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a. The gastroileal reflex is when distention of the stomach increases intestinal discharge to the large intestine. The reflex is stimulated by the presence of food in the stomach and gastric peristalsis. The gastroileal reflex causes peristalsis in the ileum which opens the ileocecal valve allow food to enter the large intestines. This is an example of a feedforward system because it works by enhancing the motility of the distal parts in order to make room for what is to come.
b. The swallowing reflex is a highly ordered sequence of events that causes the movement of food from the mouth to the pharynx and then to the stomach. The initiation of swallowing can be voluntary but from there is a totally involuntary process. The process
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The intestinal phase of gastric secretion and emptying occurs in the duodenum as a response to arriving chyme and is moderated by hormones ad nervous reflexes. It ensures that the composition and pH of chyme is correct before entering the intestines. Stretching of the duodenum enhances gastric secretion through the production of gastrin which stimulates gastric secretions. Decreased pH and lipids in the duodenum trigger chemoreceptors to send inhibitory signals to the stomach. Chyme in the duodenum also stimulate cells to release messengers that stimulate secretions in the pancreas and gall bladder. The compounds released work to suppress secretion in the gastric system and reduce the stomachs motility. This gives the duodenum time to process its contents before receiving more. The duodenum initially stimulates gastric function but then quickly works to inhibit it. This is a negative feedback system in that the receptors in the duodenum determine control the amount of material entering it through various …show more content…
We see that to the left of the arrow that lactate levels, PaCO2, PaO2, and pH remain relatively constant while ventilation and carbon dioxide production rate increase nearly linearly. This is because during this phase aerobic respiration occurs and the closely related ventilation and carbon dioxide products rates allow the pressures to remain nearly constant. To the right of the arrow, anaerobic respiration occurs. During heavy exercise, the arterial pH levels decrease as lactic acid is produced by muscle during anaerobic respiration. The decreased pH stimulates ventilation that is out of proportion to the intensity of exercise. The increase in lactic acid leads to higher carbon dioxide production rates from the oxidation of lactic acid. Hyperventilation leads to lower arterial partial pressures of carbon dioxide since more carbon dioxide is lost in the lungs. The increase in arterial partial pressure of oxygen is because uptake of oxygen
The stomach naturally produces acid, which is mainly responsible for food digestion and the destruction of any foreign pathogen or bacteria ingested with food. Acid is secreted by stimulating the partial
...roduces more blood lactate that it can reabsorb. At this point ventilation increases exponentially. The goal with lactate threshold training is to raise your threshold point to as close as possible to your maximum heart rate, and improve your ability to withstand that discomfort” (Messonnier, 2013). This concept was depicted by the trained participant. As stated in the introduction and discussion sections and depicted throughout the graphs one can conclude that the trained participant was in fact more fit and could consume more oxygen than the untrained participant.
McKenzie, D. C. (2012). Respiratory physiology: Adaptations to high-level exercise. British Journal of Sports Medicine, 46(6), 381. doi:10.1136/bjsports-2011-090824
Esophagus: Esophagus is a long straight tube which connects the pharynx to the stomach. Once the food has been reduced to a soft mush, the tongue pushes it to the throat which leads to a long straight tube called esophagus. The esophagus squeezes the mass of food with rhythmic muscle contraction called peristalsis which then forces the food to the stomach.
In order for this breakdown to happen, the ‘tube’ through which the food travels requires assistance from a number of other digestive organs starting with the salivary glands, and later receiving
...ve eaten, to break down the food into a liquid mixture and to slowly empty that liquid mixture into the small intestine. Once the bolus has entered your stomach it begins to be broken down with the help of the strong muscles and gastric juices which are located in the walls of your stomach. The gastric juices are made up of hydrochloric acid, water, and mucus- and the main enzyme inside of your stomach is what is known as pepsin, which needs to be surrounded in an acidic setting in order to do its job, that is to break down protein. Once the bolus has been inside of your stomach for long enough it begins to form into a liquid called chyme, and what keeps the chyme from flowing back into our esophagus are ring shaped muscles known as sphincters located at the beginnings and ends of the stomach and they have the task of controlling the flow of solids and liquids.
Once in the stomach, the glands that are there begin to secrete enzymes and a mucous that help to protect the stomach from its own acids. While this is being done, the muscles of the stomach are contracting. This causes the food to be turned and moved all throughout the stomach. This process turns the food into chyme, which is just a liquefied version of the food that was first taken...
Have you ever wondered where your food has gone once you consume it? Through your digestive system where the mass of food undergoes a process called digestion. Digestion is the chemical and physical breakdown of food into forms such as energy or nutrients that can be used by the body’s cells (McKenzie, 2010). The whole process starts in the mouth. The mouth contains a watery substance called saliva. Saliva is important to the whole process of food digestion, because not only does it help with sensing taste, but it is also made up of enzymes that break down the fats and starches in food at a molecular level. The esophagus is a tube where swallowed food travels down to the stomach. The stomach is a muscular sac that acts as a blender and mixes food with acid, hydrochloric acid, which breaks down the swallowed chum and flushes the nutrients into the small intestine (Columbia University, 2010). The hydrochloric acid in the stomach is so powerful it can eat through a leather shoe. However, the stomach contains other chemicals, such as gastric acid, mucus and enzymes that also soften food (Sullivan, 2008). The result thus far in the process of digestion in the stomach is now called chime (Sullivan,
•While exercising your lungs tries to increase the intake of oxygen as well as release the carbon dioxide.
