Chapter 2: The Digestive System: Mechanism for Nourishing the Body
Quiz yourself by thinking what should be in
each of the black spaces below before clicking
on it to display the answer.
Help!
|
|
||||
|---|---|---|---|---|---|
| Main structures of the digestive system? | oral cavity
esophagus
stomach
small & large intestine
🗑
|
||||
| Accessory organs | pancreas
liver
gallbladder
🗑
|
||||
| 4 layers of the lumen (tubular part of the intestine) | mucosa
submuscosa
muscularis externa
serosa or adventitia
🗑
|
||||
| Mucosa | inner most layer of lumen
interacts with food the most
🗑
|
||||
| Submucosa | connective tissue
also has submucosal plexus
🗑
|
||||
| Submucosal plexus | part of the submucosa that is part of the eneteric nervous system controlling digestion
🗑
|
||||
| Muscularis externa | circulartory muscle (circular and longitudnal smooth muscle)
myentaeric plexus
🗑
|
||||
| Myentaric Plexus | part of the enteric nervou systemt hat controls digestion
🗑
|
||||
| Composition of the oral cavity | mouth and pharynx
🗑
|
||||
| What are the organs of the oral cavity? | mouth
pharynx
salivary glands
🗑
|
||||
| Types of salivary glands | parotid
submandibular
sublingual
🗑
|
||||
| Salivary glands are the first level of what? | chemical digestion using amylases (MAIN source)
🗑
|
||||
| What is in saliva? | Enzymes that help to breakdown and santize foods
🗑
|
||||
| Main enzyme in saliva? | amylase
🗑
|
||||
| Function of the esophagus | moves bolus from oral cavity to stomach
🗑
|
||||
| Swallowing is what and occurs where? | moving the bolus down and in the esophogus
🗑
|
||||
| What are the 3 types of swallowing? | voluntary
pharyngeal
esophageal (larynx causes epiglottis to cover the glottis)
🗑
|
||||
| Peristalsis is what and where does it occur? | waves moving food down
the esophagus
🗑
|
||||
| Gastroesophageal sphincter | connects the esophagus to the stomach
🗑
|
||||
| Example of a disease of the esophagus | gastrointestinal intestinal disease (GERD)
🗑
|
||||
| Is swallowing dependent on gravity? | NO!
🗑
|
||||
| Bolus | cewed food and saliva
🗑
|
||||
| 4 main regions of the stomach | cardia
fundus
body
antrum (distal pyloric region)
🗑
|
||||
| Cardia region | GE sphincter
🗑
|
||||
| Fundus | top part
🗑
|
||||
| Antrum (DPR) | bottom; between stomach and SI
🗑
|
||||
| Function of DPR | grinds food and mixes with gastric juices to form chyme
🗑
|
||||
| DPR uses what to move chyme? | peristalsis
🗑
|
||||
| Volume of stomach full and empty? | empty: 50mL
full: 1L
🗑
|
||||
| How much saliva is produced each day? | ~1L
🗑
|
||||
| What percentage of saliva is water? | 99%
🗑
|
||||
| function of saliva? | dissolves and lubricates food
🗑
|
||||
| What does saliva contain? | antibacterial and antiviral components
🗑
|
||||
| What does GERD result from? | gastric acid entering the esophagus
🗑
|
||||
| What are some potential precipitators? | smoking, chocolate, peppermint, alcohol, and peppermint cause sphincter to relax
🗑
|
||||
| If you are prone to GERD, what should you avoid? | precipitating foods and laying down after eating
🗑
|
||||
| Gastric glands of the stomach | cardiac
oxyntic
pyloric
🗑
|
||||
| Cells in glands | neck (mucus) cells
parietal (oxyntic) cells
chief (peptic or zymogenic cells
enteroendocrine cells
🗑
|
||||
| Neck (mucus) cells | mucus forms barrier around tissue to prevent acid harm
🗑
|
||||
| Parietal (oxyntic) cells | secrete acid to activate the enzyme pepsinogen and secretes intrinsic facotr which binds to B12 for absorption
🗑
|
||||
| Chief (peptic or zymogenic) cells | secrete enzymes pepsinongen and breaks down proteins a little but not much
🗑
|
||||
| Enteroendocrine cells | secretes hormones in blood
🗑
|
||||
| Active state of pepsin | pepsinogen
🗑
|
||||
| composition of gastric juice | HCl
enzymes
mucus
intrinsic factor
🗑
|
||||
| Gastric juices are made up of HCl for these reasons | converts pepsinogen to pepsin
denatures proteins
releases nutrients from organic complexes
acts as bacteriocide
🗑
|
||||
| Denaturing of acid proteinss | acid connections become more linear and pepsinogen can cleave in
