Term
| Esophagus lies from what vertebrae to what organ? |
|
Definition
|
|
Term
| What are the contents of the oral cavity? |
|
Definition
| Lips, cheeks, gums, teeth, palate (hard, soft, uvula), tongue |
|
|
Term
| What are the contents of the oral cavity? |
|
Definition
| Lips, cheeks, gums, teeth, palate (hard, soft, uvula), tongue |
|
|
Term
| What are tge 3 kinds of mucosa in the oral cavity? |
|
Definition
| Lining (non keratinized), Masticatory (keratinized or non-keratinized), Specialized (taste bunds) |
|
|
Term
| What are the core of lips? |
|
Definition
| Skeletal muscle, lacks glands thus why we require chapstick |
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|
Term
| What is the difference between lips and cheeks? |
|
Definition
| Cheeks lack vermillion, a darkly staining region in the middle |
|
|
Term
|
Definition
| Masticatory mucosa that is not keratinized but is thick, forms barrier between tooth and oral cavity |
|
|
Term
| What defines the hard palate? |
|
Definition
| Keratinized masticatory epithelium |
|
|
Term
| What are the glands of the hard palate? |
|
Definition
| Oral side has seromucosal gland and nasal side has nasal glands |
|
|
Term
| What forms rugae ridges in the hard palate that connects it firmly to the bony core? |
|
Definition
| Lamina propria via dense connective tissue |
|
|
Term
| What defines the soft palate? |
|
Definition
| Respiratory and masticatory epithelium with seromucous glands but no bone |
|
|
Term
|
Definition
| Similar to soft palate but only has nonkeratinized epithelium |
|
|
Term
| What are the divisions of the tongue? |
|
Definition
|
|
Term
| What is in the anterior tongue? |
|
Definition
| Filiform, fungiform, and circumvallate papillae, only fungiform and circumvallate have taste buds |
|
|
Term
| What is within the posterior tongue? |
|
Definition
| Smooth and uneven due to presence of lymph nodes, contains lingual tonsils, crypts, tonsils, and waldeyer's tonsillar ring |
|
|
Term
| Where does tonsillitis begin? |
|
Definition
| Infection of posterior tongue |
|
|
Term
| What are the 3 parts of the pharynx? |
|
Definition
| Nasopharynx, oropharynx, laryngopharynx |
|
|
Term
| What are characteristics of the nasopharynx? |
|
Definition
| Respiratory with ciliated pseudostratified epithelium |
|
|
Term
| What are the characteristics of the oropharynx? |
|
Definition
| Digestive and speech with nonkeratinized stratified squamous |
|
|
Term
| What are the characteristics of the laryngopharynx? |
|
Definition
| Speech involved with same epithelium (bootom is C6) |
|
|
Term
| What are the functional layers of the digestive system distal to the pharynx? |
|
Definition
| Mucosa, submucosa, muscularis externa, serosa/adventitia |
|
|
Term
| What controls movement as well as allowing CNS innervation in the GI? |
|
Definition
| Myenteric (Auerbach) and submucosal (Meissner) plexuses |
|
|
Term
| What are the 4 types of epithelia in the GI? |
|
Definition
| Protective, secretory, absorptive, and absorptive/protective |
|
|
Term
| What makes up protective epithelial cells in the GI? |
|
Definition
|
|
Term
| What makes up secretory epithelial cells in the GI? |
|
Definition
| Simple columnar with goblet cells |
|
|
Term
| What makes up absorptive epithelial cells in the GI? |
|
Definition
| Simple columnar with goblet cells and microvilli |
|
|
Term
| What is the shape of the esophageal lumen? |
|
Definition
|
|
Term
| What makes up the upper 1/3 of the esophagus? |
|
Definition
| Musculara externis layer with skeletal muscle |
|
|
Term
| What makes up the middle 1/3 of the esophagus? |
|
Definition
| Mixed skeletal/smooth muscle |
|
|
Term
| What makes up the distal 1/3 of the esophagus? |
|
Definition
|
|
Term
| Describe the epithelia and contents of the esophagus |
|
Definition
| Protective, submucosa has glands, blood vessels, nerves, and lymph structures |
|
|
Term
| What kind of tissue change occurs at the gastroesophageal junction? |
|
Definition
| Abrupt change from stratified squamous to simple columnar |
|
|
Term
| How can damage occur at the gastroesophageal junction? |
|
Definition
| Site of heart burn, lacks anatomical sphincter but does have a muscular sphincter |
|
|
Term
|
Definition
| Longitudinal folds that allows for distention, disappears upon distention, seen in the stomach, etc. |
|
|
Term
| What are the 4 anatomical areas of the stomach? |
|
Definition
| Fundus, cardia, body, pyloris |
|
|
Term
| Describe features of the epithelial cells of the stomach |
|
Definition
