Module 3 Flashcards
What are the anatomical/structural divisions of the nervous system?
CNS and PNS
What makes up the CNS?
Brain
Spinal cord
What makes up the PNS?
Cranial nerves
Spinal nerves
Autonomic nervous system
What are the divisions of the autonomic nervous system?
sympathetic
Parasympathetic
What are the functional divisions of the nervous system?
Spinal cord level (controls automatic motor responses) Brain stem/subcortical level (controls BP, resps, equilibrium, primitive emotions) Cortical level (responsible for cognition, the storage and retrieval of info, thinking, memory, abstract thought)
What are the 3 major areas of the brain?
Cerebrum
Brain stem
Cerebellum
What does the cerebrum contain?
Hemispheres
Diencephalon
Basal ganglia
What does the diencephalon contain?
Thalamus
Hypothalamus
What does the brain stem contain?
Midbrain
Pons
medulla
RAS
What are the functions of the cerebellum?
Coordination of muscle groups
control of fine movement
Control of balance
Maintenance or feedback loops to correct movement
What are the lobes of the cerebrum?
Frontal Parietal Occipital Temporal Limbic (rhinencephalon)
What are the functions of the frontal lobe?
High level cognitive functions
Motor control of speech (Broca’s area)
Voluntary motor function
What are the functions of the parietal lobe?
Contralateral sensation
Contralateral visual fields
Receptive speech, language comprehension, calculation, L/R discrimination
What are the functions of the occipital lobe?
visual perception
Visual reflexes
Smooth eye movements
What are the functions of the temporal lobe?
Auditory reception (Wernicke’s) new memory, smell, upper lateral vision
Interpretation of sensation
Detailed past memories
What are the functions of the limbic lobe?
Self preservation
Recall of events related to emotion
Where does the crossing of motor fibres occur?
Medulla
What is the RAS?
Reticular Activating System
Brain stem portion: responsible for sleep/wakefulness
Thalamic portion: responsible for cognition and attention
What is the tentoria and what is it’s significance?
A fold of the dura mater that covers the cerebellum and supports the occipital lobes of the cerebrum.
Brain can herniate through this bone resulting on pressure to CN III and unequal pupils.
What are the mechanisms of protection for the CNS?
Cranial/spinal nerves
Meninges
CSF
Blood-brain barrier
Where is CSF contained?
Between the pia mater and the arachnoid mater in the subarachnoid space
What are the layers of meninges?
*brain* Pia mater Arachnoid mater Dura mater *skull*
Where is CSF produced?
Secreted by the choroid plexus (mainly) and the capillaries in the pia mater
Where is CSF reabsorbed?
Through the arachnoid villi
What is foramen of Monro and what is it’s significance?
Hole between the lateral ventricle and the 3rd ventricle where CSF flows through.
It is where the EVD transducer is levelled to.
What does CSF contain?
Lymphocytes
Glucose
Protein
What is the blood-brain barrier permeable to?
Water Oxygen Carbon dioxide Glucose Lipid soluble compounds
What are the 2 main sets of vessels that supply blood to the brain?
Left/right common carotid (anterior circulation)
left/right vertebral arteries (posterior circulation)
What are afferent nerves of the PNS?
Sensing nerves (body -> cord) denoted by “spino”
What are efferent nerves of the PNS?
Motor nerves (cord -> body) denoted by “spinal”
what are the components of a neurological assessment?
The patient’s story Pt’s level of consciousness Cranial nerves Motor strength Vital signs
What tests should you do to assess cranial nerve function (and associated nerves)?
- pupillary response (optic II, occularmotor III)
- corneal reflex (trigeminal V, facial VII)
- gag/cough reflex (glossopharangeal IX, vagus X)
What is Cushing’s triad?
Bradycardia, hyperventilation, hypertension with widened pulse pressure. Indicated worsening ICP
What is the equation for cerebral oxygen supply?
PaO2 + cerebral blood flow
What controls cerebral blood flow?
Cerebral perfusion pressure / cerebral vascular resistance
What are the components of CPP?
MAP - ICP
What is normal CPP?
60-100 mmHg
What factors influence cerebral vascular resistance?
- The diameter of the blood vessels
- ICP
What factors influence the diameter of cerebral blood vessels?
Autoregulation
Cerebral metabolic demand
Under what circumstances does autoregulation fail?
When CPP < 60
When ICP > 30
When MAP 60-150
TBI
What is the biophysical theory of autoregulation?
Autoregulation is controlled by stretch receptors in blood vessels
What is the chemical theory of autoregulation?
CO2 and H+ cause cerebral vasodilation