Download Thorax - Dr James Mitchell

Thoracic anatomy
Autonomic nervous system
Thoracic Anatomy
3.G.1.1
James Mitchell (December 24, 2003)
Autonomic nervous system
Division by direction
Visceral efferent
Preganglionic myelinated, postganglionic unmyelinated
Synapse in ganglia
Visceral afferent
Similar to somatic afferent
Cell body in CNS, peripheral processes travel with autonomic and somatic
fibres
Division by outflow
Sympathetic
Thoracolumbar outflow: T1-L3
Synapse in sympathetic trunk ganglia or other ganglia near CNS
Preganglionic cholinergic, postganglionic predominantly noradrenergic (also
adrenergic, cholinergic sudomotor and purinergic)
Parasympathetic
Craniosacral outflow: III, VII, IX, X, S2-4
Synapse adjacent to end-organs
Cranial nerve parasympathetic ganglia are traversed by other fibres but
contain only parasympathetic synapses
Parasympathetic anatomy
III
Edinger-Westphal nuclei → oculomotor n. → n. to inferior oblique → ciliary
ganglion → short ciliary nn. → ciliary muscle and sphincter pupillae
VII
Superior salivatory nucleus → nervus intermedius → facial n. → chorda
tympani → lingual n. → submandibular ganglion → submandibular and
sublingual glands
Geniculate ganglion → greater petrosal n. → pterygopalatine ganglion →
zygomatic and lacrimal nerves to lacrimal gland and nasal and palatine
branches to nasal mucosa
XI
Inferior salivatory nucleus → glossopharyngeal nerve → tympanic plexus →
lesser petrosal n. → otic ganglion → auriculotemporal n. → parotid gland
and oral mucosa
X
Dorsal nucleus of vagus → vagus n. → minute ganglia in respiratory tract,
heart, kidneys and gastrointestinal viscera from oesophagus to mid transverse
colon. Most vagal fibres are afferent, there is a very large ratio of
postganglionic to preganglionic efferent fibres.
S2-4
Anterior rami → sacral spinal nerves → pelvic viscera and pelvic plexus →
bladder, erectile tissue, gonads, uterus and uterine tubes, hindgut from mid
transverse colon to rectum
Sympathetic anatomy
Preganglionic efferent
Lateral column cell body → ventral root → white ramus communicans →
sympathetic trunk → synapse in trunk or other ganglia or adrenal
Postganglionic
May ascend or descend in the trunk, rejoin all spinal nerves via grey rami
communicantes or leave in direct branches to vessels or viscera
Distribution
Cranial
Internal carotid plexus arises from superior cervical ganglion and
Thoracic Anatomy
3.G.1.2
James Mitchell (December 24, 2003)
accompanies carotid into the cranium and along anterior and middle
cerebral arteries and ophthalmic artery
Cervical
Sympathetic chain condenses usually into three ganglia on each side:
superior (C2-3), middle (C6) and cervicothoracic (stellate, T1) cervical
ganglia
Cardiac plexus
Derived from T1-4 (and X) via cervical and thoracic ganglia
Surrounds heart, great vessels and coronaries
Pulmonary plexuses
Coeliac plexus
Two ganglia opposite T12-L1 with large condensation of autonomic
fibres
Gives rise to phrenic, splenic, hepatic, left gastric, intermesenteric,
suprarenal, renal, gonadal, superior and inferior mesenteric plexuses
which accompany arteries to their target organs
Superior hypogastric plexus
Inferior hypogastric plexus
Supplies hindgut, ureter, bladder, gonads, sex organs
Somatic levels of visceral afferents
Organ
Sympathetic Parasympathetic
Heart
T1-5
X
Lungs
T2-4
X
Oesophagus
T5-6
X
Stomach
T6-10
X
Liver, gallbladder
T6-10
X
Pancreas, spleen
T6-10
X
Small bowel
T9-10
X
Large bowel
T11-12
X to mid transverse
Kidney, ureter
T10-L2
X, S2-4
Adrenal
T8-L1
none
Gonads
T10-11
S2-4
Bladder
T11-L2
S2-4
Prostate
T11-L1
S2-4
Uterus
T10-L1
S2-4
Thoracic Anatomy
3.G.1.3
James Mitchell (December 24, 2003)