Digestive System Flashcards
The Two General Divisions of Digestive System
- Alimentary Canal/ Gastrointestinal Tract (GIT)
- Accessory Structures or Gland Organs
a continuous tube that extends from the mouth to the anus through the thoracic and abdominopelvic cavities.
Alimentary Canal/ Gastrointestinal Tract (GIT)
Teeth-Tounge-Salivary glands- Liver, Gallbladder- Pancreas
Accessory Structures or Gland Organs
Functions of Digestive System
Ingestion
Secretion
Mixing and Propulsion
Digestion
Absorption
Defacation
This process involves taking foods and liquids into the mouth (eating).
Ingestion
This process involves the release of water, acid, buffers, and enzymes into lumen of GI tract.
Secretion
This capability of the GI tract to mix and move material along its length is called motility
Mixing and propulsion
mechanical and chemical breakdown of food
Digestion
The entrance of ingested and secreted fluids, ions, and the products of digestion into the epithelial cells lining the lumen of the GI tract
Absorption
Wastes, indigestible substances, bacteria, cells sloughed from the lining of the GI tract, and digested materials that were not absorbed in their journey through the digestive tract leave the body through the anus in a process called _____
defecation
The four layers of the tract, from deep to superficial, are the:
mucosa
submucosa
muscularis
serosa/adventitia
-superficial or outermost layer; is a serous membrane composed of areolar connective
tissue and simple squamous epithelium (mesothelium)
Serosa
thick layer of areolar connective tissue that binds mucosa to the muscularis layer
Submucosa
mucous membrane lining the alimentary tract
Mucosa
The 3 layers of Mucosa
a. Epithelium
b. Lamina Propia
c. Muscularis Mucosae
functions in secretion and absorption, lines the stomach and intestines.
Simple columnar epithelium-
secrete hormones to the bloodstream
Endocrine cells (Enteroendocrine cells)
secrete mucus and fluid into the lumen of the GIT
Exocrine cells
-contains nerves, blood vessels and lymph vessels which are the routes by which nutrients absorbed into the GI tract reach the other tissues of the body.
-contain MALT (Mucosa-Associated Lymphoid Tissue)
Lamina Propia
contains immune system cells that protect the body against infection or diseases
MALT
Movements of the _____ ensure that all absorptive cells are fully exposed to the contents of the GI tract.
muscularis mucosae
The largest serous membrane of the body; it lines the wall of the abdominal cavity and covers some abdominal organs.
peritoneum
Types of Peritoneum
- Parietal Peritoneum
- Visceral Peritoneum
- Mesentery
- Mesocolon
- Falciform
- Lesser Omentum
- Greater Omentum
lines the wall of the abdominopelvic cvity
Parietal Peritoneum
lines the organ in the abdominal cavity
Visceral Peritoneum
space between the parietal & visceral peritoneum
PERITONEAL CAVITY
contains blood and lymphatic vesssels and nerves supplying the abdominal organs
Mesentery
-binds the LI to the posterior abdominal wall
-carries blood vessels and lymphatic vessels to the intestines
Mesocolon
-attaches the liver to the anterior abdominal wal
Falciform
- It is the pathway for blood vessels entering the liver and contains the hepatic portal vein, common hepatic artery, and common bile duct, along with some lymph nodes.
Lesser omentum
-largest peritoneal fold
Greater momentum
contains a considerable amount of adipose
tissue. Its adipose tissue content can greatly expand with weight gain, contributing
to the characteristic “beer belly” seen in some overweight individuals.
Greater momentum
the largest serous membrane of the body; it lines the wall of the
abdominal cavity and covers some abdominal organs.
peritoneum
are accessory digestive organs located in sockets of the alveolar processes of the mandible and maxillae.
Teeth/Dentes
The 3 principal Parts of the Tooth:
1. _____- is the visible portion above the level of the gums.
2. _____- is the constricted junction of the crown and root near the gum line.
3. _____– Embedded in the socket are one to three roots.
- Crown
- Neck
- Root
-a calcified connective tissue that gives a tooth its shape and rigidity; encloses
the pulp cavity
*it is harder than the bone because of its higher content of Ca salts
*70% of its dry weight consists of Ca salts
Dentin
The Physiology of Digestion in Mouth
1. _____-results from chewing (Mastication) thru the coordinated functions of the tongue
and teeth
-ingested foods is reduced to soft, flexible mass called BOLUS
2. _____ -it is facilitated by the action of 2 enzymes:
a. _____- breaks down starch
b. _____- starts the breakdown of triglycerides into f.a. and monoglycerides
- Mechanical Digestion
- Chemical Digestion
a. Salivary amylase
b. Lingual Lipase