DLA 9+10: lecture 13+14 Flashcards
alimentary canal and its associated glands come from?
endoderm of the primitive gut tube
oral cavity and anal canal come from?
ectoderm
general layers of the gastrointestinal tract
- mucosa
- submucosa
- muscular layer
- serosa / adventitia
three layers of the mucosa
- epithelium
- lamina propria
- muscular layer (usually two layers)
submucosa features
DICT
blood vessels
glands
submucosal plexus
submucosal plexus??
can be identified as clusters of neuronal bodies
cell bodies of postganglionic parasympathetic neurons
innervates muscular layer
inner vs outer longitudinal muscles
Inner:
sphincters: constricts lumen
outer:
peristalsis
myenteric plexus
part of the enteric nervous system
located between the circular and longitudinal muscles of the muscularis externa
postganglionic parasympathetic neurons
peristalsis
filiform lingual papillae
small and conical
lined by highly keratinized stratified squamous
entire dorsal surface of tongue (tips face backwards)
mechanical function; no taste buds
fungiform lingual papillae
mushroom shaped
lined by stratified squamous
mostly seen on tip of tongue
taste buds
foliate lingual papillae
found on the lateral edges of the tongue; separated by deep clefts
taste buds
rudimentary in adults
circumvallate lingual papillae
8 to 12 large and dome shaped structures found anterior to the sulcus terminalis
surrounded by ducts of serous von ebner’s glands
taste buds on lateral surface
epithelium of the esophagus
stratified squamous
Esophageal Glands Proper
found in the submucosa of the esophagus
produces lightly acidic mucus
gastroesophageal junction epithelium
quick change from stratified squamous to simple columnar
no glands in submucosa
Barrett’s esophagus and gastro-esophageal reflux disease
frequent cause of chest pain (burning chest pain)
due to weakened lower esophageal sphincter
metaplasia will occur: from strat. squamous to simple columnar
untreated can lead to cancer
cardiac vs pyloric regions of the stomach epithelium
cardiac: short pits and short cardiac glands
tubular with few branching
pyloric: long pits and short pyloric glands
branched and coiled
fundic gland secretions?
HCl by parietal cells (activation of pepsin)
glycoprotein by parietal cells (need for B12)
pepsin by chief cells (protein breakdown)
how is fructose converted to the two intermediates needed for glycolysis?
fructose to frucose-1-phosphate by fructokinase
F-1-P to glyceraldehyde by aldolase B
or direct conversion
benign fructosuria
liver fructokinase deficiency
fructose is not metabolized and is excreted in the urine
asymptomatic
detected by abnormal urinalysis report
hereditary fructose intolerance
liver aldolase B deficiency
fructose-1-P accumulates
leads to ATP deficiency and inhibits gluconeogenesis and glycogenolysis
leads to hypoglycemia
drowsy and apathetic
polyol pathway
glucose to sorbitol by aldose reductase
sorbitol to fructose by sorbitol dehydrogenase
importance of polyol pathway
sorbitol is implicated in the pathogenesis of eye issues in those with DM
increase water content of the lens
eye issues in galactosemia
elevated blood galactose which enter the lens of the eye
converted to galactitol by aldose reductase
increase water content in lens and thus cataract
galactosemia signs
jaundice hepatomegaly cataract formation developmental delay urine + for galactose
classical galactosemia
GALT deficiency
autosomal recessive
galactose and galactose-1-P accumulate
2-3rd week of life
hypoglycemia (due to Pi trapping)
trigger after lactose or galactose consumption
non-classical galactosemia
galactokinase deficiency
will have cataract formation
no galactose-1-P accumulation
less severe
urine + for galactose
