Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
79 Cards in this Set
- Front
- Back
|
Why does the body require a constant supply of nutrients? |
Function Growth Repair |
|
|
What are the four stages of digestion? |
Ingestion Digestion Absorption Egestion |
|
|
What are the six nutrient types? |
Carbohydrates Proteins Lipids and fats Vitamins Minerals and trace elements Salts |
|
|
What are the three main types of carbohydrates? |
Monosaccharides Disaccharides Polysaccharides |
|
|
What are the three types of monosaccharides? |
Glucose Fructose Galactose |
|
|
What are the three types of disaccharide? |
Sucrose Maltose Lactose They are broken down into monosaccharides for absorption |
|
|
Give two examples of a polysaccharide |
Cellulose Glycogen |
|
|
What is the chemical structure of monosaccharides? |
They are basic subunits of -CHO's |
|
|
What is the chemical structure of disaccharides? |
They are two monosaccharides linked by a glycosidic link |
|
|
What is the chemical structure of polysaccharides? |
They can be chains of one monosaccharide or different monosaccharides, branched or unbranched. |
|
|
What are proteins used for in the body? |
They are used to build cells and tissues. |
|
|
What is the chemical structure of proteins? |
They are polymers of amino acids and must be broken down into their component amino acids for absorption. |
|
|
How many amino acids are there? |
20 |
|
|
What are fats used for in the body? |
They provide a food reservoir or can be used to make cell components like cell membranes. |
|
|
What is the general chemical structure of fat? |
A glycerol molecule with three fatty acid side chains attached. |
|
|
How does the shape of the side chains affect the type of fat? |
If the chains are straight the fat is saturated. If the chains are kinked the fat is unsaturated. |
|
|
What are vitamins? |
Vitamins are molecules that the body cannot make so need to be extracted from diet. |
|
|
What are minerals and Trace elements used for? |
Assembly of different structures such as bones and enzymes. |
|
|
What are the components of the gastrointestinal tract? |
Mouth Pharynx Oesophagus Stomach Small intestine Large intestine. |
|
|
What are the accessory digestive organs? |
Tongue Teeth Salivary glands Liver Gallbladder Pancreas. |
|
|
What are the six roles of the digestive system components? |
Ingestion Mechanical breakdown Propulsion Digestion Absorption Defecation. |
|
|
Name the salivary glands. |
Parotid gland Sublingual gland Submandibular gland. |
|
|
What is the general structure of the gastrointestinal tract? |
From the Inside Out: *Mucosa - epithelium, lamina propria, muscularis mucosae. *Submucosa - submucosal gland, blood vessel, submucosal nerve plexus. *Muscularis externa - inner circular layer, myenteric nerve plexus, outer longitudinal layer *Serosa/adventitia |
|
|
What does the oesophagus do? |
Secretes mucus Transports food. |
|
|
How long is the oesophagus? |
25 cm long. |
|
|
What is the name of the place where the oesophagus passes through the diaphragm? |
Esophageal hiatus. |
|
|
What is the place where the oesophagus joins the stomach called? |
The cardial orifice where there is a smooth muscle sphincter called the gastroesophageal sphincter. |
|
|
How is the oesophagus adapted for its role? |
It has muscles for peristalsis and mucous glands for lubrication. |
|
|
How is the stomach adapted for its role? |
It has muscles for mixing, it is bag like for holding, it has secretory cells for digestion, and villi to increase the surface area. |
|
|
How is the small intestine adapted for its role? |
It has muscles for peristalsis, secretory cells for digestion, and villi for absorption. |
|
|
How is the large intestine equipped for its role? |
Muscles for peristalsis and some villi for absorption. |
|
|
How is the rectum adapted for its role? |
Stretch for holding and muscled for ejection. |
|
|
What are the three stages of swallowing (deglutition) |
Stage 1 - voluntary, food passes into oropharynx. Stage 2 - involuntary, food passes into esophagus. Stage 3 - involuntary, passes from oesophagus into stomach. |
|
|
What does the lower esophageal sphincter do? |
Prevents stomach contents from entering the oesophagus. |
|
|
What is the size of the stomach? |
*Typically 15 to 25 cm long. *Empty the stomach has a volume of 50 ml and the wall is folded. *Full the stomach can hold more than 4 litres of food. |
|
|
What is the name of the sphincter that connects the stomach and the duodenum? |
The pyloric sphincter |
|
|
How is the mucosa of the stomach specially adapted? |
Contains gastric pits. |
|
|
How much gastric juice does the gastric glands produce per day? |
