Digestive System 1

Question 1

What two categories are Digestive system made of?

Answer 1

GI organs and accessory structures

Question 2

How does the GI tract run?

Answer 2

Mouth, through thoracic, abdominopelvic cavities to the anus.

Question 3

5 GI tract organs?

Answer 3

Pharynx, esophagus, stomach, small intestine, and large intestine.

Question 4

What are accessory digestive structures?

Answer 4

Mouth, salivary glands, liver, gall bladder, and pancreas.

Question 5

What are the 6 digestive processes?

Answer 5

Ingestion, secretion, propulsion, digestion, absorption and defecation

Question 6

What are the functions of Accessory structures?

Answer 6

Send secretions into the GI to help in the process of ingestion, and digestion.

Question 7

What is ingestion?

Answer 7

The intake of food and water into the mouth

Question 8

What is secretion?

Answer 8

The secretion of chemicals, enzymes, salts, sodium bicarbonate, buffers, HCL, and water into GI

Question 9

What is propulsion?

Answer 9

Peristalsis (movement) and churning of food along the GI tract

Question 10

What is digestion?

Answer 10

The mechanical and chemical breakdown of food into smaller particles for absorption

Question 11

What is absorption?

Answer 11

The absorption of selective products or nutrients from digestion into digestive cells and bloodstream

Question 12

What is defecation?

Answer 12

The elimination of indigestible, undigested and waste products from the body

Question 13

What are the 4 membranes of the GI tract?

Answer 13

Mucosa, submucosa, muscularis, and serosa/adventita from deep to outer

Question 14

What is the mucosa?

Answer 14

The innermost membrane that encircles the lumen and functions to secrete, protect and absorb

Question 15

What are the layers of the mucosa?

Answer 15

Epethelium - type depends on function of digestive region, majority lined with stratified squamous, Lamina propria - connective tissue embedded with capillaries for nutrient absorption, muscularis mucosae - muscle fiber that provides motor function for the mucus

Question 16

What is the submucosa?

Answer 16

Made of areolar connective tissue, vascularized with types of capillaries and regulate diameter of vessel, and mucus release throughout GI, and house majority nerves

Question 17

What is the muscularis?

Answer 17

Mainly of smooth muscle except from mouth to pharynx, upper region of esophagus and external anal sphincter, produce muscle contractions through longitudinal and circular muscle layer to push food through tract

Question 18

What is the serosa?

Answer 18

Outermost layer of serous membrane that binds all layers, and secretes serous fluid to reduce friction during overlap

Question 19

What are the functions of the mouth?

Answer 19

Biting, chewing, mixing, and swallowing food.

Question 20

What is the tongue made of?

Answer 20

Skeletal muscle.

Question 21

What are the two structures of the tongue?

Answer 21

Extrinsic muscles and intrinsic muscles

Question 22

What are the functions of the extrinsic muscle?

Answer 22

Connect the tongue to the nearby structures and change the position of the tongue – side to side, in and out, and chewing and shaping food into a bolus for swallowing.

Question 23

What are the functions of intrinsic muscle?

Answer 23

Alter the shape, and width of the tongue, and help with speech and swallowing.

Question 24

What is mastication?

Answer 24

The chewing of food

Question 25

What happens during mastication?

Answer 25

Food is repositioned by the tongue for chewing and the mixing of food with saliva to form a clump of semi-digested food towards the throat.

Question 26

What is a bolus?

Answer 26

ball of chewed food mixed with saliva

Question 27

What is the pharynx?

Answer 27

Throat - common pathway for food and air

Question 28

What is the esophagus?

Answer 28

long muscular tube that connects throat to stomach

Question 29

What is the structure of the esophagus?

Answer 29

Lined with stratified squamous, skeletal upper (voluntary sphincter), smooth muscle lower (involuntary sphincter)

Question 30

What is deglutition?

Answer 30

Swallowing

Question 31

What happens during deglutition?

Answer 31

Occurs in three stages - voluntary pass of bolus into oropharynx, involuntary pass into esophageous, involuntary pass into stomach

Question 32

What happens during voluntary deglutition?

Answer 32

Food is shaped into a bolus in the mouth and pushed towards the back of throat

Question 33

What happens during the pharyngeal stage?

Answer 33

The tongue rises against the palates, causing soft palates and uvula to closes off entry of food into the nasopharynx, while the epiglottis covers the larynx (briefly reduces breathing), and food is passed into the esophagus

Question 34

What happens during the esophageal stage?

Answer 34

Muscularis contractions of longitudinal/circular muscle push bolus down the relaxed lower esophageal sphincter into stomach

Question 35

What are intrinsic salivary glands?

Answer 35

Glands under the mucous membrane of the mouth, lips, cheeks and tongue and continuously release saliva to keep the mouth moist and hydrated.

Question 36

What are extrinsic salivary glands?

Answer 36

Glands that produce saliva only in response to food entry into the mouth, to dissolve, lubricate and initiate the chemical digestion of food and regulated by brain stem.

Question 37

What are the three extrinsic salivary glands, and where are they located?

Answer 37

Parotid - near ear, submandibular - floor of mouth, sublingual - beneath tongue

Question 38

Function of Parotid gland?

Answer 38

Secrete watery saliva containing amylase

Question 39

Function of submandibular gland?

Answer 39

Secrete amylase and mucus to thicken saliva

Question 40

Function of sublingual gland?

Answer 40

Secrete mainly mucus and little amylase

Question 41

Composition of Saliva?

Answer 41

99.5% H2O, 0.5% solutes and enzymes, mucus, lysosome, immunoglobulins, urea

Question 42

Functions of saliva?

Answer 42

Moisten & hydrate mouth, begin digestion of carbs, clump food into bolus, protect teeth, neutralize acidic foods - through bicarbonate & dissolve food through taste receptors