Uploaded February 2024 | Updated September 2026, 1 week ago
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Content:
0:00 Introduction
01:35 Ganglion and Nucleus
02:06 General Structure
02:55 Sympathetic vs Parasympathetic
06:10 Neurotransmitters
07:35 Craniosacral Outflow
08:55 Cranial Part
17:42 Sacral Part
19:19 Ending
Parasympathetic nervous system is a part of the autonomic nervous system, which is under the motor division of the peripheral nervous system. Neuroanatomy
General Structures and Terms:
- Group of cell bodies in CNS - Nucleus
- Group of cell bodies outside CNS - Ganglion
- Presynaptic neuron is a cholinergic neuron (Ach binds to nicotinic receptors, allowing an influx of cations)
- Postganglionic neurons are also cholinergic neurons (Acetylcholine binds to muscarinic receptors of the target organ, activating a g-protein)
General Functional Aspects of the Sympathetic and Parasympathetic Divisions:
Antagonistic Systems:
Territory:
- Sympathetic: All areas of the body
- Parasympathetic: Not all areas, no innervation in the body wall and limbs
Activity:
- Sympathetic: More generalized and indirect. Ratio of pre- to postganglionic neurons is 1:15 or more.
- E.g., accelerated heart rate, bronchodilation, decreased peristalsis in the gut tube, closing of the sphincters, relaxation of the general bladder wall, and dilation of the pupils.
- Parasympathetic: More specific and direct, Ratio of pre- to postganglionic neurons is 1:2
- Decelerated heart rate, bronchoconstriction, increased gut peristalsis, opening of sphincters, contraction of the bladder wall, and constriction of the pupils.
Functions:
- Sympathetic: Classic ''Fight-or-Flight''. Increase levels of activity and assistance in coping with stress and physical exertion
- Parasympathetic: Classic ''Rest-and-Digest''. Homeostasis, restoration, recuperation, and relaxation
Complementary (Synergistic) Systems:
- Parasympathetic activity produces erection, and sympathetic activity results in ejaculation.
Independent function:
- Sympathetic activates sweat gland secretion, but parasympathetics play no role in sweat gland activity.
Cranial Outflow:
- Oculomotor nerve (nervus oculomotorius)
- Nucleus: Edinger-Westphal nucleus, accessory oculomotor nucleus (nucleus accessorii nervi oculomotorii)
- Synapse with Ciliary ganglion (ganglion ciliare), and innervates the ciliary body and sphincter pupillae
- Facial nerve (nervus facialis)
- Nucleus: Superior salivatory nucleus (nucleus salivatorius superior)
- Greater petrosal nerve synapse with Pterygopalatine ganglion (ganglion pterygopalatinum) to innervate the lacrimal, palatine, nasal and nasopharyngeal glands.
- Chorda tympani synapse with Submandibular ganglion (ganglion submandibulare) to innervate submandibular and sublingual glands
- Glossopharyngeal nerve (nervus glossopharyngeus)
- Nucleus: Inferior salivatory nucleus (nucleus salivatorius inferior)
- Lesser petrosal nerve synapse with otic ganglion (ganglion oticum), then innervates the parotid gland
- Vagus nerve (nervus vagus)
- Nucleus: Posterior nucleus of the vagus nerve (nucleus posterior nervi vagi)
- Innervates smooth muscle, glands, internal organs
Sacral Outflow:
- Sacral parasympathetic nuclei in the lateral horns of the spinal cord as Intermediolateral nucleus (nucleus intermediolateralis) S2, S2, and S4
- Sacral splanchnic nerves (nervi splanchnici sacrales)
- Preganglionic fibers going into the inferior hypogastric plexus (plexus hypogastricus inferior) and through organs of the lesser pelvis and synapse with purely parasympathetic ganglia.
Sources:
- Singh, I. (2017). *Human Neuroanatomy* (10th ed.).
- Wineski, L. E. (2019). *Snellβs Clinical Anatomy by Regions* (10th ed.). Pearson.
- Kozlowski, T. (2017). *Memorix Anatomy: The Complete Study Guide*. 2nd ed. Thieme Medical Publishers.
- Fryer, A. D., & Jacoby, D. B. (1998). Muscarinic Receptors and Control of Airway Smooth Muscle. *American Journal of Respiratory and Critical Care Medicine, 158*(Supplement 2), 13tac120. doi.org/10.1164/ajrccm.158.supplement_2.13tac120
- Pterygopalatine Ganglion. (n.d.). *ScienceDirect*. Retrieved 20.01.2024.
