Digestive Anatomy and Processes Pt 1

Question 1

sequence for the movement of food through the gastrointestinal tract

Answer 1

• take in food
• break food down into its component parts (nutrient molecules)
• absorb the nutrient molecules into the bloodstream
• rid the body of any indigestible remains

Question 2

Accessory organs

Answer 2

teeth, tongue, gallbladder, digestive glans

Question 3

Digestive glands

Answer 3

salivary glands, liver, pancreas

Question 4

ingestion

Answer 4

eating

Question 5

propulsion

Answer 5

moving food through the GI tract

Question 6

peristalsis

Answer 6

rhythmic waves of smooth muscle contraction - propels food through the GI tract

Question 7

mechanical breakdown

Answer 7

chewing, mixing food with saliva, churning food, segmentation

Question 8

segmentation

Answer 8

local constrictions of the SI to mix food with digestive juices

Question 9

digestion

Answer 9

series of catabolic steps in which enzymes break complex food molecules down into their chemical building blocking

Question 10

absorption

Answer 10

passage of digested fragments from the lumen of the GI tract into blood/lymph

Question 11

peritoneum

Answer 11

robust serous membranes of the abdominopelvic cavity

Question 12

visceral peritoneum

Answer 12

membrane on the external surface of most digestive organs

Question 13

parietal peritoneum

Answer 13

membrane on the wall of the abdominal cavity

Question 14

peritoneal cavity

Answer 14

• fluid filled space between the two peritoneum
• fluid lubricates the mobile organs

Question 15

mesentery

Answer 15

a double-layer of peritoneum – extends to the digestive organs from the abdominal walls

• provides routes for blood vessels, lymphatics, and nerves
• holds organs in place and stores fat

Question 16

peritoneal organs

Answer 16

organs located within the peritoneal cavity

Question 17

retroperitoneal organs

Answer 17

organs located outside - posterior to - the peritoneum

Question 18

4 tunics of the GI tract

Answer 18

1. Mucosa
2. Submucosa
3. Muscularis Externa
4. Serosa

Question 19

Mucosa

Answer 19

tunica layer that lines the lumen, a moist epithelial membrane

Question 20

3 sublayers of mucosa

Answer 20

• epithelium
• lamina propria
• muscularis mucosae

Question 21

epithelium

Answer 21

simple, columnar epithelium rich in mucus-secreting cells
- the mouth, esophagus, anus are stratified, squamous
- protects digestive organs from enzymes, eases food passage
- may create and secrete its own enzymes and hormones

Question 22

lamina propria

Answer 22

loose, areolar connective tissue
- rich supply of capillaries for nourishment and absorption
- may create lymphoid follicles to defend against microbes

Question 23

muscularis mucosae

Answer 23

very thin layer of smooth muscle

Question 24

functions of mucosa

Answer 24

• secretes mucus, digestive enzymes, hormones
• absorbs the end products of digestion
• protects against infectious disease

Question 25

Submucosa

Answer 25

- areolar connective tissue - contains blood and lymphatic vessels, lymphoids follicles, and a nerve plexus - abundant number of elastic fibers to help organs regain their shape after storing a large meal

Question 26

muscularis Externa

Answer 26

- muscle layer responsible for segmentation and peristalsis - contains an inner, circular muscle layer and an outer, longitudinal muscle layer - the circular layer occasionally thickens to form sphincters

Question 27

Sphincters

Answer 27

act as valves to prevent backflow and control the passage of food

Question 28

serosa

Answer 28

- outermost, superficial layer - same as visceral peritoneum - formed from areolar connective tissue covered with mesothelium - replaced by fibrous adventitia in the esophagus - retroperitoneal organs have both an adventitia and a serosa

Question 29

sphenic circulation

Answer 29

arteries that branch off the abdominal aorta to serve the digestive organs and hepatic portal circulation

Question 30

Arterial supply

Answer 30

- branches of the celiac trunk supply the spleen, liver and stomach - mesenteric arteries supply the large and small intestines

Question 31

hepatic portal circulation

Answer 31

collects nutrient-rich venous blood draining from the digestive viscera and brings it to the liver

Question 32

The GI tract's own nervous system is called the

Answer 32

enteric nervous system

Question 33

SLide 15

Question 34

structure on slide 19

Question 35

What is found in saliva

Answer 35

- mostly water and slightly acidic - contains electrolytes, salivary amylase, mucin, lysozyme, urea, IgA antibodies, and defensins

Question 36

functions of saliva

Answer 36

- cleanse the mouth - dissolved food chemicals for taste - moisten food, compact it into a bolus - begin breakdown of starch with the enzyme salivary amylase

Question 37

3 salivary glands

Answer 37

- parotid - submandibular - sublingual

Question 38

parotid

Answer 38

anterior to the eat, external to the masseter; parotid duct to the oral vestibule

Question 39

submandibular

Answer 39

medial to the body of the mandible; duct to the base of lingual frenulum

Question 40

sublingual

Answer 40

anterior to the submandibular; opens to the floor of the mouth via 10-12 ducts

Question 41

How many mature permanent teeth are there

Answer 41

32

Question 42

deciduous teeth

Answer 42

- 20 baby teeth - erupt between 6 and 24 months

Question 43

incisors

Answer 43

chisel shaped for cutting

Question 44

canines

Answer 44

fang-like for tearing, piercing

Question 45

premolars (bicuspids)

Answer 45

broad crowns with rounded cusps, used to grind/crush

Question 46

molars

Answer 46

broad crowns with rounded cusps, best for grinding

Question 47

where does the esophagus pierce through the diaphragm

Answer 47

esophageal hiatus

Question 48

gastroesophageal/cardiac sphincter

Answer 48

surrounds the orifice - orifice is close when food is not being swallowed - mucus cells on both sides of the sphincter helps protect the esophagus from acid reflux

Question 49

heartburn

Answer 49

- burning, radiating, substernal - pain; mimics MI pain cause: regurgitation of starch acid into the esophagus - symptoms: GERD

Question 50

hiatal hernia

Answer 50

- structural abnormality caused by abnormal weakening of the gastroesophageal sphincter - superior portion of the stomach protrudes above the diaphragm

Question 51

deglutination

Answer 51

swallowing

Question 52

2 phases of deglutination

Answer 52

- buccal phase - pharyngeal esophageal phase

Question 53

buccal phase

Answer 53

voluntary contraction of the tongue

Question 54

pharyngeal-esophageal phase

Answer 54

involuntary phase driven by the vagus nerve; controlled in the swallowing centers of the medulla and lower pons; respiration is momentarily inhibited, and all undesired routes are blocked