Gross Neuroanatomy: Gross Brain & Cranial Environment, Spinal Cord & Vertebral Compartment Flashcards
What is the CNS composed of?
- Cerebrum
- Cerebellum
- Brainstem (Midbrain, Pons, Medulla)
- Spinal cord and roots
- Pre-ganglionic autonomic neurons
What is the PNS composed of?
- Spinal nerves and rami
- Somatic nerves
- Visceral nerves
- Autonomic ganglia and post autonomic neurons
Subsections of the cerebrum
- Telencephalon: cerebral cortex and subcortical regions
2. Diencephalon: thalamus and hypothalamus (deepest part)
What is the choroid plexus?
It secretes CSF by filtering blood (plasma)
Directional flow and cycling of CSF from inside the ventricular system to the outside area surrounding the CNS
- Choroid plexus
- Uni-directional flow through ventricular system
- CSF enters through 3 small pores or subarachnoid space
- CSF is reabsorbed into veins and sinuses
How is the dorsal-ventral axis related to the rostral-caudal axis?
ALWAYS perpendicular
Brain Function, Neurological Examination and CNS Pathology of Supratentorial Compartment
- Regions: Telencephalon and Diencephalon
- CN: 1 and 2
- Awake and Oriented
- Olfactory and Language
- Cognition and Language
- Emotional and Behavioral Regualtion
- Hypothalamic and pituitary functions
Brain Function, Neurological Examination and CNS Pathology of Infratentorial Compartment
- Regions: Brainstem and Cerebellum
- CN: 3-12
- Cerebellum: motor coordination
Brain Function, Neurological Examination and CNS Pathology of Vertebral compartment
- Spinal cord, dorsal and ventral roots
- Motor and somatosensory exams
- Reflexes
Types of brain herniations
- Subfalcine (shove brain laterally)
- Central (Downward compression)
- Uncal transtentorial (temporal lobe compression/midbrain compression)
- Tonsillar (pressure on cerebellum)
**Can happen individually or all at once
Normal Intracranial Pressure Values
- < 20 cm H20 or < 15 cm Hg (these are the upper limit)
How are normal intracranial pressures measured?
- Lumbar puncture (subarachnoid space around cauda equina)
* Neurosurgical insertion of intracranial monitors
What are contra-indications for lumbar punctures
- Suspected increased supratentorial pressure (can cause herniation)
- Infection or mass in the path of needle insertion
Pathological origins causing increased intracranial pressure
- Hydrocephalus (too much CSF)
- Brain edema (swelling)
- Hemorrhage
- Tumor or mass
Symptoms of increased intracranial pressure
- Headache
- Nausea and vomiting (vomiting can occur in absence of nausea) (Vomiting center in medulla)
- Impaired consciousness
- Skull (bulging fontanelles in infants)
- Increased systemic BP
- Bradycardia (slow heart rate, disruption of medulla function)
- Papilledema (protrusion of optic disc)
What are the symptoms of Meningeal Irritation Syndrome?
- Headache/pain
- Neck Pain “nuchal rigidity”
- Infection: Meningitis
What are physical exam tests and signs of meningeal irritation syndrome?
- Kernig’s Test:
- Flexion of hips
- Extension of knee accompanied with pain
- Brudzinski’s Test
- Passive flexion of neck
- Involuntary knee flexion to reduce rural tension
What are three channels for entry for infection to enter the CNS?
- Emissary veins: from scalp, through skull, into superior sagittal sinus
- Veins from face to cavernous sinus
- Cribiform plate
