Term
| Increased transit time means food is moving ___ and you will poop ___. |
|
Definition
|
|
Term
| Decreased transit time means food is moving ___ and you will poop ___. |
|
Definition
|
|
Term
| parts of the GI tract that are skeletal muscle: |
|
Definition
- tongue
- upper 1/3 of esophagus
- external anal sphincter |
|
|
Term
| Peristalsis requires innervation from the ANS as well as from the gut's own intrinsic nervous system. But segmentation can occur without any ___, it just occurs due to the nature of the muscle. |
|
Definition
|
|
Term
| Peristalsis requires innnervation, segmentation does not. |
|
Definition
|
|
Term
| layers of the gut from inside to out: |
|
Definition
| lumen> mucosa > submucosa with glands and glandular ducts > submucosal aka meissner's nerve plexus > longitudinal muscle layer > myenteric nerve plexus > circular smooth muscle layer |
|
|
Term
| inner longitudinal layer important for ___. |
|
Definition
|
|
Term
| outer circular layer important for: |
|
Definition
|
|
Term
| Meissner's Submucosal Plexus and the Myenteric Plexus nerves are innervated by ___ and ___ nerves. |
|
Definition
parasympathetic
sympathetic |
|
|
Term
| ___ influence the arteries associated with the intestines. |
|
Definition
|
|
Term
| 3 methods of regulating digestion: |
|
Definition
1. Neural mechanisms
2. Hormonal mechanisms
3. Local mechanisms (pH, physical stimulation, chemical stimulation) |
|
|
Term
|
Definition
- involves CNS
- can be CNS acting on myenteric plexus
- can be stretch receptors and chemorecptors acting on CNS |
|
|
Term
|
Definition
| - stretch receptors or chemoreceptors acting on myenteric plexus |
|
|
Term
|
Definition
Extrinsic, autonomic nervous system
Long arc reflexes
Intrinsic, enteric nervous system
Short arc reflexes
Hormonal
Hormone producing cells |
|
|
Term
| Bolus stretching mechanoreceptor> afferent signals via chemoreceptors/mechanoreceptors, etc > enteric nerve plexus > efferent signals> smooth muscle cells > contract (just an example), could also to be to submucosal plexus to tell it to secrete |
|
Definition
|
|
Term
| examples of short arc reflexes: |
|
Definition
| segmentation and local secretions |
|
|
Term
| paraysympathetic innervation of the gut: |
|
Definition
- vagal efferent signals may be excitatory or inhibitory
- anticipatory response to meal: sight, smell
- presence of ingested food causing salivation, gastric and SI secretions
- mediates receptive relaxation of LES and gastric tone |
|
|
Term
| Vagus nerve can release acetyl choline, which is ___ to the gut, or it can release NO, which is ___ causing ___ of the gut. (talking about parasympathetics). |
|
Definition
- excitatory
- inhibitory, causing relaxation |
|
|
Term
| In general with the gut, parasympathetics are ___ and sypmpathetics are ___. |
|
Definition
|
|
Term
| The fibers of sympathetic innervation that innervate the gut originate in the __ __ and stimulation inhibits digestion by the following methods: |
|
Definition
- spinal cord
- supresses motility and secretion
- decreases blood flow to intestines
- contracts sphincter smooth muscle |
|
|
Term
| sphincters are usually contracted, they need ___ to relax. |
|
Definition
|
|
Term
| With the enteric nervous system, the cell bodies of the neurons are located in ___ positioned ___ ___ ___ of the gut. Called the little brain in the gut. |
|
Definition
- ganglia
- inside the walls |
|
|
Term
| there are just as many neurons in the enteric nervous system as there are in the CNS. |
|
Definition
|
|
Term
| The Myenteric plexus, aka ___ plexus, is located between the ___ and ___ smooth muscle layers. |
|
Definition
- Auerbach's
- longitudinal and circular |
|
|
Term
| The myenteric plexus (auerbach's) is made up of ___, ___, and ___ ___ ___. It is organized such that the mechanical forces and deformation occur during ___ ___ of stretching of the wall as the lumen fills. |
|
Definition
- neurons
- ganglia
- interganglionic fiber tracts
- muscle contraction |
|
|
Term
| location of most of the motor neurons to circular and smooth muscle layers: |
|
Definition
| Myenteric aka Auerbach's plexus |
|
|
Term
| The myenteric plexus is very involved in ___. |
|
Definition
|
|
Term
| The submucosal plexus, aka ___ plexus, is most prominent in the ___ and ___ ___. It is in the ___ ___ between the ___and ____ ___ __. It contains ___ neurons that innervate the ___ ___ and ___. It can send fibers to the myenteric plexus. |
|
Definition
- meissner's
- small and large intestine
- submucosal space
- mucosa
- circular muscle coat
- motor
- intestinal crypts
- villi |
|
|
Term
| submucosal plexus very involved with : |
|
Definition
|
|
Term
| Endocrine cells in the ___ and ___ of the ___ and in the ____ release hormones that are important for control of GI function. |
