Exam IV

Distinguish between a vitamin and a mineral. (C18LO14)

-A vitamin is an organic compound that are required in small amounts for normal metabolism that the body cells can't synthesize enough of. These are essential and come directly from food or provitamins. Each vitamin plays a role into different areas of the body to keep them strong and functioning properly. -A mineral is an inorganic element essential in human metabolism. These are obtained through the plants or animals that had eaten plants that extracted the minerals from the soil. Minerals make up 4% of the body weight and are concentrated in bones and teeth and are incorporated into organic molecules. Minerals also make up parts of the structural materials of all body cells, portions of enzyme molecules, contribute to osmotic pressure of body fluids, and play roles into impulse conduction in neurons, muscle fiber contraction, blood coagulation, and maintenance of the pH of body fluids.

List the factors that may lead to inadequate nutrition later in life. (C18LO18)

-Energy requirements decline with age -Before 50 most adults have positive energy balance but maintain weight, after 50 weight creeps up -Weight maintainable with control of food consumption and exercise -Malnutrition can be due to drug effects, disease, and depression -Caloric restrictions can lead to extended life spans but not clear how this works with human populations

Explain what desirable weight means. (C18LO11)

Desirable weight can be measured by your BMI (weight/height^2). Body Mass Index (BMI) is used to assess weight, taking height into consideration. A person is classified as underweight, normal weight, overweight, or obese. Overweight is exceeding desirable weight by 10%-20% or a BMI of 25 and 30. Obesity is exceeding desirable weight by >20% or with a BMI over 30.

Discuss the general effects of innervation of the alimentary canal by the sympathetic and parasympathetic divisions of the autonomic nervous system. (C17LO5)

Extrinsic innervations of the alimentary canal are provided by the autonomic nervous system, which includes both sympathetic and parasympathetic nerves. In general, sympathetic activation restricts the activity of enteric neurons, thereby decreasing GI secretion and motility. In contrast, parasympathetic activation increases GI secretion and motility by stimulating neurons of the enteric nervous system.

List the fat-soluble and water-soluble vitamins and summarize the general function of each vitamin. (C18LO13)

Fat-soluble vitamins dissolve in fats. They are influenced by the same factors that affect lipid absorption. Bile salts will promote fat-soluble vitamin absorption. They are stored in moderate amounts in tissues. An excess intake of this type of fat can lead to overdose. They are resistant to heat so they are not easily destroyed by cooking or food processing. These include vitamin A, D, E, and K. Vitamin A is an antioxidant that is necessary for the synthesis of visual pigments, mucoproteins, and mucopolysaccharides. They function to promote the normal development of teeth and bones. They also are responsible for the maintenance of epithelial cells. Vitamin D promotes the absorption of calcium and phosphorus and also promotes the development of bones and teeth. Vitamin E is an antioxidant that prevents the oxidation of vitamin A and polyunsaturated fatty acids. Vitamin K is required for the synthesis of prothrombin, which functions in blood clotting. Water-soluble vitamins are B vitamins and vitamin C. Cooking and food processing will destroy some of them. The B vitamins are B1, B2, B3, B5, B6, B7, B9, and B12. B1 (thiamine) is required for the oxidation of carbohydrates. B2 (riboflavin) is required for the oxidation of glucose and fatty acids. It is essential for cellular growth. B3 (niacin) is required for the oxidation of glucose and synthesis of proteins, fats, and nucleic acids. B5 (pantothenic) is required for the oxidation of carbohydrates and fats. B6 involves the production of antibodies and is needed in nucleic acid synthesis. B7 (biotin) is essential in the metabolism of amino acids and fatty acids. B9 (folacin) promotes the production of normal red blood cells. B12 (cyanocobalamin) plays a role in myelin synthesis. It is also required for normal red blood cell production and synthesis of nucleic acids. Finally, vitamin C promotes the absorption of iron and the synthesis of hormones from cholesterol.

Identify examples of positive and negative nitrogen balance. (C18LO7)

If more proteins are broken down than synthesized, it is a negative nitrogen balance and if more proteins are synthesized than broken down, then it is a positive nitrogen balance.