| No villi but does have straight glands that secrete gastric juice to convert food to chime |
|
|
Term
| What are the cell types of the fundus and body of the stomach? |
|
Definition
| Superficial to deep are surface cells for bicarbonate secretion, mucous cells secreting soluble mucous, parietal cells secreting HCL, stem cells for regeneration, chief cells |
|
|
Term
| What are the features of the cardiac region of the stomach? |
|
Definition
| Shallow, tubular with coiled base, mostly surface mucous cells |
|
|
Term
| What are features of the pyloris? |
|
Definition
| Deep, base convoluted and branched, mostly mucous neck cells |
|
|
Term
| What occurs at the gastroduodenal junction? |
|
Definition
| Transition from glandular to villus simple columnar cells, sudden submucosa gland increase, a ring of thick inner layer muscles known as the pyloric sphincter |
|
|
Term
| How is the small intestines designed to have increased surface space? |
|
Definition
| Via villi, duodenum has highest concentration of villi and decreases towards the ileum. Plicae circulares are highly folded tissues in the small intestine. They also use micro vili, goblet cells, righ lamina proper, lymphocytes, smooth muscles, and lacteals |
|
|
Term
| What are crypts of liberkuhn and where are they found? |
|
Definition
| On simple columnar epithelium, found in duodenum and contains lots of submucosal glands |
|
|
Term
| What are the cell layers of the duodenum, superficial to deep? |
|
Definition
| Absorptive, goblet, DNES, mononuclear phagocyte cells |
|
|
Term
| What are crypts of lieberkuhn? |
|
Definition
| Long and deep invaginations of the epithelium in the small intestines |
|
|
Term
| What are located at the bottom of crypts of lieberkuhn and what is their function? |
|
Definition
| Paneth cells, contain antibiotic mechanisms, tumor necrosis and defensing defenses as well |
|
|
Term
| Describe the organization of the ileum |
|
Definition
| Plica circulares, villi, crypts of liberkuhn, lymphoid vessles, submucosa, muscularis externa, serosa |
|
|
Term
| What are Peyer's patches? |
|
Definition
| Large lymph node sites in the small intestines |
|
|
Term
| What are some common epithelial features of the duodenum, jejunum, and ileum? |
|
Definition
| brush borders, goblet cells, rich lamina proper, lymphocytes, thin basement membranes |
|
|
Term
| What is the organization of the large intestine? |
|
Definition
| Cecum to appendix -> ascending, transverse, descending, sigmoid colon -> rectum -> anus |
|
|
Term
| What are some differentiating features of the large intestine? |
|
Definition
| Teniae coli, haustra coli, appendix, anal column, anal valves, anal sinuses, and pectinate line at level of anal valves |
|
|
Term
| What kind of cells are found in the appendix? |
|
Definition
| Simple columnar cells with lots of goblet cells, crypts of liberkugn, lymph, right LP layer, muscularis externus |
|
|
Term
|
Definition
| Longitudinal folds of smooth muscle in the anus |
|
|
Term
| What is the function of anal sinuses? |
|
Definition
|
|
Term
| What is the function of anal valves? |
|
Definition
| Located at the ends of anal sinuses, joins anal columns |
|
|
Term
| What defines pectinate lines? |
|
Definition
| Stratified squamous epithelium that becomes thin, represents the border between endoderm and ectoderm |
|
|
Term
| What is located just above the pectinate line and what occurs there? |
|
Definition
| Ano rectal junction where the simple columnar epithelium changes to stratified squamous |
|
|
Term
| What is the hilton's white line and where is it found? |
|
Definition
| Inbetween the internal and external sphincter, also known as intersphincteric line. Is white and th epoint where epithelium becomes keratinized |
|
|
Term
| How do sensory neurons of the enteric system extend to structures? |
|
Definition
| Submucosal and myenteric IPANs or to the brain stem via the vagus nerve or sympathetics to the spinal cord |
|
|
Term
| What is contained within the smooth muscle of the gut that can cause contraction? |
|
Definition
| Stretch activated channels, triggers depolarization, can be attached to IPAN neuronal processes that fire action potentials to sense the stretch |
|
|
Term
| How does the enteric system sense the chemical environment? |
|
Definition
| Intermediary epithelial cells on the luminal surfaces of the enterocytes, sensitive to chemical changes and secretes serotonin to activate the nearby neural ends of the IPANs |
|
|
Term
| How is the myenteric (Aerbachs) plexus distributed? |
|
Definition
|
|
Term
How is the submucosal plexus distributed?
