animal digestion

Question 1

What are the three dietary categories ?

Answer 1

Herbivores, omnivores, carnivores

Question 2

What is ingestion?

Answer 2

taking in of food into the body

Question 3

what is digestion ?

Answer 3

Breaking the food down into smaller pieces

Question 4

what is absorption ?

Answer 4

Food molecules enter body cells

Question 5

what is elimination?

Answer 5

removal of undigested waste material

Question 6

What is intracellular

Answer 6

within a cell
eg. food vacuole and lysosomes

Question 7

what is extracellular

Answer 7

in a specific compartment
eg, gastrovascular cavity

Question 8

why do animals process food in compartments ?

Answer 8

to avoid self-digestion

Question 9

What are the functions of a gastrovascular cavity ?

Answer 9

Digests food and distributes nutrients

Question 10

Describe digestion in animals with simple body parts

Answer 10

Digestion begins in cavity (gastrodermis secretes enzymes) and is completed intracellularly.engulfed by nutritive muscular cells) Excreted out through the mouth

Question 11

what is a gastrovascular cavity ?

Answer 11

a tube with one opening everything has to go in and out through this opening

Question 12

complete digestive system

Answer 12

2 openings

Question 13

incomplete digestive system

Answer 13

1 opening

Question 14

what forms the bolus in the oral cavity?

Answer 14

salivary amylase+mucin+food=bolus

Question 15

what does salivary amylase hydrolyse?

Answer 15

starch and gylcogen

Question 16

how does food move down the esophagus ?

Answer 16

food moves to stomach by involuntary contractions (peristalsis)

Question 17

What is the role of the epiglottis ?

Answer 17

when you swallow the epiglottis covers the glottis to prevent food from entering the trachea

Question 18

peristalsis

Answer 18

waves of muscular contraction

Question 19

Breakdown of carbohydrates

Answer 19

polysaccharides broken down by salivary amylase to form maltose in the oral cavity.
Polysaccharide broken down into maltose and other disaccharides by pancreatic amylase in the lumen of the small intestine.
Disaccharides broken down into monosaccharides by disaccharidases in the epithelium of small intestine.

Question 20

protein digestion

Answer 20

proteins to small polypeptides by pepsin in stomach.
Polypeptides to smaller polypeptides by pancreatic trypsin and chymotrypsin in lumen of small intestine.
Smaller polypeptides to amino acids by pancreatic carboxypeptidase in lumen of small intestine.
Small peptides to amino acids by dipeptidases, carboxypeptidase and aminopeptidase in epithelium of small intestine.

Question 21

Nucleic acid digestion

Answer 21

DNA,RNA to nucleotides by pancreatic nucleases in the lumen of the small intestine.
Nucleotides to nucleosides by nucleotidases in small intestine.
Nucleosides to nitrogenous bases, sugars and phosphates by nucleosides and phosphatases in the epithelium of the small intestine.

Question 22

fat digestion

Answer 22

fat globules to fat droplets by bile salts.
fat droplets to glycerol, fatty acids and glycerides by pancreatic lipase. All in the lumen of the small intestine.

Question 23

What happens if the stomach doesn’t have a lining ?

Answer 23

Ulcers

Question 24

Why is mucus important?

Answer 24

to protect from HCL

Question 25

Describe the gastric gland

Answer 25

It has three different types of cells that secrete different components of gastric juice. : mucus cells, chief cells and parietal cells

Question 26

Mucus cells

Answer 26

secrete mucus which lubricates and protects the cells lining the stomach

Question 27

Chief cells

Answer 27

secrete pepsinogen. an inactive form of the digestive enzyme pepsin. HCL converts pepsinogen to pepsin.

Question 28

parietal cells

Answer 28

secrete hydrochloric acid

Question 29

Do gastric juices contain HCL.

Answer 29

yes

Question 30

what is chyme?

Answer 30

Gastric juices and partly digested food

Question 31

what causes heartburn?

Answer 31

backflow of acid chyme through cardiac orifice

Question 32

What does the pyloric sphincter do?

Answer 32

Regulates passage of chyme to the small intestine.

Question 33

what are some glands in the human body?

Answer 33

salivary glands, gallbladder, liver and pancreas

Question 34

Duodenum

Answer 34

First part of intestine. enzymes are secreted from pancreas.

Question 35

what activates proteases

Answer 35

trypsin

Question 36

what is the endocrine function of the pancreas?

Answer 36

secretion of insulin and glucagon into the blood

Question 37

what is the exocrine function of the pancreas?

Answer 37

Secretion of digestive enzymes into the duodenum

Question 38

What produces bile?

Answer 38

the liver produces bile which is stored in the gallbladder

Question 39

what does bile consist of?

Answer 39

Bile salts which act as emulsifiers (fat digestion)
pigments from destruction of red blood cells

Question 40

Enterogastrone

Answer 40

secreted by the duodenum inhibits peristalsis and acid secretion by the stomach. slowing digestion when acid chyme rich in fats enters the duodenum.

Question 41

Gastrin

Answer 41

from the stomach recirculates back to the stomach where it stimulates the production of gastric juices.

Question 42

Secretin

Answer 42

Secreted by the duodenum, stimulates the pancreas to release sodium bicarbonate which neutralises acid chyme.

Question 43

Cholecystokinin

Answer 43

triggered by amino acids or fatty acids in the duodenum. it stimulates the release of digestive enzymes from the pancreas and bile from the gallbladder.

Question 44

how long is the colon?

Answer 44

1.5 m

Question 45

Three functions of the colon?

Answer 45

Reabsorption of water, absorption of vitamins, production of faeces.