Ch 25: Digestive System Flashcards Preview

A&P II: BIO426 > Ch 25: Digestive System > Flashcards

Flashcards in Ch 25: Digestive System Deck (92)
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1

What are the six functions of the digestive system?

Give a brief description of each.

  1. Ingestion: Taking in food through mouth
  2. Mechanical breakdown: In mouth and stomach
  3. Propulsion: Movement of food through the digestive tract via peristalsis
  4. Digestion: Chemical breakdown of food with enzymes all along the process
  5. Absorption: Taking in the chemical nutrients from food. Occurs mostly in the small intestines
  6. Defication: Removal of digestive waste via the anus

2

What are the two basic parts of the digestive system?

Briefly explain each.

  1. Alimentary canal: Pathway of food, from mouth to anus
  2. Accessory organs: Aid in digestion, but food does not pass through them

3

What are the two modes of digestive regulation?

  1. Extrinsic 
  2. Intrinsic

4

What is extrinsic digestive regulation?

  • Regulation that comes from outside the digestive system. 
  • Comes from brain and nervous system
  • Specifically the PNS

5

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

6

What are the anatomical parts of the alimentary canal?

  1. Mouth
  2. Pharynx
  3. Esophagus
  4. Stomach
  5. Small Intestines
  6. Large Intestines

7

What are the two accessory organs of the digestive system?

  1. Liver, including gall bladder
  2. Pancreas

8

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)

9

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 

10

The process of taking in food from the mouth is called _____.

ingestion

11

The mechanical breakdown of food in the mouth uses what parts?

  • Teeth
  • Tongue
  • Cheek muscles

12

The process of chewing is called _____.

mastication

13

Chemical digestion starts in the mouth with _____.

saliva

14

Saliva is exreted via _____.

salivary glands

15

Saliva consists of __% water, making it a _____ solution.

99%, hypotonic

16

Besides water, saliva also contains some _____, _____, _____, and _____.

acids, ions, amylase, antibiotic substances

17

*Amylase is an enzyme in _____ that breaks down _____.

saliva, starch

18

What are the antibiotic substances found in saliva and what purpose do they serve?

  • Mucin
  • Lysozyme
  • IgA
  • To kill microorganisms in food

19

Saliva is secreted constantly for _____ and _____.

cleanliness, moisture

20

The pharynx consists of...

  • Hard palate
  • Soft palate
  • Nasopharynx
  • Oropharynx
  • Tonsils
  • Laryngopharynx

21

The act of swallowing is called _____.

deglutition

22

What are the 3 phases of swallowing?

  • Buccal/Oral
  • Pharyngeal
  • Esophageal

23

Describe the Buccal/Oral phase of swallowing.

  • Voluntary
  • Tongue and cheek muscles push food to back of mouth and down to laryngopharynx

24

Describe the pharyngeal phase of swallowing.

  • Involuntary
  • Soft palate blocks nasopharynx
  • Tongue blocks entry to mouth
  • Epiglottis blocks trachea

25

Describe the esophageal phase of swallowing.

  • Food is pushed into espophagus
  • Perstalsis takes it from there, moving bolus to the stomach
  • Relaxation of the lower esophageal sphincter admits it into the stomach

26

What are the physical characteristics of the esophagus?

  • Collapsed muscluar tube
  • Mucosa consists of stratified squamous cells to protect from abrasion/acidic juices from the stomach
  • Uses peristalsis to move bolus to stomach

27

The stomach is a _____, and its walls are _____. 

storage sack, destendable

28

Define destendable.

The ability to expand due to internal pressure

29

Define rugae.

The folds of the enner walls in the stomach that allow it to be distended.

30

The first stomach sphincter of control is called the...

esophageal sphincter