MindMap Gallery Nervous system mind map
About anatomy and physiology - Nervous system mind map, including trigeminal nerve, facial nerve, glossopharyngeal nerve, etc. It’s full of useful information, friends in need should quickly collect it!
Edited at 2023-12-04 10:35:46El cáncer de pulmón es un tumor maligno que se origina en la mucosa bronquial o las glándulas de los pulmones. Es uno de los tumores malignos con mayor morbilidad y mortalidad y mayor amenaza para la salud y la vida humana.
La diabetes es una enfermedad crónica con hiperglucemia como signo principal. Es causada principalmente por una disminución en la secreción de insulina causada por una disfunción de las células de los islotes pancreáticos, o porque el cuerpo es insensible a la acción de la insulina (es decir, resistencia a la insulina), o ambas cosas. la glucosa en la sangre es ineficaz para ser utilizada y almacenada.
El sistema digestivo es uno de los nueve sistemas principales del cuerpo humano y es el principal responsable de la ingesta, digestión, absorción y excreción de los alimentos. Consta de dos partes principales: el tracto digestivo y las glándulas digestivas.
El cáncer de pulmón es un tumor maligno que se origina en la mucosa bronquial o las glándulas de los pulmones. Es uno de los tumores malignos con mayor morbilidad y mortalidad y mayor amenaza para la salud y la vida humana.
La diabetes es una enfermedad crónica con hiperglucemia como signo principal. Es causada principalmente por una disminución en la secreción de insulina causada por una disfunción de las células de los islotes pancreáticos, o porque el cuerpo es insensible a la acción de la insulina (es decir, resistencia a la insulina), o ambas cosas. la glucosa en la sangre es ineficaz para ser utilizada y almacenada.
El sistema digestivo es uno de los nueve sistemas principales del cuerpo humano y es el principal responsable de la ingesta, digestión, absorción y excreción de los alimentos. Consta de dos partes principales: el tracto digestivo y las glándulas digestivas.
🆘Nerve🆘very important
Nerves related to the oral, maxillofacial and cervical areas include: cranial nerves such as the trigeminal nerve, facial nerve, glossopharyngeal nerve, vagus nerve, accessory nerve, hypoglossal nerve, cervical spinal nerves, and cervical visceral motor nerves.
I. Overview
Peripheral nerves: cranial nerves, spinal nerves in the neck and visceral motor nerves in the neck are peripheral nerves. One end of the peripheral nerves is connected to the brain or spinal cord, called cranial nerves or spinal nerves, and the other end is connected to various systems and organs of the body through various peripheral devices. The peripheral nerves distributed on the body surface, bones, joints and skeletal muscles are called somatic nerves; the peripheral nerves distributed on the internal organs, cardiovascular, smooth muscles, and glands are called splanchnic nerves. Visceral efferent nerves are also called autonomic nerves (also called autonomic nerves) and are composed of sympathetic nerves and parasympathetic nerves.
(1) Ganglion
bipolar neurons
pseudounipolar neuron
multipolar neuron
(2) Nerve fibers
1.Cranial nerve fibers: 7 types in total
(1) General somatosensory fibers: distributed in the skin, muscles, tendons, and most mucous membranes in the orbit, mouth, and nose.
(2) Special somatosensory fibers: distributed in the special sensory organs derived from the ectoderm, namely the visual organ and the vestibulocochlear organ.
(3) General visceral sensory fibers: distributed in the head, neck, chest, and abdominal organs.
(4) Special visceral sensory fibers: distributed in taste buds and olfactory organs. Although these receptors are derived from the ectoderm, they are related to visceral functions such as eating, so the fibers connected to them are called special visceral sensory fibers.
(5) General body motor fibers: distributed in striated muscles such as extraocular muscles and tongue muscles derived from mesoderm.
(6) General visceral motor fibers: distributed in smooth muscle, cardiac muscle and glands.
