Digestive System Flashcards
Oral cavity features
superior lip
superior labial frenulum
gingivae
fauces
soft palate
uvula
lingual frenulum
gingivae
inferior labial frenulum
inferior lip
Oral vestibule
space between teeth/gums and lips/cheecks
Oral cavity proper
“mouth”
space between teeth/gums and fauces
Borders
anterior-lips, teeth, oral vestibule
lateral (walls)
cheeks
posterior
fauces
superior (roof)
hard palate and soft palate
inferior (floor)
tongue
What is the function of the mouth
secretion-lubrication
Protection-senses and analyzes foods
digestion-mechanical and chemical breakdown
Teeth
function for mastication (chewing)
located on the alveolar processes on maxilla (upper jaw)
alveolar processes on mandible (lower jaw)
Types of teeth
incisors “bite”
canines “cut/tear”
premolars “crush/grind”
Molars “crush and grind”
deciduous teeth
deciduous teeth=20
5 in each quadrant (2 incisors, 1 canine, 2 molars)
permanent teeth
=32
8 in each quadrant
incisors (2)
canines (1)
premolars (2)
molars (3)
Tongue
epiglottis
lingual tonsils-posterior 1/3, immobile and rough
papillae-anerior 2/3, mobile portion
Functions to taste, mechanical breakdown and speech
Salivary glands
secrete saliva into the oral cavity
reduces friction
chemical digestion
What are the 3 salivary glands
parotid gland
sublingual gland
submandibular gland
Parotid gland
largest
secretes salivary amylase
serous secretions
sublingual gland
muccous secretions
salivary glands
seromucous secretions
Bolus
soft, flexible mass of food that cant be swallowed
Pharynx
“throat”
funnel-shaped tube
inferior borders
foodway
oro-pharynx, laryngopharynx
Esophagus
long, collapsible muscular tube
secretes muccous
lubricates lumen
transports food to stomach
NO ABSORPTION
NO DIGESTIVE ENZYMES
pathway is
larynopharynx
inferior neck
mediastinum
esophageal hiatus
stomach
Where is the esophagus situated
anterior to vertebral column
posterior to trachea
What is peristalsis
involuntary muscle contractions
upper esophageal sphincter
lower esophageal sphincter
Mechanism of swallowing
teeth-mechanical digestion
tongue-maneuvers food
uvula and epiglottis-direct bolus
pharynx-oropharynx, larynpharynx
esophagus-UES, peristalsis, LES`
What is the structure the esophagus enters the abdomen through
esophageal hiatus
Lower esophageal sphincter
where the esophagus enters the stomach
Epigastric region
stomach
Location of stomach
deep to border of ribs
inferior to diaphragm
stomach
Structure of stomach
J-shaped
lesser curvature (right)
greater curvature (left)
Functions of stomach
food storage
mechanical and chemical breakdown
chemical breakdown by gastric juice
gastric juice-hydrochloric acid, lipase, pepsin
chyme= gastric juice mixed with gastric content
Location of small intestine
coiled
central/inferior abdomen
inferior to stomach
surrounded by large intestine
begins with the pyloric sphincter
ends into the large intestine
What is the purpose of microvilli?
prevents a “garden hose” like behaviour
increases contact with the intestinal walls
increases surface area
allows for more absoprtion and digestion of food
Small intestine has 3 parts
duodenum
jejunum
ileum
Duodenum
recieves chyme from stomach
recieves digestive secretions from pancreas
recieves bile from liver
“mixing bowl”
Jejunum
mostly in upper left abdomen
function is most of the chemical digestion and nutrient absorption (largest pilcae circulares)
Ileum
Mostly in lower right abdomen
enters large intestine through ileocecal valve
functions to further digest food
peyers patches
prevents infection by regulating pathogens
Where is peyers patches
ileum
where is pilcae circulaires
jejunum
order of small intestine
duodenum, jejunem, ileum
large intestine
begins-ileocecal valve
ends-anus
inferior to stomach and liver
surrounds small intestine
shorter than small intestine
what is the function of the colon
water and electrolyte removal
rectum
recieves stool from colon
holds in stool until excretion
Function of large intestine
absorption of water and electrolytes
compaction
defecation
“garbage compacter”
Why do we have accessory organs?
secrete substances required for chemical digestion
food does not actually pass through these organs
Name the regions
epigastric
umbilical
pubic
left hypochondriac
left lumbar
left inguinal
right hypochondriac
right lumbar
right inguinal
Pancreas
located at the left upper quadrant (hypochondriac and epigastric region)
closely associated with spleen and stomach
Structure of the pancreas
accessory pancreatic duct
pancreatic duct
body
tail
uncinate process
head
Inside the pancreas, what are important secretory structures
minor duodenal papilla
hepatopancreatic ampulla
major duodenal papilla
Blood supply to the pancreas
celiac trunk
splenic artery
superior mesenteric artery
Venous drainage of the pancreas
portal veins
superior mesenteric vein
splenic vein
Pancreas role in digestion
exo-pancreatic juice secretions into duodenum
endo-hormone secretion
pancreatic acini are 99% glandular epithelial cells
1% is pancreatic islets of Langerhans
Islets of Langerhan
insulin-beta
glucagon-alpha
somatosatin
pancreatic polypeptide
Liver lobes
left lobe
right lobe
caudate lobe
quadrate lobe
liver ligaments
coronary ligament
falciform ligament
ligamentum teres
porta hepatis
hepatic portal vein
proper hepatic artery
common hepatic duct
Liver blood supply and venous drainage
blood supply-portal vein and proper hepatic artery
venous drainage-hepatic veins
Liver histology
hepatocytes
portal triad-small bile duct, branch of portal vein, branch of hepatic artery
Hepatic blood flow
oxygenated blood from hepatic artery and nutrient rich deoxygenated blood from portal vein go into hepatic sinusoids to the central vein to the hepatic veins to the IVC
liver’s role in digestion
metabolic regulations
bile production
detoxification
storage
Where is the liver located
inferior surface of liver
RUQ
Gallbladder function
stores and concentrates bile before release into duodenum
Gallbladder
cystic duct
neck
body
fundus
Biliary tree
minor duodenal papilla
major duodenal papilla
What does bile do?
emulsifies fat
breaks down fat into smaller molecules that can be absorbed during digestion
Bile from liver to duodenum
hepatocytes produce bile
bile canaiculi
small bile ducts
right hepatic duct and left hepatic duct
bile duct
hepatopancreatic ampulla
duodenum
Peritoneum
double-layered serous membrane
parietal peritoneum-lines walls of abdominopelvic cavity
visceral peritoneum-lines organs in the abdominopelvic cavity
Organ classification
inter-peritoneal organs-completely covered by visceral peritoneum (mobile)
retroperitoneal organs-covered anteriorly by parietal peritoneum (fixed)
Intraperitoneal organs
colon (transverse and sigmoid)
spleen
stomach
jejunum
ileum
liver
gallbladder
Retroperitoneal organs
duodenum
pancreas
colon (ascending and descending)
rectum and anal canal
kidneys and adrenal glands
ureters
Peritoneal Folds
greater omentum-attaches stomach to SI and transverse colon
lesser omentum-attaches stomach and duodenum to the liver
falciform ligament-attaches liver to anterior abdomial wall and diaphragm
mesentery-anchors jejunum and ileum to posterior abdominal wall
mesocolon-anchors transverse and sigmoid colon to posterior abdominal wall