Identify the function of each enzyme secreted by the small intestine. (C17LO23)

Intestinal enzymes (table 17.9) include: Enterokinase - converts trypsinogen into trypsin Peptidase - break down peptides to amino acids Intestinal lipase - breaks down fats into fatty acids and glycerol sucrase, lactase, maltase - breaks down disaccharides to monosaccharides

Describe aging-related changes in the digestive system. (C17LO29)

Life-span changes to the digestive system are slow and slight. They usually include... -Tooth enamel thins, so teeth can become very sensitive -Gums recede -Teeth can begin to loosen causing them to break or fall out -The GI tract becomes less efficient -Heartburn -Gastric secretions slow -Constipation becomes more frequent -Nutrient absorption decreases -Lactose intolerance increases -Accessory organs age

Describe how cells use lipids. (C18LO4)

Lipids have a few different uses them. The fat supplies energy to the body. It is broken down into glycerol and fatty acids to release energy. The glycerol and fatty acids are used to synthesize storage fat in adipose tissue. The excess glucose and amino acids can be converted into fat molecules. The liver can convert fatty acids from one form to another. Lipids can combine with proteins to form lipoproteins for transportation in blood. Lips are the principle component of cell membranes.

List the major minerals and trace elements, and summarize the general functions of each. (C18LO15)

Major minerals- Calcium, Phosphorus, Potassium, Sulfur, Sodium, Chlorine, Magnesium. 1. Calcium- make up bone and teeth structure; essential for neurotransmitter release, muscle fiber contraction, cardiac action potential, and blood coagulation; activates certain enzymes 2. Phosphorus- Structure of bone and teeth, in nearly all metabolic reactions, in nucleic acids, proteins, and some enzymes and vitamins; in cell membrane, ATP, and phosphate of body fluids 3. Potassium- Maintain intracellular osmotic pressure and regulate pH, required for impulse conduction in neurons 4. Sulfur- Part of certain amino acids 5. Sodium- Maintain osmotic pressure of extracellular fluid; regulate water movement; impulse conduction in neurons; regulate pH and transport of substances across membranes 6. Chlorine- Maintain osmotic pressure; regulate pH, maintain electrolyte balance; forms hydrochloric acids 7. Magnesium- Metabolic reactions in mitochondria that produce ATP; breaks down of ATP to ADP

Name the major organs of the digestive system. (C17LO2)

Major organs of the digestive system: - mouth - pharynx - esophagus - stomach - small intestine - large intestine - rectum - anus -anal canal

Describe how pancreatic secretion is regulated. (C17LO18)

Pancreatic secretion is principally regulated by the hormones secretin and cholecystokinin, which are produced by the walls of the duodenum, and by the action of autonomic innervation. The release of these hormones into the blood is stimulated by the entry of the acidic chyme into the duodenum. Exocrine gland of pancreas produces bicarbonate to neutralize gastric acid. Exocrine gland of pancreas produces enzymes to digest proteins, carbohydrates, lipids, and nucleic acids. CCK induces the pancreas to produce and secret digestive enzymes. Secretin induces the pancreas to release bicarbonate ions. Also during the cephalic phase of digestion control, the parasympathetic system induces the pancreas to produce digestive enzymes.

Describe how cells use proteins. (C18LO6)

Proteins are digested into amino acids, they are used to synthesize new proteins, used to produce energy, or converted into glucose or fat.

Describe how saliva secretion is controlled. (C17LO10)

Saliva is another thing that is controlled by the sympathetic and parasympathetic nerves. The parasympathetic nerve supply is most active during the day, whilst eating and creates more watery, or serous saliva; predominantly produced by the parotid gland, and partly by the submandibular gland.

Identify the function of salivary amylase. (C17LO9)

Salivary amylase is made by the salivary glands. Salivary amylase is an enzyme that begins the digestive by breaking down starch when you chew your food, converting it into maltose.

Describe how small intestinal secretions is regulated. (C17LO24)

Secretions of the small intestine digestive enzymes are regulated by hormones, including secretin that decrease gastric secretions and increases secretions from the pancreas and gallbladder; and cholecystokinin that decreases gastric secretions and increases gall bladder contraction and pancreas enzymes secretions. The secretion of the hormone CCK is induced by the presence of proteins and fats in the duodenum. The secretion of secretin is induced by low pH levels in the duodenum.