|
Definition
- mucosa and submucosa
- stomach
- pancreas |
|
|
Term
| Paracrine substances are released from cells in the ___ and __ __ ___ and are important for control of GI function. |
|
Definition
- stomach
- GI immune system |
|
|
Term
| Hormones and paracrines act on ___ __, the ___, ___ ___ __, and ___. They alter ___ and ___ functions of the GI tract. |
|
Definition
- secretory cells
- liver
- smooth muscle cells
- sphincters
- secretory
- motor |
|
|
Term
| histamine and somatostatin are examples of paracrines |
|
Definition
|
|
Term
| There are receptors in the back of the throat called __ receptors. When food touches these the ____ ___ of the swallowing process begins, after this, you cannot stop swallowing. |
|
Definition
- touch receptors
- involuntary response |
|
|
Term
| Mouth mucosa produces ____. |
|
Definition
|
|
Term
| parotid glands have ___ secretions. |
|
Definition
- serous (watery with enzymes and ions)
Think "PS" |
|
|
Term
| Submandibular gland has ___ and ___ secretions. |
|
Definition
- serous and mucus
Think "submandibular" has an S and an M |
|
|
Term
| Sublingual gland has ___ and ___ secretions. |
|
Definition
- serous and mucus
Think "sublingual" wants to be like submandibular so it has both. |
|
|
Term
| Buccal glands have ___ secretions. |
|
Definition
|
|
Term
|
Definition
- cleanses mouth
- dissolves food chemical for taste
- moistens food
- aids in bolus formation
- begins digestion of starches
- bacteriocidal |
|
|
Term
|
Definition
Water - 99.4%
Electrolytes: Na, K, Cl, PO4, HCO3
Digestive enzymes: amylase, lipase
Proteins: mucin, lysozymes, IgA
Metabolic wastes: urea, uric acid
pH 6.0 - 7.4
Hypotonic relative to plasma |
|
|
Term
| Saliva secretion is only stimulated by ____. Saliva is always ___ compared to plasma, which means it has to be less than ___mOsM |
|
Definition
parasympathetics
hyptonic
300 |
|
|
Term
| Initial saliva is secreted by ___ cells that secrete an ___ solution, which gets modified. ___ and ___ get taken out and ____ and ___ get put in. |
|
Definition
- acinar
- isotonic
- sodium and chloride
- potassium and bicarbonate |
|
|
Term
| With basal salivation, it can stay in the salivary duct for a long time, so ___ and ___will be at its lowest and ___ will be at its highest with basal salivation |
|
Definition
- sodium
- bicarbonate
- potassium |
|
|
Term
| With fast salivation, you are specifically stimulating the duct cells to secrete ____ to counteract the stomach's acidity and b/c ____ makes a good environment for salivary amylase. |
|
Definition
- bicarbonate
- bicarbonate |
|
|
Term
| Salivation is regulated by ___ nervous signals from the ___ nuclei in the brainstem. |
|
Definition
- parasympathetic
- salivatory |
|
|
Term
| The salivatory nuclei in the brainstem is innervated by cranial nerves ___ and ___ and by ___ nerves. |
|
Definition
- VII (facial) and XI (accessory)
- sympathetic |
|
|
Term
| Both parasympathetic and sympathetic stimulation ___ salivation, but ___ stimulation has stronger and longer lasting effect through ___, ___ __, and ___. |
|
Definition
- increase
- parasympathetic
- Ach
- substance P
- VIP |
|
|
Term
| sympathetic stimulation causes ____ which ____ secretions via ___, thus the increase is transient. |
|
Definition
- vasoconstriction
- decreases
- norepinephrine |
|
|
Term
| Hormones only ___, NOT control reconditioning in the ducts. Aldosterone increases ___ reabsorption. |
|
Definition
|
|
Term
| Various stimuli of salivation: |
|
Definition
- taste
- tactile
- thought
- smell
- GI irritation
- influenced by stimuli from other CNS centers, reflexes (vomitting, nausea), emotional state |
|
|
Term
| basal and maximal rates of salivary secretions: |
|
Definition
basal= 30 ml/hr
maximal= 400-600 ml/hr |
|
|
Term
| The chewing reflex is a ___ reflex initiated by ___ of ___ in the mouth. It aids in digestion of food by increasing surface area available for enzymes to act. It also mixes food with the saliva. |
|
Definition
- central
- presence of food |
|
|
Term
| The ___ allows food to transfer to the esophagus. |
|
Definition
|
|
Term
| The upper esophageal sphincter allows entry of food into the esophagus and protects the ___ from swallowed material. |
|
Definition
|
|
Term
| The esophagus transports food from the ___ to the ___. It also clears material refluxed from the stomach. |
|
Definition
|
|
Term
| The lower esophageal sphincter protects the esophagus from gastric reflux. |
|
Definition
|
|
Term
| The swallowing reflex is a ___ reflex with two phases. First is the voluntary or ____ phase that initiates the swallowing reflex. During this phase you can start or stop swallowing at will. This phase involves ___ ___ activation of ___ muscle. During this phase the food gets pushed back into the ___ which stimulates ____ ___ and pharyngeal nerve receptors around the pharynx. Once the nerves are stimulated you cannot stop swallowing. |
