Which of the following organs/tissues receive their PSNS innervation from the Va

Question

Which of the following organs/tissues receive their PSNS innervation from the Vagus nerve (CN X)? 1. Heart (SA & AV nodes) 2. Urinary bladder 3. Gall Bladder 4. Gastric pits in stomach 5. Erectile tissue (Penis/Clitoris) 6. Lacrimal glands a. 1, 2, 6 b, 1, 3, 4 c, 2, 3, 5, 6 d. 1, 3, 4, 6 e. 1, 2, 3, 4, 5, 6 Place the following events in the correct chronological sequence as they would occur during your sense of vision (seeing an object). 1. Photons of light enter the eyeball by passing through the cornea & the pupil. 2. PDE cleaves cGMP to GMP thereby losing cGMP-gated cation channels-hyperpolarizing the photoreceptor cell. 3. Light rays are refracted by the lens of the eye onto the retina as an inverted image of the original. 4. IPSP causing neurotransmitter no longer Bipolar cell which now can depolarize. 5. Photons strike 11-cis retinal and cause it to isomerize into All-trans retinal, activating opsin. 6. Bipolar neuron neurotransmitter causes EPSP in Ganglion cell. 7. Opsin activates transducin (G protein) which activates Phosphodiesterase (PDE) enzymes in photoreceptor disc membranes. 8. Ganglion cell reaches threshold and "fires" potentials that propagate along optic Nerve through optic tracts & radiations back to the Visual Cortex of occipital lobe for interpretation. a. 1, 3, 7, 2, 5, 8, 6, 4 b. 1, 2, 3, 4, 5, 6, 7, 8 c. 1, 3, 5, 7, 2, 4, 6, 8 d. 8, 6, 4, 2, 7, 5, 3, 1 e. 1, 2, 6, 3, 4, 7, 6, 8 Which cranial Nerves are the "cranio-" part of the Parasympathetic Nervous system (craniosacral)? 1. Oculomotor nerve 2. Glossopharyngeal nerve 3, CN VIII 4.Facial nerve 5. CN IV 6. Vagus nerve a. 1, 2, 3 b. 2, 4, 5, c, 2, 3, 5 d 1, 2, 4, 6 e. 1, 2, 3, 4, 5, 6

Explanation / Answer

Hello,

For Question no. 69. The answer is b (1,3,4)

The organs which recive PSNS intervention from vagus nerve are Heart, Gall bladder and stomach.

The vagus nerve is the 10th cranial nerve (CN X). It is a functionally diverse nerve, offering many different modalities of innervation.

The vagus nerve is associated with the derivatives of the fourth pharyngeal arch.

Sensory: Innervates the skin of the external acoustic meatus and the internal surfaces of the laryngopharynx and larynx. Provides visceral sensation to the heart and abdominal viscera.

Special Sensory: Provides taste sensation to the epiglottis and root of the tongue.

Motor: Provides motor innervation to the majority of the muscles of the pharynx, soft palate and larynx.

Parasympathetic: Innervates the smooth muscle of the trachea, bronchi and gastro-intestinal tract and regulates heart rhythm.

In the thorax and abdomen, the vagus nerve is the main parasympathetic outflow to the heart and gastro-intestinal organs.

The Heart

Cardiac branches arise in the thorax, conveying parasympathetic innervation to the sino-atrial and atrio-ventricular nodes of the heart.

These branches stimulate a reduction in the resting heart rate. They are constantly active, producing a rhythm of 60 – 80 beats per minute. If the vagus nerve was lesioned, the resting heart rate would be around 100 beats per minute.

Gastro-Intestinal System

The vagus nerve provides parasympathetic innervation to the majority of the abdominal organs. It sends branches to the oesophagus, stomach and most of the intestinal tract – up to the splenic flexure of the large colon.

The function of the vagus nerve is to stimulate smooth muscle contraction and glandular secretions in these organs. For example, in the stomach, the vagus nerve increases the rate of gastric emptying, and stimulates acid production.

For Question NO. 70, Answer is C (1,3,5,7,2,4,6,8)

For Question No. 71, Answer is D (1,2,4,6)

The parasympathetic nervous system consists of 4 cranial nerves: the oculomotor, facial, glossopharyngeal and vagus nerves, which are also known as cranial nerves III, VII, IX and X.

Cranial Nerve III, the Oculomotor Nerve

The oculomotor nerve controls several muscles of the eye. As with all parasympathetic cranial nerves, its signals originate in the brain cells, or neurons, in the brainstem and travel down long, thin extensions called nerve fibers. These nerve fibers connect with their target organ. The oculomotor nerve's target is the eye.

Cranial Nerve VII, the Facial Nerve

The facial nerve has both sensory and motor nerve endings throughout the face, which are responsible for sensation and muscle movement. Parasympathetic fibers in the facial nerve control a number of glands that secrete fluid or mucus. One such gland is the lacrimal gland, which makes tears to keep the eyes moist. In the mouth, parasympathetic facial nerve fibers control the submaxillary/submandibular and sublingual glands, which are glands that secrete saliva. Parasympathetic fibers also stimulate the release of mucus by the numerous mucus-secreting glands dispersed throughout the lining of the nose, mouth and throat.

Cranial Nerve IX, the Glossopharyngeal Nerve

The glossopharyngeal nerve has a number of functions related to taste and eating. Parasympathetic fibers in this nerve control the parotid glands, the largest of the salivary glands. Salivation is necessary for eating, a "peace time" function. Parasympathetic stimulation evokes a good flow of saliva.

Cranial Nerve X, the Vagus Nerve

Of all the parasympathetic cranial nerves, the vagus nerve, which contains about 80 percent of all parasympathetic fibers in the body, is the most important. Fibers from the vagus nerve pass all over the body, influencing almost every organ below the neck -- including the heart, lungs, esophagus, trachea, stomach, small intestine, first part of the colon, liver, gallbladder, pancreas and ureters.

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