Digestive System (quiz 3)

Question 1

What are the 2 ways to get out of the GI tract?

Answer 1

absorption or excretion

Question 2

The digestive system consists of the digestive tract- oral cavity, esophagus, stomach, small and large intestines, and the anus- and its associated glands/structures are….

Answer 2

salivary glands, liver, and pancreas

Question 3

The inner layer of the entire digestive tract forms an important protective barrier between the content of the tract’s _________ and fluids of the body

Answer 3

lumen

Question 4

The GI tract is a hollow tube with a lumen of variable diameter and a wall made up of 4 main layers. What are they?

Answer 4

-mucosa
-submucosa
-muscularis
-serosa

Question 5

The oral cavity is lined with which tissue?

Answer 5

stratified squamous epithelium

may be keratinized, partially keratinized, or nonkeratinized depending on the location

Question 6

In the oral cavity, the keratinized cell layers resists damage from abrasion and are best developed in the…

Answer 6

masticatory mucosa on the gingiva (gum) and hard palate

Question 7

In the oral cavity, the nonkeratinized squamous epithelium predominates in the lining mucosa over the….

Answer 7

soft palate, cheeks, the floor of the mouth, and the pharynx

Question 8

In the oral cavity, the lining mucosa overlies a thick submucosa containing _________________ which secrete continuously to keep the mucosal surface wet and diffuse lymphoid tissue

Answer 8

salivary glands

Question 9

The tongue is a mass of ____________ muscle covered by mucosa, which manipulates ingested material during mastication and swallowing. The muscle fibers are oriented in all directions, allowing a high level of mobility.

Answer 9

striated

Question 10

What does glossus mean?

Answer 10

mechanically breakdown food (tongue and hard palate do this)

Question 11

Taste buds are structures within the stratified epithelium on the tongue’s surface. A taste bud has 50-100 cells, about half of which are elongated ____________ cells/neurons

Answer 11

gustatory

Question 12

What are papillae?

Answer 12

projections on the surface of the tongue that holds clusters of epithelial cells w/ neurons

the clusters are called taste buds which contain gustatory cells/neurons (the gustatory cells are receptors for neurons)

Question 13

There are ______ permanent teeth, arranged in 2 bilaterally symmetric arches in the maxillary and mandibular bones

Answer 13

32 (these are secondary dentition)

Question 14

Each tooth has a _________ exposed above the gingiva, a constricted __________ at the gum, and one or more ___________ that fit firmly into bony sockets in the jaws called dental alveoli

Answer 14

crown, neck, roots

Question 15

The crown of a tooth is covered by a very hard acellular __________

Answer 15

enamel

Question 16

The roots of a tooth are coated by a bone-like tissue called ____________

Answer 16

cementum

Question 17

The enamel and cementum of the tooth meet where?

Answer 17

at the neck of the tooth

(enamel covers the crown, cementum covers the roots)

Question 18

The bulk of a tooth is composed of calcified material called dentin which surrounds an internal….

Answer 18

pulp cavity (arteries and veins are here)

Question 19

Dental pulp is highly vascular and consists largely of _____________________ CT

Answer 19

loose mesenchymal

(these are stem cells that help replace odontocytes)

Question 20

Food mixed with saliva and is mechanically chewed up is called what?

Answer 20

bolus

Question 21

The esophagus is a muscular tube that transports material from where to where?

Answer 21

from pharynx to the stomach

Question 22

The esophageal mucosa has what type of tissue?

Answer 22

nonkeratinized stratified squamous epithelium

Question 23

In the esophagus, the submucosa contains small mucus-secreting glands called the _____________ glands which lubricate and protect the mucosa

Answer 23

esophageal

Question 24

The upper 1/3 of the esophagus has a muscularis layer that is exclusively skeletal muscle. Why?

Answer 24

voluntary control for swallowing and vomiting

Question 25

What tissue is found at the middle portion of the esophagus?

Answer 25

combination of skeletal and smooth muscle fibers

Question 26

What tissue is found at the lower 1/3 of the esophagus, muscularis layer?

Answer 26

exclusively smooth muscle

Question 27

The distal 1-2cm of the esophagus is covered by serosa, the rest is enclosed by the loose CT of the......

Answer 27

adventitia

Question 28

What does the mucosa consist of?

Answer 28

-an epithelial lining -an underlying lamina propria of loose CT rich in blood vessels -lymphatics, lymphocytes, smooth muscle cells, small glands -thin layer of smooth muscle called the muscularis mucosae separating the mucosa from the submucosa and allowing local movements of the mucosa

Question 29

What is another name for the mucosa?

Answer 29

mucous membrane

Question 30

The submucosa contains denser CT with larger blood and lymph vessels than the mucosa. The submucosal layer also contains a _______________ plexus of autonomic nerves, glands, and significant lymphoid tissue

Answer 30

Meissner

Question 31

The thick muscularis or muscularis externa, is composed of smooth muscle cells organized as _____ sublayers. The internal sublayer (closer to the lumen) has a fiber orientation that is generally circular, and the external sublayer is longitudinal. The CT between the muscle sublayers contains blood and lymph vessels, and the _____________________ nerve plexus. Contractions of the muscularis, which mix and propel the luminal contents forwards, are generated and coordinated by the myenteric plexus

Answer 31

2+, myenteric (Auerbach)

Question 32

The serosa is a thin sheet of loose CT that is rich in blood vessels, lymphatics, and adipose tissue. It is covered with a simple squamous covering epithelium or _______________.

