Digestion Flashcards
What is Digestion (as a whole)?
The process of BREAKING DOWN nutrients and ABSORBING them into the blood to carry to cells.
What are the 4 main steps of digestion?
Ingestion, Digestion, Absorption, and Egestion.
What is Ingestion?
TAKING IN nutrients.
What is Digestion (step)?
CHEMICAL and PHYSICAL breakdown.
What is Absorption?
The TRANSFER of digested NUTRIENTS to the circulatory system.
What is Egestion?
The REMOVAL of waste food materials from the body.
What are the types of Digestion?
Mechanical and Chemical.
What is Mechanical Digestion?
Digestion in the MOUTH and STOMACH, involving tearing, chewing, grinding, and peristalsis.
What is Chemical Digestion?
Digestion in the MOUTH, STOMACH, and SMALL INTESTINE, where food is COATED with saliva, containing digestive enzymes.
Label the Digestive Organs
:)
What is the order of organs in the Digestive System?
Mouth, Esophagus, Stomach, Small, Large, Rectum and Anus.
What 2 types of Digestion occur in the Mouth?
Physical Digestion and Chemical Digestion.
What is Physical Digestion (mouth)?
Food is BROKEN DOWN into smaller pieces by teeth.
What is Chemical Digestion (mouth)?
BREAKING DOWN of food using chemicals (saliva and acid).
What does Saliva do/ contain?
It contains ENZYMES (amylase) and MUCUS (helps swallow), and dissolves food particles (allows us to taste the food).
What is a Bolus?
A BALL OF FOOD formed from chewing.
Where does the Bolus travel?
Pushed by the tongue to the BACK of the mouth, SWALLOWED, into PHARYNX (ingestion), and down the ESOPHAGUS to the STOMACH.
What does the Epiglottis do in Digestion?
It COVERS the entrance to the trachea when you swallow (blocks from lungs).
What does the Soft Palate do in Digestion?
It is RAISED to PREVENT food from entering the nasal passage (blocks it).
What moves food from the Mouth to the Stomach?
The ESOPHAGUS.
What is the Esophagus?
A long, muscular TUBE.
What is Peristalsis?
WAVE OF CONTRACTIONS that squeeze the bolus DOWN the esophagus.
What is the Stomach?
A J-shaped, muscular organ that can hold up to 2L. Where PROTEINS are PARTIALLY DIGESTED (not lipids or carbohydrates). Food enters when it’s relaxed.
What is Rugae?
Folded, smooth muscle that COVERS the inside of the STOMACH.
What do the Sphincters do?
CONTROL MOVEMENT of food IN and OUT of the Stomach.
Where is the Gastroesophageal (cardiac) Sphincter located?
Where the Esophagus MEETS the Stomach.
What are the 4 layers of the Stomach (from inner to outer)?
The Mucosa, Submucosa, Muscularis, and Serosa.
What does the Mucosa do?
SECRETES gastric juices (digestive enzymes, acid, and mucus). It’s cells divide to HEAL damage.
What does the Submucosa do?
It is CONNECTIVE TISSUE that CONNECTS nerves and blood vessels.
What does the Muscularis do?
It consists of smooth muscles that CHURN and MIX food with gastric juices to CREATE CHYME.
What does the Serosa do?
HOLDS the Stomach in place and SECRETES a lubricating fluid to eliminate friction between organs.
What is Chyme?
A SEMI-LIQUID material in the Stomach .
What controls Digestion?
Enzymes, hormones, and nerves.
What is Gastrin?
A HORMONE released into the bloodstream that goes to the gastric cells to tell them TO RELEASE gastric juices. Gastrin is released when nerves detect that FOOD IS PRESENT.
What is Acid Reflux (Heartburn)?
A BURNING sensation in the LOWER THROAT.
What causes Acid Reflux (Heartburn)?
When the GASTROESOPHAGEAL sphincter does NOT CLOSE completely, acid from the stomach can ENTER the esophagus. An OVERFILLED stomach can FORCE acid into esophagus (smoking relaxes sphincter and produces acid too).
How long does it take to process the contents of a meal in the Small Intestine?
3 to 5 hours.
What digest carbs, proteins, and lipids in the Small Intestine?
With the help of hormones and enzymes.
What happens in the Small Intestine?
Most DIGESTION and ABSORPTION occurs (further digest food from stomach-lipids and carbs). LONG tube (up to 7m, skinny-2.5cm).
What are the 3 sections of the Small Intestine?
The Duodenum, Jejunum, and Ileum.
What is the Duodenum?
