Ch 25: Digestive System Flashcards
(92 cards)
What are the six functions of the digestive system?
Give a brief description of each.
- Ingestion: Taking in food through mouth
- Mechanical breakdown: In mouth and stomach
- Propulsion: Movement of food through the digestive tract via peristalsis
- Digestion: Chemical breakdown of food with enzymes all along the process
- Absorption: Taking in the chemical nutrients from food. Occurs mostly in the small intestines
- Defication: Removal of digestive waste via the anus
What are the two basic parts of the digestive system?
Briefly explain each.
- Alimentary canal: Pathway of food, from mouth to anus
- Accessory organs: Aid in digestion, but food does not pass through them
What are the two modes of digestive regulation?
- Extrinsic
- Intrinsic
What is extrinsic digestive regulation?
- Regulation that comes from outside the digestive system.
- Comes from brain and nervous system
- Specifically the PNS
What is intrinsic digestive regulation?
- Regulation that comes from inside the digestive system
- Occurs via gut hormones and the enteric nervous system via a group of nerves found in submucosa of plexus that provide for hunger feelings of the stomach
What are the anatomical parts of the alimentary canal?
- Mouth
- Pharynx
- Esophagus
- Stomach
- Small Intestines
- Large Intestines
What are the two accessory organs of the digestive system?
- Liver, including gall bladder
- Pancreas
Where is the esophageal sphincter and what is its purpose?
- It is located at the base of the esophagus where it meets the stomach.
- It closes to prevent backflow of stomach contents into the esophagus
- Prevents stomach acid from damaging esophageal tissues (acid reflux/heartburn)
Where is the pyloric sphincter, and what is its purpose?
- The pyloric sphincter is located at the exit point of the stomach where it meets the intestines.
- It controls the release of stomach contents to the duodenum
The process of taking in food from the mouth is called _____.
ingestion
The mechanical breakdown of food in the mouth uses what parts?
- Teeth
- Tongue
- Cheek muscles
The process of chewing is called _____.
mastication
Chemical digestion starts in the mouth with _____.
saliva
Saliva is exreted via _____.
salivary glands
Saliva consists of __% water, making it a _____ solution.
99%, hypotonic
Besides water, saliva also contains some _____, _____, _____, and _____.
acids, ions, amylase, antibiotic substances
*Amylase is an enzyme in _____ that breaks down _____.
saliva, starch
What are the antibiotic substances found in saliva and what purpose do they serve?
- Mucin
- Lysozyme
- IgA
- To kill microorganisms in food
Saliva is secreted constantly for _____ and _____.
cleanliness, moisture
The pharynx consists of…
- Hard palate
- Soft palate
- Nasopharynx
- Oropharynx
- Tonsils
- Laryngopharynx
The act of swallowing is called _____.
deglutition
What are the 3 phases of swallowing?
- Buccal/Oral
- Pharyngeal
- Esophageal
Describe the Buccal/Oral phase of swallowing.
- Voluntary
- Tongue and cheek muscles push food to back of mouth and down to laryngopharynx
Describe the pharyngeal phase of swallowing.
- Involuntary
- Soft palate blocks nasopharynx
- Tongue blocks entry to mouth
- Epiglottis blocks trachea