2 to 3 Litres a Day. |
|
|
What four substances do the gastric glands produce? |
Mucus from the mucus producing cells. Pepsin from the chief cells. HCL from the parietal cells. Intrinsic factor from the parietal cells. |
|
|
What is intrinsic factor and what does it do? |
It is a glycoprotein Binds to vitamin B12 Essential for absorption. |
|
|
What does HCL do? |
*Activates lingual lipase which is the enzyme that breaks down lipids and pepsin, a protein digesting enzyme. *Initiates digestion plant material and connective tissue. *Destroys ingested bacteria and pathogens. |
|
|
What do chief cells produce? |
Pepsinogen which is activated by HCL to produce pepsin. |
|
|
How long before food exits the stomach? |
Between 30 minutes to 4 hours. |
|
|
What are the three areas of the small intestine? |
Duodenum Jejunum Ileum |
|
|
How long is the small intestine? |
Over 6m long. |
|
|
What is the length, characteristics, and roll of the duodenum? |
It is 25 cm long. Is the shortest and widest. It's role of to digest and absorb nutrients. |
|
|
What is the endocrine role of the pancreas.? |
It releases insulin and glucagon into the bloodstream from the islets of langerhans. |
|
|
What is the exocrine role of the pancreas? |
Releases 1.2 to 1.5 litres of pancreatic juice into the gut. *Proteases for proteins *Amylase for starch *Lipases for fats *Nucleases for nucleic acids. |
|
|
What does the gallbladder do? |
It's stores bile which is produced in the liver. |
|
|
What do bile salts do? |
Emulsify fats to enable their absorption. |
|
|
What is the length and shape of the jejunum and ileum? |
2.5m and 3.6m long. Sausage like coils. Suspended from posterior abdominal wall by mesentery. Inner surface covered with villi. Contains absorptive cells, mucus secreting cells, and has enzymes. |
|
|
What is the size of the large intestine? |
5 ft long and 7 cm in diameter. |
|
|
What connects the small intestine to the large intestine? |
The ileocaecal valve. |
|
|
What do the bacteria in the large intestine do? |
Ferments cellulose and other undigested CHO's, as well as synthesising vitamin K and B. |
|
|
How many functions does the Liver have? |
Over 500 documented functions. |
|
|
How much does the Liver weigh? |
1.5 to 2 kg |
|
|
Where is the gallbladder located? |
On the underside of the liver. |
|
|
Slide 46 |
Slide 46 |
|
|
What is catabolism and anabolism? |
Catabolism breaks down larger molecules. Anabolism builds large molecules from smaller precursors. |
|
|
What are carbohydrates? |
A large group of compounds including sugars, starch and fibre. |
|
|
How is excess glucose stored? |
As the polysaccharide glycogen in the liver
As triacylglycerols in adipose tissue. |
|
|
What is fibre? |
Polysaccharides from plant material which cannot be broken down and digested. |
|
|
Name two fatty acids. |
Linoleic and alpha-linoleic acid. |
|
|
How can fatty acids influence levels of cholesterol? |
Saturated fatty acids raise cholesterol and unsaturated fatty acids lower it. |
|
|
What are the four most common elements in our diet? |
Carbon Hydrogen Oxygen Nitrogen |
|
|
What are minerals? |
Chemical elements. |
|
|
What is a common mineral deficiency? |
Anaemia which is an iron deficiency. |
|
|
What are vitamins? |
Organic micronutrients. |
|
|
What does saliva contain? |
Salivary amylase and lysozyme. |
|
|
What cells are present in the stomach and what to do each secrete? |
*Parietal cells secrete HCL and intrinsic factor. *Chief cells secrete pepsinogen *Goblet cells secrete mucus. |
|
|
What is the pH of the stomach? |
pH of 1.5 to 3.0. This destroys salivary amylase but activates pepsin from pepsinogen |
|
|
What bacteria causes gastric ulcers? |
Helicobacter pylori which is resistant to the destructive action of stomach acid. |
|
|
What is the function of gastric mucus? |
It protects the epithelial cells of the stomach from HCL. |
|
|
Where is bile produced and what does it do? |
In the liver and emulsifies fat. |
|
|
What happens in the small intestine? |
Proteins, carbohydrates and lipids are all broken down into their base units and absorbed here. |
|
|
Where does dietary water absorption take place? |
Via paracellular and transcellular Routes by the process of osmosis. |
|
|
What happens in the large intestine? |
Most water and salts that reach here are absorbed. |
|
|
What is synthesized in the large intestine? |
Vitamin B12 Vitamin K ThiaminRiboflavin Riboflavin |
|
|
What are the three stages of swallowing (deglutition) |
Stage 1 - voluntary, food passes into oropharynx. Stage 2 - involuntary, food passes into esophagus. Stage 3 - involuntary, passes from oesophagus into stomach. |
