* Chapter 39

Question 1

Difference between incomplete and complete digestive system?

Answer 1

Incomplete: has one opening and is bidirectional (For example a flatworm)
Complete: a tube with two openings, allowing food to move in one direction through lumen, unidirectional-> travels to specialized regions and whatever not absorbed leaves butt.

Question 2

the digestive tube is how long…?

Answer 2

30 ft long, 20 ft of it consists of small intestine

Question 3

function of the esophagus

Answer 3

connects mouth to stomach

Question 4

what makes up the alimentary canal?

Answer 4

the mouth, esophagus, stomach, small intestine, large intestine

Question 5

What are the accessory organs and their functions?

Answer 5

• Salivary glands: secrete liquid that contains digestive enzyme amylase, to aid digestion & neutralize acids
  This accessory organ secretes saliva into mouth (enzymes), that moisten food for easier swallowing, initiate chemical break down of food, and dissolves food components enabling you to taste food
• pancreas: regulates blood sugar (insulin - & glycogen +),
  secretes enzymes to break down carbohydrates +fats +protein
• Liver: largest internal organ we have, produces bile
• Gallbladder: Stores and releases bile

Question 6

Complete digestion of proteins=
Complete digestion of carbohydrates=
Complete digestion of DNA=

Answer 6

• amino acids
• monossacchraids
• Nucleotides

Question 7

What does saliva contain and what are their functions?

Answer 7

• Salivary amylase: catalyzes the hydrolysis of starch into disacchrides. Begins carbohydrates digestion. break carb polyssaccarides
• Bicarbonate: neutralizes acids and protects inner lining of mouth mouth from acidic food
• mucins: lubricate and stick substances that bind food together into a ball to swallow with ease

Question 8

Functions of the tongue?

Answer 8

1. tongue exerts initial force on ball of food to go to the esophagus
2. mix food with saliva
3. tastebuds help us chose food to ingest
4. taste buds also help us compare normal foods so we dont get food poisoning
5. taste= happiness, so system wants

Question 9

food moves down esophagus by _______

Answer 9

rhythmic peristaltic contractions

Question 10

What type of muscle tissue lines the entire digestive tube?

Answer 10

smooth muscle tissue

Question 11

What is the Sphincter?

Answer 11

ring of smooth muscle tissue that can contract, close junction and open junction to determine how much food goes down stomach

Question 12

The stomach is a muscular sac that …..

Answer 12

stores and mixes food, secretes substances that dissolve and degrade food, and controls the rate at which food enters the small intestine

Question 13

Gastric fluid consists of …?

Answer 13

hydrochloric acid, pepsinogen (inactive) and mucus

Question 14

what is HCI

Answer 14

dissolves bits of food to form a soupy chyme (dissolved food)
it also converts pepsinogen (inactive) to pepsin (active)

Question 15

pepsin begins the digestion of ____

Answer 15

proteins

Question 16

What protects the stomach lining. What happens if these are blocked?

Answer 16

Mucus and Bicarbonate. If these are blocked, a peptic ulcer may be resulted (holes in lining of stomach)

Question 17

Peristaltic contractions churn the chyme and keep the sphincter of the stomach’s exit ____, but small amounts are released at regular intervals into the ____

Answer 17

closed; small intestine

Question 18

The small intestine is composed of three regions? what are they?

Answer 18

• Duodenum: (beginning of small intestine) where most digestion occurs (complete digestion)
• Jejunum: Central section, place where food is absorbed (longest section), it is the longest so food has more opportunities to be absorbed
• ileum: whatever is left behind will be brought to the large intestine for elimination

Question 19

Secretions from the small intestine contain digestive enzymes such as…?

Answer 19

intestinal peptidase (carbohydrates), lactase (lactose), lipase (lipase) and sucrase (sucrose/sugar).

Question 20

The pancreas secrete digestive enzymes including :

Answer 20

pancreatic amylase: *oolgiossacchrides will be broken down into monosacchrides (saliva amylase does this too)

lipases, nucleases and trypsin and chymotrysin that digest proteins into peptide fragments and carboxypeptidase and aminopeptidase.

These enzymes are taken into duodenum for complete digestion

Question 21

Pancreas consist of exocrine and endocrine glands, describe their functions

Answer 21

Exocrine glands: produce fluids that travel through ducts and most of their fluids go to outside of your body
Endocrine glands: produce and release hormones directly into the blood stream

Question 22

_____ from the pancreas buffers the acid from the stomach

Answer 22

bicarbonate

Question 23

Function of liver

Answer 23

1. liver destroys old blood cells,
2. stores glycogen
3. and adds glucose to the bloodstream when levels drop
4. it produces biles salts which are stored as bile in the gallbladder
5. the liver also stores and synthesizes certain nutrients and detoxifies alcohol and other poisons

Question 24

function of bile

Answer 24

Bile breaks up fat droplets in the small intestine

Question 25

What is emulsification?

Answer 25

break down of lipase into smaller molecules of lipid

Question 26

What are the layers of the small intestinal wall and what are their function?

Answer 26

• The mucosa: the epithelial lining that faces the lumen of the gut; connective tissue underlies it
• The submucosa: contains blood and lymph vessels plus nerve networks
• A muscle layer (longitudinal and circular): is covered with the outermost serosa

Question 27

How is absorptive surface area increased?

Answer 27

by finger-like projections of the intestinal lining called villi, the cells of which bear smaller microvilli

Question 28

what are the absorption mechanisms

Answer 28

1. repeated segmentation contractions create an oscillating movement that mixes the food
2. monosaccharides (glucose) and amino acids cross the gut libing by active transport and enter the bloodstream
3. Triglycerides leave the cells by exocytosis to enter the lymph vessels

Question 29

The large intestine (colon) stores and concentrates feces…. what are feces?

Answer 29

undigested and unabsorbed material, water and bacteria

Question 30

The large intestine begins as a cup-shaped pouch called ____. ____ is at the junction of colon with the small intestine (appendix attached here)

Answer 30

cecum

Question 31

function of pharynx

Answer 31

the pharynx (or throat) is lined with sensory receptors that can detect pressure.
 The pharynx permits the passage of swallowed solids and liquids into the esophagus and conducts air to and from the trachea, or windpipe, during respiration.

Question 32

Mucosa are richly ____

Answer 32

folded

Question 33

villus is made up of

Answer 33

simple columnar

Question 34

function of lymph vessels

Answer 34

carries lipids to adipose tissue to be stored

Question 35

The rectum stores ___

Answer 35

feces

Question 36

sodium is actively transported out of the _____ and water follows

Answer 36

colon

Question 37

what system controls the progression of the material through the colon and its eventual expulsion at the anus?

Answer 37

the nervous system

Question 38

What favors growth of bacteria in the colon?

Answer 38

the slow movement of materials through the colon

Question 39

What are the functions of bacteria residing in the human intestine ?

Answer 39

to break down nutrients and produce vitamins such as vitamin K

Question 40

non-pathogenic bacteria create?

Answer 40

vitamin B

Co-enzymes (NADand FAD)–> ATP
^^^^ derived by vitamin B

Question 41

Feces contain pathogenic bacteria that can _____ if it stays in the intestine too long

Answer 41

infect

Question 42

H20 from large intestine go to ____

Answer 42

hypertonic solution

–> water conservation is very important

Question 43

From feces… H2O is reabsobered by….

Answer 43

osmosis