Describe how stomach secretion is controlled. (C17LO15)

Stomach secretion is controlled by the secretions of two hormones: gastrin and histamine. The hormones increase the secretion of gastric glands. Gastric glands are also regulated by the sympathetic and parasympathetic nervous systems. Parasympathetic increases secretions while sympathetic inhibit. Gastric secretions are also increased by intestinal gastrin. Gastric secretions and motility are inhibited by the hormones CCK and secretin.

Describe the structure of the wall of the alimentary canal. (C17LO3)

The alimentary canal wall has four main layers. The outermost layer is the mucosa, the next layer is the submucosa, then the muscularis, and the innermost is called the serosa.

Identify the function of each enzyme secreted by the pancreas. (C17LO17)

The carbohydrate-digesting enzyme, pancreatic amylase, splits molecules of starch and glycogen into dissaccharides. The fat-digesting enzyme, pancreatic lipase, breaks down triglycerides into fatty acids and monoglycerides. The protein-splitting enzymes, trypsin, chymotrypsin, and carboxypeptidase, work together to split the bonds between particular combinations of amino acids in proteins. The nucleases break down nucleic acid molecules into nucleotides.

Identify the functions of the large intestine. (C17LO27)

The functions of the large intestine include the removal of water, removal of ions, microbial activity, and defecation of feces. The primary function of the large intestine is water recovery. Also defecation

Locate the gallbladder and describe the release of bile. (C17LO21)

The gallbladder is located on the right side of the abdomen beneath the liver. It has right and left hepatic ducts. It holds a digestive fluid called bile that is released into the small intestine. Bile is released when fats and proteins in the duodenum trigger CCK to release. The CCK causes inhibition of gastric motility, secretion of digestive enzymes from the pancreas, and then bile is released from the gallbladder. Bile emulsifies fats and transports bilirubin and cholesterol to the small intestine. Secretin also increase the release of bile from gallbladder.

Describe the secretions of the stomach. (C17LO14)

The stomach secretes the hormones gastrin and histamine, these hormones increase stomach secretions. The stomach also secretes water, electrolytes, hydrochloric acid, and glycoproteins. Also the enzymes such as pepsinogen (which is inactive until exposure to acid converts it to pepsin) and gastric lipase.

peri-

around

mal-

bad

bas-

base

cec-

blindness

frenul-

bridle

cari-

decay

decidu-

falling off

lip-

fat

obes-

fat

aliment-

food

pyl-

gatekeeper

vill-

hairy

calor-

heat

chym-

juice

hepat-

liver

-meter

measure

nutri-

nourish

hiat-

opening

pell-

skin

gastr-

stomach

rect-

straight

sorpt-

to soak up

lingu-

tongue

Locate the salivary glands and describe their secretions. (C17LO8)

-The salivary glands are exocrine glands that are alveoli in structure. The three main glands are the parotid, submandibular, and sublingual. -The parotid gland is the largest gland. It opens at the upper second molar. It is waterly and has amylase. -The submandibular gland opens on each side of the frenulum and is more viscous. -The sublingual gland is the smallest gland. It is below the mucous membrane of the oral cavity floor. Each gland gas 10 to 12 opens in the floor. It is thick and stringy.

Contrast the physiological impact of positive and negative energy balance. (C18LO10)

A positive energy balance, in which energy intake exceeds the amount that causes weight gain, with 60-80 % of the resulting weight gain being attributable to body fat. In negative energy balance, when energy expenditure exceeds intake, the resulting loss in body mass is also accounted for by 60-80 % body fat.

Describe how cells use carbohydrates. (C18LO2)

Carbohydrates are primarily used in respiration or energy production, excess carbs are converted to either glycogen or fats, used as starting points for synthesis of 5 carbon sugars of nucleic acids, you need at least 125-175 grams per day to avoid breaking down proteins to make glucose, glucose is made from the carb starch which, glucose, is broken down into co2 and h2o, and energy when needed, and excess glucose converted into glycogen by glycogenesis and stored in muscle cells and liver.