|
Definition
- central
- buccal phase
- motor neuron activation of skeletal muscle
- pharynx
- nerve endings |
|
|
Term
| Stimulation of pharyngeal receptors causes ___ ___. |
|
Definition
|
|
Term
| With the buccal phase the tongue presses against the ____ ____ and forces the ___ into the ____. |
|
Definition
- soft palate
- bolus
- oropharynx |
|
|
Term
| Primary peristalsis goes all the way down the esophagus and stops just before the stomach. |
|
Definition
|
|
Term
| The involuntary, or ____ phase, of the Swallowing reflex is controlled by the ___ ___ in the ____. It is initiated by stimulation of ___ ___ ___ and slightly inhibits the ___ ___. The ___ and ___ get covered by the epiglottis to prevenet aspiration. The bolus gets squeezed through the pharynx and into the esophagus by persistalsis. |
|
Definition
- pharyngeal
- swallowing center
- brainstem
- pharyngeal swallowing receptors
- respiratory center
- trachea and nasopharynx |
|
|
Term
| During the involuntary phase of swallowing, respiratory passages get closed by the rising of the ____ and ___. The ___ __ ___ relaxes and food moves into the esophagus. |
|
Definition
- uvula
- larynx
- upper esophageal sphincter |
|
|
Term
| During pharyngeal phase of swallowing the constrictor muscles of the pharynx ___ forcing the bolus into the esophagus, then the ___ ___ ___ contracts after the food enters the esophagus. |
|
Definition
- contract
- upper esophageal sphincter |
|
|
Term
| The esophageal involuntary phase of the swallowing reflex promotes passage of food from the the ___ to the stomach. Solids pass in 4-8 seconds, fluids pass in 1-2 seconds. |
|
Definition
|
|
Term
| During primary persistalsis, the ___ muscle contricts befor the bolus, while the _____ muscle contracts after the bolus. |
|
Definition
|
|
Term
| Achlasia is an ____ ____ ___ where the ___ ___ of the esophagus is missing the ganglia of the ____ ____, so it is always ____. So since it can't relax, food just accumulates. This promotes esophageal cancer. |
|
Definition
- esophageal motility disorder
- distal portion
- myenteric plexus
- contracted |
|
|
Term
| Diffuse esophageal spasms are caused by ___ between nerves along the length of the esophagus, so each region of the esophgaus is contracting at the same time. This feels like a heart attack. Give patient ___ so the muscle will relax. |
|
Definition
|
|
Term
| LES is ____ or ___ sphincter due to its position below the diaphragm. There is slight thickening of ___ smooth muscle. It is ___ ____ due to positive pressure of stomach and nerves. There is ___ ____ of the LES and stomach during swallowing. Prevents reflux. |
|
Definition
- functional or physiological
- circular
- tonically constricted
- receptive relaxation |
|
|
Term
| Modulators that increase tone of the LES: |
|
Definition
An Able Good Mobile Person CAP.
- acetylcholine
- alpha- agonists
- gastrin
- motilin
- protein
- coffee
- antacids
- prostaglandins |
|
|
Term
| Modulators that decrease tone of LES: |
|
Definition
Please Be Cool So Happy Vikings Present Fat Cheap Chocolate And Nice Alcoholic Peppermints.
- purinergic
- beta-agonists
- CCK
- secretin
- histamine
- VIP
- progesterone
- Fat
- CHO
- chocolate
- anticholinergics
- nicotine
- alcohol
- peppermint |
|
|
Term
| Pregnant women in third trimester are more likely to experience heart burn b/c: |
|
Definition
- increased progesterone
- increased intragastric pressure |
|
|
Term
| main body of esophagus is lined by ___ ___ cells, gastric end is lined by ___ ___ cells. |
|
Definition
- simple mucus cells
- compound mucus cells |
|
|
Term
| Gastroesophageal reflux symptoms are similar to ____. Causes are pregnancy, obesity, running, hiatal hernia, anesthesia. |
|
Definition
|
|
Term
| empty stomach is ____ but can expand up to ___ or ____. |
|
Definition
|
|
Term
| Absorption in stomach is minimal due to ___ junctions, but the following can be absorbed: |
|
Definition
- tight
- aspirin
- alcohol
- lipid soluble drugs |
|
|
Term
| In the stomach, ___ cells are in the connective tissue close to parietal and chief cells. |
|
Definition
|
|
Term
| Gatric pit cells and what they secrete: |
|
Definition
- mucous neck cells- acidic mucus
- parietal cells- HCl and intrinsic factor
- chief cells- pepsinogen, lipases |
|
|
Term
| Enteroendocrine cells of the stomach and their secretions: |
|
Definition
- G-cells> gastrin (serotonin)
- Mast cells > histamine (endorphins, opiates)
- D-cells > somatostatin (cholecystokinin) |
|
|
Term
| When the pH is less than 2, __ cells release ___, which inhibits gastrin from the G cells, which inhibits ___ secretion from parietal cells. |
