Grand tour of the alimentary canal Flashcards
4 main functions of the digestive system
digestion
secretion
absorption
motility
function of the pancreas is to generate and secrete
digestive enzymes for the digestion of fats, carbohydrates and proteins
function of the liver creates
biles salts for digestion/absorption of fats in the small intestine
gall bladder function
stores and concentrates bile
small intestine function
the final stage of chemical digestion
nutrient absorption
large intestine function
water absorption
bacterial fermentation
formation of faeces
dumping syndrome
too many molecules in the gut tube - making it expand
4 distinctive layers of the gut tube
mucosa
submucosa
muscularis externa
serosa/adventitia
3 layers of the mucosa
epithelium
lamina propria
muscularis muscosae
submucosa is much ….. than lamina propria
thicker
since it is made up of connective tissue
submucosa is where the
nerves and blood vessels enter
myenteric plexus
controls motility
the oesophagus and first part of the duodenum are the only 2 parts that contain
glands
what type of epithelium is in the mouth, oesophagus and anal canal?
stratified squamous
what type of epithelium is in the stomach, small and large intestine?
simple columnar
mucosa epithelium allows for the synthesis and secretion of….?
digestive enzymes
hormones
mucus
lamina propria (in the mucosa layer) is made up of what?
loose connective tissue (glands, blood/ lymph vessels)
muscularis mucosae (part of the mucosa layer) is made up of what?
thin smooth muscle.
submucosa is made up of…?
thick, irregular, connective tissue
submucosa function is to
support the mucosa
submucosa contains
neurons
blood vessels
lymphatic vessels
neurones in the submucosa form an extensive network called the…?
submucosal (meissners) plexus
parasympathetic
submucosal glands can be found in the ?
oesophagus and duodenum
what is the serosa/adventitia in the gut tube?
connective tissue of the outer layer of the alimentary canal
outside the peritoneal cavity the adventitia attaches the …?
oesophagus and rectum to surround structures
inside the peritoneal cavity the serosa surrounds the
stomach, small intestine and large intestine
muscularis externa
two concentric thick layers of smooth muscles
has an inner and an outer layer
inner layer of the muscularis external is a
circular muscle that constricts the lumen
outer layer of the muscularis external is a
longitudinal muscle that shortens the tube
peristalsis
a series of wave-like muscle contractions that moves food to different processing stations in the digestive tract
muscularis externa produces motility by
peristalsis and segmentation
muscularis externa has a………..between its circular an longitudinal muscles
myenteric plexus
the submucosal and the myenteric plexuses together creates the?
enteric nervous system (ENS)
the enteric nervous system controls allows the gut to
control its own function
automatic control of alimentary function is by the
long (parasympathetic) and short (ENS) reflexes
parasympathetic control of alimentary function is by the
vagus nerve
except salivation which is by facial and glossopharyngeal nerves
parasympathetic control of the alimentary system is STIMULATORY - therefore there is an increase in
motility and secretion
REST AND DIGEST
sympathetic control of the alimentary system is INHIBITORY - therefore there is a decrease in
motility and secretion
sympathetic control of the alimentary system is by the
splanchnic nerve
except salivation
the celiac trunk supplies which organs?
stomach
small intestine
pancreas
liver
the superior mesenteric artery supplies which organs?
small intestine
caecum
ascending colon
transverse colon
the inferior mesenteric artery supplies which organs?
descending colon
sigmoid colon
rectum
the liver and the gut are in…..
series
the liver acts as a filter
the gastric veins, splenic vein, superior mesenteric vein and inferior mesenteric vein all drain into?
hepatic portal vein
the hepatic portal vein drains into the
hepatic vein
the hepatic vein drains into the
inferior vena cava