Explain how energy values of food are determined. (C18LO8)

Food is heated in a sealed container surrounded by water until completely burned off and the rise in water temperature determines the number of calories within the food. Energy values of food are expressed as the number of calories per 1 gram of macronutrient within the food. A bomb calorimeter will over estimate the nutritional calories available in a food because some forms of carbohydrates (fiber i.e. cellulose) can not be digested by humans but will burn and release heat in a calorimeter.

List the major sources of carbohydrates. (C18LO1)

Major sources of carbohydrates are ingested in many forms. Complex carbohydrates, polysaccharides, come from starch from plant foods and glycogen from meats. However, many foods have starch and glycogen as well as vitamins and minerals. Simple carbohydrates, disaccharides, come from milk sugar, cane sugar, beet sugar, and molasses. Monosaccharides come from honey and fruits. Cellulose is another form of complex carbohydrate abundant in food that acts as a fiber.

Distinguish between primary and secondary malnutrition. (C18LO17)

Malnutrition is poor nutrition that is from a lack of essential nutrients and not being able to use them properly. Primary malnutrition is problems in the diet that under or oversupplies the body. Secondary malnutrition is when a person's needs make a normally adequate diet insufficient.

Explain how the contents of the alimentary canal are mixed and moved. (C17LO4)

The contents mix when the smooth muscle in the small segments contract rhythmically. This happens every 20 seconds to allow the food to mix with the digestive juices from the mucosa. But when it is in the small intestines, the contractions alternate to move it back and forth. The movements are called peristalsis where a ring contracts in the wall of the tube and move the mixture along the canal. This pushes the contents within the tube ahead.

Describe the processes carried out by the digestive system. (C17LO1)

The digestion system breakdowns our food. The functions of the digestive system include ingestion, propulsion, secretion, absorption, and defecation. Propulsion is the movement of food through the digestive system. The secretion is endocrine and exocrine. The absorption is the passage of digested food from the GI tract into the cardiovascular and lymphatic system for distribution. Defecation is the indigestible substances.

Explain the factors that affect an individual's energy requirements. (C18LO9)

The factors that affect an individual's energy requirements are gender, body size, body temperature, and level of endocrine gland activity. Children and teens need more energy to be able to grow and develop. The level of physical activity someone does also affects an individual's energy requirement.

Describe the mechanism of swallowing. (C17LO12)

The first stage is when the food is being chewed and mixed with saliva. Next, the tongue rolls this mixture into a bolus and forces it into the oropharynx. The second stage is when the sensory receptor around the pharyngeal opens and triggers a swallowing reflex. The soft palate rises and the hyoid bone and larynx are elevated. The epiglottis closes off the top of the trachea. The tongue is pressed against the soft palate and uvula. The longitudinal muscles contract pulling the pharynx upward toward the food. The inferior constrictor muscles relax, which open the esophagus. The superior constrictor muscles contract forcing the food into the esophagus. The third stage is transporting the food in the esophagus to the stomach.

Explain how hormones control appetite. (C18LO12)

The hormone peptide Y stimulates appetite. The hormone leptin inhibits peptide Y which decreases appetite while the hormone ghrelin stimulates peptide Y which increases appetite.

Locate the large intestine and describe its structure. (C17LO26)

The large intestine begins in the right iliac region of the pelvis just at or below the waist. The large intestine is larger in diameter than the small intestine. It begins at the ileocecal junction, where the ileum enters the large intestine, and ends at the anus. The large intestine consists of the colon, rectum, and anal canal. Four section- cecum, has the ileocecal valve, colon- has ascending, descending, transverse, and sigmoid, rectum, and anal canal.

Explain the various liver functions. (C17LO20)

The liver has a lot of functions. The first function is detoxifying the blood. This is done by converting ammonia to urea that is released into the blood and then taken to the kidneys. From there the kidneys pass it out through urine. The second function is carbohydrate metabolism. This is when it takes up glucose and converts it into glycogen, or the other way around. The next function is lip metabolism. This is where fatty acids turn into phospholipids by oxidation. The fourth function is protein synthesis. The liver produces albumin, fibrogen, globulins, and clotting factors. The next function is being able to convert one nutrient to another. The last two functions are storing iron and vitamins and secreting bile. The liver also produces bile. The liver also plays a role in lipid metabolism. It produces cholesterol. It also produces the protein complexes (HDL, LDL, VLDL) which transports lipids in the blood. The liver removes LDL and VLDL from the blood and converts them into HDLs.

