The Effect Of Neural Reflexes On The Gastrointestinal Tract, Independent Of The Brain And Spinal Cord

Response: That specific cranial nerve is the Hypoglossal (XII) nerve and it belongs to the Sensory Somatic nervous system.

The stomach is an organ that is part of the digestive system. The stomach is located in the upper left part of the abdominal cavity, below the diaphragm and next to the liver (Stomach, 2013). The inner walls of the stomach contain small pores called gastric pits. The gastric pits contain cells that secrete chemicals that aid in the digestion of food (Nguyen, 2015). In this essay, I will discuss the different cell types of the stomach, how they work together to provide the overall function of the stomach, why each organ requires different cell types, why the stomach can’t be comprised of just one cell type, and the advantage of having different types of cells.

Describe the role of the parasympathetic nervous system relative to digestive movements. The PNS is responsible for stimulating digestion by increasing blood flow to the digestive tract. The PNS stimulates salivary gland secretion and increases peristalsis. This increases the

Once stimulated by the chemoreceptor trigger zone, the integrative vomiting centre coordinates the activation of all the nearby neural structures required to produce the multifaceted patterned response that will then lead to the processing and action of vomiting. The integrative vomiting centre coordinates the various inputs to the motor component of the emetic reflex, consisting of both somatic and autonomic systems, as the reflex involves both voluntary and involuntary processes. The abdominal and respiratory musculature, and visceral components involved in mediating changes in gastric motility and gastric tone are controlled by somatic pathways, while the autonomic pathways control sweating, salivation and pallidity of the skin. The activation of autonomic pathways plays a role in the intensity and duration of the nausea that accompanies emesis, as opposed to the actual action of vomiting (myVMC,

2. If Zachary has a peptic ulcer affecting his stomach and or duodenum, which components of the peritoneum will be affected?

The function of the pancreas has a substantial part in the regulation of the digestive system. The small intestine alongside the pancreas also contributes many features to the signaling pathways protein and other major enzymes must undergo before reaching the exocytosis stage. Specific hormones and receptors help in the necessary release of such enzyme. Secretagogues initiates particular signals throughout the progression and development of the digestive system. The enteric nervous system will later address the complexity of neurotransmitters as well as intra and extracellular mechanisms.

The enteric nervous system (ENS) is an essential, independent system of monitoring and control regulating nutrient absorption, secretion, motility, blood flow, and sensation in the gastrointestinal (GI) tract (reviewed by Beattie and Smith, 2008; Molderings, 2012). The ENS consists of more than 100 million neurons scattered throughout the gut in clusters called ganglia, which innervate adjacent tissues and organs, including the esophagus, stomach, intestines, pancreas, and gallbladder. At the molecular level, more than 30 transmitters and cotransmitters have been identified, including serotonin. As is the case with the central nervous system (CNS) (reviewed by Gillette, 2006), the main role that serotonin plays in the gut is neuromodulatory (reviewed by Molderings, 2012). In particular, the enteric serotonergic pathways are important for regulating smooth muscle tone, peristalsis, secretion, and sensation (reviewed by Beattie and Smith, 2008).

As Health Harvard states it, “the brain has a direct effect on the stomach.” The brain and digestive system could honestly be considered as one system because they’re so close to each other. Also, the digestive tract is already connected to the brain via sympathetic nerves connecting from the gut to the spinal cord and back up to the brain. The two systems share neurotransmitters. Information is passed through these, such as when a person thinks about eating a nice, warm, juicy steak, cooked just right. All the person did was imagine eating the food, yet the digestive system already started secreting the fluids necessary for digestion. This connection helps someone greatly in the sense that when they shouldn’t eat anymore, their brain will them that the stomach was already filled to the brim with food, and to stop

Underneath the gastric mucosa lies the submucosa, muscularis, and serosa layers. The submucosa consists of connective tissues, blood vessels and nerves. The blood vessels provide nutrients to the lining of the stomach and the nerves monitor smooth muscle contraction. This smooth muscle layer is called the muscularis and is composed of 3 layers of muscle fibers which aid in the mixing and propulsion of food through the digestive tract. Surrounding the muscularis is the serosa, which is the outermost layer of the stomach. It consists of a thin membrane which secretes serous fluid to prevent friction of the outside wall of the stomach as it expands.

