Visceral and Somatic Reflex Arcs

What occurs during a visceral reflex

visceral sensory neurons send info about chemical changes, stretch, temperature, and irritation of viscera

what are receptors

free nerve endings scattered in viscera

where are cell bodies located

in dorsal root ganglia and in sensory ganglia of cranial nerves

Visceral reflex arc components

receptor

sensory neuron

integration center

motor neuron

effector

why is the visceral arc different than the somatic arc

(1) the visceral arc has 2 consecutive neurons in motor pathway

(2) afferent fibers are visceral sensory neurons

(3) effectors are smooth muscle, cardiac muscle, and glands (not skeletal muscles)

examples of visceral reflexes

enteric reflexes (digestive motility, defecation, swallowing, vomiting)

coughing

pupillary reflex

micturition (urinating)

baroreceptor reflex - BP

Functions of somatic reflex arcs

control skeletal muscle responses

produce rapid, voluntary-like protective movements

maintain posture and balance

key features of the somatic reflex arc - motor neuron pathway and effectors

motor neuron pathway is one motor neuron

effectors are skeletal muscles only

how many motor neurons does the visceral reflex arc use

two consecutive motor neurons

preganglionic neuron → ganglion → postganglionic neuron

effectors of visceral reflex arc

smooth muscle, cardiac muscle, glands

afferent (sensory) fibers are

visceral sensory neurons

monitor stretch, chemical changes, temperature, irritation

effectors of visceral reflex arc

smooth muscle, cardiac muscle, glands

how many motor neurons in somatic reflex arc

one motor neuron

effector of somatic reflex arc

skeletal muscle