- Selective Serotonin Reuptake Inhibitors for Premature Ejaculation: Review of Erectile and Ejaculatory Side Effects - Scientific Figure on ResearchGate. Available from: researchgate.net/figure/Fig-1-Nitric-oxide-mediated-signaling-in-the-erectile-response-The-cavernosal-nerve_fig1_259845239 [accessed 23 Jan, 2024]
- University lectures and notes
Programs:
- Complete Anatomy: 3d4medical.com
- Biorender: biorender.com
- PowerPoint
- Camtasia 2023
Pictures and Visuals used under licenced permission
π Website: taimtalksmed.com
π« Help keep this content free: youtube.com/channel/UCEr7pkSXVsHcBLLBcJAGV-Q/join
π¬ Get 10% off anatomy lab models (affiliate link): https://anatomywarehouse.com?aff=34
π² Other Links:
Instagram: instagram.com/taimtalksmed
Discord: discord.com/invite/DENMUpS8ey
Content:
0:00 Introduction
01:35 Ganglion and Nucleus
02:06 General Structure
02:55 Sympathetic vs Parasympathetic
06:10 Neurotransmitters
07:35 Craniosacral Outflow
08:55 Cranial Part
17:42 Sacral Part
19:19 Ending
Parasympathetic nervous system is a part of the autonomic nervous system, which is under the motor division of the peripheral nervous system. Neuroanatomy
General Structures and Terms:
- Group of cell bodies in CNS - Nucleus
- Group of cell bodies outside CNS - Ganglion
- Presynaptic neuron is a cholinergic neuron (Ach binds to nicotinic receptors, allowing an influx of cations)
- Postganglionic neurons are also cholinergic neurons (Acetylcholine binds to muscarinic receptors of the target organ, activating a g-protein)
General Functional Aspects of the Sympathetic and Parasympathetic Divisions:
Antagonistic Systems:
Territory:
- Sympathetic: All areas of the body
- Parasympathetic: Not all areas, no innervation in the body wall and limbs
Activity:
- Sympathetic: More generalized and indirect. Ratio of pre- to postganglionic neurons is 1:15 or more.
- E.g., accelerated heart rate, bronchodilation, decreased peristalsis in the gut tube, closing of the sphincters, relaxation of the general bladder wall, and dilation of the pupils.
- Parasympathetic: More specific and direct, Ratio of pre- to postganglionic neurons is 1:2
- Decelerated heart rate, bronchoconstriction, increased gut peristalsis, opening of sphincters, contraction of the bladder wall, and constriction of the pupils.
Functions:
- Sympathetic: Classic ''Fight-or-Flight''. Increase levels of activity and assistance in coping with stress and physical exertion
- Parasympathetic: Classic ''Rest-and-Digest''. Homeostasis, restoration, recuperation, and relaxation
Complementary (Synergistic) Systems:
- Parasympathetic activity produces erection, and sympathetic activity results in ejaculation.
Independent function:
- Sympathetic activates sweat gland secretion, but parasympathetics play no role in sweat gland activity.
Cranial Outflow:
- Oculomotor nerve (nervus oculomotorius)
- Nucleus: Edinger-Westphal nucleus, accessory oculomotor nucleus (nucleus accessorii nervi oculomotorii)
- Synapse with Ciliary ganglion (ganglion ciliare), and innervates the ciliary body and sphincter pupillae
- Facial nerve (nervus facialis)
- Nucleus: Superior salivatory nucleus (nucleus salivatorius superior)
- Greater petrosal nerve synapse with Pterygopalatine ganglion (ganglion pterygopalatinum) to innervate the lacrimal, palatine, nasal and nasopharyngeal glands.
- Chorda tympani synapse with Submandibular ganglion (ganglion submandibulare) to innervate submandibular and sublingual glands
- Glossopharyngeal nerve (nervus glossopharyngeus)
- Nucleus: Inferior salivatory nucleus (nucleus salivatorius inferior)
- Lesser petrosal nerve synapse with otic ganglion (ganglion oticum), then innervates the parotid gland
- Vagus nerve (nervus vagus)
- Nucleus: Posterior nucleus of the vagus nerve (nucleus posterior nervi vagi)
- Innervates smooth muscle, glands, internal organs
Sacral Outflow:
- Sacral parasympathetic nuclei in the lateral horns of the spinal cord as Intermediolateral nucleus (nucleus intermediolateralis) S2, S2, and S4
- Sacral splanchnic nerves (nervi splanchnici sacrales)
- Preganglionic fibers going into the inferior hypogastric plexus (plexus hypogastricus inferior) and through organs of the lesser pelvis and synapse with purely parasympathetic ganglia.
Sources:
- Singh, I. (2017). *Human Neuroanatomy* (10th ed.).
- Wineski, L. E. (2019). *Snellβs Clinical Anatomy by Regions* (10th ed.). Pearson.
- Kozlowski, T. (2017). *Memorix Anatomy: The Complete Study Guide*. 2nd ed. Thieme Medical Publishers.
- Fryer, A. D., & Jacoby, D. B. (1998). Muscarinic Receptors and Control of Airway Smooth Muscle. *American Journal of Respiratory and Critical Care Medicine, 158*(Supplement 2), 13tac120. doi.org/10.1164/ajrccm.158.supplement_2.13tac120
- Pterygopalatine Ganglion. (n.d.). *ScienceDirect*. Retrieved 20.01.2024.
- Selective Serotonin Reuptake Inhibitors for Premature Ejaculation: Review of Erectile and Ejaculatory Side Effects - Scientific Figure on ResearchGate. Available from: researchgate.net/figure/Fig-1-Nitric-oxide-mediated-signaling-in-the-erectile-response-The-cavernosal-nerve_fig1_259845239 [accessed 23 Jan, 2024]
- University lectures and notes
Programs:
- Complete Anatomy: 3d4medical.com
- Biorender: biorender.com
- PowerPoint
- Camtasia 2023
Pictures and Visuals used under licenced permission
