Digestive system Flashcards
ingestion
process of bringing food into mouth
digestion
reducing food that you brought in body into its basic molecular building blocks
mechanical- physically breaking down food
chemical- in the intestines, food broken down into simplest form ; breaking chemical bonds
absorption
food brought across into body from GI tract
-food absorption takes place in small intestine, and some water absorption in large intestine
egestion
elimination/defecation/pooping/waste removal
dorsal cavity
cranial & spinal cavity
ventral cavity
thoracic & abdominopelvic cavity
peritoneum
surrounds organs in the abdominopelvic cavity
The mesentery that secures the small intestine is the:
mesentery proper
omenta
fold of peritoneum that connects stomach with another viscera
lesser omentum
runs from liver to lesser curvature of stomach
~functions to secure position of the stomach inferior to the liver
greater omentum
big flap that drops down from the stomach and covers the small intestine
~largest mesentery in the body; filled with adipose tissue
general fx of digestive system
to digest, mix, transport, and break down food
absorb nutrients, expel wastes
bolus
food mixed with saliva that goes down the digestive tract
chyme
stomach converts bolus into chyme
oral cavity
-teeth& tongue: mechanical digestion
-openings for salivary glands (chemical digestion start)
boundary-roof of mouth
oral cavity is lined by:
non-keratinized stratified squamous epithelium
pharynx
- nasopharynx (only part of respiratory system- airway)
- oropharynx- behind oral cavity; shared passageway for air and food
- laryngopharynx; connects to esophagus; broad opening into trachae; during swallowing, food has right of way not air.>stomach.
Oro & Laryngopharynx have non-keratinized stratified squamous epithelium
-pharyngeal constrictors- peristalsis, constrict to help propel bolus downwards
4 tunics of GI tract in order
Mucosa- innermost
Submucosa
Muscularis
Serosa/adventitia
Mucosa
-inner epithelium (tissue varies)
-underlying areolar CT called Lamina Propria
-thin layer of smooth muscle called muscularis mucosa
Submucosa
arealor or irregular dense CT binds mucosa to the muscularis
-mucin secreting glands to protect digestive tract against digestion
muscularis
2 layers of smooth muscle
-inner circular layer which contracts like a sphincter to help push food
-outer longitudinal layer shortens the tube; mixing food
serosa/adventitia
arealor CT with collagen and elastic fibers; if covered with visceral peritoneum then called Serosa, if not than it is adventitia
esophagus
conducts food inferiorly through thoracic cavity down into the stomach
-has all 4 tunics/layers
-made of skeletal & smooth muscle
stomach
upper left quadrant of the abdomen
-continues mechanical and chemical digestion of bolus
-bolus is processed into chyme
-temporarily stores food
4 regions
- cardia- entryway where esophagus meets stomach
- fundus- superior, lateral part; dome
- Body; largest part
- pylorus- exit region/funnel
Has greater (inferior) and lesser (superior) curvature