cranial fossa: brain and spinal cord pa 544 tony serino, ph.d. clinical anatomy
TRANSCRIPT
Cranial Fossa:Brain and Spinal Cord
PA 544
Tony Serino, Ph.D.
Clinical Anatomy
Central Nervous System (CNS)
• Gray vs. White matter• Protection of CNS
– Meninges– CSF flow
• Brain– Development– Selected structures
• Spinal cord– Selected structures
Cranial Fossa
Anterior
Middle
Posterior
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
Gray and White Matter
• Since the cerebrum and cerebellum outgrow their cores, gray matter ends up on outside of both structures.
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
Meninges of the Spinal Cord
Pia materArachnoid
Dura mater Meninges
Centrum
Epidural space
Subdural space
Subarachnoid space
Dorsal Root Ganglion
Brain Meninges
Extensions of Dura Materhold brain in cavity
Sellar diaphragm (not shown)
Venous Sinuses of Cranium
Superior Sagittal
Inf. Sagittal
Straight
Cavernous
Sigmoid
Transverse
Lateral Venous Lacunae
Arachnoid villi
Maxillary A.
Middle Meningeal A.
Middle Meningeal Artery
Brain Ventricles
Choroid Plexus
CSF (cerebral-spinal fluid) Flow
Hydrocephalus
• Blockage of CSF flow can lead to severe brain and/or head enlargement.
• In an adult, such swelling would be fatal.
Brain
• Development• Structures• Functional Areas
Neural Tube
forming
Neural Tube
Brain Vesicles
Flexures and Cerebral Cortex Growth
Major Divisions of Brain
Brain Stem = midbrain + pons + medulla
Brain Anatomy (req’d)
Projections vs. Commissures
Functional Areas of Cerebrum
Primary Motor and Somatosensory Gyri
Basal Nuclei: cerebral nuclei
Putamen and Globus Pallidus
Subthalamic nuclei andthe Substantia nigra are usually included
Reticular FormationExtends along length of brain stem; used in maintaining alertnesswhile awake; also includes motor nuclei such as centers for Cardiac,Respiratory and Vasomotor control.
RAS receives inputs from eye, ear and general sensation to maintain alertness
Limbic System: functional system; responsible for emotion and memory
Cingulate Gyrus
Fornix
Mammillary body
Hypothalamus Control of Pituitary
Posterior Pituitary
Anterior Pituitary
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
Internal Carotid Artery
Blood Supply(Circle of Willis)
Vertebral A.
Internal Carotid A.
Ant. Communicating
Post. Communicating
Ant. Cerebral
Post. Cerebral
Middle Cerebral
Basilar A.