Exam 4 - Digestive System 1

Question 1

Ingestion

Answer 1

intake of food

Question 2

Digestion

Answer 2

mechanical and chemical breakdown of food

Question 3

Absorption

Answer 3

uptake of nutrients (into blood/lymph)

Question 4

Defecation

Answer 4

elimination of undigested residue

Question 5

Mechanical digestion

Answer 5

• PHYSICAL BREAKDOWN of food into smaller particles

- responsibility of TEETH and CHURNING ACTION OF STOMACH and intestines

Question 6

Chemical digestion

Answer 6

• series of HYDROLYSIS reactions that break macromolecules into their MONOMERS
• involves enzymes from SALIVA, STOMACH, PANCREAS, and INTESTINES

Question 7

Digestive tract (GI tract)

Answer 7

• 30 foot long TUBE extending from mouth to anus

- LUMINAL CONTENTS are considered EXTERNAL TO BODY

Question 8

Accessory organs

Answer 8

• teeth
• tongue
• salivary glands
• liver
• gallbladder
• pancreas

Question 9

How are the functions of the digestive tract controlled?

Answer 9

• Nervous system
• Hormones
• Paracrine secretions

Question 10

Nervous system: short myenteric reflexes (swallowing)

Answer 10

Stretching or chemical stimulation acts through MYENTERIC PLEXUS to produce contractions in muscularis externa (muscularis layer)

Question 11

Where is the myenteric plexus?

Answer 11

between the MUSCULARIS MUCOSAE and MUSCULARIS LAYER

Question 12

Nervous system: long vagovagal reflexes

Answer 12

(parasympathetic stimulation of digestive motility and secretion)
- act through autonomic fibers and carry sensory signals from digestive tract to CNS, and motor signals back to digestive tract

Question 13

Hormones that control digestive tract

Answer 13

messengers diffuse into bloodstream to reach distant targets

EX) gastrin, secretin

Question 14

Paracrine secretions that control digestive tract

Answer 14

messengers diffuse to nearby target cells

EX) histamine, prostaglandins

Question 15

intrinsic muscles of the tongue

Answer 15

change the shape of the tongue (making a taco)

Question 16

extrinsic muscles of the tongue

Answer 16

protrude or retract tongue and move it from side to side

Question 17

Styloglossus m.

Answer 17

pulls your tongue back

Question 18

Hyoglossus m.

Answer 18

pulls your tongue down

Question 19

Genioglossus m.

Answer 19

sticks out the tongue

Question 20

Primary, deciduous, milk, baby teeth

Answer 20

• 20 teeth that start erupting at 6 MONTHS

- 1 PAIR OF TEETH PER MONTH (until you get 20)

Question 21

Permanent or secondary teeth (adult teeth)

Answer 21

• 32 teeth total

- erupt between age 6 and 12

Question 22

Incisors

Answer 22

used for biting (flat, narrow surface that slice food)

Question 23

Canines/cuspids

Answer 23

tearing (vampire teeth)

Question 24

Premolars and molars

Answer 24

crushing and grinding (2 humps - bicuspids, multiple humps - molars)

Question 25

Anatomic crown

Answer 25

enamel-covered part of tooth

Question 26

Clinical crown

Answer 26

section of tooth above the gum line

Question 27

Neck

Answer 27

enameled part of tooth below gum line

Question 28

Dentin

Answer 28

living, cellular, calcified tissue

Question 29

Pulp cavity

Answer 29

filled w/ blood vessels, nerves and connective tissue

Question 30

Periodontal ligaments

Answer 30

hold tooth in socket

Question 31

Gingiva

Answer 31

dense, fibrous connective tissue covered by stratified squamous epithelium

Question 32

Cementum

Answer 32

bone-like substance which is penetrated by periodontal ligament

Question 33

Where does a cavity have to penetrate when you experience at tooth ache?

Answer 33

pulp cavity