(7) Special visceral motor fibers: distributed in masticatory muscles, expression muscles and throat muscles
2. Spinal nerve fibers: 4 types
(1) Somatosensory fibers: Distributed in the skin, skeletal muscles, tendons and joints, they transmit impulses from the superficial sensations of the skin (pain, temperature, etc.) and the deep sensations (kinesthetic sense, positional sense) of the tendons and joints to the central nervous system.
(2) Visceral sensory fibers: distributed in viscera, cardiovascular and glands, transmitting sensory impulses from these structures to the central nervous system.
(3) Somatic motor fibers: distributed in skeletal muscles and controlling their voluntary movement.
(4) Visceral motor fibers: distributed in viscera, cardiovascular and glands, controlling the movement of myocardium and smooth muscle, and controlling gland secretion.
(3) Distribution of cranial nerves
Cranial nerves: 12 pairs in total, divided into sensory nerves, motor nerves, and mixed nerves according to their nature. (emphasis)
1. Sensory nerves: olfactory nerve, optic nerve, vestibulocochlear nerve, they only contain sensory fibers and are connected to special sensory organs in the head.
2. Motor nerves: The oculomotor nerve, trochlear nerve, abducens nerve, accessory nerve and hypoglossal nerve are motor nerves.
3. Mixed nerves: trigeminal nerve, facial nerve, glossopharyngeal nerve, vagus nerve
2. Trigeminal nerve
Trigeminal nerve: It is the largest pair of cranial nerves. It is a mixed nerve and consists of two nerves.
Trigeminal ganglion: It is the largest cranial ganglion, also known as the semilunar ganglion. It is located at the trigeminal nerve imprint at the tip of the petrous part of the temporal bone, about 4.5~5.0cm deep from the posterior end of the zygomatic arch root, and is located in the trigeminal nerve cavity formed by the two layers of the dura mater. Inside and above is the temporal lobe of the brain, the inner edge is adjacent to the back of the cavernous sinus and the internal carotid artery, the foramen ovale and the foramen spinosum are on the outside, and the motor root of the trigeminal nerve and the course of the greater petrosal nerve are on the deep side.
(1) Ocular nerve (sensory)
The ophthalmic nerve is a sensory nerve and is the smallest of the trigeminal nerves. It originates from the anteromedial side of the trigeminal ganglion, runs through the lateral wall of the cavernous sinus, and is divided into three terminals near the superior orbital fissure: the lacrimal nerve, the mental nerve, and the nasociliary nerve. branch, then enters the orbit through the superior orbital fissure forward, and is distributed in the orbit, eyeball, conjunctiva, lacrimal gland, upper eyelid, forehead and top skin above the palpebral fissure, most of the skin of the nose, and part of the nasal mucosa.
(2) Maxillary nerve (sensory)
Maxillary nerve: originates from the middle of the anterior edge of the trigeminal ganglion, travels forward along the lower part of the lateral wall of the cavernous sinus, passes through the round foramen to the upper part of the pterygopalatine fossa, enters the orbit through the infraorbital fissure and is renamed the infraorbital nerve, and travels forward along the infraorbital groove and orbit. The inferior canal emerges from the infraorbital foramen and reaches the face. The maxillary nerve can be divided into four segments according to its course.
1. Middle cranial fossa segment: The maxillary nerve sends out the middle meningeal nerve in the middle cranial fossa segment and distributes in the dura mater.
2. Pterygopalatine fossa segment: The maxillary nerve sends out the zygomatic nerve, pterygopalatine nerve and retrosuperior alveolar nerve in the pterygopalatine segment.
① Zygomatic nerve: enters the orbit through the infraorbital fissure, passes through the zygomatic canal on the lateral wall of the orbit, is divided into a zygomaticotemporal branch and a zygomaticofacial branch, and supplies the zygomatic and temporal skin. The zygomatic nerve also uses the communicating branch to introduce parasympathetic postganglionic fibers from the facial nerve into the lacrimal gland nerve to control lacrimal gland secretion.