|
Definition
- D cells
- somastatin
- acid |
|
|
Term
| The vagus nerve synapses on the enteric nerves which release ___ which acts on the ___, ___, ___, and ___ cells. The chief cells are stimulated to release ___ into the lumen. The parietal cells are stimulated to release ___ into the lumen. The mast cells are stimulated to release ____ into the ___ ___. The G cells are stimulated to release ___ into the blood. |
|
Definition
- acetylcholine
- chief, parietal, mast, and G
- pepsinogen
- HCl
- histamine
- lamina propria
- gastrin |
|
|
Term
| Histamine from mast cells further stimulates secretions from ___ and ___ cells. |
|
Definition
|
|
Term
| Hydrochloric acid gets secreted into the lumen via a ___ __ which in turn takes up ___. Then on the apical surface ___ gets pumped out in exchange for ____. There is also sodium potassium ATPase on the apical surface. |
|
Definition
- proton pump
- potassium
- bicarbonate
- chloride |
|
|
Term
| So when you are making lots of acid, you are also making lots of ___, so you blood becomes ___, this is called an ___ ___. |
|
Definition
- bicarbonate
- alkaline
- alkaline high |
|
|
Term
| explain how acetylcholine regulates acid secretion: |
|
Definition
| - acetylcholine> receptor > IP3 > calcium > activates proton pump to pump out more hyrogen ions into the stomach |
|
|
Term
| Explain how histamine modulates acid secretion in stomach: |
|
Definition
| - histamine> H2 receptor (g protein receptor) > increased cAMP> stimulates hydrogen pump to secrete hydrogen ions into lumen |
|
|
Term
| Gastrin and acetylcholine increase acid secretion via increasing IP3 and calcium. Histamine, somatostatin, and prostaglandins increase acid secretion by increasing cAMP. |
|
Definition
|
|
Term
| parietal cells have receptors for: |
|
Definition
- gastrin
- acetylcholine
- histamine
GAH |
|
|
Term
| HCl secretion is stimulated by gastrin, acetylcholine, and histamine via ___ ___ systems. Release of HCl is low if only of these ligands binds, but is high if all three bind, this is called ____. |
|
Definition
second messenger
potentiation |
|
|
Term
| Antihistamines block ___ receptors and decrease ___ secretion. These have no effect on ___ blockers. Cimetadine. |
|
Definition
|
|
Term
| The cephalic phase is completely mediated by parasympathteics |
|
Definition
|
|
Term
|
Definition
Interdigestive – between meals
Cephalic
Sight, smell, thought of food
Stimulation of central neural centers
Gastric
Mechano- and chemo- receptor stimulation in stomach
Intestinal – early
Mechano- and chemo- receptor stimulation in small intestine
Intestinal – late
Mechano- and chemo- receptor stimulation in small and large intestine |
|
|
Term
| Cephalic phase prepares the stomach for arrival of food. It is short. ___ mechanism in which ____ fibers in the ___ nerve synpase on the ____ plexus. Primary action is stimulation of ___, ___ and ___ production, leading to increased volume of gastric juice. Secondary action is to stimulate __ cells to release ___. |
|
Definition
- Neural
- preganglionic
- vagus
- submucosal
- mucus
- enzymes
- acid
- G cells to release gastrin |
|
|
Term
| The gastric phase enhances secretions of cephalic phase. It ___ and ____ the chyme and initiated digestion of ___ by ___. This phase is long (3-4 hours). It is a ___ mechanism by which __ reflexes triggered by ___ receptors and ___. Also has a ___ mechanism that stimulats release of ___ from G cells. Also has a local mechanism that release __ from mast cells. Its main action is increased ___ and ___ production, increased ___, and initiation of ___ ___. |
|
Definition
- homogenizes
- acidifies
- proteins
- pepsin
- neural
- short
- stretch and chemoreceptors
- hormonal
- gastrin
- histamine
- acid and pepsinogen
- motility
- mixing waves |
|
|
Term
| The intestinal phase controls rate of ___ entry into the ___. It is long. It has a neural mechanism which is triggered by ___ of the ___. Also has a hormonal mechanism, which is the stimulation of __, __, and ___ by acids, CHOs, and lipids. Also by a hormonal mechanism, ___ is released in response to undigested proteins. Its main function is ___ ___ of gastric acid and pepsinogen production and reduction of gastric motility. |
|
Definition
- chyme
- duodenum
- distention of the duodenum
- CCK, secretin, GIP
- gastrin
- negative feedback |
|
|
Term
| If you cut the vagus nerve how will gastrin release be affected? |
|
Definition
no gastrin release in cephalic stage
still get other gastrin release b/c local stretch causes release of gastrin |
|
|
Term
| Gastrin is secreted by G cells in the ___ of the stomach. It stimulates ___ ___ on ___ cells and increases ___ secretion, gastric and intestinal ___, ___ secretions. Gastrin is also necessary for proper growth of the ___ ___. |
