Unit VII - Visceral Afferents & Parasympathetics Flashcards
Which is generally considered cholinergic: sympathetics or parasympathetics?
Parasympathetics
Which is generally considered adrenergic: sympathetics or parasympathetics?
Sympathetics
Where are the cell bodies located in the visceral afferent system?
In posterior root ganglia or relevant cranial nerve ganglion
Where do sympathetic afferents travel?
Through sympathetic trunk and to spinal ganglia by passing through white ramus communicans
Where do parasympathetic afferents travel?
In sacral spinal nerves and cranial nerves
Preganglionic parasympathetic fibers are carried in what cranial nerves?
Oculomotor, facial, glossopharyngeal, and vagus nerves (3, 7, 9, and 10)
Preganglionic parasympathetic fibers are carried in what sacral spinal nerves?
2, 3, and 4
Where do preganglionic parasympathetic fibers generally synapse?
On postganglionic neurons in peripheral ganglia
What is the effect of postganglionic parasympathetic fibers on cardiac output?
Decreased
What is the effect of postganglionic parasympathetic fibers on the bronchial tree?
Constricts
What is the effect of postganglionic parasympathetic fibers on the pupils?
Constricts
What is the effect of postganglionic parasympathetic fibers on peristalsis?
Stimulates
What do the parasympathetic fibers of cranial nerves III, VII, and IX supply?
Structures in the head
What do the parasympathetic fibers of cranial nerve X supply?
Cardiac, respiratory, and digestive structures in the neck, thorax, and abdomen
What do the parasympathetic fibers of sacral spinal nerves 2, 3, and 4 supply?
Distal parts of the digestive system and urogenital systems
Which fibers have more variability in the amount of neurotransmitters available for use: pre or postganglionic?
Postganglionic
Dendrites of visceral afferent neurons carry impulses from viscera via what structures?
Via autonomic ganglia, plexus, or even somatic nerves (without synapse)
Axons of visceral afferent nerves enter the CNS through what structures?
Posterior root or specific spinal nerve
Visceral afferent neurons are associated with receptors that are sensitive to what kinds of things?
Pressure, chemical concentrations, and muscle stretching
What kinds of parasympathetic fibers are associated with cranial nerves 3, 7, 9, and 10 and S2-4?
Preganglionic
What neurotransmitter is most commonly used by the preganglionic parasympathetic fibers of cranial nerves 3, 7, 9, and 10 along with S2-4?
Acetylcholine
Where are preganglionic parasympathetic cell bodies located for cranial nerve III?
Accessory oculomotor nucleus
Where do preganglionic parasympathetic fibers of cranial nerve III synapse?
Ciliary ganglion
What is the location of the accessory oculomotor nucleus?
Periacqueductal gray - midbrain
Postganglionic fibers of cranial nerve III are carried in what nerves?
Short ciliary nerves
What muscles are supplied by the postganglionic fibers of cranial nerve III?
Sphincter pupillae and ciliary muscle
What is the action of the ciliary muscle?
Increase convexity of the lens to enable focus on closer objects
What is the action of the sphincter pupillae muscle?
Constriction of the pupil
Where are preganglionic parasympathetic cell bodies of the facial nerve located?
Superior part of salivary nucleus
The preganglionic parasympathetic fibers of the facial nerve exit the CNS via what nerve?
Intermediate nerve
Preganglionic parasympathetic fibers from cranial nerve VII are carried in what two branches of the facial nerve?
Greater petrosal nerve and chorda tympani
The greater petrosal nerve leaves the facial nerve at what ganglion?
Geniculate ganglion
The greater petrosal nerve re-enters the petrous part of the temporal bone through what opening?
Foramen lacerum
The greater petrosal nerve travels in the pterygoid canal and ultimately joins with what ganglion?
Pterygopalatine ganglion
Postganglionic parasympathetic fibers of the greater petrosal nerve are distributed in what nerves?
Lacrimal and pterygopalatine nerves
What are supplied by the postganglionic parasympathetic facial nerve fibers from the greater petrosal nerve?
Lacrimal, nasal, palatine, and pharyngeal glands
Preganglionic parasympathetic fibers of the chorda tympani travel through what area in the CNS?
Tympanic cavity
Preganglionic parasympathetic fibers of the chorda tympani leave the temporal bone through what opening?
Pterygotympanic fissure
After leaving the temporal bone, the chorda tympani combines with what nerve?
Lingual nerve, a branch of the mandibular division of the trigeminal nerve
The preganglionic fibers of the lingual nerve after its joining with the chorda tympani reach what ganglion?
Submandibular ganglion
Postganglionic fibers from the chorda tympani travel to what areas?
Submandibular and sublingual glands
What other areas also receive parasympathetic information from the submandibular gland?
Glands found in the mucous membranes of the oral cavity and lingual glands on the anterior part of the tongue
Where are preganglionic cell bodies located of the glossopharyngeal nerve?
