Why does vagal stimulation cause bradycardia?

Via the vagus nerve, the parasympathetic nervous system stimulates neurons that release the neurotransmitter acetylcholine (ACh) at synapses with cardiac muscle cells. Acetylcholine then binds to M2 muscarinic receptors, causing the decrease in heart rate that is referred to as reflex bradycardia.

What is Danini ashner reflex?

The oculocardiac reflex, also known as Aschner phenomenon, Aschner reflex, or Aschner–Dagnini reflex, is a decrease in pulse rate associated with traction applied to extraocular muscles and/or compression of the eyeball.

How is bradycardia reflex treated?

Since the reflex is vagally-mediated, premedication with an anti-cholinergic (e.g., atropine or glycopyrrolate) may be a suitable preventative measure. A decrease in arterial blood pressure and a change in heart rate may occur with surgical manipulation of abdominal contents.

Does epinephrine cause reflex bradycardia?

Key Teaching Points. Recognize the potential for epinephrine to induce unwanted side effects, including reflex bradycardia and heart block due to heightened parasympathetic tone.

Does atropine block vagal response?

Atropine works by blocking peripheral muscarinic receptors of the heart and causes increased firing at the sinoatrial node as well as conduction through the AV node. This opposes the vagal response, or the efferent limb, of the OCR.

How do you block Peribulbar?

Peribulbar block: the needle is inserted through the fornix below the lateral limbus after the lower fornix was exposed (by pulling the lower lid down gently). Instil one drop of topical anaesthetic eye drops. Insert the needle through the fornix below the lateral limbus.

Can vagus nerve causes bradycardia?

An overactive vagus nerve can also result in an abnormally low heart rate, or bradycardia. Individuals with an overactive vagus nerve that results in abnormally low heart rate may also be at risk for first-degree heart block.

What is Gasserian ganglion?

The gasserian ganglion is a collection of nerve cell bodies that help provide sensation to the head and face and provide movement to the muscle of mastication (chewing muscles). The gasserian ganglion lies inside the skull on each side of the head. From the ganglion, the trigeminal nerve separates into three branches.