② Pterygopalatine nerve: The pterygopalatine nerve, also known as the ganglionic branch, is usually two small branches that descend in the pterygopalatine fossa, pass through the pterygopalatine ganglion, and together with its postganglionic fibers form the orbital branch, nasal branch, palatine nerve and pharyngeal nerve. Nerve etc.
Nasal branch A: The nasal branch enters the nasal cavity through the sphenopalatine foramen and is distributed in the mucosa of the turbinates and nasal septum. One of the nerves is called the nasopalatine nerve, which runs downward along the deep surface of the nasal septal mucosa, distributes in the nasal septum, exits the incisive foramen through the incisal canal, distributes to the palatal mucoperiosteum and gums of the maxillary anterior teeth, and sends out branches to communicate with the upper teeth. The anterior alveolar nerve communicates with the maxillary central incisors and has another branch that anastomoses with the anterior palatine nerve on the palatal side of the maxillary canines.
When the maxillary anterior teeth are extracted, nasopalatine nerve block anesthesia can be performed using incisive foramen injection.
B Palatine nerve: It is divided into three branches, anterior, middle and posterior, all descending in the pterygopalatine canal. The anterior palatine nerve is also called the greater palatine nerve. The most commonly used method for maxillary nerve block anesthesia is pterygopalatine canal injection, that is, the needle is inserted through the greater palatine foramen. In addition, when extracting maxillary premolars and molars, greater palatine foramen injection is often used to perform anterior palatine nerve block anesthesia.
③Superior retroalveolar nerve
It is a branch of the maxillary nerve that originates in the pterygopalatine fossa and enters the infratemporal fossa through the pterygomaxillary fissure.
Distribution range: first molar, sometimes premolar or canine area
3. Intraorbital segment
(1) Middle maxillary alveolar nerve: distributed in the mesiobuccal roots of the maxillary premolars and maxillary first molars and their periodontal ligament, alveolar bone, buccal gingiva and maxillary sinus mucosa. About 1/3 of Chinese people are missing the middle alveolar nerve, and its distribution area is replaced by the anterior superior alveolar nerve and the posterior superior alveolar nerve.
(2) Superior prealveolar nerve: It originates from the midpoint of the infraorbital canal, descends through the alveolar canal on the anterolateral wall of the maxillary sinus, branches to join the superior alveolar plexus, and distributes to the maxillary anterior teeth and their corresponding periodontal ligament, alveolar bone, labial gingiva and maxillary sinus mucosa.
4. Noodles
(1) Subpalpebral branch: distributed in the skin of the lower eyelid.
(2) Lateral nasal branch: the skin distributed on the side of the nose
(3) Medial nasal branch: the skin distributed in the vestibule of the nasal cavity
(4) Upper lip branch: distributed in the skin and mucous membrane of the upper lip
(3) Mandibular nerve (mixed nerve)
Mandibular nerve: It is a mixed nerve mainly composed of sensory nerves, and is the largest branch of the trigeminal nerve.
1. Meningeal branch: distributed in the dura mater
2. Medial pterygoid nerve: It is distributed in the medial pterygoid muscle and has 1 to 2 thin branches that penetrate the auricular ganglion and distribute to the tensor tympani muscle and tensor veli palatini muscle.
3. Mandibular nerve trunk: distributed in the temporalis muscle, masseter muscle, and lateral pterygoid muscle. Sensory fibers are almost entirely concentrated in the buccal nerve.
(1) Deep temporal nerve: one at the front and one at the front, respectively called the anterior deep temporal nerve and the deep posterior temporal nerve. They both enter the deep surface of the temporal muscle through the upper edge of the lateral pterygoid muscle and distribute in this muscle.
(2) Masseter nerve: often shares its trunk with the posterior deep temporal nerve.
