Ingestion + Digestion Flashcards
Taking in Nutrients
Ingestion
Breakdown of Nutrients
Digestion
What are the two types of digestion?
- Physical/Mechanical Digestion
- Chemical (enzymes) Digestion
Transportation of digested nutrients via blood
Absorption
Removal of undigested waste
Elimination
The human digestive tract is how long?
About 6.5m to 9m long
What are the 4 components of Digestion?
- Ingestion
- Digestion
- Absorption
- Elimination
What type of Digestion is the mouth?
Physical/Chemical Digestion
Where does digestion begin?
In the Mouth
Food is chewed to form a what?
Bolus
Breaking down food into smaller pieces increases what for chemical digestion?
Surface Area
Fluid produced by Salvary Glands
Saliva
What are the two functions of Saliva?
- Contains Salivary Amylase enzymes which breaks down complex carbs (chemical digestion)
- Dissolves food particles (flavour receptors on tongue, lubricates food)
Tube from mouth to stomach
Esophagus
Food bolus enters the esophagus and activates what?
- Walls of the esophagus to stretch
- Peristalsis
What is it called when the smooth muscle that lines the esophagus involuntarily contracts to help move the food?
Peristalsis
Food entry into the stomach is controlled by the ring like muscular structure called what?
Esophageal Sphincter
- J-shaped organ
- Site of food storage and initial (chemical) protein digestion
Stomach
What is the pH range in the stomach?
1.0 to 3.0 (Acidic)
The folded layers in the stomach increases what?
Surface Area
How is physical digestion happening in the stomach?
Churning of food by stomach muscles
What controls the emptying of stomach contents into the small intestine?
Pyloric Sphincter
What secrets Gastric Juices?
Cells lining the stomach
What contributes to the chemical digestion of food and converts it into Chyme?
Stomach
Kills harmful substances and converts pepsinogen into its active form “pepsin”
HCL (Hydrochloric Acid)
Protein digesting enzyme
Pepsin
Protective alkaline layer that prevents stomach from being broken down by HCL (catalyst for pepsinogen)
Mucus
What is it called when the Mucous layer in the stomach breaks down and the stomach wall is exposed to HCL and pepsin?
Ulcers
What are the 3 sections the Small Intestine is composed of?
- Duodenum
- Jejunum
- Ileum
What is the first part of the small intestine?
Duodenum
Which section of the Small Intestine is where most digestion occurs?
The Duodenum
Chyme (from stomach) moves through the Small Intestine by what?
Peristalsis
Physical Digestion = ____________ = Chyme sloshing back and forth
Segmentation
Ridged inner lining of the Small Intestine are covered in tiny projections called what?
Villi
What are Villi covered in?
Microvilli
What does Villi and Microvilli increase in the Small Intestine?
Absorptive Surface Area
Each Villus (Villi) is supplied with capillary network and lymph vessels called what?
Lacteals
Lacteals transport products of what?
Fat Digestion
Allows fluid and gas exchange to occur with the blood stream
Capillary
Releases enzymes to the Small Intestine
Pancreas
What do the Enzymes released by Pancreas chemically digest?
- Proteins (by Trypsin)
- Carbs (by Amylase)
- Lipids (by Lipase)
During Protein digestion in the Small Intestine, Chyme enters Small Intestine soaked in HCL and ______ from gastric secretions
Pepsin
During Protein digestion in the Small Intestine, the HCL triggers the conversion of the hormone Prosecretin into what?
Secretin
During Protein digestion in the Small Intestine, what tells Pancreas to release Bicarbonate (base) ions (HCO3-)?
Secretin