Inferior part of the salivary nucleus
Preganglionic fibers of the glossopharyngeal nerve are carried in what nerve?
Tympanic nerve
Where does the tympanic nerve come off of the glossopharyngeal nerve?
Inferior ganglion
Preganglionic fibers of the tympanic nerve are carried through what opening into the tympanic cavity?
Tympanic canaliculus
In the tympanic cavity, the tympanic nerve receives postganglionic sympathetic fibers from what location and what is then formed?
Superior cervical ganglion; tympanic plexus
The preganglionic parasympathetic fibers of the tympanic nerve travel through the tympanic plexus and reform as what nerve?
Lesser petrosal nerve
The lesser petrosal nerve travels through the lesser petrosal canal to synapse where?
Otic ganglion
Postganglionic parasympathetic fibers from the otic ganglion (cranial nerve IX) are carried to what locations?
Parotid and posterior lingual glands
Postganglionic parasympathetic fibers reach the parotid gland via what nerve?
Auriculotemporal nerve, a branch of the mandibular division of the trigeminal nerve
The posterior lingual glands receive parasympathetic fibers through what nerve?
Lingual branch of the glossopharyngeal nerve
What are some examples of visceral afferent information carried in the glossopharyngeal nerve?
Special sensory (taste), afferents in the branch of the carotid sinus from baroreceptors in the carotid sinus, chemoreceptors in the carotid body
What is the preganglionic cell body location of the vagus nerve?
Posterior (dorsal) nucleus of the vagus
What is the postganglionic cell body location of the vagus nerve?
In the organs supplied or blood vessels that supply the organs (myocardium, submucosal plexus, myenteric plexus)
Preganglionic fibers of the vagus nerve are carried in what nerves to the heart?
Superior and inferior cardiac nerves
Where do preganglionic parasympathetic fibers of the vagus nerve synapse in the pathway to the heart?
In the cardiac plexus at the base of the heart and wall
Postganglionic parasympathetic fibers of the vagus nerve to the heart are carried to what locations?
Sinoatrial node, atrioventricular node, atrioventricular bundle to reach subendocardial branches (Pukinje fibers)
What effect do parasympathetic inpulses of the vagus nerve have on the heart?
Inhibit myocardium and constrict the coronary arteries
Preganglionic vagal fibers are carried in what branches to the lungs?
Anterior and posterior bronchial branches
Where do preganglionic vagal fibers synapse in the pathway to the lungs?
Pulmonary plexuses surrounding the bronchial tree
Postganglionic vagal fibers reach what areas in the pathway to the lungs?
Bronchial musculature and bronchial glands
What is the effect of parasympathetic vagal impulses on the lungs?
Constriction of bronchial tree and increased secretions of bronchial glands
What respiratory condition is to be considered when analyzing the parasympathetic effects on the lungs?
Asthma
Preganglionic parasympathetic fibers travel to the esophagus in what nerves?
Recurrent laryngeal nerves as well as the anterior and posterior esophageal branches
Where do preganglionic parasympathetic fibers traveling to the esophagus synapse?
Wall of esophagus
What do the postganglionic parasympathetic fibers supply in the pathway to the esophagus?
Esophageal smooth muscle fibers
What supplies the upper 1/3 of the esophagus that is composed of skeletal muscle and is voluntary?
Recurrent laryngeal nerve
Preganglionic parasympathetic fibers travel to the stomach via what nerves?
Branches from both the anterior (about 4 branches) and posterior (about 6 branches) vagal trunks
Where do preganglionic parasympathetic vagal fibers synapse in the stomach?
Submucosal (Meissner’s) and myenteric (Auerbach’s) plexuses in the wall of the stomach
Postganglionic parasympathetic vagal fibers reach what areas of the stomach?
Smooth muscle fibers of the submucosal and myenteric plexuses
Preganglionic parasympathetic vagal fibers reach the small intestine, cecum, vermiform appendix, and ascending and descending transverse colon via what nerve?
Posterior vagal trunk
Preganglionic parasympathetic vagal fibers reach the duodenum by what specific structure?
Celiac plexus
The preganglionic parasympathetic vagal fibers reach their destinations of the lower GI tract via what nerves and structures?
Traveling through the celiac plexus and continuing through the superior mesenteric plexus
Where do preganglionic parasympathetic vagal fibers synapse in the lower GI tract?
Submucosal and myenteric plexuses
Postganglionic parasympathetic vagal fibers reach what locations of the lower GI tract?
Smooth muscle
What is the effect of parasympathetic vagal stimulation of the GI tract?
Contraction of smooth muscle and secretomotor for intestinal glands
What is the importance of visceral afferents of the vermiform appendix?
Nociception
Preganglionic parasympathetic fibers reach the gall bladder, pancreas, and biliary tree via what structures?