|
Definition
- antrum
- gastrin receptors
- parietal
- acid
- motility
- pancreatic
- GI mucosa |
|
|
Term
| Regulation of gastrin secretion: |
|
Definition
- distention
- vagal stimulation (acetylcholine, gastrin releasing peptide (GRP aka bombesin)
- enterogastrones
- pH (somatostatin inhibits gastrin secretion when pH is less than 3)
- food products (secretagogues): protein digestion products: coffee
- alcohol
- calcium |
|
|
Term
| Histamine binds to ___ __ on ___ cells and potentiates secretions produced by acetyl choline and gastrin. It is stimulated to release by ___ ___, ___, ___, and ___. It has feedback inhibition on ___ by __ when pH is less than __. |
|
Definition
- H2 receptors
- parietal
- vagal stimulation, gastrin, HCl, and pepsin
- gastrin by somatostatin
- 3 |
|
|
Term
| Pepsinogen is secreted in inactive form and is activated by ___ and previously formed ___ in the stomach. It is a proteolytic enzyme that begins protein digestion, its optimal pH is between __ and __. |
|
Definition
|
|
Term
| During the cephalic phase, ___ stimulated ___ neurons within the ___ nervous system directly stimulate ___ cells to secrete ___. |
|
Definition
- vagally
- cholinergic
- enteric
- chief
- pepsinogen |
|
|
Term
| During the gastric phase, __ __ activates ___ reflexes that enhance pepsinogen secretion. |
|
Definition
|
|
Term
| During the intestinal phase, ___ enhances pepsinogen release. |
|
Definition
|
|
Term
| Intrinsic factor is secreted by ____ cells along with acid. It is essential for absorption of B12 in the ___ ___. If parietal cells are destroyed via chronic gastritis, ____ will develop and you will get ______ ___ due to failure of ___ of the ___. |
|
Definition
- parietal
- terminal ileum
- hypochlorhydria or achlorhydria (low or absent acid)
- macrocytic/pernicious anemia
- maturation
- RBCs |
|
|
Term
| 2 possible causes of macrocytic pernicious anemia: |
|
Definition
- destruction of parietal cells so can't absorb B12 b/c no intrinsic factor
- removal of terminal ileum so can't absorb B12 |
|
|
Term
| The mucosal barrier in the stomach is ___ rich and has ___ junctions between the epithelial cells.The ___ membrane is impermeable to acid. |
|
Definition
- bicarbonate
- tight
- plasma |
|
|
Term
| The bicarb in the mucus is to protect from acid, if don't have this, the pepsinogen comes in contact with the cells and you get __ ____ ___. |
|
Definition
|
|
Term
| Gastritis is acute or chronic inflammation of the underlying layers of the stomach wall. Peptic ulcers result from persistent damage to the underlying tissues leading to ____. locations: |
|
Definition
- erosions
- esophagus
- stomach
- duodenum |
|
|
Term
| most common cause of gastritis: |
|
Definition
|
|
Term
|
Definition
- excess gastric acid and pepsin secretion (Zollinger-Ellison Syndrome)
- Disruption of mucosal barrier by H. pylori (75-90%), smoking, nicotine, alcohol, coffee, NSAIDS, stress, reflux, bile salts, proteases, free radicals, ischemia, hereditary,age |
|
|
Term
| Zollinger-Ellison syndrome: |
|
Definition
| - tumor on pancreas secretes gastrin all the time> so you are also secreting acid and pepsinogen all the time |
|
|
Term
| Stomach pressure remains constant until ___ of food is ingested. This relative unchanging pressure results from ___ ____ ___ and ____. |
|
Definition
- 1 liter
- reflex-mediated relaxation and plasticity |
|
|
Term
| Reflex mediated events of stomach include: |
|
Definition
- receptive relaxation: as food travels in esophagus, stomach muscle relax
- adaptive relaxation: stomach dilates in response to gastric filling |
|
|
Term
|
Definition
| intrinsic ability of smooth muscle to exhibit stress-relaxation reponse |
|
|
Term
| Peristaltic waves in the stomach move food toward pylorus at rate of 3 per minute. This ___ ___ ___ is initated by pacemaker cells aka ___ of ___ in the body of the stomach. Most vigorous mixing occurs near pylorus. |
|
Definition
- basic electrical rhythm (BER)
- cells of Cajal |
|
|
Term
| electrical slow wave rates in stomach, duodenum, and ileum: |
|
Definition
- stomach: 3 per minute
- duodenum: 12 per minute
- ileum: 9 per minute |
|
|
Term
|
Definition
| food moves downstream from where contractions are faster to where the are slower |
|
|
Term
| Gastric emptying is regulated by ___ ____ reflex and ____ ____ mechanisms. These mechanisms inhibit ___ ___ and ___ ___. |
|
Definition
- neural enterogastric reflex
- hormonal enterogastroen mecahnisms
- inhibit gastric secretion and duodenal filling |
|
|
Term
| CHO rich chyme moves quickly/slowly through duodenum. |
|
Definition
|
|
Term
| Fatty chyme is digested more slowly so food stays in stomach longer. |
