Functions Of Reticular Formationand Electrical Activity Of Brain Flashcards
(27 cards)
The sensory neurons of reticular formation make interconnections with each other that allow?
Convergence, divergence and after discharge
Sensory neurons of reticular formation, recieves Afferents from?
- Long ascending sensory tracts (spine thalamic and dorsal column)
- Trigeminal, visual, auditory, and olfactory nervous pathway
- Basal ganglia
- Vestibular apparatus
- Hypothalamus
- Cerebellum
- Cerebral cortex
The motor neurons of the reticular formation are divided into Which 2 groups?
- Pontine reticular nuclei
- Medullary reticular nuclei
What is the bulboreticular facilitatory area also called?
Pontine reticular nuclei
Is the pontine reticular area inhibitory or excitatory?
Excitatory
Where is the pontine reticular nuclei located?
Pons and midbrain
What is the function of the reticular activating system?
Responsible for arousal and consciousness
Where do the reticular fibers of the RAS go?
All areas of the cerebral cortex
What signals do the ascending fibers discharge?
Excitatory
What signals are descending fibers of the pontine reticular nuclei transmitting?
Facilitatory signal
Where do the descending fibers of the pontine reticular nuclei go to?
Motor neurons that’s control antigravity muscles
What tract do descending fibers of pontine reticular nuclei transmit through
Ventral reticulo spinal tract
The activity of the reticular excitatory area is increased by impulses from?
- Area 4
- Neocerebellum
- Vestibular nucleus
- Caudate nucleus
Acitivity of reticular excitatory area is inhibited by impulses from?
- Reticular inhibitory area
- Inhibitory areas of cerebral cortex
- Paleocerebellum
- Basal ganglia
- Red nucleus
Where is the medullary reticular nuclei located?
Medulla oblongata
The reticular inhibitory area sends impulses to spinal motor neurons through what tract?
Lateral reticulospinal tract
What results from the stimulation on the medullary reticular nucleus?
General inhibitory effect on both flexor and extensor muscles, predominant effect on extensor
What stimulates the medullary reticular nucleus?
- Inhibitory areas of the cerebral cortex
- Paleocerebellum
- Basal ganglia
- Red nucleus
What pathway does the RAS use
Reticulo-thalamo-cortical pathway
How does the RAS contribute to arousal consciousness?
RAS discharges to the thalamus and cortex to potentiate thalamic and cortical activity
How does the RAS contribute to attention?
Mediates transition from relaxed wakefulness to periods of high attention and alertness
Factors stimulating RAS?
- Sensory signals from periphery particularly pain
- Signals from cerebral cortex
- Analeptic and sympathomimetic drugs
- Stress
- Caffeine
- Thyroid hormone
Factors inhibiting RAS
- Lack of sensory signals from cerebral cortex
- Signals from sleep centers
- General anesthesia
- Damage like by tumors and vascular lesions
- Alcohol
- Sleep inducing drugs
- Tranquilizers
Functions of reticular formation
- Vital link between higher centers in the brain and lower centers in the spinal cord
- Maintenance of posture and equilibrium and muscle tone
- Alertness and consiousness
- Contains many areas concerned with regulation of heart rate, blood pressure, respiration and many digestive activities
- Pain modulation
- REM sleep
