Flashcards in Reticular Activating System Deck (20):
You encounter a patient with an irregular heartbeat who also cannot sense pain. What region of the brain is most likely affected?
Where is the raphe nuclei found?
Along the midline of medulla and midbrain.
It is important in maintaining wakefulness.
You are studying the function of raphe nuclei in mice. A lesion to the raphe nuclei will produce what symptoms in the mice?
The mice will not be wakeful and will most likely be in a permanent coma.
All sensory input that enters the brain via the medulla is also sent to neurons of what structure?
You are dozing off during class. Your professor then announces a pop quiz and you immediately wake up. Your wakefuless is caused by what region of the brain?
Where does the reticular formation receive input from?
The cerebral cortex
What are the two zones of the reticular activating system?
What types of neurons are found in the magnocellular zone?
A specific type of neuron with long radiating dendrites.
What brain structures pick up information from the magnocellular zone?
Sensory cranial nerves
Cerebral cortex (premotor cortex)
Where do the long ascending/descending pathways of the magnocellular zone terminate?
Midline and intralaminar thalamic nuclei
Segments of spinal cord
Long ascending fibers from the magnocellular zone include ... ?
Lower pons and medulla
What neurotransmitters are used in the magnocellular zone?
Serotonergic pathways originate in what brain structure?
Where to serotonergic pathways terminate?
Substantia gelatinosa (pain)
Limbic structures (mood and behavior)
You administer a drug to mice that inhibits serotonin synthesis. How will this affect the mice?
The mice will have insomnia.
What is an example of a noradrenergic pathway?
The pathway that arises from lateral reticular formation and innervates the hypothalamus and other limbic structures.
What is best-known group of cells in the noradrenergic pathways?
They project to every major region of the brain and spinal cord.
Where do most adrenergic fibers terminate?
On small blood vessels and capillaries in the brain.
They may help regulate blood flow in the brain.
Where are the majority of dopaminergic cells located?
In the substantia nigra.