|
Definition
|
|
Term
| vagal stimulation promotes ___ ___. |
|
Definition
|
|
Term
|
Definition
- distention, inflammation, irritation of duodenum
- abnormal sensory signals outside GI tract
- nervous system signals from the chemoreceptor trigger zone (CTZ)
- drugs (apomorphine, morphine, digitalis, ipecac, copper sulfate), rapid changes in direction of motion |
|
|
Term
|
Definition
- alkalosis
- hyponatremia |
|
|
Term
|
Definition
- anti-histamines- diphenhydramine or Benadryl (act at vomitting center on cortex)- BLOCK H1 RECEPTORS NOT H2 FOR NAUSEA
- anticholinergics
- phenthiazines |
|
|
Term
| secretions of small intestine: |
|
Definition
1-2 liters daily
pH = 7.4-7.8 slightly alkaline for enzymes to be active
Stimulus: distension or irritation by hypertonic or acidic chyme
Secreted by intestinal glands in response to distension or irritation of the mucosa
Slightly alkaline and isotonic with blood plasma
Largely water, enzyme-poor, but contains mucus |
|
|
Term
| ___ ___ are in the first few cm of the duodenum and secrete ___ mucus for protection in response to tactile stimuli, acetylcholine, and GI hormones like CCK or secretin. |
|
Definition
|
|
Term
| The ___ of ____ are tubular pits with ___ ___ cells and ___ cells that secrete ____ fluid,___ daily. Secrete watery vehicle for absorption of substances. Stimulated by ___, ___, irritation by ____ chyme, acid. |
|
Definition
Crypts of Lieberkuhn
mucous goblet cells
epithelial cells
extracellular fluid
1-2 liters daily
distension
tactile
hypertonic |
|
|
Term
| Cholera stimulates the ___ of ___ by increasing amounts of ____, which leads to the excretion of lots of ___ and ___ resulting in diarrhea. |
|
Definition
crypts of Lieberkhan
cAMP
chloride and water |
|
|
Term
| Brush border enzymes are not secreted by the brush border but are associated with the brush border. They include: |
|
Definition
- peptidases
- sucrase
- maltase
- isomaltase
- lactase
- intestinal lipase
- enterokinase |
|
|
Term
| brush border enzymes are essential for digestion of ____. |
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Definition
|
|
Term
| with celiac disease, brush border enzymes are lacking so sugars pass into the colon and have water excretion and diarrhea. |
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Definition
|
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Term
| Enteroendocrine cells are in the intestinal glands and produce: |
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Definition
- gastrin
- cholecystokinin
- secretin |
|
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Term
| When chyme gets into the duodenum, weak peristalic movments move it to the jejunum. |
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Definition
|
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Term
| Peristaltic contractions are ____ reflexes that are not under ___ control. ____ stimulation accelerates local peristalsis and segmentation. |
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Definition
- myenteric
- not under CNS control
- Parasympathetic |
|
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Term
| The gastroenteric reflex stimulates ___ and ____ along the entire small intestine. |
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Definition
|
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Term
| The gastroileal reflex triggers ____ of the ___ valve which allows material to pass from the small intestine into the large intestine. |
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Definition
|
|
Term
| most common motion of the small intestine: |
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Definition
| Segmentation/mixing contractions |
|
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Term
| Segmentation in the SI is initiated by ___ cells aka ___ cells. The rate is related to electrical slow waves. Stimulus is distention. |
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Definition
| - pacemaker cells aka Cajal cells |
|
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Term
| After nutrients have been absorbed in the SI, you have ___ aka ____ contractions: |
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Definition
Propulsive aka Peristaltic contractions:
Distention
Usually weak
Peristalsis begins with each wave starting distal to the previous
Meal remnants, bacteria, mucosal cells, and debris are moved into the large intestine
Parasympathetic and myenteric nerves
Influenced by nervous signals, hormonal factors |
|
|
Term
| Local enteric neurons of the GI tract coordinate intestinal motility. |
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Definition
|
|
Term
| Parasympathetic cholinergic neurons cause; |
|
Definition
