Gastrointestinal system 1 Flashcards
what are the roles of the oral cavity
mastication and lubrication
gustation
limited chemical digestion
speech
hard palate vs soft palate
hard is further forward
what is digested in the limited chemical digestion in the oral cavity
glucose and lipids
what epithelium is the oral mucosa lined with
stratified squamous
oral vestibule
the space between lips and gums/teeth
salivary secretion ducts
frenulum connects lip to gingiva
role of the uvula
prevents food from entering the nasal cavity
roles of the tongue
mechanical digestion and manipulation of food
sensory: gustation and temperature
lubrication of bolus
how many teeth do humans have
20 during development
32 after development
salivary glands locations and secretions
parotid gland: parotid duct - vestibules, serous secretion (amylase)
sublingual gland: under the tongue, secretes mucous
submandibular gland: beneath the jaw, serous and mucous secretions
roles of saliva
lubricate and moisten bolus
limited digestion
dissolving chemicals for gustation
buffer
controls bacterial populations (antibodies and lysosomes)
parts of the pharynx
what epithelium do they have
nasopharynx - pseudostratified ciliated columnar epithelium
oropharynx - stratified squamous epithelium
laryngopharynx - stratified squamous epithelium
stages of deglutination and the structures involved in each
buccal phase: soft palate, tongue, uvula
pharyngeal phase: pharynx muscle, epiglottis, uvula
oesophageal phase: oesophagus, involuntary - approaching bolus triggers opening of lower oesophageal sphincter
where is mucosal epithelium present in the GIT
what type of epithelium is it
oral cavity
pharynx
oesophagus
anal cavity
stratified squamous epithelium
where is simple columnar epithelium present in the GIT
stomach
small intestine
large intestine
lamina propria
layer of connective tissue located beneath mucosal epithelium
contains blood vessels, muscles, lymph vessels and nerves
muscularis mucosa
thin layer of smooth muscle and elastic fibres that separates the mucosa from the submucosa
deepest layer of mucosa
inner circular layer and outer longitudinal layer
regulates shape of the lumen
submucosa
connective tissue binding mucosa and muscular layer
contains blood and lymph vessels and nerves (submucosal plexus)
exocrine glands
muscular layer
muscularis propria
smooth muscle coordinated by the ENS myenteric plexus
inner circular layer
outer longitudinal layer
serous membrane
outermost connective tissue layer
adventitia in structures not lined with visceral peritoneum
what causes spontaneous depolarisation of the muscularis mucosa and muscular layer
pacesetter cells
peristalsis
rhythmic waves of contraction
propulsion process to move bolus forward
segmentation
contraction of intestines to churn, fragment and mix
no pattern and does not move in any direction
mucosa of oesophagus
stratified squamous epithelium
submucosa of oesophagus
contains oesophageal glands
muscular layer of oesophagus
superiorly skeletal and transitions to smooth inferiorly
role of the adventitia of the oesophagus
anchors to posterior body wall
gastro-oesophageal reflux disease
heartburn, chest pain, difficulty swallowing, regurgitation
can lead to ulcer, strictures, Barret’s oesophagus
ascites
abnormal fluid build up in the peritoneum
what are mesenteries
what are its roles
double sheets of peritoneal membrane that attaches the intestine to the wall around the stomach area and holds it in place
prevents volvulus: twisting of a loop of intestine around itself and the mesentery that supplies it
routes for blood, lymph and nerve supply
greater omentum
pouch of adipose tissue
provides padding and insulation
lesser omentum
mesentery that supplies stomach and liver
falciform ligament
mesentery that supplies liver and abdominal wall
mesentery proper
mesentery that supplies duodenum and pancreas
mesocolon
mesentery that supplies colon and rectum
attached to abdominal wall
what are the layers of the mucosa
mucosal epithelium
lamina propria
muscularis mucosae
what is the function of rugae in the stomach
allow for expansion
muscular layer of the stomach
inner circular and longitudinal layers
extra oblique layer overlaying the mucosa
regions of the stomach
cardia: oesophagus entry
fundus: superior region
body
antrum: inferior region
pylorus: entry to duodenum
role of the cardia
entry point for the stomach
contains mucous gland that protects oesophagus
epithelium of stomach
simple columnar epithelium
gastric pits that produce secretory sheet of alkaline mucous
gastric glands and their secretions
fundus: acids and enzymes
parietal cells: intrinsic factor (B12) and indirect HCl
chief cells: pepsinogen
pyloric: mucous, gastrin
gastritis
inflammation of the lining of the stomach (can lead to cancer)
stomach discomfort, nausea, vomiting, burning sensation, bloody stool