(3) Lateral pterygoid nerve: runs deep to the lateral pterygoid muscle, and branches to the upper and lower heads of the lateral pterygoid muscle.
(4) Buccal nerve: The long buccal nerve, the only sensory nerve in the anterior trunk, runs forward and outward, passes between the two heads of the lateral pterygoid muscle, runs forward and downward on the medial edge of the coracoid process along the front edge of the mandibular branch, and ends in the temporalis muscle. Covered by the anterior edge of the masseter muscle, it passes through the buccal fat layer and is distributed on the buccal gingiva and buccal mucosa and skin of the mandibular molars and second premolars.
4. Posterior trunk of mandibular nerve: thicker and mainly divided into three nerves, namely auriculotemporal nerve, lingual nerve and inferior alveolar nerve. The first two are sensory nerves, and the inferior alveolar nerve is a mixed nerve.
(1) Auriculotemporal nerve: Mostly two nerves surround the middle meningeal artery and then merge into one trunk. They run backward between the deep surface of the lateral pterygoid muscle and the tensor veli palatini muscle, and pass between the sphenomandibular ligament and the condylar neck. Enter the upper and lower branches of the upper part of the parotid gland along the back of the temporomandibular joint.
① Superior branch: After branching from the main trunk of the auriculotemporal nerve, it bends upward at almost a right angle, passes through the upper edge of the parotid gland, ascends along the back of the superficial temporal artery, crosses the root of the zygomatic arch and enters the temporal region, and is divided into articular branch, preauricular branch, The external auditory canal branch, parotid gland branch, and superficial temporal branch are distributed in the temporomandibular joint, the anterior and upper part of the auricle, the external auditory canal, the parotid gland, and the skin of the temporal region.
②Inferior branch: descends in the parotid gland parenchyma and communicates with the facial nerve.
(2) Lingual nerve: It originates from the posterior trunk of the mandibular nerve, passes through the deep surface of the lateral pterygoid muscle to its lower edge, descends between the medial pterygoid muscle and the mandibular branch, forms an arch forward and inward, and crosses the distal to the mandibular third molar. It lies below the lingual side, then forward and downward, between the hyoid muscle and mylohyoid muscle, and is located above the submandibular gland and its duct.
(3) Inferior alveolar nerve: It is the largest branch of the mandibular nerve. It descends on the medial side of the lateral pterygoid muscle, passes through the lower edge of the lateral pterygoid muscle, and connects with the inferior alveolar artery and vein between the sphenomandibular ligament and the mandibular branch. Along with the mandibular nerve groove, it passes through the mandibular foramen and enters the mandibular canal. It also terminally exits the mental foramen and is the mental nerve. It distributes to the labial and buccal gums, lower lip mucosa and skin of the mandibular anterior teeth and first premolar, as well as the skin of the chin. skin.
The distribution of maxillary and mandibular nerves in the oral cavity
3. Facial nerve
Facial nerve: arises from the facial nerve nucleus in the ventrolateral part of the inferior pontine reticular formation.
(1) Branches of facial nerve canal segment
1. Greater petrosal nerve: mainly contains parasympathetic preganglionic fibers.
2. Stapedius nerve
3. Chordrum tympani: taste buds in the front 2/3 of the tongue
(2) Extracranial segment of facial nerve and its branches
1. Main trunk of facial nerve: refers to the section of the facial nerve from the stylomastoid foramen to the bifurcation of the facial nerve. It is about 2cm long and 2.5mm in diameter. The facial nerve is superficial and is easily damaged during surgery.
