Exam 3 Chapter 17 Digestive System

What is the digestive system also known as

Alimentary Canal

What is digestion

breaking food into smaller pieces

What is mechanical digestion

physical breakup

ex. chewing

What is chemical digestion

breaking the molecules into smaller pieces

What are the alimentary canal organs

digestive tract or GI tract, mouth, pharynx, esophagus, stomach, and intestines

What are the accesory organs

Salivary glands, pancreas, liver, and gallbladder

What are the walls of the alimentary canal

1. mucosa

2. submucosa

3. muscularis externa

4. serosa

What is motility

muscle contraction

What is segmentation

pushes contents back and forth

what is peristalsis

pushes contents in one direction

What is the mouths’ purpose

mechanical digestion

What is the palates’ purpose

separate oral and nasal cavities

What is the tongues’ purpose

• Sense properties of food​

  • Push food around in mouth and toward pharynx to swallow​

What is the teeth’s purpose

mechanical digestion

What do incisors do

cut food

what do canines do

tear food

what do bicuspids do

grind food

what do molars do

grind food

What is the crown

visible portion of the tooth

What is the root

inside the maxilla or mandible

what is the internal stucture

dentin (hard substance), pulp cavity (soft tissues), and root canal (blood and nerves enter)

What is the salivary gland

secretes saliva that contains

1. amylase

   1. mucus

what is the pharynx

contains the nasopharynx, oropharynx, and laryngopharynx.

What is the esophagus

• Transports food through thoracic cavity to stomach​

What are the two sphincers in the esophagus

• Upper esophageal sphincter opens to let food in from pharynx​

  • Lower esophageal (cardiac) sphincter opens to allow food into stomach, stays closed to prevent reflux​

what is the function of the stomach

• Chemical digestion of protein​

  • Some absorption​

What is rugae

• ridges of mucosa & submucosa​

  • Allow for expansion​

What are goblet cells

mucus to protect mucosa​

What are gastric glands

tubes of mucosal cells that secrete gastric juice​

what is gastric emptying

• Partially digested food + gastric juice forma paste called chyme​

What does the pancreas do

secrete enzymes &buffers​

What are pancreatic enzymes

they digest

1. amylase- polysaccharides

2. lipase- triglycerides

3. nuclease- nucleic acids

4. proteolytic enzymes- proteins

How many lobes does the liver have

2

right- largest

left- second largest

What does the liver do

by producing bile, metabolizing nutrients, and detoxifying substances to ensure the body efficiently absorbs and uses food.W

What does the gallbladder do

stores, concentrates, and releases bile to help digest fats and absorb fat-soluble vitamins in the small intestine.

What does bile do

Emsuilify fats

What is bile production

• Primary digestive function of liver​

Main functions of the liver

1. Store glycogen & release glucose​

2. Synthesize lipids & plasma proteins​

3. Store iron & Vitamins A, D, B12​

4. Phagocytosis (bacteria & damagedRBCs) by Kupffer cells​

5. Detoxify alcohol & drugs​

   1. Secrete bile​

What does the small intestine do

• Complete digestionof chyme​

  • Absorb nutrients​

What are the 3 sections of the small intestine

1. Duodenum​

2. Jejunum​

   1. Ileum​

What is the large intestine

• Absorb water & electrolytes​

  • Create feces & store it until defecation​

What are the parts of the large intestine

cecum, colon, rectum, anal canal​

What does the duodenum do

• Secretions from liver & pancreas enterhere​

What is the surface area of the wall

• Three ways it is increased:​

1. Plicae circulares: ridges of submucosa​

2. Villi: little fingers of mucosa​

   1. Microvilli: more fingers on individualcells​

What are the regions of the colon

1. Ascending: up toward liver​

2. Transverse: across toward spleen​

3. Descending: down​

4. Sigmoid: S-shaped​

What is defication reflux

stretching of rectum​