Kin 2YY3 - Exam Review 209 complete
solutions.
Kin 2YY3 - Exam Review 209 complete
solutions.
Pharynx - ANSWER extends from internal nares to esophagus (posteriorly) + larynx (anteriorly)
beginning of deglutition (swallowing) facilitated by saliva + mucous
Esophagus - ANSWER posterior to trachea
enters mediastinum anterior to vertebrae
pierces through diaphragm at esophageal hiatus
ends at superior portion of stomach
secretes mucous + transports food to stomach (lubes the bolus)
4 layers of esophagus - ANSWER 1) Mucosa = stratified squamous - terminal end - mucous glands
2) Submucosa = mucous glands
3) Muscularis = upper 1/3 - skeletal, middle - mixed, lower 1/3 - smooth
4) Adventitia (outer layer) - areolar CT (connects esoph. to other structures in mediastinum)
doesn't have serosa layer
Sphincters of muscularis layer of esophagus - ANSWER formed at either end
upper esophageal sphincter = skeletal muscle
lower esophageal sphincter = smooth
Deglutition stages - ANSWER 1) Voluntary stage
,Kin 2YY3 - Exam Review 209 complete
solutions.
2) Pharyngeal stage
3) Esophageal stage
Deglutition - voluntary stage - ANSWER bolus pushed into oropharynx
tongue moves upwards to soft palate
Deglutition - pharyngeal stage - ANSWER involuntary
sensory nerves send signals to deglutition center in brainstem - soft palate = lifted to close nasopharynx
larynx = lifted and epiglottis bent to cover glottis
Deglutition - esophageal stage - ANSWER bolus enters esoph.
upper sphincter relaxes when larynx is lifted
peristalsis - pushes food down
- circular fibers behind bolus
- longitudinal fibers in front bolus - contract and shorten distance of travel, pull esoph. up to bolus
travel time - 4-8sec. for solids, 1 sec. for liquids
lower sphincter - relaxes as food approaches
4 regions of stomach - ANSWER 1) Cardia - closest to esophagus
2) Fundus - lateral and superior to cardia, hold bolus for up to hour
3) Body - largest portion
4) Pyloric part - closer to small intest.
,Kin 2YY3 - Exam Review 209 complete
solutions.
3 regions of pyloric part - ANSWER 1) Pyloric antrum
2) Pyloric canal - leads to small intest.
3) Pylorus - opening into small intest.
at level of pylorus, muscularis layer creates pyloric sphincter (control movement of fluids in stomach
into small intest.)
Rugae of mucosa - ANSWER ridges in body portion of stomach
formed in mucosa layer
allow for expansion of stomach as fills with food
decrease ridges as fills with food
Lesser omentum - ANSWER extension of serosa in region of lesser curvature
Greater omentum - ANSWER extension of greater curvature
Functions of stomach - ANSWER 1) mixes saliva, food + gastric juice to form chyme
2) serves as reservoir for food before release into small intest.
3) secretes gastric juice contain HCl (kills bacteria + denat. prot.), pepsin (digestion of prot.), intrinsic
factors (aids absorption of vit. B12) + gastric lipase (aids digestion of triglyc.)
4) secretes gastrin into blood (endocrine cells secrete this)
Gastric glands - ANSWER columns of secretory cells near base of extensions of lamina propria
form narrow channels (gastric pits)
, Kin 2YY3 - Exam Review 209 complete
solutions.
have 3 exocrine cells/glands
Mucous cells - ANSWER surface + neck cells
produce slightly alkaline mucous = protect cells from stomach acids
Parietal cells - ANSWER release HCl + intrinsic factor
located in gastric pits
Chief cells - ANSWER release enzyme (pepsinogen - break protein + gastric lipase)
located in gastric pits
G cell - ANSWER endocrine gland cell
secrete hormone into blood = control digestive processes
found with in pyloric antrum region in stomach
hormone = gastrin
Digestion in stomach - mechanical - ANSWER fundus - storage (1 hr.) - salivary amylase
peristaltic waves (every 15-25 sec.)
pyloric sphincter - slightly open - allow only liquids to move through
body - vigorous mixing (propulsion + retropulsion)
produce chyme - as it moves into intest. = gastric emptying (slow process)
- 3mL chyme moving through pyloric sphincter at any given time
solutions.