2. Anterior parotid branch of facial nerve
(1) Postauricular nerve: innervates the postauricular and occipital muscles
(2) Digastric branch: innervates the posterior belly of the digastric muscle
(3) Stylohyoid muscle branch: innervates the stylohyoid muscle
3. Intraparotid branch of facial nerve: two major branches: temporofacial trunk and cervicofacial trunk
(1) Temporal branches: 1 to 2 branches, which originate from the temporofacial trunk, pass through the superficial surface or front edge of the condyle, 10 to 15 mm in front of the tragus, and exit the upper edge of the parotid gland. Distributed in frontalis muscle, superior part of orbicularis oculi muscle, preauricular muscle and supraauricular muscle. This branch is damaged and the forehead lines on the same side disappear.
(2) Zygomatic branch: mostly 2 to 3 branches, arising from the temporal and facial trunk. The eyelid cannot close if the zygomatic branch is damaged.
(3) Buccal branches: mostly 3 to 5 branches, originating from the cervicofacial trunk, or from the temporal and cervicofacial trunks.
(4) Mandibular marginal branch: There are mostly 2 branches, which originate from the cervicofacial trunk, pass through the parotid gland for a long time, and have large location variations.
(5) Cervical branch: mostly 1 branch, which is the terminal branch of the cervical facial trunk. After exiting the lower edge of the parotid gland, deep to the platysma muscle, it travels forward and downward to the submandibular triangle, and is distributed to the platysma muscle, where it can be emitted. The branches communicate with the transverse cervical nerve.
(3) Applied anatomy of facial nerve
1. Supranuclear palsy
2. Subnuclear paralysis
4. Glossopharyngeal nerve
Glossopharyngeal nerve: contains five fibers
①Special visceral motor fibers: originate from the nucleus ambiguus and innervate the stylopharyngeus muscle
②General visceral motor fibers: originate from the inferior salivation nucleus of the medulla oblongata
③General visceral sensory fibers: originate from cells in the lower ganglion and end in the nucleus of the solitary tract
④Special visceral sensory fibers: originate from cells in the lower ganglion, the peripheral processes are distributed in the taste buds in the posterior 1/3 of the tongue to conduct taste impulses, and the central processes terminate in the nucleus of the solitary tract.
⑤ General somatosensory fibers: originate from cells in the superior ganglion, peripheral processes are distributed in the skin behind the ear, and central processes terminate in the nucleus of the spinal tract of the trigeminal nerve.
(1) Branches of the glossopharyngeal nerve
1. Tympanic nerve: manages parotid gland secretion
2. Carotid sinus branch: chemoreceptors conduct stimulation to the brain and regulate heartbeat, blood pressure and respiration.
3. Pharyngeal branch: distributed in the pharyngeal mucosa
4. Muscular branch: innervates stylopharyngeus muscle
5.Tonsillar branch
6. Lingual branch: distributed in the mucosa and taste buds in the back 1/3 of the tongue, responsible for the general sensation and taste there.
(2) Applied anatomy of glossopharyngeal nerve
After damage to the glossopharyngeal nerve, there will be reduced or lost sensation in the soft palate and pharynx on the affected side, general sensory and taste disorders in the back 1/3 of the tongue, weakened or lost gag reflex, abnormal secretion function of the parotid gland, etc. Tumors that invade the glossopharyngeal nerve can cause pain in the sensory distribution area of the glossopharyngeal nerve or glossopharyngeal nerve paralysis. Clinically, paroxysmal severe pain in the glossopharyngeal nerve distribution area without a clear cause is called primary glossopharyngeal neuralgia.
5. Vagus Nerve
Vagus nerve: contains five types of fibers
① General visceral motor fibers: originate from the dorsal nucleus of the vagus nerve and terminate in ganglia in the walls of the cervical, thoracic and abdominal organs. After exchanging neurons, their postganglionic fibers are distributed in the cervical, thoracic and abdominal organs to control the myocardium. , smooth muscle and glandular activity
②Special visceral motor fibers: originate from the nucleus ambiguus in the oblongata and innervate the pharyngeal muscles, laryngeal muscles, soft palate muscles and upper esophageal muscles
③General somatosensory fibers: originate from cells in ganglia, peripheral processes are distributed in the skin behind the ear and external auditory canal, and the dura mater in the posterior cranial fossa, and the central process terminates in the nucleus of the spinal tract of the trigeminal nerve.
