autonomic nervous system

components

parasympathetic, sympathetic, enteric

target tissues

cardiac, smooth, glandular tissue

what is the ans involved in

• percieved sensation

• involuntary inhibition or excitation of visceral and glandular tissue

• homeostasis

• complements the endocrine system

components of the ans

• general visceral efferent motor neurons- visceromotor fibres- target tissues

• general visceral afferent sensory neurons- enteroreceptors (chemoreceptors, baroreceptors)- viscero sensory fibres. Sensory fibres coveyed from the periphery to the cns via cranial nerves and somatic spinal nerves

• central integration centres (brain)- hypothalamus, brain stem (pons, medulla)

anatomy of the ans

2 neuron system in the periphery

1. pre-ganglionic neuron- cell body in brain or spinal cord

2. post-ganglionic neuron-cell body lies outside cns in autonomic ganglia

which is parasympathetic and sympathetic from craniosacral outflow and thoracolumbar outflow

• craniosacral- parasympathetic

• thoracolumbar- sympathetic

parasympathetic

• cranial parasympathetic outflow via:

• cranial nerves III, VII, IX AND X

• to visceral and glandular tissues of the head

• CN X - vagus nerve

• heart

• most of the GIT

• sacral outflow (S1-S3)

• caudal GIT

• urinary tract

• reproductive organs

sympathetic

• thoracolumbar outflow via

• spinal nerves T1 to L4

• via sympathetic chain

• to head and neck T1-T3

• to organs of thorax abdomen and pelvis

• disributed via several peripheral ganglia