Physiology Of Saliva
Introduction
The volume of saliva secreted per day is 1000 mL to 1500 mL. When awake the rate is approximately about 1 mL/min but when asleep little secretion of saliva occurs. The major salivary glands are the parotid gland, the submaxillary gland and the sublingual gland. Also, there are many tiny buccal glands.
Composition Of Saliva
Mixed saliva contains 99.5% water and 0.5% solids. The composition of saliva varies with salivary flow rate. The components interact and are responsible for the various functions of saliva
Organic Substances
Mucins
Mucins are elaborate glycoproteins, found as high and low molecular weight mucins (MC1&2).
Mucins give saliva its lubrication properties. Mucins form homotypic complexes making
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When food is taken into the mouth, it is moistened and dissolved by saliva. Saliva has three digestive enzymes, namely salivary amylase, maltase and lingual lipase.
Amylase (ptyalin)
It acts on starch and converts it into dextrin,maltose and maltotriose favoring the formation of the food bolus. Though starch digestion starts in the mouth, major part of it occurs in stomach because, food stays only for a short time in the mouth..Saliva has a pH between 6.0 and 7.0, a favorable range for the digestive action of ptyalin (amylase). It is inactivated in the stomach due to the low pH.
Lingual Lipase
Lingual lipase is a lipolytic enzyme. It is secreted from serous glands situated on the behind the tongue. It digests pre-emulsied fats by hydrolyzing triglycerides into fatty acids and glycerol
• The constant secretion of saliva washes off food debris and shed epithelial cells from teeth and out of the oral cavity serves as a protective function. By removing these materials saliva they prevent bacterial growth. However if bacterial growth still occurs saliva has further protective functions. Saliva has antimicrobial proteins which will kill the bacteria reducing risk of dental caries and periodontal infection. There are two types of antimicrobial
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Ex. glucose in diabetes mellitus. Or substances found in saliva are excreted in large quantities. Ex. excess urea during nephritis and excess calcium is excreted during hyperparathyroidism.
Regulation Of Body Temperature
In dogs panting helps in the loss of heat. However, in humans this doesn’t occur but the below occurs.
Regulation Of Water Balance
When the body is dehydrated, salivary secretion is reduced as there is less water. This causes dryness of the mouth and induces thirst. This thirst is quenched by intake of water resulting in the restoration of body water content.
Cools Hot Food
Since its soluble, it dilutes hot food reducing the possibility of damaging the mucosa. It also moistens dry food.
Appreciation Of Taste
Also since its soluble, saliva dissolves the solid food substances which can now stimulate the taste receptors.
Tissue Repair
The time taken for saliva to coagulate is accelerated compared the other tissues, although the resulting clot is less solid than normal. In investigative studies in mice it was seen that in the presence of saliva wound contraction is much faster due to the epidermal growth factor which is produced by the submandibular
It may not seem like a very pressing issue to have, but there are several roles that saliva has in the oral cavity. Not only does it keep the
When these starches enter the mouth, it stimulates the salivary glands in the mouth to secrete saliva which contains salivary amylase and begins chemical digestion of the starch. Then once chewed and swallowed, the starches make their way into the stomach where it does not undergo any further chemical digestion until it reaches the small intestine. Once the stomach is done churning the food, the pancreas secrets bile for lipid digestion..... Im sorry I cant finish this, my stomach is killing me. Correct Answer:
Due to the this procedure we know that the digestive system functions with an alliance to the salivary gland, In the beginning of digestion the gland releases saliva, which contains amylase, to form the food into a based elementary molecule. It would help continue the next stride of digestion, due to the fact that the low pH levels of hydrochloric acid it alienates the function of amylase which helped us understand how amylase behave under precise variables (pH levels,
Mary Roach dives into the world of science and biology throughout the novel, Gulp, and explains it particularly in reference to the alimentary canal. She starts at the beginning with simply how eating works when it comes to taste preferences. Since humans tend to “taste” through their noses, the act of eating is actually more of an olfactory experience, surprisingly enough. Next, the food must travel past the saliva which carries digestive enzymes and kills proteins in order for the food to get to the stomach. The gastric acid within the stomach then breaks down the food and sends it to be filtered back out through the anus.
Objective Bio160 Lab 5: Enzyme Activity May 7, 2015 The objective of this experiment was to note the effect of temperature effects on enzyme rates of reaction. Enzymes are macromolecules that make up significant portions of living organisms. They are made up of repeating subunits of monomers that are referred to as polymers.