④General visceral sensory fibers: cells originating from the lower ganglion, with peripheral processes distributed in the carotid sinus, carotid body, pharynx, larynx, esophagus, bronchi, lungs, heart, chest and abdominal organs, and central processes ending in the solitary tract nuclear
⑤Special visceral sensory fibers: cells originating from the lower ganglion, with peripheral processes distributed in the epiglottis and taste buds of the soft palate, and the central process also terminates in the nucleus of the solitary tract.
(1) Branches of the vagus nerve
1. Pharyngeal branch: Together with the glossopharyngeal nerve and the pharyngeal branch of the sympathetic nerve, it forms the pharyngeal plexus. Its branches innervate the pharyngeal muscles (except the stylopharyngeal muscle, which is innervated by the glossopharyngeal nerve) and the soft palate muscles (except the tensor veli palatini muscle, which is innervated by the trigeminal nerve). Outside the innervation of the mandibular nerve)
2. Superior laryngeal nerve: originates from the inferior ganglion and is divided into internal and external branches. The internal branch is distributed in the epiglottis, the laryngeal mucosa above the glottis fissure and part of the base of the tongue; the external branch is distributed in the cricothyroid muscle.
3. Recurrent laryngeal nerve: The left and right recurrent laryngeal nerves have different courses. Distributed in the laryngeal muscles except the cricothyroid muscle and the laryngeal mucosa below the glottis fissure.
(2) Applied anatomy of the vagus nerve
See P161
6. Accessory nerve
Accessory nerve: It is a motor nerve originating from the medulla oblongata and spinal cord, and is composed of two nerve roots. The medullary root originates from the nucleus ambiguus in the medulla oblongata, and the spinal root originates from the accessory nerve nucleus in the anterior horn of the spinal cord in segments 1 to 5 of the cervical spinal cord.
(1) Branches of accessory nerve
1. Medial branch: innervates the pharyngeal muscles and soft palate muscles.
2. Lateral branch: innervates the sternocleidomastoid and trapezius muscles
(2) Applied anatomy of accessory nerves
P161
7. Hypoglossal nerve
Hypoglossal nerve: It is a motor nerve that innervates all internal and external muscles of the tongue except the palatoglossal muscle. It only contains general somatic motor nerve fibers, which originate from the hypoglossal nucleus of the medulla oblongata. The fibers from this nucleus form the hypoglossal nerve root filaments, which exit the brain from the anterolateral sulcus between the medulla oblongata vertebrae and olives.
(1) Branch distribution of hypoglossal nerve
It passes through the hypoglossal canal and exits the skull, and descends between the internal carotid artery and vein. At the level of the mandibular angle, the nerve curves forward in an arcuate shape, crosses the superficial surface of the internal and external carotid arteries, and enters the submandibular triangle through the deep surface of the posterior belly of the digastric muscle.
(2) Applied anatomy of hypoglossal nerve
If this nerve is damaged, it can lead to paralysis and atrophy of the tongue muscle on the affected side. When the tongue is extended, the tip of the tongue will deviate to the affected side. When the tongue is in a resting position in the oral cavity, the tip of the tongue will deviate to the healthy side.
8. Cervical spinal nerves
Cervical spinal nerves: There are eight pairs in total, of which the anterior branches of 1 to 4 pairs of cervical nerves form the cervical plexus, which is distributed in the neck muscles, diaphragm, and skin of the head, neck, shoulders and chest.
(1) Superficial branch group of cervical plexus: The superficial branch group of cervical plexus is a cutaneous nerve. Each branch penetrates the deep surface of deep cervical fascia at the midpoint of the posterior edge of sternocleidomastoid muscle, levator scapulae muscle and middle scalene muscle. the front. The cervical plexus consists of two groups of superficial and deep branches.
