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

  1. 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