Autonomic Nervous System Flashcards
What does it mean to say motor neurons have dual motor control in autonomic nervous system?
Many organs have both parasympathetic and sympathetic nerve supply which both are motor controls that tend to act in opposite ways
What 3 tissues do motor neurons supply in the autonomic nervous system?
- cardiac muscle
- smooth muscle
- glands
What are 4 things monitored by sensory neurons in the autonomic nervous system?
- heart rate
- BP
- digestion
- Gland secretions
What part of the brain is mostly responsible for regulating autonomic nervous systems?
Hypothalamus
What cell bodies are in lateral horns and on which vertebral levels are they found only?
- cell bodies of presynaptic sympathetic neurons
- T1-L2
What is the pathway of the sympathetic axon when it exits lateral horn?
Lateral horn -> anterior rootlet and roots -> spinal nerve -> anterior rami -> exits this through white rami -> joins sympathetic chain
What are the 4 routes the presynaptic sympathetic axon can take once it enters sympathetic trunk?
- Ascend and synapse
- Synapse at level of entry
- Descend and synapse
- Pass through trunk without synapse and another abdominopelvic splanchnic nerve
All spinal nerves have sympathetic innervation because of the sympathetic trunk. True/false?
True.
Where do the 2 sympathetic branches to the heart synapse?
In T1 or in the cervical paravertebral ganglia
What specific parts of the heart are innervated by postsynaptic sympathetic axons?
- SA and AV nodes
- myocardium
What is the name of the postsynaptic sympathetic nerves to the heart and lungs?
Cardiopulmonary splanchnic nerves
Where do the presynaptic sympathetic axons to the lungs synapse?
Upper thoracic paravertebral ganglia
What 2 specific tissues do the postsynaptic sympathetic axons to the lungs innervate?
Bronchiolar smooth muscle and mucous glands
Where do the presynaptic sympathetic axons to the abdominopelvic organs synapse?
Prevertebral ganglia
What are the four prevertebral ganglia?
- celiac ganglion of celiac plexus
- aorticorenal ganglion
- superior mesenteric ganglion of SM plexus
- inferior mesenteric ganglion of IF plexus
What part of gut do postsynaptic sympathetic axons from celiac ganglion innervate?
Foregut
What part of gut do postsynaptic sympathetic axons from aorticorenal ganglion innervate?
kidney
What part of gut do postsynaptic sympathetic axons from superior mesenteric ganglion innervate?
Midgut
What part of gut do postsynaptic sympathetic axons from inferior mesenteric ganglion innervate?
Hindgut and pelvic/perineal organs
What is significant about the presynaptic sympathetic axon to the adrenal medulla and what is its pathway?
only sympathetic nerve that doesn’t synapse till its at the organ,
passes through sympathetic trunk -> passes through aorticorenal ganglion (1 of the paravertebral ganglia) to synapse directly onto the adrenaline/noradrenaline secreting cells of adrenal medulla
Craniosacral outflow and thoracolumbar outflow - which is sympathetic and which is parasympathetic?
- craniosacral -> parasympathetic
- thorocolumbar -> sympathetic
What cranial nerves and what sacral vertebral levels do parasympathetic nerves leave at?
- Cranial nerves III, VII, IX and X
- S2, S3, S4
Where does presynaptic parasympathetic axon from CN III synapse and what does it supply?
- ciliary ganglion
- supplies iris and ciliary muscles
Where does presynaptic parasympathetic axon from CN VII synapse and what does it supply?
-pterygopalatine ganglion (supplies lacrimal, nasal, palatine, pharyngeal glands) and submandibular ganglion (supplies sublingual and submandibular glands)
Where does presynaptic parasympathetic axon from CN IX synapse and what does it supply?
- Otic ganglion
- supplies parotid gland
Where does presynaptic parasympathetic axon from CN X synapse and how far does it supply?
- at the organs themselves
- as far as midgut (ends at splenic flexure of colon)
Where does presynaptic parasympathetic axon from S2,S3 and S4 synapse and what does it supply?
- synapse at organs
- supplies Hindgut, pelvis and perineum
