digestive system Flashcards
What is the function of the digestive system?
1) Mechanical and chemical breakdown of food.
2) Absorbing nutrients from this food and excreting waste.
What is the digestive track? (Not in depth)
Oral cavity (Mouth) –> Pharynx (throat) –> Epiglottis –> Esophagus –> Lower esophagus sphincter –> Stomach –> Pyloric sphincter –> Duodenum –> Jejunum –> Ileum –> Colon (Large intestine) –> Rectum –> Anus
What is the ENTIRE digestive track lined with?
Epithelial tissues
-> Made up of goblet cells and cilia
-> Secrete mucus and overall protects the digestive track from digestive enzymes.
The importance/function of the mouth/oral cavity?
(2 important functions)
-Contains teeth
-Contains salivary glands
-> Teeth mechanically breaks down food into smaller pieces, which increases surface area for digestive enzymes.
-> Salivary glands produce saliva, lubrication for food.
-> Saliva breaks starch down to sugar, because it contains the enzyme “amylase”
After food is in your mouth and covered in saliva, what is it’s official name/what does it turn into?
“Food bolus”
-The food that leads to the next part of the digestive track
Pharynx importance/function?
Connects the oral cavity to the rest of the system.
-> A tube, usually known as your throat.
Epiglottis importance/function?
Muscular flap that prevents food from getting into your trachea (windpipe)
Esophagus importance/function?
A muscular tube connecting your mouth to your stomach.
->Made up of smooth muscle, therefore going through “peristalsis” to move the food
PERISTALSIS: Muscle contractions.
-> Reason why gravity does not play a role in digestion
Sphincters! -The function and purpose of both your lower esophagus sphincter and pyloric sphincter?
Sphincter, a ring-shaped muscle that relaxes in tightens when needed
-> Lower esophagus sphincter prevents “heartburn”
-Closes while digestion, so that HCL (gastric acid) does not burn through your tissues.
-Heartburn is the act of this sphincter NOT functioning properly, therefore “burning your tissues”
->Pyloric sphincter controls the movement of “chyme” (semi-digested food), ensures that properly digested food enters your duodenum
How does your stomach acid not burn through your stomach?
Stomach lining cells secrete a mucus that protects your stomach from burning, these cells are known as “rugae”
-> If mucus is not properly secreted, it can create an ulcer!
The 4 causes of an ulcer? (Factors contributing to an ulcer?)
1) Smoking
2) Bacterial Infection
3) Anti-inflammatory medication (Asprin)
4) Weakened mucus lining.
Importance/function of your stomach?
-> Holds food, churns it and chemically breaks it down.
-> Releases HCL (gastric acid) that lowers the PH level of the food down to 2.
-> Lower PH = PEPSIN (a digestive enzyme) can begin breaking down and absorbing proteins
What are the names (in order) of the “3” parts of your small intestine?
1) Duodenum
2) Jejunum
3) Ileum
What are accessory organs? (Name them and their functions?)
Accessory organs, are organs that help with the process of digestion but are NOT in the digestive track.
- Liver (Creates bile)
- Gallbladder (Stores Bile)
- Pancreas (Neutralizes stomach acid and produces pancreatic juices that help with digestion)
Function/role of the duodenum?
(Note: and the accessory organs)
-> Surrounded by 3 accessory organs, continues chemical digestion
Has “ducts” (Small canals) that allow substances from the accessory organs to enter the duodenum.
-> Common bile duct: between the gallbladder and the duodenum
-> Pancreatic duct: between the pancreas and the duodenum
GALLBLADDER releases “bile”
-> An enzyme that “emulsifies” fats, breaking it down into small and smaller pieces for INCREASED surface area.
NOTE: Bile is created in the liver, stored in the gallbladder
PANCREAS: Neutralizes the chyme and releases pancreatic juices (a mixture of enzymes)
-> Neutralizes chyme by secreting sodium bicarbonate (an alkaline)
-> AFTER,
trypsin (enzyme that breaks down protein)
amylase (enzyme that breaks down starch)
Lipase (enzyme that breaks down fat)
is produced!