|
|
Definition
| Only in the small and large intestines |
|
|
Term
| Describe the axons of the enteric system |
|
Definition
| Unmyelinated, plexuses do contain glia cells but do not myelinate axons, only provides nourishment |
|
|
Term
| Which signals are exitatory? |
|
Definition
|
|
Term
| Which signals are inhibitory? |
|
Definition
|
|
Term
| What do enteric neurons stimulate in stomach parietal cells? |
|
Definition
|
|
Term
| What stimulates secretion in exocrine glands of the gut? |
|
Definition
| Neurons innervating crypts of lieberkhun and parietal cells in the stomach |
|
|
Term
| What do exocrine glands of the gut secrete? |
|
Definition
| Cl - into the lumen, water follows osmotically |
|
|
Term
| Extrinsic is what kind of innervation? |
|
Definition
|
|
Term
| Parasympathetic extrinsic innervation is via what? |
|
Definition
|
|
Term
Parasympathetic extrinsic innervation via the vagus or pelvic nerve use what neurotransmitter?
|
|
Definition
|
|
Term
| Postganglionic neurons of the parasympathetic fibers are located where? |
|
Definition
|
|
Term
| Parasympathetic signals generally have what effect in the GI? |
|
Definition
| Increased peristalsis and secretory responses |
|
|
Term
| How do parasympathetic postganglionic fibers arrive in the GI? |
|
Definition
| Paravertebral or prevertebral ganglia |
|
|
Term
| What kind of chemoreceptors do sympathetic fibers in the GI use? |
|
Definition
|
|
Term
| What are intestinofugal neurons? |
|
Definition
| Neuron with cell body located within intestine that when stimulated, relays signal to prevertebral sympathetic ganglia, modulates secretory inhibitors and motility inhibitors |
|
|
Term
|
Definition
| Waves of depolarization in the GI, do not contract unless the depolarization reaches the threshold level to make a spike in depolarization |
|
|
Term
| What creates slow waves in the GI? |
|
Definition
| Intrinsic Interstitial Cells of Cajal |
|
|
Term
| Describe the function of intrinsic interstitial cells of cajal |
|
Definition
| Pacemaker cells, non-neuronal, excitatory and inhibitory, found between muscles and the neural cells, creates slow waves |
|
|
Term
| What does a bolus of food entering the intestine activate? |
|
Definition
| IPANs, sends signals via ascending neurons to contract and the descending neurons to relax so food moves through the tract |
|
|
Term
| What controls the upper 1/3 of skeletal muscle in the GI? |
|
Definition
| Somatic neurons, however enteric neurons do form synapses on the motor endplate and appear to modulate synaptic activity |
|
|
Term
| What innervates expansion of the stomach? |
|
Definition
|
|
Term
| What regulates peristalsis and amplitude of gastric movement? |
|
Definition
| Peristalsis = vagal, amplitude = enteric regulation |
|
|
Term
| Distention triggers what? |
|
Definition
| IPANs to stimulate descending neurons which activate secretory cells as well as vasodilators and CL- secretion |
|
|
Term
| What is the response to noxious stimulants such as cholera toxin? |
