anatomy and function of the digestive tract Flashcards
Outline the components of the digestive system from proximal to distal and describe their main functions Understand what is meant by the term ‘peritoneum’ Describe the regions of the abdominal cavity
what is the function of the digestive tract
transport of foodstuffs
breakdown of foodstuffs
absorption of sugars proteins fats and vitamins, minerals and water
excretion of waters
what is absoped in the digestive tract
sugars proteins vitamins minerals water fats
what is the digestive tract also known as
the GI tract
what does GI tract stand for
Gastro intestinal tract
what shape is the GI tract
a long muscular tube
what substances are emptied into the tract to aid digestion
enzymes
acid
bile
what are the major subdivisions of the digestive tract
- oral cavity, teeth, tongue
- pharynx
- oesophagus
- stomach
- small intestine SI
- large intestine LI
what do the oral cavity teeth and tongue do
mechanical processing
moistening
mixing with saliva
what does the pharynx do
muscular propulsion of materials into the oesophagus
what does the oesophagus do
transport materials to the stomach
what does the stomach do
chemical breakdown of materials by acid and enzymes
mechanical processing through muscular contractions
what does the SI do
enzymatic digestion and absorption of water organic substances vitamins and ions
what does the LI do
enzymatic digestion and absorption of water organic substances vitamins and ions
what are the accessory organs of the digestive system
salivary glands
liver
gallbladder
pancreas
what do salivary glands do
secretion of lubricating fluid which contains enzymes that break down carbohydrates
what does the liver do
secretion of bile (important for lipid digestion)- storage of nutrients and many other vital functions
what does the gallbladder do
storage and concentration of bile
what does the pancreas do
exocrine cells secrete buffers and digestive enzymes,
endocrine secrete hormones
what do exocrine cells release from the pancreas
buffers and digestive enzymes
what do endocrine cells release from the pancreas
they secrete hormones
what is the order of organs in the tube from proximal to distal
oral cavity oesophagus stomach SI LI rectum Anus
what level does the oesophagus pierce the diaphragm
T10- oesophagus has 10 letters
what does the oral cavity do
the mechanical breakdown of food
chemical breakdown of food- parotid gland
which muscle allows us to keep food on our teeth surface
Buccinator
which is the largest salivary gland
parotid
which clues can we see of GI tract/ systemic diseases in the mouth
oral thrush decay ulceration discolouration of teeth softened teeth/erosion abscesses
describe the oesophagus
muscular tube which connects the mouth to the stomach
what does the oesophagus consist of
smooth muscle
which organ connects the oral cavity to the oesophagus
pharynx
how does the bolus of food move down the oesophagus
by waves of contractions of the smooth muscle in the oesophagus
what shape is the stomach
J shaped bag
what does the stomach connect
the oesophagus to the SI
what does the inner surface of the stomach have
small folds called rugae
why do we need rugae
increase SA
allows the stomach to expand
what are the functions of the stomach
mechanical digestion from solid to liquid
chemical digestion
acid secretion and antibacterial action
what is the anatomy of the SI
duodenum proximal)
jujunum
ileum
what does the ileum connect
the SI to the LI
what is the function of SI
nutrient absorption
what the the SI attached to the posterior abdominal wall by
a mesentery
what does the mesentery contain
a lot of blood vessels
why is a lot of blood vessels important in the SI
FOR ABSOPRITON of nutrients
describe the duodenum
first part of the intestine
receives secretions from the pancreas
as well as bile from the gallbladder to aid digestion
what is special about the jejunum and the ileum
the fact that the inner surface is highly folded to increase SA
WHAT ARE THE PARTS of the LI
the cecum ascending colon transverse colon descending colon sigmoid colon
where does the ileum connect to
the ileum connects to the cecum of the LI
what is the function of the LI
water absroption
production of faecal matter
secretion of mucus
what is the pancreas
accessory organ of digestion
what re the four sections of the pancreas
head
neck
body
tail
what is the function of the pancreas
Secretes enzymes into the duodenum for protein digestion (exocrine)
Secretes hormones including insulin and glucagon for blood sugar control (endocrine)
what is the exocrine function of the pancreas
Secretes enzymes into the duodenum for protein digestion (exocrine)
what is the endocrine function of the pancreas
Secretes hormones including insulin and glucagon for blood sugar control (endocrine)
what are the four anatomical lobes of the liver
right 1
left 2
quadrate 3
caudate 4
what are the functions of the liver
Bile production Detox – drugs, alcohol Albumin production (main protein of blood plasma) Clotting factors Storage of glycogen
describe the gallbladder
Stores and secretes bile in to the duodenum
Emulsifies fat
what components are included in the portal triad which pass into the liver
Bile Duct out of the liver
Hepatic Artery Proper into the liver
Hepatic Portal Vein into the liver
what is the peritoneum
membranes of the abdomino-pelvic cavity
which duct passes out from the gallbladder
the cystic duct
passes through the pancreas
how does bile pass to the liver and the duodenum
the common duct
what duct lies in the pancreas
pancreatic duct
where does the hepatic portal vein collect blood from
the GI tract-
why does the hepatic portal vein carry blood into the liver
to be cleaned
where do we find the portal triad
in the free edge near the lesser omentum-
what connects the liver to the duodenum
the hepatoduodenal ligament
what connects the liver to the stomach
hepatogastric ligament
what is the lesser omentum made up of
the hepatogastic ligament
and the hepaduodenal ligament
what is the peritoneum made up of
visceral-covers the external surfaces of most digestive organs
parietal- lines the inner body walls
what does visceral peritoneum cover
the external surfaces of most digestive organs
SHINY
what does the parietal peritoneum cover
lines the inner body walls
what is the peritoneal cavity
the potential space between the visceral and parietal peritoneum
what is found in the peritoneal cavity
fluid which helps with lubrication
what forms the mesentery
two layers of visceral peritoneum
when is the organ considered as intraperitoneal
A mesentery attaches an organ to the posterior abdominal wall and means the organ can be mobilized.
when is the organ considered as retroperitoneal
If the visceral peritoneum runs over the organ, anchoring it to the posterior abdominal wall,
what is the greater omentum
hangs from the greater curvature of the stomach, covering the GI tract and providing protection. It is a large fold of visceral peritoneum.
what is the lesser omentum
Connected from the liver to the lesser curvature of the stomach
how is the omentum different to the mesentery
the omentum is a double layer of parietal peritoneum rather than visceral peritoneum
