Term
| overall function of the GI tract |
|
Definition
| breaking down food for the absorption of nutrients into the body |
|
|
Term
| six main processes related to food intake |
|
Definition
1. ingestion
2. fragmentation
3. digestion
4. absorption
5. elimination
6. immune surveillance |
|
|
Term
|
Definition
| bringing food into digestive tract |
|
|
Term
|
Definition
| breaking down food into small particles that can be digested |
|
|
Term
|
Definition
| breakdown of food into chemicals that can be absorbed by cells |
|
|
Term
|
Definition
| uptake of chemicals into the body |
|
|
Term
|
Definition
|
|
Term
| nutrition requirements (4) |
|
Definition
1. energy
2. protein
3. essential fatty acids
4. vitamins |
|
|
Term
|
Definition
A sedentary individual requires 14 to 16 calories (actually kcals) per pound/day
Energy can come from any one of the three basic chemical types that make up living tissue. carbohydrates, protein and fat |
|
|
Term
|
Definition
| Humans cannot synthesize 9 amino acids that are used in the thousands of proteins that our cells produce. We must get these amino acids from proteins we eat. |
|
|
Term
|
Definition
| Some fatty acid chains that have double bonds at specific residues are not synthesized by human cells and must be acquired from ingested fats. |
|
|
Term
|
Definition
| An organic chemical that acts as a coenzyme and/or regulator of metabolic processes. There are 13 known vitamins. |
|
|
Term
|
Definition
| non-organic chemicals required by the body |
|
|
Term
|
Definition
| lips, teeth, tongue, cheeks, salivary glands |
|
|
Term
|
Definition
-taste food
-ingest food
-fragmentation of food
-begin digestion process |
|
|
Term
| covering of the inside of the mouth function |
|
Definition
| protect the bone from ingested food |
|
|
Term
|
Definition
Epithelia: A thick stratified squamous epithelia (non keratinized)
Lamina propria dense irregular connective tissue rich in type 1 collagen this is bound to bone. |
|
|
Term
|
Definition
| fragmentation of food, covered previously |
|
|
Term
|
Definition
| help move food to be framented by teeth and to be swallowed. taste |
|
|
Term
|
Definition
-facilitate food ingestion by lubricating oral cavity and sticking food together so it can be easily swallowed
-begin digestion of carbs
-antimicrobial secretions
-facilitate taste |
|
|
Term
| gross anatomy of salivary glands |
|
Definition
three major glands: parotid, sublingual, submandibular
-other small glands throughout oral cavity |
|
|
Term
| histology of salivary glands |
|
Definition
| All glands are complex tubulo ascinar glands with serous and mucous secretory cells. These glands secrete mucus and as well as enzymes such as amylase that begins the digestion of carbohydrates. |
|
|
Term
|
Definition
|
|
Term
| cells of sublingual glands |
|
Definition
|
|
Term
| cells of submandibular glands |
|
Definition
|
|
Term
| how many types of ducts do these glands have? what is their function |
|
Definition
-two types
-intercalated ducts found between ascini
-Striated ducts classic ion transporting ducts that add water to the saliva. There is a lot of water in saliva -Both duct types have been implicated in the production of IgA, lysozyme and lactoferrin all of which have antimicrobial effects. |
|
|
Term
| mucosa of the GI tract proper |
|
Definition
| -epithelium -lamina propria: the underlying CT -muscularis mucosa: layer of smooth muscle |
|
|
Term
| submucosa of the GI tract proper |
|
Definition
| main body of underlying CT, contains a submucosal nerve plexus |
|
|
Term
muscularis propria of the GI tract proper
|
|
Definition
| circular and longitudinal layers of smooth muscle contain also myenteric nerve plexis |
|
|
Term
adventitia/serosa of the GI tract proper
|
|
Definition
| outermost layers, can be CT layer or mesothelium |
|
|
Term
|
Definition
| move food from mouth to stomach |
|
|
Term
|
Definition
Mucosa
Epithelium: stratified squamous (non keratinized)
Submucosa: contains some mucus secreting glands
Muscularis propria: upper parts of the organ contain skeletal muscle this lessens as it descends to stomach |
|
|
Term
|
Definition
| fragmentation, digestion and absorption (minimal--things such as alcohol) |
|
|
Term
|
Definition
| 4 regions: cardia, fundus, body, pylorus |
|
|
Term
| epithelium of mucosa of stomach |
|
Definition
| The epithelium of the stomach is simple cuboidal epithelia that are extensively invaginated into gastric pits. The pits have branched tubular glands draining in to them |
|
|
Term
| cells of the epithelium of the stomach |
|
Definition
-surface mucus secreting cells
-parietal cells (oxytonic)