|
Definition
| Mass serotonin release that further activates IPANs and stimulates excessive Cl- secretion leading to diarrhea and massive fluid loss, releases serotonin by L-channels |
|
|
Term
| What controls GI sphincters? |
|
Definition
| Enteric except lower esophageal sphincter (vagus) and external anal sphincter (somatic-voluntary) |
|
|
Term
| What controls the sphincter of Oddi and what is its function? |
|
Definition
| Enteric system, regulates passage of bile from the gallbladder and pancreas into duodenum, located at the major duodenal papilla |
|
|
Term
| Infants suffering from severe constipations from failure of neurons to innervate distal bowel, leading to absence of ganglia in distal bowel and large distention of proximal bowel describes what disease? |
|
Definition
|
|
Term
| High frequency of bowel movement, abdominal pain and altered bowel motility that fluctuates from constipation to diarrhea, possibly caused by hyperactivity of sensory fibers, and lacking any effective treatment describes what disease? |
|
Definition
|
|
Term
| Numerous cells contain opoid receptors, mainly excitatory cellls have opiod receptors, but a decrease in cholinergic release by motor neurons describes what? |
|
Definition
| Opiod induced dysfunction, exogenous opoids given for pain management, inhibits propulsion of food bolus in the intestines |
|
|
Term
| Food intake is ultimately regulated by what? |
|
Definition
|
|
Term
| How does the hypothalamus of the CNS affect food intake? |
|
Definition
| Along with nucleus tractus (brainstem) and other centers such as the amygdala, provides feedback control of appetite |
|
|
Term
| How does the lateral hypothalamic area affect appetite? |
|
Definition
| Stimulates food intake and calorie storage, active via the neuropeptide Y pathway |
|
|
Term
| How does ventromedial nuclei affect appetite? |
|
Definition
| Satiety center, limits food intake, active via the melanocortin pathway |
|
|
Term
| How does the endocrine system affect appetite? |
|
Definition
| Insulin and leptin regulates food intake, decreases appetite and increases metabolism |
|
|
Term
| How does the enteric and autonomic nervous system regulate appetite? |
|
Definition
| CCK, ghrelin, and peptide YY are gastric hormones, Ghrelin increases appetite, decreases metabolism, CCK and PYY decrease appetite |
|
|
Term
| What is the definition of digestion? |
|
Definition
| The chemical and enzymatic breakdown of complex ingested nutrients into simpler molecules |
|
|
Term
| What is the definition of absorption? |
|
Definition
| Movement of digested and other nutrients out of the GI lumen into the blood, regulates water, electrolytes, and other digestive products |
|
|
Term
|
Definition
| Peristalsis and the mixing movements of the GI |
|
|
Term
| Where is the myenteric plexus located cross-sectionally? |
|
Definition
| Between longitudinal and circular muscle |
|
|
Term
Where is the submucosal plexus located cross-sectionally?
