FUNCTIONAL ANATOMY - Brainstem Flashcards
What is the function of the brainstem?
The brainstem controls body physiology
What are the three anatomical components of the brainstem?
Mesencephalon (midbrain)
Pons
Medulla oblongata
What is brainstem conduction?
All information relayed between the periphery and the cerebrum and cerebellum must pass through the brainstem
Which cranial nerves emerge from the brainstem?
Cranial nerves III to XII
What are the three integrative functions of the brainstem?
Cardiovascular control
Respiratory control
Consciousness/alertness
Where is the cardiovascular centre within the brainstem?
Medulla oblongata
What is controlled by the cardiovascular centre of the brainstem?
Heart rate
Describe briefly how the cardiovascular centre of the brainstem controls heart rate
The cardiovascular centre of the brain stem receives sensory information on changes in blood oxygen levels detected by chemoreceptors, and changes in blood pressure detected by baroreceptors in the aortic arch and carotid sinuses. The cardiovascular centre integrates this sensory information and alters the heart rate accordingly through sending motor information to the sinoatrial node via autonomic fibres
Where is the respiratory centre within the brainstem?
Medulla oblongata
Pons
What is controlled by the respiratory centre of the brainstem?
Rate and depth of respiratory movements
Describe briefly how the respiratory centre of the brainstem controls respiratory rate and depth
The respiratory centre of the brain stem receives sensory information on changes in blood CO2 and pH levels detected by chemoreceptors. The respiratory centre integrates this sensory information and alters the respiratory rate and depth accordingly
What is the ascending reticular activating system (ARAS)?
A collection of neuronal cells bodies that form an ill-meshwork known as the reticular formation in the brainstem which is responsible for the levels of consciousness/alertness
What are the six mentation status grades?
Occasional alterness
Depression/delirium
Semi-comatose (responds to visual stimuli)
Semi-comatose (responds to auditory stimuli)
Stupor (only responds to noxious stimuli)
Coma
What are the six possible clinical signs of brainstem dysfunction?
Decreased mentation
Ipsilateral proprioceptive deficits
Head tilt and wide base stance
Cranial nerve III - XII deficits
Abnormal heart rate
Abnormal respiratory rate
