Digestive System

Question 1

what is the purpose of the digestive system?

Answer 1

Mechanical and chemical breakdown of food, and the absorption of nutrients

Question 2

mechanical digestion

Answer 2

Breaks large pieces into smaller pieces WITHOUT changing the chemical composition

Question 3

chemical digestion

Answer 3

breaks food into simpler chemicals

Question 4

alimentary canal

Answer 4

digestive system tube: open at both ends, has specialized regions

Question 5

lumen

Answer 5

In some areas it is folded over to increase surface area.

Question 6

accessory organs

Answer 6

salivary glands, liver, gallbladder, and pancreas

Question 7

alimentary canal (what it consists of)

Answer 7

mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, anus

Question 8

cheeks and lips (purpose)

Answer 8

Cheeks are outer layers of skin with subcutaneous fat
Help with expressions, chewing, and maintaining a moist inner liner
Lips are highly mobile
Have skeletal and sensory receptors
Used to sense the temperature and texture of foods

Question 9

tongue

Answer 9

Mostly skeletal tissue used to help mix food particles with saliva during chewing and move food to the pharynx during swallowing

Question 10

Frenulum

Answer 10

is the fold on the midline of the tongue that connects it to the floor of the mouth

Question 11

palate

Answer 11

The roof of the oral cavity
Contains a soft (posterior) and hard (anterior) part
Closes off the nasal cavity during swallowing

Question 12

teeth (anatomy and purpose)

Answer 12

2 sets of teeth throughout development
The first is primary and usually erupts from 6 months to 4 years
The second is secondary - appears at 6 years and is complete between 17 and 25 years
Teeth begin mechanical digestion
Front 4 are incisors
Canine (cuspid)
Premolars (bicuspid)
Molars

Question 13

parotid glands

Answer 13

Largest of the major salivary glands
Secrete a clear watery fluid that is rich in amylase
Breaks down carbohydrates

Question 14

Submandibular Glands

Answer 14

Located on the floor of the mouth
Predominantly serous glands
Secrete viscous fluid

Question 15

sublingual glands

Answer 15

Smallest
Below the tongue
Primarily mucous cells
Secretions are thick and stringy

Question 16

nasopharynx

Answer 16

Communicates with the nasal cavity and provides a passageway for air during eating

Question 17

Oropharynx

Answer 17

Posterior to the soft palate
Passageway for food moving downward from the mouth and for air moring to and from the nasal cavity

Question 18

Laryngopharynx

Answer 18

passageway to the esophagus

Question 19

3 stages of swallowing

Answer 19

1. Food is chewed and mixed with saliva. The tongue rolls the mass of food into a bolus and forces it into the pharynx.
2. Swallowing reflex (6 steps)
3. Peristalsis transports food from the esophagus to the stomach

Question 20

swallowing reflex

Answer 20

1. Soft palate raises
2. Hyoid bone and larynx are elevated, and epiglottis closes off the top of the larynx
3. The tongue presses against the soft palate which seals off the oral cavity from the pharynx
4. Longitudinal muscles contract which pulls the pharynx toward the food
5. Muscles in the lower portion of the pharynx relax and open the esophagus
6. Peristaltic waves begin and force food into the esophagus

Question 21

esophagus

Answer 21

Straight collapsible tube that connects the pharynx to the stomach

Question 22

Where is the pancreas

Answer 22

Extends horizontally across the abdomen in the C-shape of the duodenum.

Question 23

pancreas

Answer 23

secretes insulin which breaks down sugars
Pancreatic Juice also breaks down fat
Both Chemicals empty into the duodenum

Question 24

structure of the liver

Answer 24

Right lobe and a smaller left lobe
Each lobe is separated into hepatic lobules
A lobule contains many hepatic cells that radiate from the central vein
Hepatic sinusoids separate the groups of cells
Kupffer cells remove bacteria or other foreign particles

Question 25

functions of the liver

Answer 25

1. Maintain blood glucose levels
2. breakdown of lipids and fats
3. protein metabolism
4. stores vitamins
5. recycles RBCs
6. removes toxins
7. secretes bile

Question 26

bile

Answer 26

yellowish-green liquid aids in digestion, breakdown of fat

Question 27

gallbladder

Answer 27

stores bile

Question 28

3 sections of the small intestine

Answer 28

Duodenum
jejunum
ileum

Question 29

small intestine wall

Answer 29

The inner wall appears velvety due to little projections of mucous membrane called intestinal villi

Question 30

secretions of small intestine

Answer 30

mucus, thick alkaline mucus, Peptidase, sucrase, maltase, lactase

Question 31

absorption of the small intestine

Answer 31

Most important absorbing organ of the alimentary canal because of villi
Intestinal villi absorb the broken-down materials that the specific enzymes create earlier in the alimentary canal

Question 32

amylase

Answer 32

breaks down starch and glycogen

Question 33

pepsin

Answer 33

begin protein digestion

Question 34

lipase

Answer 34

breaks down fats into fatty acids and glycerol

Question 35

nucleases

Answer 35

breaks down nucleic acids in nucleotides

Question 36

peptidase

Answer 36

breaks down peptides into amino acids

Question 37

sucrase, maltase, lactase

Answer 37

breaks down disaccharides (complex sugars) into monosaccharides (simple sugars)

Question 38

movement small intestine

Answer 38

Mixing and peristalsis
Small, and periodic movements → takes about 3 to 10 hours to travel the length of the small intestine
The ileocecal sphincter joins the small intestine to the large intestine

Question 39

anatomy of large intestine

Answer 39

roughly 1.5 meters.
Composed of 4 major sections
Cecum
Colon
Rectum
Anal canal

Question 40

colon

Answer 40

Ascending, transverse, descending, sigmoid

Question 41

functions of large intestine

Answer 41

Little digestive function - only secretes mucus
Absorbs water and electrolytes from the chyme in the alimentary canal
Forms and stores feces
break down molecules that pass through the rest of the digestive tract

Question 42

intestinal flora

Answer 42

bacteria that normally inhabit the large intestine

Question 43

movement of large intestine

Answer 43

Mixing and peristalsis
Movements are slower and less often (2 or 3 times a day)

Question 44

feces

Answer 44

undigested materials, water (75%), electrolytes, mucus, ched intestinal cells, and bacteria.

Question 45

Walls of alimentary canal (4)

Answer 45

Mucosa (inner)
Submucosa
Muscular layer
Serosa layer (outer)