digestive tract 1 mouth to stomach Flashcards
two parts of the digestive system
digestive tract and accessory organs
primary regions of the digestive tract
oral cavity (mouth), pharynx, oesophagus, stomach, small intestine, large intestine, rectum/anus
layers of the GI tract
lumen, mucosa, submucosa, muscularis, serosa
functions of the mucosa layer of GI tract
- lines the GI tract
- secretes mucus and lubricates and protects the tract
what is the mucosa layer of the GI tract
mucous membrane
what type of tissue make the submucosa layer of GI tract
connective tissue
function of submucosa layer
contain blood vessels, lymph vessels and nerves
layers of the muscularis layer
two layers of smooth muscle:
- circular for constriction
- longitudinal for pulsation
what type of tissue make the serosa layer of GI tract
connective tissue
what is the function of the serosa layer
secrete fluid to lubricate the outside of the GI tract
boundaries oral cavity
lips anteriorly
cheeks laterally
palate superiorly
tongue inferiorly
layers of lips
exterior: skin
interior: stratified squamous epithelium
middle: orbicularis oris muscle
what attaches the lips to the gums
the labial frenula
muscles of oral cavity
cheeks
layers of cheeks
exterior: skin
inferior: stratified squamous epithelium
middle: buccinator muscle - for chewing
rounded contour: buccal fat pad
obicularis oris: surround lips and helps movement
bones in the hard palate (anterior 2/3)
maxillae and palatine bones
soft palate (posterior 2/3) consisted of
skeletal muscle, connective tissue and uvula
types of pharyngeal arches
palatoglossal and palatopharyngeal
where is the anterior tongue attached to
to floor via lingual frenulum
what is the posterior tongue connected to
hyoid bone (via muscles) - not connected to any bone, epiglottis and oropharynx
what is the pharynx
common passageway for food and air
how is the pharynx connected to other systems
connected to respiratory system at larynx
connected to digestive system at oesophagus
3 regions of pharynx
nasopharynx (behind nasal cavity)
oropharynx (behind oral cavity)
laryngopharynx (behind larynx)
how is the pharynx lined?
ciliated pseudostratified columnar epithelium (nasopharynx)
moist stratified squamous epithelium (oropharynx and laryngopharynx)
muscles in the pharynx
posterior walls of oropharynx and laryngopharynx
pharyngeal constrictors: superior, middle and inferior
helps push down the food down
what is the oesophagus
muscular tube
continuation of the laryngopharynx superiorly and the stomach inferiorly
what is the oesophageal hiatus
at the T10, hole that allows the oesophagus go through diaphragm - how it passes from the thoracic cavity into the abdominal cavity
lining of oesophagus
moist stratified squamous epithelium
layers of muscle of oesophagus
outer longitudinal and inner circular
sphincters in oesophagus
upper oesophageal and lower oesophageal (cardiac)
what is the cardiac
the lower sphincter in oesophagus - entrance to stomach
where is the stomach situated
upper left abdominal quadrant
what are the rugae
the folds in the stomach walls
what is the fundus
the upper part of the stomach
what is in the pyloric region of the stomach
pyloric antrum, canal, orifice, sphincter (pylorus) that surrounds the pyloric orifice
what two structures does the pyloric sphincter divide
the stomach and small intestine
lining of stomach
mucosa:
simple columnar epithelium
how are gastric glands formed
by tube-like gastric pits formed by mucosa lining
muscle layers of the stomach
outer longitudinal
middle circular
inner oblique
why do muscles in the stomach have different directions
to be able to contract in any type of configuration
what is the function of gastric glands
secrete hydrochloric acid, enzymes and hormones to digest the food
indicate when we are full