- contraction and shortening of the circular muscle layer
- shortening of longitudinal layer
- distention of the intestine |
|
|
Term
| The gastroileal reflex and gastrin: |
|
Definition
- relax the ileocecal sphincter
- allow chyme to pass into small intestine |
|
|
Term
| Control of SI motility in the gastric phase, ___ ___ ___ like the gastroileal reflex and ____cause increased gastric emptying and motility, increased activity in the ileum, increased segmentation in ileum |
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Definition
- long neural reflexes
- gastrin |
|
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Term
| During the intestinal phase, distension of the small intestine causes long and short neural reflexes that increase stregth of segmentation |
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Definition
|
|
Term
| During the inestineal phase, fasting and decreased volume will cause high blood motilin will result in long and short neural reflexes that cause migrating motility (peristalsis) that continues until next meal. |
|
Definition
|
|
Term
| factors that increase SI motility: |
|
Definition
ACh (vagal, myenteric)
Distension (pressure)
Gastrin
Motilin
Hyperthyroid
Fever
Intense irritation |
|
|
Term
| factors that decrease SI motility: |
|
Definition
Norepinephrine (sympathetic)
Epinephrine
VIP
GIP
Secretin
CCK
Over-distension
Hypothyroidism
Trauma |
|
|
Term
| Pancreatic exocrine secretion is ___ liters/day. Digestive enzymes come from the ___ cells and include ____, ____, ___, and ____ ____. Also secretes ___ ___ and ___ via ___ cells of ducts (___). |
|
Definition
1-1.5 L/day
- acini
- proteases
- amylases
- lipases
- cholesterol esterases |
|
|
Term
| Proteases are secreted from pancreas in inactive form.If they were active, they would degrade the pancreas. The ___ inhibitor prevents proteases from being active in the pancreas. |
|
Definition
|
|
Term
| Enzymes from the acinar cells get washed into the duodenum by ductal secretions. The ductal cells are stimualted to release ___ solution by ___. This also forms a hydrogen ion, which goes into the venous blood making it slightly acidic. This is called the ___ ___. |
|
Definition
- bicarbonate
- secretin
- acid tide |
|
|
Term
| Pancreas secretes trypsinogen, chymotrypsinogen, and procarboxypeptidase. Trypsinogen gets activated by _____ to ___. Trypsin then activates more trypsinogen and ____ to ___ and _____ to ____. |
|
Definition
- enteropeptidase
- chymotypsinogen
- chymotrypsin
- procarboxypeptidase
- carboxypeptidase |
|
|
Term
| Secretin and CCK are released into the ___ when ___ or __ chyme enters the duodenum. Upon reaching the pancreas CCK induces secretion of ____ rich pancreatic juice, while secretin causes release of ____ rich pancreatic juice. Vagal stimulation also causes release of ___ rich pancreatic juice. |
|
Definition
- bloodstream
- fatty
- acidic
- enzyme
- bicarbonate
- enzyme |
|
|
Term
| During cephalic and gastric phases, ___ ___ stimulation cuases release of pancreatic juices. Then acidic chyme enteric duodenum causes release of ___, while fatty chyme causes release of ___. |
|
Definition
- vagus nerve
- secretin
- CCK |
|
|
Term
| CCK is released by I cells in the duodenum |
|
Definition
|
|
Term
|
Definition
Is the largest visceral organ (1.5 kg)
Lies in right hypochondriac and epigastric regions
Extends to left hypochondriac and umbilical regions
Performs essential metabolic and synthetic functions |
|
|
Term
| Bile is secreted from ____ which radiate out from the central vein. Then it goes to ____ and then ___ ___. |
|
Definition
| - hepatocytes> calliculi> hepatic ducts |
|
|
Term
| Hexagonal shaped liver lobules are the structural functional units of the liver. They are composed of ____ ___ radiating outward from a __ ___. __ ___ are found at each of the six corners. portal triads consist of a __ __, ___ __, and ___ ___ __. |
|
Definition
- hepatocyte plates
- central vein
- Portal triads
- bile duct
- hepatic artery
- hepatic portal vein |
|
|
Term
|
Definition
| enlarged leaky capillaries between hepatic plates |
|
|
Term
|
Definition
| hepatic macrophages found in the sinusoids |
|
|
Term
|
Definition
- produce bile
- process bloodbourne nutrients
- store fat soluble vitamins
- detoxify |
|
|
Term
| Secreted bile flows between ___ toward the ___ ___ in the ___ ___. |
|
Definition
- hepatocytes
- bile duct
- portal triad |
|
|
Term
| bile secretes ____ ml/day. |
|
Definition
|
|
Term
| Bile is secreted in two stages, explain: |
|
Definition
- hepatocytes secrete the bile dependent fraction which contains bile, bile salts, cholesterol, pigment, neural fats, phospholipids. This functions to emulsify fats, facilitate fat and cholesterol absorption, and solubilize cholesterol.
