VPB 121: Veterinary Physiology - II (2+1)

RETICULO SPINAL TRACT

• Originate from Pontine and medullary reticular formations.
• Pontine reticular fibres are ipsilateral.
• Medullary reticular fibres descend bilaterally.
• They exert an influence upon the motor neurons (alpha and gamma) of the spinal cord without the involvement of interneurons.
• But the majority use interneurons for their influence upon somatic motor activity
•  Visceral functions are mediated by this tract include  the control of respiration , micturition, defecaton,cardiovascular alterations and gastrointestinal activity.
• This tract is tonically active and influences lower gamma motor neurons, the gamma loop mechanism mediated by this tract causes reflex contraction in the anti gravity muscle to maintain postural muscle tone