Answer 32

mesothelium

Question 33

What layer is this? It is the outermost layer of the digestive tract located within the abdominal cavity

Answer 33

serosa

Question 34

The serosa of the small and large intestines is continuous with portions of the ____________, which is a large fold of adipose CT covered on both sides by mesothelium that suspends the intestines

Answer 34

mesentery

Question 35

What tissue is found in the esophagus compared to the stomach?

Answer 35

esophagus = stratified squamous stomach = simple columnar

Question 36

The stomach is a greatly dilated segment of the digestive tract. It is made up of 4 major regions. What are they?

Answer 36

-cardia -fundus -body -pylorus

Question 37

What part of the stomach is this? narrow transitional zone between the esophagus and the stomach

Answer 37

cardia

Question 38

What part of the stomach is this? funnel-shaped region that opens into the small intestine

Answer 38

pylorus

Question 39

What 2 regions of the stomach are primarily involved with mucus production and are histologically similar?

Answer 39

cardia and pylorus

Question 40

What 2 regions of the stomach are identical in microscopic structure and are the sites of gastric glands releasing acidic gastric juice?

Answer 40

fundus and body

Question 41

The mucosa and the submucosa of the empty stomach have large, longitudinally directed folds called _________, which flatten when the stomach fills with food

Answer 41

rugae (not seen when stomach is full)

Question 42

At the esophagogastric junction, stratified squamous epithelium lining the esophagus is abruptly replaced by....

Answer 42

simple columnar epithelium

Question 43

The mucosa of the stomach wall contains invaginations called gastric pits that lead into ____________. These structures are lined by simple columnar epithelium containing 5 functional cell types

Answer 43

gastric glands

Question 44

What is chyme?

Answer 44

once bolus but has been converted to liquid form in the stomach

Question 45

What cells are found within the fundus and body regions of the stomach (gastric pit > gastric gland)?

Answer 45

-mucus cells -parietal cells -chief cells -endocrine cells

Question 46

Where are the mucus cells found?

Answer 46

at the top of the gastric pits (within the fundus and body regions of the stomach)

Question 47

What do mucus cells do?

Answer 47

release mucus through exocytosis and line the stomach the mucus protects the stomach from its own acid

Question 48

What do parietal cells do?

Answer 48

secrete HCI (low pH will unfold protein and denture it in the stomach)

Question 49

What do chief cells do?

Answer 49

release pepsinogens (hits HCI and then becomes pepsin to breakdown proteins within the stomach

Question 50

What do endocrine cells do?

Answer 50

release hormones/chemical messengers into the stomach

Question 51

The muscularis has 3 layers within the stomach. What are they?

Answer 51

-outer longitudinal layer -middle circular layer -innermost oblique layer (these layers are used for rhythmic contractions to mix ingested food (bolus) and chyme with mucus, HCI, and digestive enzymes)

Question 52

What is the small intestine designed for?

Answer 52

absorption and get in as many nutrients as possible

Question 53

The small intestine is where nutrients (products of digestion) are absorbed by cells of the.....

Answer 53

epithelial lining

Question 54

What are the segments of the small intestines?

Answer 54

-duodenum -jejunum -ileum these 3 segments are similar in histological features

Question 55

The lining of the small intestine has permanent circular or semilunar folds called __________________, consisting of mucosa and submucosa. Covering the entire mucosa are short villi that project into the lumen. The villi are covered by a simple columnar epithelium with microvilli

Answer 55

pilcae circulares (pleated to increase SA)

Question 56

What organs empty its contents into the small intestine?

Answer 56

liver, gallbladder, and pancreas

Question 57

The pancreas releases how many enzymes into the small intestine? For what?

Answer 57

4 enzymes to breakdown carbs, lipids, proteins, and nucleic acids

Question 58

What does the gallbladder release into the small intestine?

Answer 58

bile (detergent to emulsify fats)

Question 59

What is the largest internal/visceral organ?

Answer 59

liver

Question 60

How many lobes does the liver have?

Answer 60

2 major lobes (L and R) and 2 smaller inferior lobes

Question 61

Which organ is the major interface between the digestive system and the blood?

Answer 61

liver (nutrients absorbed in the small intestine are processed in the liver before distribution throughout the body)

Question 62

What are the key cells of the liver and the most functionally diverse cells of the body?

Answer 62

hepatocytes (large cuboidal or polyhedral epithelial cells, with large, round central nuclei and eosinophilic cytoplasm rich in mitochondria)

Question 63

The liver parenchyma is organized as thousands of small lobules in which hepatocytes form hundreds of irregular plates arranged radially around a small central vein. Peripherally, each lobule has 6 portal areas each of which contains 3 structures that form the....

Answer 63

portal triad