C9 - Sympathetic system

Question 1

Give the division of the nervous system

Answer 1

• Autonomic nervous system is a division of peripheral nevous system that is not under voluntary control
• Autonomic nervous system is divided into:
  • Sympathetic nervous system
    
    • ​Fight or flight response
  • Parasympathetic nervous system
    
    • ​Rest and digest
    • Regulates body functions under normal conditions
  • Enteric nervous system
    
    • ​Contains branches from sympathetic and parasympahtetic nervous system
    • Regulates functions of the gastrointestinal tract

Question 2

Autonomic nervous system

Role

Answer 2

• Regulates:
  
  • Respiration
  • Circulation
  • Digestion
  • Metabolism
  • Body temperature
  • Water balance
  • Urination
  • Pupillary response
  • etc…
• There is a close interaction between the autonomic nervous system, the endocrine system and the immune system

Question 3

Autonomic nervous system

Structure

Answer 3

• The afferent components can be divided into:
  
  • Sympathetic
    
    • ​Transmitter: Noradrenaline
  • Parasympathetic
    
    • ​Transmitter: Acetylcholine
• Both sympathetic and parasympathetic systems consists of pairs of neurons that link the CNS to the innervated structure
• The first neuron preganglionic neuron is myelinated, and synapses with the second, postganglionic non-myelinated neuron
• The parasympathetic system and the sympathetic system can be diiferentiated according to the transmitter substance

Question 4

Sympatheric system

Give the transmitter of the sympathetic system

Answer 4

Noradrenalin

(Parasympathetic: acetylcholine)

Question 5

Sypathetic system

Structure

Answer 5

• The cell bodies to the preganglionic neuron of the sympathetic system are located in the lateral column of the spinal cord
  
  • ​Between Th1 → L3 segment of the spinal cord
• Their axons joins the ventral root to reach the spinal nerves from which they pass the vertebral ganglia of the sympathetic trunk as the white communicating branches
• From there they either:
  
  • Synapses immediatly
  • Run along the trunk
  • Pass through the trunj to synapse in prevertebral ganglia, located at the origins of the visceral braches of the aorta abdominalis → splanchnic nerves

Question 6

Sypathetic system

Sympathetic trunk

Answer 6

• Several divisions

Cephalic & cervical part:

• Cephalic part
  
  • ​Runs in a common sheath with n. vagus forming vagosympathetic trunk
• Cervical part
  
  • ​Starts at the ggl. stellate which is connected to middle cervical ganglion via the ansa subclavia
• ​At the atlas the sympathetic part separates from n. vagus to terminate in ggl. cervicale craniale
• Postganglionic fibers from the ggl. cervicale craniale join the IX, X, XI and XII nerves
• N. carotis interna arises from the ggl. cervicale craniale
  
  • ​Innervation: blood vesses within the cranial cavity
• Ggl. stellate gives rise to the following branches:
  
  • Communicating branches
  • N. vertebralis
  • Cervical cardiac nerves (innervates cardiac plexus
  • Perivascular branches (accompany by a. subclavia)

Thoracic part

• Caudodorsal continuation of ggl. stellate
• From the 6^th thoracic ganglion caudally, preganglionic neurons pass through the ganglia to reach the n. splanchnicus major which enters the abdomen
• N. splanchnicus minor leaves caudal to the n. splanchnicus major and continues to the abdominal cavity
• Both the minor and major n. splanchnicus pass to the paired ggl. celiaca and ggl. mesenterica cranialis

Abdominal part

• N. splanchnicus lumbalis pass from ggl. lumbales to the ggl. celiaca and ggl. mesenterica cranialis
• The solar plexus is formed around the roots of a. celiaca and a. mesenterica cranialis
• ggl. prevertebralis are connected with each other by the
  
  • N. splanchnicus
  • Sympathetic trunk
  • Abdominal aortic plexus

Sacral and coccygeal parts

• N. splanchnicus pelvici pass from the ggl. sacralia to the retroperitoneal pelvic plexus

Question 7

Name the ganglons of the sympathetic system and their innervation

Answer 7

• Ggl. cervicale craniale
  
  • ​Esophagus
  • Trachea
  • Ggl. cervicale media
• Ggl. stellate
  
  • ​With anas around a. subclavia
  • Give n. vertebralis (with a. vertebralis)
  • Give sympathetic trum with interganglionic? branch
• Ggl. coeliacum
  
  • ​Liver
  • Duodenum
  • Pancreas
  • Spleen
• Ggl. mesentericum craniale
  
  • ​Pancreas
  • Ileum
  • Jejunum
  • Caecum
  • Colon ascendens
• Ggl. mesentericum caudale
  
  • ​Colon transversus
  • Colon descendens
  • Rectum
• Ggl. pelvina
  
  • ​Colon
  • Rectum
  • Penis
  • Scrotum
• Ggl. coeliacum & ggl. mesentericum craniale give the n. splanchnicus major and minor

Question 8

Draw the sympathetic system

Answer 8