First 30cm of Small Intestine, where most enzymes are ADDED and digestion BEGINS.
What is the Jejunum?
Where digestion CONTINUES in the Small Intestine and SOME nutrients are ABSORBED.
What is the Ileum?
The last section of the Small Intestine, where the MAJORITY of the nutrients are ABSORBED.
Why does the inside of the Small Intestine have max surface area?
For efficient NUTRIENT ABSORPTION.
What are Villi?
Small, FINGERLIKE projections in the INNER LAYER of the Small Intestine.
What are Microvilli?
Microscopic Villi on the Epithelial Cell (on the SURFACE) of the Villi, they INCREASE surface area even more.
What are Epithelial Cells?
Cells that LINE YOUR BODY.
What are Villi filled with?
Capillaries.
What are Capillaries?
A network of TINY BLOOD VESSELS (that fill the Villi).
What are Lacteals?
SMALL VESSELS that TRANSPORT digested fats to the lymphatic system, then the bloodstream.
What is the Pyloric Sphincter?
A muscle that controls the PASSAGE of CHYME from the Stomach to the Small Intestine (relaxes to release small amounts-slow prevents overloads and allows digestion time).
What is the Pancreas?
A long, flat GLAND between the Stomach and Duodenum that SECRETES (makes) ENZYMES and HORMONES to REGULATE absorption and storage of glucose.
What signals to the Pancreas to secrete substances?
When Chyme ENTERS the the Duodenum and CCK (hormone) is SECRETED.
What causes the Liver to make Bile?
When ACIDIC Chyme ENTERS the Small Intestine (also causes the Pancreas to secrete lipid and protein enzymes).
Why does the Pancreas secrete bicarbonate ions?
To NEUTRALIZE the acidity of Chyme.
What enzymes does the Pancreas release?
Trypsinogen and Lipases.
What do Lipases do?
BREAK DOWN lipid chains into shorter chains and individual fatty acid molecules.
What is the Liver and Gall Bladder?
A Digestive Gland (largest internal organ) that PRODUCES and SECRETES BILE. When fat enters the duodenum the gall bladder contracts and squeezes out the bile. It also PRODUCES and SORTS NUTRIENTS.
What does the Liver do to blood?
PROCESSES it before sending it to the Heart. REMOVES and BREAKS DOWN toxins (like alcohol).
What are the 2 types of Transport in the Small Intestine?
Active and Passive Transport.
What is Passive Transport?
Movement of materials that does NOT REQUIRE ENERGY.
What are the types of Passive Transport?
Diffusion, Osmosis, and Facilitated Diffusion.
What is Diffusion?
When particles move from an area of HIGHER concentration to an area of LOWER concentration to be EVENLY DISTRIBUTED (amino acids in the bloodstream).
What is Osmosis?
DIFFUSION of WATER molecules through a SEMI-PERMEABLE membrane (water from food).
What is Facilitated Diffusion?
DIFFUSION across a membrane using TRANSPORT PROTEINS (proteins that move other materials across biological membranes).
What is Active Transport?
Materials are moved from LOWER concentration to HIGHER concentration using energy PROVIDED BY THE CELL (for molecules too big or with a strong/ uneven charge).
What is the Large Intestine?
A short, TUBE like organ (1.5m), but wide (7cm). Digestion is COMPLETE by the time digested material reaches it, most of the WATER is ABSORBED here (takes 4-72 hours).
What are the 4 parts of the Large Intestine?
The Cecum, Colon, Rectum, and Anus.
What is the Cecum?
A ‘pouch-like’ DEAD END that receives the processed material from the Small Intestine (first part of the Large Intestine).
What is the Appendix?
A FINGER-LIKE projection from the Cecum.
What is the Colon?
LONGEST part of the Large Intestine with 4 segments.
What are the 4 segments of the Colon?
Ascending Colon, Transverse Colon, Descending Colon, and Sigmoid Colon.
What is the Rectum?
Last 20cm of the Large Intestine that HOLDS WASTE PRODUCTS of digestion until the are ELIMINATED through the ANUS.
What is Egestion?
The act of ELIMINATING/ excreting DIGESTIVE WASTE (unusable). Absorption of water in the Large Colon turns liquid into feces.
What leads to Constipation or Diarrhea?
Constipation is from too MUCH water absorption and Diarrhea is from too LITTLE water absorption.
What is an Endoscopy?
Medical procedure that uses an ENDOSCOPE to look inside the body (narrow tube with a light and camera). Less painful than open surgery and shorter recovery period.