Before the addition of Acetylcholine, basal activity was measured for the intestinal segment as depicted in Figure 5 where an amplitude for intestinal tension was calculated to be approximately 0.099 grams of force, with a consistent contraction period of 1.880 seconds between subsequent contractions. Once Acetylcholine is added it is able to bind and activate muscarinic receptors on the smooth muscle causing a cascade of events to occur involving the enhanced permeability of Calcium ions through the three main ion channels, which allows for the depolarization of the single- unit smooth muscles and an increase in intestinal motility (Bolton, 1991). These expected results were demonstrated in Figure 6, in which the amplitude for intestinal tension increased to 0.231 grams of force from the basal activity of only 0.099 grams. In terms of frequency, the contraction period for succeeding contractions increased from 1.880 seconds to near 2.040 seconds for each contraction, suggesting that the addition of Acetylcholine allows for intestinal contractions to become stronger while proceeding over a longer periods of time. These results may have some deviations in them due to the use of a new intestinal segment for this exercise, which may not have been well oxygenated or tied properly to the

The Trochlear Nerve (Cranial Nerve IV) is the longest and thinnest nerve emerging from the central nervous system, more specifically the dorsal aspect of the Midbrain, its nucleus is located just below the Oculomotor Nucleus (Cr. III) at the level of the inferior colliculus, its fibers arc around the periaqueductal grey matter, decussate before exiting the midbrain on its dorsal aspect by piercing the superior medullary vellum, goes around its dorsum, passing between the cerebral peduncles and the temporal lobe; then it courses between the Superior and Posterior Cerebral Arteries (SCA, PCA), pierces the dura just beneath the free edge of the Tentorium cerebelli behind the posterior clinoid process, enters the cavernous sinus and runs through its lateral wall above the ophthalmic nerve and below the oculomotor nerve, before exiting the cavernous sinus it positions above the oculomotor nerve and enters the superior orbital fissure lateral to its common tendinous ring, passes above the superior elevator palpebral(1,2,3) muscle attaching to the superior

The duodenum is a part of the small intestines. It helps further the process of food digestion. The duodenum gets the chyme, which is both digested food and stomach acids. The way the duodenum gets the chyme is through the pylorus. The pylorus is a valve between the duodenum and the stomach. Here, the chyme gets mixed with more digestive enzymes and intestinal juices to help digest it further. Another function of the duodenum is that is gets bile and pancreatic juice from the liver, gallbladder, and pancreas. The duodenum has more functions than just digesting the food. It also regulates gastric emptying. When the stomach empties into the duodenum, that is gastric emptying, and the duodenum controls the rate at which this happens. Another

The layers work in unison to contract, circulate and eventually transport food material via the digestive tract through the stomach.

The digestive system is made up organs that help the body make use of food to keep the body healthy, system of organs responsible for getting food in and out the body. The digestive system includes the salivary glands, mouth, esophagus, stomach, liver, gallbladder, pancreas, small intestine, colon, and rectum. Inside this tube is a lining called the mucosa. In the mouth, stomach, and small intestine, the mucosa contains tiny glands that produce juices to help digest food. It involves four main processes. The actual intake of food through the mouth is called indigestion. With the help of amylase, that soften the food and the teeth that break down food into smaller pieces, our tongues move the food down the pharynx through the esophagus and down to the stomach.

Since an inhibitory response to nerve stimulation was observed in all (or most) of the tissues studied in the practical, how is differential control (i.e., both inhibition and excitation) of gut contraction achieved in the body? Is it always inhibitory in vivo? What happens in the intact animal?