The tenth cranial nerve, and one of the most important, is the vagus nerve. All twelve of the cranial nerves, the vagus nerve included, emerge from or enter the skull (the cranium), as opposed to the spinal nerves which emerge from the vertebral column. The vagus nerve originates in the medulla oblongata, a part of the brain stem.
The vagus nerve is a remarkable nerve that relates to the function of numerous structures in the body. The vagus nerve supplies nerve fibers to the pharynx (throat), larynx (voice box), trachea (windpipe), lungs, heart, esophagus and most of the intestinal tract (as far as the transverse portion of the colon). And the vagus nerve brings sensory information back from the ear, tongue, pharynx and larynx.
The term “vagus” (Latin for “wandering”) is apt because the vagus nerve wanders all the way down from the brainstem to the colon, a long wandering trek.
Complete interruption of the vagus nerve causes a characteristic syndrome. The back part of the palate (the soft palate) droops on that side. The capacity to gag (the gag reflex) is also lost on that side. The voice is hoarse and nasal. The vocal cord on the affected side is immobile. The result is dysphagia and dysphonia (trouble swallowing and trouble speaking).
One of the best known branches of the vagus nerve is the recurrent laryngeal nerve. After leaving the vagus nerve, the recurrent laryngeal nerve goes down into the chest and then loops back up to supply the larynx (the voice box). Damage to the recurrent laryngeal nerve can result from diseases inside the chest (intrathoracic diseases) such as a tumor or an aneurysm (ballooning) of the arch of the aorta or of the left atrium of the heart. The consequence is laryngeal palsy, paralysis of the larynx (the voice box), on the affected side. Laryngeal palsy can also be caused by damage to the vagus nerve before it gives off the recurrent laryngeal nerve.
- ter in die (on prescription)
If a medicine is to be taken every so-many hours, it is written “q_h”; the “q” standing for “quaque” and the “h” indicating the number of hours. So, for example, “2 caps q4h” means “Take 2 capsules every 4 hours.”
thyroid medication, blood thinners, and lithium are just a few examples. In these cases, female patients should work carefully with their doctors to determine if an alternative treatment is possible before and during pregnancy. In some cases the danger of birth defects is limited to a certain part of the pregnancy, and medication can be […]
- Teratogen, coumadin as
The anticoagulant (“blood- thinner”) coumadin is a known teratogen, an agent that can disturb the development of the embryo and fetus and lead to birth defects. Coumadin taken by a woman during pregnancy can cause bleeding into the baby’s brain (cerebral hemorrhage), underdevelopment (hypoplasia) of the baby’s nose and stippling of the ends (the epiphyses) […]
- Teratogen, Ecstasy as
1441-1442.) This study was not large enough to prove a link between Ecstasy and birth defects, but these initial findings indicate that Ecstasy should be avoided by pregnant women.
- Teratogen, warfarin as
The anticoagulant warfarin (COUMADIN) is a known teratogen, an agent that can disturb the development of the embryo and fetus and lead to birth defects. Warfarin taken by a woman during pregnancy can cause bleeding into the baby’s brain (cerebral hemorrhage), underdevelopment (hypoplasia) of the baby’s nose and stippling of the ends (the epiphyses) of […]