Then bile ducts secrete water/electrolytes or the bile independent fraction, with a high concentration of bicarbonate |
|
|
Term
| cholesterol is converted to ____ ___ ___ which get secreted by the liver into the intestine and there get converted by bacteria into secondary bile acids. |
|
Definition
|
|
Term
| bile secretions by liver: |
|
Definition
- primary bile acid
- bile salts conjugated to bile acids (ionized)
- cholic acid and chenodeoxycholic acids
- bilirubin |
|
|
Term
| gallbladder storage of bile: |
|
Definition
Liver produces and secretes 500-1,000 ml daily while gallbladder stores 60 ml
Bile concentrated in gall bladder 12-20 fold by active absorption of Na+ (with Cl- and water) |
|
|
Term
| ___ tells the gallbladder to contract and sphincter of Oddi to relax. |
|
Definition
|
|
Term
| Enterohepatic circulation of bile. Conservation of bile via absorption in the ___ ___> __ ___> liver via ___ ___ blood> resecreted by hepatocytes |
|
Definition
| terminal ileum> blood stream> hepatic portal blood > liver> resecreted by hepatocytes |
|
|
Term
|
Definition
Important role in fat digestion and absorption
detergent action – emulsification of fat breaks into tiny particles with agitation to make more accessible to digestive enzymes in small intestine
micelle transport of lipids to intestinal mucosa for absorption
Buffering of gastric acid
Means of excretion of waste products from blood
bilirubin (bile pigments)
excesses of cholesterol
toxic substances |
|
|
Term
| 2 sources of bicarb that counter act stomach acidity: |
|
Definition
- pancreatic bicarbonate
- ductal cells in liver secrete bicarbonate |
|
|
Term
| ___ ___ and ____ in the blood stream stimulate the liver to produce bile more rapidly. |
|
Definition
|
|
Term
| vagal stimulation causes weak contraction of gall bladder |
|
Definition
|
|
Term
| decreased bile will cause what? |
|
Definition
| - malabsorption of fats> steatorrhea |
|
|
Term
| Bile salts in the colon cause what? |
|
Definition
| - irritation,inhibition of water and sodium absorption > watery diarrhea |
|
|
Term
| Interdigestive migrating myoelectric complex system: |
|
Definition
- bursts of rhythmic contractions occurs in cycles during the fasting state, lasting 5-10 minutes, travel 10-70 cm
- recurrs every 1.5 to 2 hours
- starts at gastric antrum and goes to ileum
- related to motilin
- stops immediately with feedings |
|
|
Term
| functions of ileocecal valve: |
|
Definition
Principle function: prevent back-flow of fecal material from colon into small intestine
Lips of valve protrude into lumen of the cecum and are forcefully closed when the cecum fills
Only 750 ml chyme empties into cecum daily
Resistance to emptying by valve prolongs stay of chyme in ileum, and therefore, facilitates absorption |
|
|
Term
| absorption in the proximal colon, storage in distal colon, periodically get peristalsis throughout colon. |
|
Definition
|
|
Term
| valves of the rectum and anus: |
|
Definition
Three valves of the rectum stop feces from being passed with gas
The anus has two sphincters:
Internal anal sphincter composed of smooth muscle
External anal sphincter composed of skeletal muscle
These sphincters are closed except during defecation |
|
|
Term
| The colon does not have ___. |
|
Definition
|
|
Term
| Large intestine does have the ___ of ____ and mucous cells that secrete lots of bicarbonate mucous. But the LI does not have ___ or ___. |
|
Definition
- crypts of Lieberkhan
- no enzymes or villi |
|
|
Term
|
Definition
Protection against excoriation (scratching of surface lining of colon by hard feces)
Adherent medium for fecal material
Protection against bacterial activity
Barrier to acids which are formed by bacteria |
|
|
Term
| stimuli of large intestine: |
|
Definition
- tactile
- parasympathetic pelvic nerves |
|
|
Term
| Irritation in the LI results in: |
|
Definition
| - secretion of lots of water and electrolytes causing diarrhea |
|
|
Term
| emotional stress has what effect on LI? |
|
Definition
| - emotional stress> strong PS stimulation > lots of mucus> increased motility> ropy mucus stools every 30 minutes |
|
|
Term
| Mixing movements of the colon are called: |
|
Definition
|
|
Term
|
Definition
Bulging out like bag-like sacs
Move slowly analward
Myogenic; myenteric plexus
Sluggish (4-6 per min)
Dig into fecal material to allow maximal absorption of water and electrolytes |
|
|
Term
| Propulsive mass movements of the colon: |
|
Definition
- occur 1-3 times daily, especially 15 minutes after eating breakfast
- initiated by gastrocolic and duodenocolic reflexes, and irritation |
|
|
Term
| Mass movements of the colon are transmitted through ____ ___ nerves and the ___ plexus. This is a modified type of peristalsis. Persists ___ minutes, if defecation does not occur, new set of mass movements might not recurr for another half day or day. |
|
Definition
- parasympathetic pelvic
- myenteric
- 10-20 minutes |
|
|
Term
|
Definition
- mass movement forces feces into rectum
- distension of rectal walls caused by feces stimulates contraction of rectal walls and relaxes the internal anal sphincter
- voluntary signals stimulate relaxation of the external anal sphincter and defecation occurs
- intrinsic defecation reflex is weak
- mostly the parasympathetic defecation reflex |
|
|
Term
| sequence of events with defecation reflex: |
|
Definition
| - distension of rectal walls> stimulation of receptors> PS reflex> contraction of rectal walls and relaxation of internal anal sphincter> conciously relax external anal sphincter> defecation |
|
|
Term
| Bacteria in the colon comes from the bacteria surviving the ___ ___ and entering the ___ and that entering the anus. Most bacteria is killed by ____, ___, and ____. |
|
Definition
- small intestine
- colon
- lysozomes
- HCl
- defensins
- proteases |
|
|
Term
| substances formed by bacteria: |
|
Definition
- colonize the colon
- ferment indigestible CHOs resulting in formation of dimethyl sulfide, H2, N2, CH4, CO2
- release irritating acids and gases
- synthesize B complex vitamins (biotin, pantothenic acid) and vitamin K (blood coagulation) |
|
|
Term
|
Definition
Water 95%
Dead bacteria 30%
Fat 10-20%
Inorganic matter 10-20%
Protein 2-3%
Undigested fiber
Bile Pigments
Sloughed epithelial cells
Color due to stercobilin and urobilin
Odor due to indole, skatole, mercaptans and hydrogen sulfide |
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