain Vesicles
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Flexures and Cerebral Cortex Growth
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Major Divisions of Brain
Brain Stem midbrain pons medulla
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Brain Anatomy (reqd)
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Projections vs. Commissures
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Functional Areas of Cerebrum
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Primary Motor and Somatosensory Gyri
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Basal Nuclei cerebral nuclei
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Reticular Formation
Extends along length of brain stem used in
maintaining alertnesswhile awake also includes
motor nuclei such as centers for
Cardiac, Respiratory and Vasomotor control.
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RAS receives inputs from eye, ear and general
sensation to maintain alertness
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Limbic System functional system responsible for
emotion and memory
Cingulate Gyrus
Fornix
Mammillary body
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Hypothalamus Control of Pituitary
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Posterior Pituitary
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Anterior Pituitary
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Pineal Gland

• Plays a major role in circadian rhythm control
  through its sympathetic connection to the
  hypothalamus
• Melatonin increases at night and decreases during
  daylight
• Implicated in the control of major life changes
  (such as the onset of puberty and adulthood

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Internal Carotid Artery
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Blood Supply(Circle of Willis)
Ant. Cerebral
Ant. Communicating
Middle Cerebral
Internal Carotid A.
Post. Communicating
Post. Cerebral
Basilar A.
Vertebral A.