Digestive system Flashcards
What is the purpose of the digestive system?
provides fuel to keep all the body’s cell functioning
supplies building blocks needed for cell growth and repair
What are two groups of the organs compose the digestive system
the digestive canal and the accessory digestive organs
What is a digestive canal
It is a continuous tube that extends through thoracic and abdominal cavities from the esophagus to the anus
What organs includes in GI tract?
esophagus
stomach
small intestine
large intestine
anal canal
The accessory organs include:
mouth
teeth
tongue
salivary glands
pharynx,
liver,
gallbladder
pancrease
ingestion
the process involve taking food and liquids into the mouth
secretion
cells with walls of the digestive canal and accessory digestive organs secret about 7 l of water, acid, buffers and enzymes into the lumen
digestion
a process of breaking down ingested food into small molecules that can be used by body cells
mechanical digestion
the teeth cut and grind before it is swallowed
smooth muscles of the stomach and intestine churn the food to further assist the process
chemical digestion
the large carbohydrate, lipid, protein and nucleic acid molecules in food are split into smaller molecules by hydrolysis
Motility
alternating contractions and relaxations of smooth muscle in the walls of the digestive canal mix food and secretions and move them toward the anus
Absorption
The movement of the products of digestion from the lumen of the digestive canal into blood plasma or lymph. Once absorbed these substances circulate to cells through the body
Defecation
Waste, indigestible substances, bacteria cells sloughed from the digestive canal and digested material that was not absorbed that was not absorbed in their journey through the digestive canal leave the body through the anus a process called defecation
what are layers of the digestive canal
mucosa
submucosa
musclaris
serosa or adventitive
Mucosa
nonkeratinized stratified squamous epithelium = mouth
pharynx
esophagus
anal canal
PROTECTIVE FUNCTION
simple columnar epithelium=
stomach
small intestines
DECRETION AND ABSORPTION
what kind of the glands located among the epithelium cells
exocrine gland= secret mucus and fluid into the lumen of the digestive canal
endocrine glands=enteroendocrine glands =secrets hormones
What is mucosa composed of?
epithelium
lamina propira
muscularis mucosae
Lamina propria of mucosa
Areolar CT contains many blood vessels and lymphatic vessels which are the routes by which nutrients absorbed into the digestive canal reach the other tissues of the body.
what kind of the cells lamina proper contains
mucosa-associated lymphoid tissue MALT