7b Regulation Of Digestion Flashcards
(46 cards)
What are the accessory organs in the digestive system?
Salivary glands: sublingual, parotid, submandibular glands
Liver
Pancreas
Gallbladder
Teeth
Tongue
What do teeth do?
Masticate, physical digestion, breaks food into smaller pieces
Classified in term of shape and function
What are the two sets of teeth humans have?
Deciduous: baby teeth, milk teeth
Permanent teeth
What do the salivary glands do?
Cleanse the mouth
Dissolves food chemicals to allow for taste
Moistens food and aids in compacting it into a bolus
Contains enzymes like amylase that begin chemical breakdown of carbs
What does saliva contain?
Water
Salts
Mucin (protein of mucus)
Lysozymes
Antibodies
Growth factors
Amylase (enzymes)
What is the pH of saliva and why?
6.35-6.85, slightly acidic
Ideal pH for enzyme amylase to start breakdown of polysaccharides into short chains
Where does the cystic duct start at and go to?
Starts at gall bladder and goes to common hepatic duct
Describe the passage of bile from all sides.
Gallbladder-> cystic duct->common hepatic duct-> bile duct-> duodenum
Right and left hepatic ducts->common hepatic duct-> bile duct ->duodenum
Note: common hepatic duct becomes the bile duct when the cystic duct joins the common hepatic duct coming from the liver
Describe the pancreas and its role.
Extends across the spleen to duodenum
Produces wide spectrum of digestive enzymes that break down all types of food
Makes pancreatic juice
Produces hormones
Where does the pancreas send its digestive enzymes?
Duodenum
What is pancreatic juice?
Alkaline fluid with enzymes that neutralizes acidic chyme coming from stomach
Acidic due to gastric juice
What are the hormones produced by the pancreas and their role?
Insulin: transporting glucose to cells from bloodstream
Glucagon: releasing storage of glucose into bloodstream
Describe the liver and its function.
Largest gland in the body
Right side, under diaphragm
Produces bile for digestive system
What is bile and what does it do?
Yellow-green, watery solution with: bile salts and bile pigments, cholesterol, phospholipids, electrolytes
Emulsifies fats (makes fat droplet smaller so easier for enzymes to break them down into glycerol and fatty acid chains
What is the role of the gallbladder?
Bile backs up into the cystic duct for storage
Gallbladder concentrates bile by removing water
Released when fatty acids are sensed in duodenum
What is a cholecystectomy and what does it imply?
Removal of gallbladder
No storage of bile so less emulsification of fat occurs at duodenum so harder to digest fats
Why do people who get part of the duodenum taken out as part of gastric bypass surgery lose weight?
Duodenum is main site of chemical breakdown, so if that site is removed or reduced, less chemical breakdown will occur and less nutrients will be able to be absorbed into blood stream
What is the process of hydrolysis of polymers?
Enzymes chemically break down a large molecule into their building blocks by adding a water molecule and breaking the covalent bond
What are the different groups of organic molecules broken down into?
Polysaccharides-> monosaccharides
Proteins-> amino acids
Fats-> fatty acids and glycerol
Where does the majority of chemical digestion occur?
Duodenum
What nervous systems regulate digestion?
CNS, autonomic nervous system such as: parasympathetic, sympathetic and enteric nervous systems (ENS)
What is the enteric nervous system?
Intrinsic nervous system of the GI tract
Nervous system exclusive to Gi tract
What does the ENS control?
Enteric
Local activity of smooth muscle (churning, segmentation, propulsion)
Controls gland secretion to optimize digestive and absorptive functions
Does this stuff indépendant from the brain
What are the intrinsic nerve plexuses and what do they control?
Network of neurons
Myenteric nerve plexus controls smooth muscle
Submucosal nerve plexus controls glands