Kin 2YY3 - Exam Review 209 complete
solutions.
Pharynx - ANSWER extends from internal nares to esophagus (posteriorly) + larynx (anteriorly)
beginning of deglutition (swallowing) facilitated by saliva + mucous
Esophagus - ANSWER posterior to trachea
enters mediastinum anterior to vertebrae
pierces through diaphragm at esophageal hiatus
ends at superior portion of stomach
secretes mucous + transports food to stomach (lubes the bolus)
4 layers of esophagus - ANSWER 1) Mucosa = stratified squamous - terminal end - mucous glands
2) Submucosa = mucous glands
3) Muscularis = upper 1/3 - skeletal, middle - mixed, lower 1/3 - smooth
4) Adventitia (outer layer) - areolar CT (connects esoph. to other structures in mediastinum)
doesn't have serosa layer
Sphincters of muscularis layer of esophagus - ANSWER formed at either end
upper esophageal sphincter = skeletal muscle
lower esophageal sphincter = smooth
Deglutition stages - ANSWER 1) Voluntary stage
,Kin 2YY3 - Exam Review 209 complete
solutions.
2) Pharyngeal stage
3) Esophageal stage
Deglutition - voluntary stage - ANSWER bolus pushed into oropharynx
tongue moves upwards to soft palate
Deglutition - pharyngeal stage - ANSWER involuntary
sensory nerves send signals to deglutition center in brainstem - soft palate = lifted to close nasopharynx
larynx = lifted and epiglottis bent to cover glottis
Deglutition - esophageal stage - ANSWER bolus enters esoph.
upper sphincter relaxes when larynx is lifted
peristalsis - pushes food down
- circular fibers behind bolus
- longitudinal fibers in front bolus - contract and shorten distance of travel, pull esoph. up to bolus
travel time - 4-8sec. for solids, 1 sec. for liquids
lower sphincter - relaxes as food approaches
4 regions of stomach - ANSWER 1) Cardia - closest to esophagus
2) Fundus - lateral and superior to cardia, hold bolus for up to hour
3) Body - largest portion
4) Pyloric part - closer to small intest.
,Kin 2YY3 - Exam Review 209 complete
solutions.
3 regions of pyloric part - ANSWER 1) Pyloric antrum
2) Pyloric canal - leads to small intest.
3) Pylorus - opening into small intest.
at level of pylorus, muscularis layer creates pyloric sphincter (control movement of fluids in stomach
into small intest.)
Rugae of mucosa - ANSWER ridges in body portion of stomach
formed in mucosa layer
allow for expansion of stomach as fills with food
decrease ridges as fills with food
Lesser omentum - ANSWER extension of serosa in region of lesser curvature
Greater omentum - ANSWER extension of greater curvature
Functions of stomach - ANSWER 1) mixes saliva, food + gastric juice to form chyme
2) serves as reservoir for food before release into small intest.
3) secretes gastric juice contain HCl (kills bacteria + denat. prot.), pepsin (digestion of prot.), intrinsic
factors (aids absorption of vit. B12) + gastric lipase (aids digestion of triglyc.)
4) secretes gastrin into blood (endocrine cells secrete this)
Gastric glands - ANSWER columns of secretory cells near base of extensions of lamina propria
form narrow channels (gastric pits)
, Kin 2YY3 - Exam Review 209 complete
solutions.
have 3 exocrine cells/glands
Mucous cells - ANSWER surface + neck cells
produce slightly alkaline mucous = protect cells from stomach acids
Parietal cells - ANSWER release HCl + intrinsic factor
located in gastric pits
Chief cells - ANSWER release enzyme (pepsinogen - break protein + gastric lipase)
located in gastric pits
G cell - ANSWER endocrine gland cell
secrete hormone into blood = control digestive processes
found with in pyloric antrum region in stomach
hormone = gastrin
Digestion in stomach - mechanical - ANSWER fundus - storage (1 hr.) - salivary amylase
peristaltic waves (every 15-25 sec.)
pyloric sphincter - slightly open - allow only liquids to move through
body - vigorous mixing (propulsion + retropulsion)
produce chyme - as it moves into intest. = gastric emptying (slow process)
- 3mL chyme moving through pyloric sphincter at any given time
