Gastrointestinal system - week 8 Flashcards
which type of epithelium are the tongue and mouth covered in?
stratified sqaumous
name the 3 salivary glands
parotid, submandibular and sublingual
which salivary gland secretes serous saliva and which secretes mucous saliva?
parotid = serous
sublingual = mucous
where in the saliva glands is saliva produced by the active filtration of ions from blood?
acini
what type of saliva is produced by para and sympathetic stimulation?
para = large volume, watery
sympathetic = small volume, mucous
name the 7 functions of saliva
lubrication
digestion
protection of oral mucosa through lubrication
antibacterial
thirst stimulation
speech
absorption in mouth
what in saliva aids lubrication?
mucins
what in saliva aids digestion?
alpha amylase
how does the saliva protect oral mucosa ? 3 ways
lubrication, rinsing action and alkaline pH
which molecule makes saliva antibacterial?
antimicrobial thiocyanate
which 2 muscles aid pulverisation and bolus fomation?
tongue and buccinator in cheeks
name the 4 muscles of mastication
temporalis
masseter
lateral pterygoid
medial pterygoid
the muscles of mastication move which bone, bringing it into contact with the teeth connected to which bone? what is the name of the joint which moves?
mandible, maxilla, temporomandibular joint
which muscles of mastication sit deep?
pterygoids
which is the major effector muscle of mastication?
temporalis
which fibres of the temporalis can retract the jaw if it has been protruded?
posterior
which muscle of mastication elevates and protrudes the lower jaw
masster
which muscles of mastication help protrude the lower jaw unilaterally - moving it side to side?
medial and lateral pterygoids
what happens in the next step after the bolus is pushed to the back of the pharynx, triggering the swallowing reflex in the pharyngeal stage of swallowing?
the soft palate rises to block off the nasopharynx
what happens after the soft palate rises to block off the nasopharynx in the pharyngeal stage of swallowing?
elevation of the larynx moves the epiglottis over the trachea
in the elevation of the larynx to move the epiglottis over the trachea, which muscles lift the larynx to close off the trachea?
suprahyoid muscles
what happens after the elevation of the larynx to move the epiglottis over the trachea in the pharyngeal stage of swallowing?
the pharyngeal constrictors contract sequentially to push the food down the pharynx and into the oesophagus
at which vertebral level does the oesophagus pass through the diaphragm?
T10
what is the type of epithelium which lines the oesophagus?
stratified squamous
which third of the oesophagus is skeletal muscle which two thirds are smooth?
upper third is skeletal, lower 2 are smooth
what happens in a hiatus hernia?
when the upper part of the stomach squeezes through the oesophageal hiatus causing reflux of stomach contents into the oesophagus
what is the name of the opening where the stomach opens into the duodenum
pyloric orifice
where is the fundus of the stomach?
the top, above the greater curvature
where is the pyloric antrum of the stomach?
at the bottom by where the pyloric sphinchter opens into the duodenum
where is the cardia of the stomach?
where the oesophagus joins the stomach
the fundus and body of the stomach secrete acid from which type of cells? and what do peptic/chief cells secrete?
parietal, pepsin precursor and pepsinogen
what are the 3 endocrine secretions from the antrum of the stomach?
gastrin, histamine, somatostatin
what is the type of epithelium lining the stomach? what type of junctions connect it?
columnar, tight
which type of cells secrete alkaline mucous in the stomach’s gastric muscoa? what does this prevent and provide?
mucous cells, damage to tissue from acid secretions and a mechanical barrier to pathogens
what are the 3 muscle layers of the stomach?
circular, longitudinal and oblique
name the 4 parts of the duodenum and which vertebral level they travel at
superior = L1
descending = L3
horizontal = L3
ascending = L2
name the 3 parts of the small intestine
duodenum, jejunum and ileum
which structure anchors the jejunum and ileum to the posterior body wall?
mesentery
which 2 parts of the small intestine are the primary sites of nutrient absorption?
jejunum and ileum
what is the main function of the large intestine?
absorption of ions and water and some nutrients in the proximal colon
what are the 3 bands of longitudinal smooth muscle in the large intestine which move the contents towards the anus?
taeniae coli
name the regions of the large intestine
caecum, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, anal canal
what is the left colic flixure? what organ can be found here?
the 90 degree bend formed of the transverse colon meeting the descending colon (spleen)
What junction is the vermiform appendix close to?
iliocaecal junction
name the 5 main functions of the liver
glucose storage as glycogen
protein, lipoprotein and cholesterol synthesis
production of bile and bile salts
storage of fat soluble vitamins
toxin and drug metabolism/excretion
what is the most abundant blood protein? what is its function?
albumin, transports and helps maintain reabsorption of fluid from tissues to blood
where is excess cholesterol secreted to?
bile
what do bile salts do?
emulsify fats in intestines to increase their SA
name the 4 fat soluble vitamins
A D E K
which substance, released by the spleen is modified by the liver? where is it excreted to?