🗑
|
||||
| Release of organic complexes | form an ionic bond from food to release nutrient
🗑
|
||||
| Enzymes in the stomach | some amylase (not much)
pepsin
lipase
🗑
|
||||
| Mucus | provides about 2mm of pr?otection from acid
🗑
|
||||
| Why is there amylase in the stomach? | it travels with the saliva
🗑
|
||||
| What limited chemical digestion takes place in the stomach? | -initiation of protein synthesis
-limited continuation of starch hydrolysis
-absorption of water, alcohol, and a few drugs and minerals
-HCl important for iron and IF for B12
🗑
|
||||
| What is HCl important for? | iron
🗑
|
||||
| What is IF (intrinsic factor) important for? | B12 absorption
🗑
|
||||
| Hormones and peptide that INHIBIT gastric secretion. | PYY, GIP, secretin, somatostatin
🗑
|
||||
| Hormones and peptides that STIMULATE gastric secretion. | gastrin releasing peptide
gastrin
HCl
🗑
|
||||
| What is the release of HCl stimulated by? | gastrin, acetylcholine, histamine
🗑
|
||||
| Cause of peptic ulcers | H. Pylori
🗑
|
||||
| Treatment of peptic ulcers | H2 blocker= (pepcid/zantac) antagonize signals of histamine
OR
Proton Pump Inhibitors: (priolosec) inhibit HCl by binding receptor
🗑
|
||||
| H. Pylori | bacteria that's acid resistant and a cause of peptic ulcers
🗑
|
||||
| What can disrupt the mucus barrier? | aspirin, alcohol, ibuprofen,
🗑
|
||||
| The small intestine was made to do what? | maximize surface area to increase absorption
🗑
|
||||
| Structural aspects of SI | folds of Kerckring
Villi
microvilli
brush border
crypts of Lieberkuhn
🗑
|
||||
| Folds of Kerckring | large circular folds of mucosa
🗑
|
||||
| Villi | at the end of the folds of Kerckring;
finger-like projections
🗑
|
||||
| Microvilli | hair-like extensions of the cells' plasma membranes
🗑
|
||||
| Crypts of Lieberkuhn | in between villi and replace the old villi
🗑
|
||||
| Enterocytes in the SI are replaced? | every 3-5 days
they are slothed off and digested, which from that, the nutrients are used to make a new one!
🗑
|
||||
| What is the relaxation reflex of the stomach? | controlled by vagud nerve
🗑
|
||||
| Some people use a ____ to control contractions | pacemaker
🗑
|
||||
| What causes ____ contractions that move from fundus to antrum? | myoelectric complex complex; wave-like
🗑
|
||||
| What is the release of chyme regulated by? | volume and osmolarity
🗑
|
||||
| Overall gastric emptying takes how long? | 2-6 hours
🗑
|
||||
| When chyme leaves the stomach it goes where? | through to the pyloric sphincter
🗑
|
||||
| The SI is the main site of what? | digestion and absoption
🗑
|
||||
| What are the sections of the small intestine? | duodenum
jejunum
ileum
🗑
|
||||
| What increases intestinal secretions and motility? | vasoactive intestinal polypeptide (VIP)
neuropeptide substance P, Motlin, CCK
🗑
|
||||
| Where are vasoactive intestinal polypeptides found? | in neurons within the gut
🗑
|
||||
| What decreases intestinal secretions and motility? | PYY, secretin, glucagon-like peptides
🗑
|
||||
| What are the 2 tissues that help to protect the GI tract? | MALT (mucus)
GALT (gut)
🗑
|
||||
| What is the pancreas? | ductless endocrine cells that secrete hormones into the blood
🗑
|
||||
| The pancreas contains what type of enzymes? | digestive that are produced by acinar exocrine cells
🗑
|
||||
| Pancreatic juices contain | bicarbonate
electrolytes
pancreatic digestive enzymes
🗑
|
||||
| Contractions of the SI | segmentation and peristaltic waves
🗑
|
||||
| Segmentation | alternating contractions of circular smooth muscles, which breaks down and mixes intestinal contents
🗑
|
||||
| Peristaltic waves | progressive contractions that move SI contents distally though the SI and toward the LI
🗑
|
Review the information in the table. When you are ready to quiz yourself you can hide individual columns or the entire table. Then you can click on the empty cells to reveal the answer. Try to recall what will be displayed before clicking the empty cell.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Created by:
starryeyes213
Popular Science sets