List the major sources of proteins. (C18LO5)

The major sources of proteins are meats, fish, poultry, cheese, nuts, milk, eggs, and cereals. Legumes can be considered protein as well, although they contain less protein.

Describe the mechanism of defecation. (C17LO28)

The mechanism of defecation starts with the stimulation of peristaltic waves. Then the internal anal sphincter relaxes. The diaphragm lowers and the glottis closes. The abdominal walls contract and the external anal sphincter relaxes. Two to three peristaltic waves per day results in the movement of contents into the rectum and then defecation.

Locate the pancreas and describe its secretions. (C17LO16)

The pancreas has a large head that fits into the curvature of the duodenum. The tail lies against the spleen. The endocrine gland of the pancreas is islets of Langerhans and secretes insulin and glucagon. The exocrine gland has acinar cells. It secretes bicarbonate, protein, carbohydrates, lipids, and nucleic acids. The protein involves trypsin, chymotrypsin, and carboxypeptidase. The carbohydrate is pancreatic amylase. The lipids are triglycerides of pancreatic lipase. The nucleic acids are nucleases.

Locate the pharynx and esophagus, and describe their general functions. (C17LO11)

The pharynx and esophagus are located in the throat, connecting the mouth and stomach through a tube. The pharynx receives air and food from the mouth; the esophagus moves food to the stomach through muscle contractions.

Explain how the products of digestion are absorbed in the small intestine. (C17LO25)

The products of digestion are amino acids, monosaccharides, fatty acids, and monoglycerides. Amino acids and monosaccharides are polar and do not cross the plasma membrane. They are transported by facilitated diffusion or active transport. Fatty acids and monoglycerides are absorbed in the small intestine because bile emulsifies fats then fuse with intestine epithelium when they are resynthesized into triglycerides. Active transport of amino acids and monosaccharides is most done using 2nd active transport. The Na+ gradient powers this transport. The resynthesized triglycerides are packaged into chylomicrons which are exocytosed from the basal side of the columnar epithelial cells. Amino acids and monosaccharides are transported from the small intestine by the blood while the chylomicrons are transported away in the lymph.

Locate the small intestine and describe its structure. (C17LO22)

The small intestine is inferior to the stomach. This is the largest organ of the digestive system. The small intestine is divided into 3 parts; duodenum, ileum, jejunum. The small intestine has a large surface area to allow for the absorption of monomers. The plicae circulares are folds in mucosa and submucosa layers. The villi is a fold of mucosa that contains an arteriole, venule, capillary network, and a lacteal. The epithelial cells have peptidases, lipase, and disaccharidases bound to cell membranes.

Locate the stomach and explain its function. (C17LO13)

The stomach is located on the left side of the upper abdomen. It breaks down proteins by pepsin into polypeptides, carbohydrates by having acid inhibit amylase so digestion stops, fats are broken down by gastric lipase. Stomach also does adsorption, the stomach wall is impermeable to most materials into the blood and it absorbs water, electrolytes, certain drugs and alcohol. Three muscle layers to mix contents, longitudinal, circular, and oblique. Most digestion occurs in the small intestines.

Describe how different types of teeth are adapted for different functions, and list the parts of a tooth. (C17LO7)

There are 4 incisors in the oral cavity. They are single-rooted and have a sharp edge to them to make it able for them to cut food. There are 4 canines in the oral cavity. They fit the corner of the mouth and have a pointed cusp to make it able for them to tear food apart. There are 8 premolars in the oral cavity. They have 3 or 4 cusps to make it able for them to tear food up easily. There are 12 molars in the oral cavity. They are the biggest teeth that have a flat surface to make it easy to crush and tear food apart. These teeth make up the oral cavity, of which 20 are primary teeth and 32 are secondary teeth. The different parts of a tooth are the enamel, which is the outer layer. The middle layer is the dentin. The inside core is the pulp cavity that has blood vessels and nerves.

carot-

carrot