bilirubin, bile
name the 4 lobes of the liver
right left caudate and quadrate
where is the caudate lobe of the liver located? what about quadrate?
caudate at top, quadrate at bottom
which 3 parts can the gallbladder be divided into? what does it store? which part of the gallbladder is the cystic duct connected to?
fundus body and neck, bile, connected to neck
which type of cells in the liver produce bile
hepatocytes
what lies between layers of hepatocytes to allow portal blood supply? what are the names of the small channels between hepatocytes which remove waste and drain into bile ducts?
sinusoids, cancaliculi
from which 2 ducts does bile drain from the liver? what do these 2 ducts join together to form?
left a right hepatic ducts - common hepatic duct
what joins the common hepatic duct to form the common bile duct?
cystic bile duct
which 2 places can bile go from the common hepatic duct?
the cystic duct to be stored in the gallbladder or carry on to the descending duodenum via the common bile duct
where does the main pancreatic duct join the common bile duct?
the hepatopancreatic ampulla/ ampulla of vater
which 5 regions is the pancreas split into
uncinate process, head, neck, body and tail
what are the 2 components of pancreatic juice?
alkaline and enzyme rich secretion
where does pancreatic juice enter the duodenum?
sphincter of oddi
which type of stimulation increases secretions from the pancreas?
parasympathetic
what is the peritoneum and what does it cover?
a layer of conective tissue covering the walls and all of the viscera in the abdomen
what is the structure which creates a reflection off the abdominal contents and would be the first visible structure if you were to remove the anterior abdominal wall?
greater omentum
what is the name of the potential space continuous around the abdominal organs?
peritoneal cavity
what are the 4 layers of the epithelium of the digestive tract
mucosa, submucosa, muscularis externa, serosa
name the 3 layers of the mucosa
epithelium, lamina propria, muscularis mucosa
which layers of the mucos is a layer of connective tissue and has a good blood supply, containing lymphatics
lamina propria
which 3 things does the submucosal plexus in the submucosa control?
secretion and blood flow and information to the gut stretch receptors
which part of the nervous system is the submucosal plexus?
enteric (autonomic)
name the 2 plexi of the enteric nervous system and give their old names
myenteric and submucosal plexi, meissner’s and auerbach’s
name the 2 layers of muscle in the muscularis externa and their function
inner circular and outer longitudinal, peristalsis contractions
which part of the enteric nervous system lies between the two muscle layers of the muscularis externa? what does it control?
myenteric, GI motility
what type of cells are contained in the gastric pits of the stomach?
secretory cells
which vein does the capillary network of the small intestine eventually drain into?
portal vein
name the 4 types of cells present in the epithelium of the villi of the small intestine and say what they secrete
absorptive cells - digestive enzymes
goblet cells - mucus
granular cells - enzymes
APUD cells - endocrine secretions for GI motility
which 2 types of cells are located at the base of the crypts of the small intestine villi and which ascend from the base?
granular and APUD at base, absorptive and gobelt ascend
which 3 types of cells are present on the epithelium of the LARGE intestine? which type of cell is more numerous in the large than the small intestine?
goblet, absorptive, APUD. goblet more numerous
name the 3 branches of the abdominal aorta supplying the GI tract starting with the most superior and give their vertebral levels
coeliac trunk at T12
superior mesenteric artery at L1
inferior mesenteric at L3
branches of the coeliac trunk supply which foregut strcutures?
stomach, superior duodenum, liver, gallbladder, spleen and pancreas
name the 3 branches of the coeliac trunk (see diagram and learn)
common hepatic, left gastric and splenic arteries
which 4 arteries supply the stomach (see diagram)
L/R gastric, L/R gastroepiploic
which arteries supply the pancreas? (see diagram)
pancreaticoduodenal and pancreatic branches of the splenic artery
branches from which artery supply the jejunum and ileum
superior mesenteric
which artery supplies the terminal ileum, caecum , appendix and proximal ascending colon
ileocolic
which artery supplies the distal ascending colon
right colic
which artery supplies the distal transverse colon
middle colic
which hindgut structure does the inferior mesenteric artery supply
large intestines
which artery supplies the descending colon
left colic
which artery, supplying the descending colon, anastomoses with the middle colic artery
left colic
which artery supplies the sigmoid colon
sigmoid arteries
which artery supplies the proximal rectum
superior rectal
branches from which artery supply the distal rectum?
internal iliac
after blood drains from the intestines which 3 veins and which organ must it go back through to go back to the heart and lungs?
superior and inferior mesenteric, splenic, hepatic portal vein and then the liver
what are arcades in the GI tract? what do they form the blood supply to? where do they run from and to? between layers of what?
Blood vessels that take the form of a series of arches. They form the blood supply to the jejunum and ileum. The arcades run from the aorta to the small intestine between the layers of peritoneum (mesentery)