1. Lesser occipital nerve: distributed behind the auricle and occipital skin. Fibers from 2nd or 3rd cervical nerve
2. Greater auricular nerve: distributed in the skin behind the auricle and mastoid. The great auricular nerve is superficial and easy to find, and can be used as a donor for facial nerve transplantation clinically. Fibers from 2nd or 3rd cervical nerve
3. Transverse cervical nerve: The fibers come from the 2nd or 3rd cervical nerve and are distributed in the skin of the anterolateral neck.
4. Supraclavian nerve: The fibers come from the 3rd and 4th cervical nerves and are distributed in the skin of the lower neck, upper chest and shoulders.
The superficial branches of the cervical plexus all penetrate the deep cervical fascia from the midpoint of the posterior edge of the sternocleidomastoid muscle, so nerve block anesthesia of the superficial branches of the cervical plexus is clinically feasible here.
(2) Deep branch group of cervical plexus
1. Phrenic nerve
2. Accessory phrenic nerve: It is an unstable branch of the cervical plexus. Its occurrence rate in Chinese people is 48%, and it is commonly found on one side.
(3) Communicating branch of cervical plexus
There are some communicating branches between the cervical plexus and other nerve branches distributed in the neck, such as the accessory nerve, vagus nerve and sympathetic nerve.
Cervical loop: After part of the fibers of the first cervical nerve leave the trunk, they join the hypoglossal nerve and go down with it. After traveling a short distance, they leave the hypoglossal nerve and continue to go down, forming an independent descending branch of the hypoglossal nerve.
9. Neck visceral motor nerves
(1) Sympathetic nerve
The low-level center is located in: T1~T3 of the spinal cord, the intermediolateral nucleus of the lateral column of gray matter (the cells of this nucleus where the preganglionic fibers of the sympathetic ganglia originate).
Peripheral: sympathetic trunk, sympathetic ganglia, branches from the ganglia, and sympathetic plexus.
Sympathetic trunks: one on the left and one on the left. The upper end starts from the base of the skull and is arranged along both sides of the spine. The lower end goes directly to the sacrum. This trunk is called the cervical sympathetic trunk in the neck.
1. Cervical sympathetic trunk: It is composed of three cervical sympathetic ganglia and intersegmental branches connected in series. It is located in front of the transverse process of the cervical vertebra, behind the cervical vascular sheath, on the superficial and deep surfaces of the prevertebral layer of the cervical fascia, and sometimes on the tendons. intramembrane
2. Injury to the cervical sympathetic trunk. Injury to the cervical sympathetic trunk during cervical plexus anesthesia or neck lymphadenectomy can lead to cervical sympathetic nerve dysfunction, which is clinically called Homer syndrome. Its specific manifestations are:
(1) The pupil on the affected side is constricted due to dysfunction of the pupillary dilator muscle.
(2) Due to palsy of Miller's muscle of the eyelid, the upper eyelid on the affected side is mildly drooped and the palpebral fissure becomes narrowed, and therefore appears to be enophthalmos.
(3) Due to sympathetic nerve dysfunction in the face and neck vasoconstriction and sweat gland secretion, the blood vessels in the skin of the affected side of the neck are dilated and sweat gland secretion is reduced.
(2) Parasympathetic nerves
The visceral motor fibers in the cranial nerves are all parasympathetic components, respectively in the oculomotor nerve, facial nerve, glossopharyngeal nerve and vagus nerve. The visceral motor fibers originate from the brain and terminate in the corresponding parasympathetic ganglia. The intraganglionic neurons then send out fibers that are distributed in smooth muscle, cardiac muscle and glands. Visible to the naked eye are the ciliary ganglion, pterygopalatine ganglion, auricular ganglion and submandibular ganglion. The parasympathetic ganglia connected to the vagus nerve are mostly located near or within the walls of the organs where they are distributed.