|
|
Definition
| Between muscularis mucosa and inner cicrular layer |
|
|
Term
| Parasympathetic is generally what kind of innervation? |
|
Definition
|
|
Term
| Sympathetic is generally what kind of innervation in the GI? |
|
Definition
| Noradrenergic, inhibitory |
|
|
Term
| Substance P has what effect? |
|
Definition
|
|
Term
|
Definition
| Controlled from within the ENS, includes peristalsis, secretion, mixing |
|
|
Term
|
Definition
| Controlled by CNS and ENS together, defacation reflexes, stomach and duodenum to the CNS via vagus nerve and from guit via prevertebral ganglia neurons, pain causes general inhibition of the entire GI tract |
|
|
Term
|
Definition
| Secreted by I cells in the duodenum and jejunum, target is the gallbladder to secrete bile |
|
|
Term
|
Definition
| Gastric Inhibitory Peptide, secreted by K cells in duodenum and jejunum, targets pancreas to increase insulin secretion, inhibits gastric motility and emptying |
|
|
Term
|
Definition
| Secreted from G cells in antrum of stomach, targets the parietal cells o fstomach to increase H+ and pepsinogen secretion |
|
|
Term
|
Definition
| Secreted by M cells in the duodenum and jejunum to increase GI motility via initiating the MMC (migrating motor complex) |
|
|
Term
|
Definition
| Secreted by S cells in small intestine to increase bicarbonate secretion from pancreas and decrease gastrin secretion from the stomach |
|
|
Term
|
Definition
| Increases the number of spikes, increases tension of smooth muscle |
|
|
Term
|
Definition
| Downregulates peristalsis |
|
|
Term
|
Definition
| Basic electrical rhythm, the spontaneous cycles of depolarization of GI smooth muscles in waves, occurs faster in the stomach than in the intestine, can trigger spikes for contractions |
|
|
Term
| Smooth muscles contract due to what? |
|
Definition
| Ca influx, repolarization due to K efflux |
|
|
Term
|
Definition
| ICC cells, though there are NO SLOW WAVES in the esophagus and proximal stomach |
|
|
Term
Describe rhythmic contractions of GI smooth muscle cells
|
|
Definition
| For luminal sections of the gut such as the ilium, jejunum, etc. |
|
|
Term
Describe tonic contractions of GI smooth muscle cells
|
|
Definition
| Occurs at sphincters of the GI and the orad of the stomach |
|
|
Term
| Describe the pattern of GI motility |
|
Definition
| 8-10 seconds to reach stomach, 1-2 hrs in stomach, up to 3 days as feces, smooth muscles can actively contract or relax, motility via peristalsis |
|
|
Term
| How does enteric system affect peristalsis? |
|
Definition
| Can achieve basic peristalsis on its own, but other system regulat its activity, ENS is the point of integration with the CNS |
|
|
Term
| Myogenic control of GI motility is what? |
|
Definition
| Local control, contractile rhythm establishing the BER |
|
|
Term
| What hormones affect GI motility? |
|
Definition
| Minor role is motilin which activates the MMC |
|
|
Term
| Chewing is a reflex of what? |
|
Definition
|
|
Term
| What are the 3 phases of swallowing? |
|
Definition
| Chewing (only voluntary phase), Pharyngeal phase initiated by epithelial receptor in the pharynx, closes the trachea, inhibits respiration, Esophageal phase where UES opens, persitalsis propulsion, secondary ensures complete sweep of esophagus |
|
|
Term
| Intra-thoracic pressure is what? |
|
Definition
|
|
Term
| Intra-abdominal pressure is what? |
|
Definition
|
|
Term
| What is receptive relaxation? |
|
Definition
| Lower esophageal sphincter relaxes shortly before bolus arrives |
|
|
Term
| What is primary peristalsis? |
|
Definition
| Broad contractile wave controlled by the vagus nerve |
|
|
Term
| Describe secondary wave of peristalsis |
|
Definition
| In response to esophageal distention |
|
|
Term
|
Definition
| Loss of lower esophageal relaxation, loss of esophageal peristalsis, caused by degeneration of mysenteric plexus inhibitory neurons NO and VIP, noted by bird beak esophagus |
|
|
Term
|
Definition
| Heartburn, opposite of achalasia, hypotesnive LES regurgitates gastric juice into esophagus |
|
|
Term
| What are some triggers for stomach relaxation? |
|
Definition
|
|
Term
| How far apart are weak peristalsic contractions? |
|
Definition
|
|
Term
| When emptying isotonic or non-caloric fluids, rate of gastric emptying is what? |
|
Definition