The circulatory system and respiratory system share a highly important relationship that is crucial to maintaining the life of an organism. In order for bodily processes to be performed, energy to be created, and homeostasis to be maintained, the exchange of oxygen from the external environment to the intracellular environment is performed by the relationship of these two systems. Starting at the heart, deoxygenated/carbon-dioxide (CO2)-rich blood is moved in through the superior and inferior vena cava into the right atrium, then into the right ventricle when the heart is relaxed. As the heart contracts, the deoxygenated blood is pumped through the pulmonary arteries to capillaries in the lungs. As the organism breathes and intakes oxygenated air, oxygen is exchanged with CO2 in the blood at the capillaries. As the organism breathes out, it expels the CO2 into the external environment. For the blood in the capillaries, it is then moved into pulmonary veins and make
In order to use the food we eat our body has to break the food down into the smaller molecules that can process, it also has to excrete waste. The process begins in the mouth. It first begins with your mouth and your salivary glands. Just at the sight of the food your mouth begins to develop saliva, which will be used to moisten and lubricate the food as you are chewing your food. This is called the motility and mechanical processing. Once the food has been chewed its broken down by the chemical action of the salivary enzymes. You have smooth muscles and the movements of the smooth muscles help your food make its way into the esophagus. The digestive tube is mainly lined with four layers. There are smooth muscles called sphincters that are between the junctions of the GI tract. These sphincters are what help the food pass through the digestive system and then they relax in order to deposit the food into the stomach. The main function of the digestive system is to break down food
As the exercise intensifies, you need more energy and therefore more oxygen. Your blood carries oxygen from the lungs to your muscles. To keep up with these increased oxygen needs, you have to have more blood going into your muscles. As a result, your heart pumps faster, sending more oxygenated blood to your muscles per second. Aim-
Alveolar hyperventilation causes a decreased partial pressure of arterial carbon dioxide (PaCO2). The decrease in PaCO2 increases the ratio of bicarbonate concentration to PaCO2 which increases the pH level. The decrease in PaCO2 develops when a strong respiratory stimulus causes the respiratory system to remove more carbon dioxide than is produced. Respiratory alkalosis can be acute or chronic. Acute respiratory alkalosis is when the PaCO2 level is below the lower limit of normal and the serum pH is alkalemic. Chronic respiratory alkalosis is when the PaCO2 level is below the lower limit of normal, but the pH level is relatively normal or near normal. Respiratory alkalosis is the most common acid-base abnormality observed in patients who are critically ill. It is associated with numerous illnesses and is a common finding in patients on mechanical ventilation. Many cardiac and pulmonary disorders can occur with respiratory alkalosis. When respiratory alkalosis is present, the cause may be a minor or non–life-threatening disorder. However, more serious disease processes should also be considered in the differential diagnosis (Byrd, 2017). Hyperventilation is most likely the underlying cause of respiratory alkalosis. Hyperventilation is also known as over breathing (O’Connell, 2017).
Next the food is traveled through the esophagus where three layers including the mucosa, mascularis, and adventitia are found. The Mucosa is the inner lining of the esophagus, responsible for absorbing water from the food, the Muscaris is responsible for the wave of contraction that helps guide the food down the esophagus which in result: peristalsis and finally the Adventitia/serosa is the smooth membrane consisting of two layers of epithelial cells which is used to secrete serous fluids. After it has traveled down the esophagus, it makes its way to the stomach. Like humans, a stingray’s stomach is very similar as it secretes acids and enzymes that ultimately digest the food bolus. In the stomach, muscles contract periodically churning the food to enhance digestion. Once this process is done, the now chyme makes its way into the anterior intestine. The anterior intestine also known as the Duodenum is the initial portion of the spiral intestine and plays a vital role in the chemical digestion chyme. Compared to bony species of fish, stingrays have in fact a much shorter anterior intestine, therefore the spiral valve is prolonged to compensate. It
A reflex pathway, or a reflex arc, is a neural pathway that is involved in the activation of a reflex. Reflexes are reactions that respond to stimuli. They usually happen without the sensory neurons having to pass directly through the brain. Therefore, reflexes are called involuntary reactions since they happen without a command. This allows the reflex action to occur quickly because the electrical signal can be sent to the spinal cord immediately without needing to go through the brain. The brain receives sensory input as the action occurs, but not before. The human body has lots of reflex pathways. However, if a disruption occurs in these pathways, the person most likely has a certain kind of neurological disorder that will make the person