Digestive System Flashcards
What is W and what is its function?
Mouth
- To mechanically (teeth) and chemically (salivary amylase) break down food, acting as the point of entry and start of ingestion and digestion
What is B and what are its 4 functions?
Tongue
- Moves food bolus towards teeth during mastication so it can be mechanically digested
- Moves food bolus towards back of throat so it can be swallowed
- Speech
- Taste
What is U and what is its function?
Oesophagus
- To provide a passageway for the food bolus from the pharynx to the stomach via peristalsis (smooth muscle contractions and relaxations behind the bolus to push it down)
What is G and what are 3 of its functions?
Liver
- To produce and secrete bile (dark yellow/green substance that aids in the digestion of lipids) to the gallbladder
- To metabolise lipids, carbohydrates and proteins
- To remove toxins from the body
What is H and what is its function?
Gallbladder
- To store, concentrate and release bile into the duodenum via the common bile duct
What is I and what are its structure and 3 functions?
Duodenum
- S = 1st part of small intestine, lined w villi and microvilli
- F = - final stage of digestion using bile from the gallbladder and enzymes from the pancreas (chemical)
- beginning of absorption of nutrients into bloodstream
- produces secretin in response to acidic chyme, stimulating the pancreas to release alkaline chemicals to maintain pH
What is J and what is its structure and function?
Jejunum
- S = middle section of small intestine, lined with villi and microvilli
- F = to absorb nutrients e.g. proteins, CHO, vitamins etc from digested food
What is K and what is its structure and function?
Ileum
- S = final section of small intestine, lined with villi and microvilli
- F = to absorb nutrients and most water from digested food
What is L and what is its structure and function?
Anus
- S = external opening to the digestive system, containing an internal sphincter (involuntary smooth muscle) and external sphincter (voluntary skeletal muscle)
- F = to provide a pathway for faeces out of the body
What is F?
Parotid gland (below ears)
What is D?
Sublingual gland
What is E?
Submandibular gland
What is V and what is its structure and function?
Pharynx
- S = tube containing smooth muscle, lined with a mucous membrane. It has 3 parts: nasopharynx oropharynx, laryngopharynx
- F = to provide a passageway for food from the oral cavity to the oesophagus
What is T and what is its structure and function?
Stomach
- S = a C-shaped muscular bag located in the LUQ
- F = to mechanically (churn food through muscle contractions) and chemically (HCl and enzymes e.g. pepsin) digest food
What is S and what is its structure and function?
Pancreas
- S = feather-shaped abdominal organ located posterior to the stomach
- F = to produce and release enzymes e.g. amylase, lipase, trypsin (breaks down protein) for chemical digestion into the duodenum via the pancreatic duct, as well as hormones e.g. insulin and glucagon for maintenance of blood sugar levels
What is R?
Transverse colon
What is Q?
Ascending colon
What is O?
Descending colon
What is P?
Caecum
What is N?
Sigmoid colon (terminal/end)
What is X?
Appendix
What is M and what is its structure and function?
Rectum
- S = short tube starting at the sigmoid colon and terminating at the anal canal, inferior to the intestines, contains stretch receptors which send a message to nervous system to stimulate voluntary contraction of anal sphincter to push out faeces
- F = to store and compact faeces prior to elimination
What is the function of the digestive system?
To break chemically and mechanically down ingested food, absorb nutrients and excrete waste products
What is digestion?
The process of breaking down large, insoluble molecules into smaller, soluble molecules by chemical and mechanical means
What is mechanical digestion? Give an example
- To physically break down food into smaller pieces, increasing their surface area, without changing the chemical structure, such as through chewing and muscular movements
- e.g. churning food in the stomach or mastication by the teeth
What is chemical digestion? Give an example
- To break down food by changing the chemical structure, such as through acids or enzymes
- e.g. salivary amylase in the mouth or HCl in stomach
Components of the digestive system
- Alimentary/digestive tract: mouth, pharynx, oesophagus, stomach, small intestine (duodenum, jejunum, ileum), large intestine (ascending, transverse, descending, sigmoid colon), rectum, anus
- Accessory components: salivary glands, pancreas, liver, gallbladder, appendix
What is the mesentery?
Folded membrane that attaches the intestines to the abdominal cavity and holds them in place
What is a bolus?
Semi-solid mass of food
Structure and function of the small intestine
- S = has 3 sections (duodenum, jejunum, ileum), located in the abdominal cavity between the stomach and large intestine in the alimentary tract
- F = to absorb nutrients into the bloodstream e.g. carbohydrates/lipids/proteins
Function of the salivary glands
To secrete saliva which:
- Lubricates food to make it easier to move through the digestive system
- Chemically digests food with salivary amylase (breaks down starch)
- Cleans the oral cavity
- Destroys ingested pathogens using lysozymes
An/o
Append/o
Anus
Appendix
Appendic/o
Cholecyst/o
Appendix
Gallbladder
Col/o
Colon/o
Colon
Or/o
Stomat/o
Mouth
What is a colostomy?
Surgical creation of an opening by connecting the colon to an opening in the abdominal wall
Enter/o
Duoden/o
Intestines
Duodenum
Oesophag/o
Gastr/o
Oesphagus
Stomach
Hepat/o
Ile/o
Liver
Ileum
Jejun/o
Pancreat/o
Jejunum
Pancreas