E. Jayne’s science fair project was on if dogs, cats, or humans have the most bacteria. She said since dogs put their mouths places people or cats don’t then the dogs would have more bacteria in their mouths. She used 10 humans, 10 cats, and 10 dogs and collected saliva samples from them. She used
And here you are, spreading them all over delicate scientific equipment without a care in the world. Well, anything’s worth it for science. Even your life can have meaning under extreme circumstances.” Salivary glands, he knew, were traditionally stimulated by the presence of food. That was their function, after all; saliva was crucial in assisting the body with digestion and breaking down matter to pass easily through the esophagus.
Thirst is a response which gives mammals a need to drink fluids this is a part of homeostasis as more fluid is needed to be regulated and is a key part of basic survival. The need to drink originates from many different reasons such as psychogenic drives, and knowing that our bodies need to be regulated and that we will eventually need more water. When water is lost from our bodies due to urination and sweat it’s commonly lost from intracellular and extracellular compartments. If the compound sodium chloride is lost more extracellular fluid will be lost rather than intracellular fluid as sodium chloride is usually found in extracellular fluid when it’s with water so if sodium chloride is lost in sweat so will extracellular fluid if water was
When we see dogs lick themselves, we often assume that it is just a natural habit akin to tail wagging. But licking, especially when it happens far too often, can be a sign of a more serious problem. Lick granuloma, also called Acral lick dermatitis, is a serious problem that can be caused by a variety of things, like allergies, itchiness, pain or discomfort, insect bites, arthritis. and even by psychological factors like stress, boredom, separation anxiety, or obsessive compulsive disorder. When dogs face any of these factors, they may start licking their limbs or paws obsessively.
The stomach is a very important part of the digestive system. It is a j- shaped muscular organ that acts as a bag or sac to collect churn food with digestive juices. When the stomach is filled with food the rugae stretch out, and disappear. The food mixes with hydrochloric acid and other gastric juices to form a liquid mixture called chyme, which then passes through the remaining portion of the digestive system. So this means to me that when you eat something it goes to the stomach and is mixed with acids that breaks it down and dissolves the food.
The saliva of the bat contains anticoagulant and fibrinolytic proteins, which are inhibitors of coagulation, plasminogen activators, and inhibitors of platelet
Bio Chem lab Report 04 Enzyme Biochemistry Group Member: Chan Man Jeun Duncan (16002621) Law Sze Man (16000478) Introduction Enzyme is a protein base structure substance in our body. It works at a biocatalyst that will catalyzing the chemical reaction, which helps to speed up the chemical reaction. Enzyme could only function in specific shape, and the shape of enzyme is depending on the environment, therefore it is hard for an enzyme to function well in an extreme environment. The aim of this experiment is to see can the enzyme functions normally in different environment(pH, temperature and salt concentration) via using starch solution, amylase from saliva, 0.5M HCl solution, 0.5M NaOH solution and NaCl solution, and using iodine solution
Hydrolysis of triacylglycerols by pancreatic lipase (modified from [56]) The optimal activity of pancreatic lipase is between pH 6.5 to 8.0 [55]. Pancreatic lipase binds to the emulsion interface with the help of prior binding of colipase which is an essential cofactor for exerting pancreatic lipase action. Naturally secreted bile salts help in removing adsorbed water soluble proteins including lipase from the surface which prevents from inhibiting
INTRODUCTION: Lipase also called as triacylglycerol acylhydrolaseis an enzyme known for its enormous applications for industry and diagnostics. Their basic activity is to convert fats into fatty acids and glycerol. These enzymes are water soluble in nature. They also convert polar solvents into more lipolytic substances.
In order to utilize casein, bacteria cells secrete proteolytic exoenzymes (amylases, proteases, pectinases, lipases, xylanases and cellulases) outside of the cell that hydrolyze the protein to amino acids. The amino acids can then be used by cells after crossing the cell membrane via transport proteins [169]. Starch hydrolysis test is used to differentiate bacteria based on their ability to hydrolyze starch with the enzyme α-amylase or oligo-l, 6-glucosidase. These enzymes hydrolyze starch by breaking the glycosidic linkages between the sugar subunits. It aids in the differentiation of species from the genera Corynebacterium, Clostridium, Bacillus, Bacteroides, Fusobacterium and members of Enterococcus [170].