| Proportional to volume, hypotonic or hypertonic fluids empty more slowly |
|
|
Term
| Lower pH has what effect on gastric emptying? |
|
Definition
|
|
Term
| What is the migrating motility complex? |
|
Definition
| Pattern of contraction from the stomach tot he end of the small intestine during fasting, causes stomach growls after 90 minutes, initiated by motilin, contrasts with absorptive (fed) phase |
|
|
Term
| Rather than peristalsis, what kind of movement is in MMC? |
|
Definition
| Haustrations, more longitudinal |
|
|
Term
| The enterogastric reflex is activated by what? |
|
Definition
| Intestinal receptors via distention or osmolarity changes |
|
|
Term
| The Iliocecal reflex is activated by what? |
|
Definition
| Distention of the ileum and allows chyme to pass, distention of the colon causes sphincter to contract |
|
|
Term
| What causes the gastroileal reflex? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| When do you get sensation you need to defecate? |
|
Definition
|
|
Term
| What intrinsic enteric input do you need to defecate? |
|
Definition
| Rectospincteric reflex caused by distention of rectal sigmoid colon, causes internal anal sphincter to relax |
|
|
Term
| what extrinsic input do you need for defecation? |
|
Definition
| Parasympathetic increases urge to defecate and greatly increases peristalsic waves to further relax the internal anal sphincter |
|
|
Term
| What voluntary control is there of defecation? |
|
Definition
| Via pudendal nerve, lets you poo |
|
|
Term
| What is the cephalic phase of GI secretion? |
|
Definition
| Food not in GI tract yet, pavlov signals salivate for food |
|
|
Term
| Describe the gastric phase of GI secretion |
|
Definition
| Occurs mechanically via muscle distention, stimulated by caffeine and alcohol, regulated via vagus and enteric |
|
|
Term
| Describe the intestinal phase of GI secretion and regulation |
|
Definition
| Food is in the intestines, can take around 72 hrs, stimualted mainly via circulating AA produced from chyme actions, inhibited by secretion of gastrin and nervous mechanism |
|
|
Term
|
Definition
| Water, enzymes, immunoglobins, blood group antigens, sex steroids, hypotonic due to resporption of electrolytes by salivary glands |
|
|
Term
| How is salivary secretion regulated? |
|
Definition
| Parasympathetic stimulates, sympathetic also contributes but is more thicker and mucousy, aldosterone increases Na/K ATP in saliva glands to modulate secretion |
|
|
Term
| Describe electrolyte balance in saliva |
|
Definition
| At high flow rates, Na and CL increase in concentration, K and HCO3 stay the same, saliva is ALWAYS hypotonic |
|
|
Term
| Parietal cells secrete what? |
|
Definition
| HCl, Intrinsic factor which allows Vit B12 absorption |
|
|
Term
| Chief cells secrete what? |
|
Definition
|
|
Term
| How do gastric secretions decrease luminal pH? |
|
Definition
| K/H+ antitransportor, ATP dependent |
|
|
Term
| What stimulates gastric secretion? |
|
Definition
| Ach, histamine, gastrin all via vagus nerve |
|
|
Term
| What downregulates H+ secretion? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| When is gastric secretin inhibited? |
|
Definition
| 1hr after meal, emptying into duodenum stimulates secretin secretion, inhibits gastric secretion |
|
|
Term
| Parietal cells secrete what? |
|
Definition
|
|
Term
| Chief cells secrete what? |
|
Definition
|
|
Term
| Mucus cells secrete what? |
|
Definition
| Mucus that protects the gastric epithelium from acidic stomach contents |
|
|
Term
|
Definition
|
|
Term
| How does HCl play a role in gastric digestion? |
|
Definition
| Activates pepsinogen into pepsin which then activates trypsinogen into trypsin which then activates the rest of the digestive enzymes |
|
|
Term
|
Definition
|
|
Term
| When does gastric pH begin to drop after a meal? |
|
Definition
| after 1hr when gastrin is at max |
|
|
Term
| Describe regulation of gastric H+/K+ atpase activity |
|
Definition
| Pumps H+ into lumen for K+, join Cl- to form HCL |
|
|
Term
| Gastrin, secretin, CCK and histamines all stimulate what? |
|
Definition
| Gastric secretion, histamines stimulated by Ach, inhibited by somatostatin |
|
|
Term
| What stimulates enterochromafin-like cells? |
|
Definition
| Stimulated to release histamine via Ach via vagus nerve, inhibited by stomatostatin |
|
|
