Campos Alondra, Digestive System P.6🫁
Major Functions of the Digestive Systems
Digest food
Absorb Nutrients
Elimination of solid food waste
Consists of organs that are involved in breaking down of food
Into molecules that can pass through the wall of the digestive tract
And can be taken up by the cells
Gl tract- passage for food
Accessory Organ: Supply secretions such as enzymes, salvia,mucus
Aids in breakdown of food
Major Organs of Digestive Systems
Mouth: opening into the oral cavity
Esophagus: Collapsible tube runs from the pharynx to stomach
Food empties into duodenum of small intestine at pyloric sphincter
Pass through diaphragn
Food enters at the cardio esophageal sphincter
Located posteriorly to the trachea
Stomach: Located left of the abdominal cavity in left hypochondriac region
Food transported by peristalsis
Small Intestine Muscular tube extending from Pyloric Sphincter to ieocecal valve
Chemical digestion of fat begins
Where most chemical digestion of all foods occur by enzymes produced by accessory organs
Site of nutrient absorption into blood and lymphatic vessels
Large Intestine: Site of absorption of water and electroytes
Produces vitamins
Eliminates indigestible food from body as feces
Anus: Eliminates feces from rectum to exterior
Liver: Largest gland in body
made of four lobes, located interior to diaphragm
Palciform ligament holds lobes to abdominal wall
Gall bladder: pear-shaped organ
Located on the underside of liver on the right of abdominal cavity
Pancreas: located behind stomach surrounded by duodenum
Produces digestive enzymes lipase, pancreatic amylase & typin & chymotrypsin
Regulates blood sugar by producing insulin
Digestive Enzymes
There are 3 main types of digestive enzymes
Proteases: breaks down protein into small peptides
It also breaks down amino acids
Lipases: breaks down fat into three fatty acids
It also breaks down a glycerol molecule
Amylases: breaks down carbs like starch into simple sugars
Digestive Enzymes break down enzymes which break down polymeric macromolecules into smaller building blocks
Pepsin: it breaks down proteins into polypeptides
Trypsin: it helps us digest protein
it continues the digestion that begins in the stomach
Nucleases: it cleaves the chains of nucleotide in nucleic acids into the smaller units
Location and absorption of each macromolecule
are known as sugars
Chymotrypsin breaks down proteins in the small intestine
They are water -soluble polymers that are held together by the glycosidic bonds.
But the carbohydrates are digested in the small intestine
In order to absorb the sugars into our cells , our body needs to digest into the monomeric sugars.
Carbohydrates: are located in the pancreas
Proteins: are located all around your body, hair, muscles, bone, skin, etc.
Macromolecule: contains many atoms
they consist of amino acids which are held together by peptide bonds.
In order to absorb the proteins our body needs to remove the proteins
- needs to break down into the amino acid form
Lipids: they are find in many parts: cell membranes, cholesterol, blood cells, and brain
Lipids are different because they are not water soluble nor polymers
They can come in many different forms
they regulate metabolisms, reproduction, stress response, brain function and nutrition
Layers of the GI Tract
Mucosa: Its the most most inner layer
It's also known as the mucus membrane
Mucous membrane: produces mucus for reduction & protections
Submucosa: 2nd inner layer
Areolar connective tissue containing major blood vessel
Contains blood & lymphatic vessels, lymph node for nourishment
Submucosal plexus : in submucosa
Autonomic nerves supply
Glands and lymphatic tissue
Muscularis or Muscular layer: 2nd to last most exterior
Two layers of smooth muscles to allow peristalsis and segmentation
Inner Circular layer: squeeze, decrease size of lumen
In some areas act as a sphincter or valves
Outer longitudinal layer: shortens intestine
Serosa: outer covering of the Gl tract
Serous membrane: composed pf thin layer of areloar connective tissue
It's also composed of simple squamous and epithelium
Produces serious fluid for lubrication
Layers of the Stomach
Stomach located left of abdominal cavity in left hypochondriac region
Food enters at the cardio esophagus sphincters
Food empties into duodenum of small intestine at plylotic sphincter
Regions of stomach:
Cardiac region: near heart
Fundus: dome, shaped, filled with gas
Body: main portion
Pylorus: funnels shaped end
Pyloric sphincter: controls food leaving stomach and entering small intestine