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

INTRODUCTION

• This includes all nervous structures, the peripheral ganglia, spinal nerves, cranial nerves and the autonomic nerves, located out of the brain and the spinal cord.
• It functions to provide communication between the receptor organ and the CNS (sensory), from the CNS and the effector organs (motor). 
• Peripheral nerves are myelinated.
• It is divided into motor (efferent) and sensory (afferent) subsystems.
• The motor peripheral nerves that supply to skeletal muscles are referred to as somatic motor nerves and those that supply the cardiac and smooth muscles and exocrine glands are referred to as autonomic nerves.
• The afferent (sensory) system is of two types:  Somatic and visceral. 
  Somatic sensory nerves carry impulses from the photoreceptors (eye), auditory receptors (ear) and stretch receptors (skeletal muscles), whereas the visceral sensory nerves carry visceral sensations from the chest and abdomen.