Hepatic branch of the right vagal trunk (hepatic plexus)
The hepatic plexus is an extension of what?
Celiac plexus
Where do preganglionic parasympathetic vagal fibers synapse in the gall bladder, pancreas and biliary tree?
Muscular walls of gall bladder and biliary tree, glandular tissue of the pancreas
The postganglionic parasympathetic vagal fibers of the gall bladder, pancreas, and biliary tree reach what locations?
Smooth muscles fibers or glands of their intended target
What is the effect of parasympathetic stimulation of the gall bladder, pancreas, and biliary tree?
Increases smooth muscle activity in the gall bladder and biliary vessels, secretomotor for the pancreatic glands
How do preganglionic parasympathetic vagal fibers reach the spleen?
Posterior vagal trunk via splenic plexus
What is the splenic plexus an extension of?
Celiac plexus
How do preganglionic parasympathetic fibers reach the kidneys?
Renal plexus from posterior vagus
Any fibers reaching the kidneys via parasympathetic pathways are likely to be what type of fibers and why?
Visceral afferents because the motor supply to the kidney is strictly sympathetic
Preganglionic parasympathetic vagal fibers to the liver are primarily from what structure?
Anterior vagal trunk (some coming from posterior)
How do preganglionic parasympathetic vagal fibers reach the liver?
Via hepatic plexus
Parasympathetic supply to what organs is likely to be primarily afferent?
Kidneys, liver, suprarenal glands
Parasympathetic vagal fibers are carried in what structure to the suprarenal glands?
Posterior vagal trunk
Which sacral nerves make up the sacral parasympathetic pathways?
S2, S3, and S4
From where in the spinal cord do sacral parasympathetic pathways arise?
Lateral horns of S2-4
S2-S4 are carried inferior in what structure?
Cauda equina
S2-S4 exit what osseous openings?
Anterior sacral foramina
S2-S4 are carried in what nerves?
Pelvic splanchnic nerves
Pelvic splanchnic nerves travel to what plexus to be distributed to organs?
Inferior hypogastric (pelvic) plexus
The inferior hypogastric plexus is a network of ganglia and nerves covering what organs?
Rectum, internal genitalia, and base of the urinary bladder
How do sacral parasympathetic fibers reach the distal part of the digestive tract?
Through the inferior hypogastric plexus to the superior hypogastric and inferior mesenteric plexuses
How do sacral preganglionic parasympathetic fibers travel the distal colon?
Through inferior hypogastric plexus to the superior hypogastric and inferior mesenteric plexuses by way of the “hypogastric nerve”
How do sacral postganglionic parasympathetic fibers reach the distal colon?
From inferior mesenteric
How do sacral preganglionic parasympathetic fibers travel to the rectum and anus?
Head to inferior hypogastric plexus
How do sacral postganglionic parasympathetic fibers reach the target of the rectum and anus?
Inferior hypogastric plexus
How do sacral preganglionic parasympathetic fibers travel to the urinary bladder?
Inferior hypogastric plexus
How do sacral postganglionic parasympathetic fibers reach the urinary bladder?
Inferior hypogastric plexus
What is technically the official target of the sacral postganglionic parasympathetic fibers when reaching the urinary bladder?
Detrusor muscle
What kind of neural stimulation initiates the emptying of the bladder: sympathetic or parasympathetic?
Parasympathetic
What part of the urinary pathway possesses somatic supply?
External urethral sphincter
When are the neurons involved with the somatic supply to the external urethral sphincter inhibited?
As the bladder empties
How do sacral preganglionic parasympathetic fibers travel to the prostate gland and seminal vesicle?
Prostatic plexus via inferior hypogastric plexus
What structures do sacral postganglionic parasympathetic fibers reach in the pathway to the prostate gland and seminal vesicle?
Smooth muscles of prostatic urethra and seminal vesicle
How do sacral preganglionic parasympathetic fibers reach the uterus?
Inferior hypogastric plexus
Where are sacral postganglionic parasympathetic fibers distributed in the uterus?
Throughout myometrium
Which plays a larger role in the uterus, especially during pregnancy: parasympathetic stimulation or hormonal factors?
Hormonal factors (example = oxytocin)
What kind of neural stimulation inhibits the muscles of the uterus: sympathetic or parasympathetic?
Parasympathetic
What is the pathway to the vagina for sacral preganglionic parasympathetic fibers?
Synapse in vaginal plexus via inferior hypogastric plexus
What is the effect of parasympathetic stimulation on the vagina?
Vasodilation and increased secretory activity at the target
Sacral parasympathetic fibers reaching the inferior part of the vagina may reach their target via what nerve?
Pudendal nerve
What is the pathway of sacral preganglionic parasympathetic fibers to the penis/clitoris?
Cavernous plexus via inferior hypogastric plexus
What is the effect of parasympathetic activity on the penis/clitoris?
Vasodilation and filling of the sinuses of erectile tissue