-mucus secreting cells of the neck
-chief, peptic (zymogenic) cells
-stem cells
-neuroendocrine cells |
|
|
Term
| surface mucus secreting cells |
|
Definition
| these cells produce mucus that protects the lining of the stomach from the other cellular secretions. |
|
|
Term
| parietal cells (oxytonic) |
|
Definition
| large cells with a centrally located nucleus and an eosinphilic cytoplasm. These are found in the isthmus of the pit as well as in the glands proper. These cells secrete HCL that denatures proteins to aid in digestion. The acid also serves to break down and dissolve other components of food. These cells also produce intrinsic factor that facilitates the endocytosis of vitamin B12 in the small intestine. These cells have abundant mitochondria for the transport of H+ against a gradient. |
|
|
Term
| mucus secreting cells of the neck |
|
Definition
| these cells secrete mucus that is distinct from that of the surface mucus cells; The mucus protects the cells of the stomach from being digested by the acids and enzymes produced by the organ. |
|
|
Term
| chief, peptic (zymogenic) cells |
|
Definition
| found in the basal region of the glands. Very intensely stained basophilic cells. Secrete the enzyme precursor pepsinogen. When exposed to acid will become pepsin that will cleave proteins into peptides. Also, this cell secretes lipase that cleaves lipids into fatty acid components. |
|
|
Term
|
Definition
| found in the neck of the glands and capable of giving rise to all the cell types listed above. |
|
|
Term
|
Definition
| generally found at near the base of the glands. These cells secrete various hormones into the blood stream (ie basal lateral secretion). These hormones serve to coordinate the digestive process. Examples of some of the hormones: gastrin stimulates acid release from the parietal cells; glucagon stimulates hepatocytes to perform glycogenolysis |
|
|
Term
| muscularis propria of stomach |
|
Definition
| 3 smooth muscle layers; the additional layer is the inner most with an oblique orientation. The increased muscular investment of the stomach illustrates the important role of agitation in the fragmentation and digestion of food to chyme. |
|
|
Term
|
Definition
| very thin covered by adventitia |
|
|
Term
| histological differences between stomach regions |
|
Definition
| The body and fundus of the stomach have short gastric pits and straight glands. The pyloric stomach has much longer gastric pits and the glands are branched and coiled. Here cells of the glands are mainly mucus producing cells and they are also enriched with neuroendocrine cells that produce the hormone gastrin. |
|
|
Term
|
Definition
-affect 10% of americans
-ulser refers to an erosion of the epithelium of a type of organ
-in peptic ulcers, erosions found in the body/pylorus region of stomach and upper section of small intestine (duodenum)
-histologically, ulcers characterized by absence of epithelia, CT very enriched with inflammatory cells types
-can lead to blood loss and perforation of organs
-action of pepsin and acid on epithelial cells that line organs are cause of ulcers
-underlying cause of legions is complex
-in stomach, tissue normally exposed to destructive forces which are held at bay by some defense mechanisms (mucus production, bicarbonate production, regenerative capacity of epithelia)
-ulcers can result from smoking, alcohol, increased acid/pepsin production, infection from H. Pylori
-H. pylori found in 70 to 90% of ulcers. it secretes enzymes including proteases that break down mucus in stomach
-ulcers can be caused when normal defense mechanisms are compromised, like: NSAIDs on epithelial proliferation and altered GI function
-because of balance between destructive forces and defensive mechanisms, possible to treat ulcers with approaches like: neutralization of stomach acids, stimulation of increased mucus production, inhibition of acid secretion and antibiotics |
|
|
Term
| what region of digestive tract do peptic ulcers affect |
|
Definition
| the body/pylorus region of the stomach and the upper section of the small intestine (duodenum) |
|
|
Term
| what are the normal secretions of the glands of the stomach? |
|
Definition
| mucus, pepsinogen, HCL, lipase, intrinsic factor |
|
|
Term
| what histological findings characterize a peptic ulcer? |
|
Definition
| loss of the epithelial lining and inflammatory cells in the submucosa |
|
|
Term
| how could the bacteria H Pylori contribute to the formation of an ulcer? |
|
Definition
| H Pylori secretes enzymes including proteases and creases that break down the mucus that coats the epithelium of the stomach |
|
|
