BookRiff

If you don’t like to read, you haven’t found the right book

What are secretomotor Fibres?

Secretomotor refers to the capacity of a structure (often a nerve) to induce a gland to secrete a substance (usually mucus or serous fluid). However, these nerves fibers originate from the facial nerve (VII) and only travel briefly with fibers from the trigeminal nerve.

What are secretomotor neurons?

Secretomotor neurons are excitatory motor neurons in the ENS that innervate the intestinal crypts of Lieberkühn (Fig. 12-6). Secretomotor neurons have receptors that receive excitatory and inhibitory synaptic input from other neurons in the integrative circuitry of the ENS and from sympathetic postganglionic neurons.

What are parasympathetic fibers?

The nerve fibres of the parasympathetic nervous system are the cranial nerves, primarily the vagus nerve, and the lumbar spinal nerves. When stimulated, these nerves increase digestive secretions and reduce the heartbeat.

Are secretomotor Fibres parasympathetic?

Parasympathetic fibres are secretomotor to the gland as the efferent path of the lacrimal reflex, which initiates and maintains secretion. This includes preganglionic fibres passing via the facial nerve (to the greater petrosal nerve then nerve of the pterygoid canal) to the pterygopalatine ganglion.

What are vasomotor fibers?

1. ( Pharmacology) a drug, agent, or nerve that can cause dilatation (vasodilatation) of the walls of blood vessels. 2. ( Physiology) a drug, agent, or nerve that can cause dilatation (vasodilatation) of the walls of blood vessels.

What Innervates the lacrimal gland?

Nerve supply The lacrimal gland is innervated by the lacrimal nerve, which is the smallest branch of the ophthalmic nerve, itself a branch of the trigeminal nerve (CN V). After the lacrimal nerve branches from the ophthalmic nerve it receives a communicating branch from the zygomatic nerve.

What is the parasympathetic nervous system also known as?

Sometimes called the rest and digest system, the parasympathetic system conserves energy as it slows the heart rate, increases intestinal and gland activity, and relaxes sphincter muscles in the gastrointestinal tract. …

Is sympathetic secretomotor?

Postganglionic neurons of the sympathetic nervous system are an important source of inhibitory input to the secretomotor neurons. Norepinephrine released from sympathetic axons acts at α2a noradrenergic receptors to inhibit firing of the secretomotor neurons.

What is the secretomotor nerve supply of parotid gland?

Remember the secretomotor pathway of the parotid gland with the mnemonic “IT has Lesser Options Anywhere”, which stands for; Inferior salivatory nucleus. Tympanic branch of 9th nerve. Lesser petrosal nerve.

What are the vasomotor nerves?

vasomotor nerves The nerves of the autonomic nervous system that control the diameter of blood vessels. Vasoconstrictor nerves decrease the diameter (see vasoconstriction); vasodilator nerves increase it (see vasodilation). A Dictionary of Biology.

Where are sensory fibers located in the facial nerve?

Sensory and Secretomotor Divisions of Cranial Nerve VII. The sensory fibers of the facial nerve, called the chorda tympani nerve, respond to taste input from the taste buds of the tongue. The cell bodies of these fibers are in a sensory ganglion located near the inner ear (called the geniculate ganglion).

Where does the somatic motor component of the facial nerve originate?

These nuclei all combine to travel, via the internal auditory meatus, to the geniculate ganglion. The somatic motor component, which innervates the muscles of facial expression and the stapedius muscle of the ear, originates in the pons at the facial nucleus.

Which is the largest parasympathetic nerve fibre in the body?

The pterygopalatine ganglion is the largest of these structures. It contains parasympathetic nerve fibers, as well as sympathetic and sensory fibers.

Where do the fibers of the maxillary nerve go?

These are the fibers of the maxillary nerve passing through the Pterygopalatine ganglion and go along with each pterygopalatine ganglionic branch to their destinations. Pterygopalatine ganglion has the following fibers that enter to pterygopalatine ganglion.