Digestion Test Flashcards
(98 cards)
1
Q
aliment-
A
food (alimentary canal)
2
Q
chym-
A
juice (chyme)
3
Q
decidu-
A
falling off (deciduous teeth)
4
Q
gastr-
A
stomach (gastric gland)
5
Q
hepat-
A
liver (hepatic duct)
6
Q
lingu-
A
tongue (lingual tonsils)
7
Q
nutri-
A
nourish (nutrient)
8
Q
peri-
A
around (peristalsis)
9
Q
pyl-
A
gatekeeper (pyloric sphincter)
10
Q
vill-
A
hairy (villi)
11
Q
What is digestion?
A
mechanical and chemical breakdown of food and the absorption of the resulting nutrients by cells
12
Q
define mechanical deigestion
A
breakdown larger pieces into smaller ones
13
Q
define chemical digestion
A
breaks food into simpler chemicals
14
Q
where does chemical digestion start?
A
in the mouth with saliva
15
Q
while individual metabolism rates are different, how long does food take to pass through the alimentary canal?
A
normally 18-20 hours
16
Q
What is the alimentary canal?
A
digestive system from mouth to anus with accessory organs which secrete substances into the canal
17
Q
Name the parts of the alimentary canal.
A
mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, and anus
18
Q
Name the accessory organs associated with the alimentary canal.
A
salivary glands, liver, gallbladder, pancreas
19
Q
What is a general characteristic of the alimentary canal?
A
8 feet long
20
Q
Describe the structure of the alimentary canal wall.
A
made up of 4 layers
(innermost) mucosa, submucosa, muscular layer, and lastly the (outermost layer) serososa
21
Q
Describe the mucosa or mucous membrane
A
- surface epithelium underlying connective tissue and small amount of smooth muscle form this layer
- in some regions it is folded with tiny projections that extend in the lumen of the digestive tube. This increases surface area for digestion.
- glands that secrete mucus and digestive enzymes and also protect underlying layers as it carries on secretion and absorption
22
Q
Characterize the submucosa layer
A
- Made of considerable loose connective tissue as well as glands, blood vessels, lymphatic vessels, and nerves
- Its vessels nourish surrounding tissues and carry away absorbed materials
23
Q
Characterize the muscular layer
A
- consists of two coats of smooth muscle tissue that produces movements of the tube
- circular inner fibers contract which cause the tubes diameter to decrease
- longitudinal outer fibers run the length of the tube and when they contract, the length of the tube shortens
24
Q
Characterize the serosa or serous layer
A
- Outer epithelial layer with connective tissue underneath. This is visceral peritoneum
- Cells of the serosa protect underlying tissues and secrete serous fluid to moisten and lubricate the tube’s outer surface, reducing friction with other organs
25
The motor functions of the alimentary canal are of two basic types-
mixing movements and propelling movements
26
What is the mixing movement of the tube?
occurs when smooth muscles in small segments of the tube contract rhythmically
27
What are some examples of mixing movements?
stomach and segmentation (does not follow a set pattern) in the small intestine
28
What is the propelling movement of the tube?
wavelike motion called peristalsis. Ring of contraction occurs in the wall of the tube
29
What is mastication?
the action of when the mouth receives food and begins digestion by mechanically breaking up solid particles into smaller pieces and mixing them with saliva
30
Cheeks and lips-
lipss contain skeletal muscles and sensory receptors for temperature and texture of food
31
Tongue-
a. is covered by a mucus membrane
b. The lingual frenulum connects the midline of the tongue to the floor of the mouth
c. it is mostly skeletal muscle
d. mixes food particles and saliva
e. papillae on the surface provides friction for food and contains taste buds
f. posterior or root of the tongue is anchored to the hyoid bone and covered with lymphatic tissue called lingual tonsils
32
Palate-
forms in the roof of the oral cavity
33
Describe the hard palate
bony anterior part
34
Describe the soft palate
includes the uvula, palatine tonsils and pharyngeal tonsils (adenoids) made of lymphatic tissue to fight off infection
35
How many primary or deciduous teeth do we have?
20 total, 10 in each jaw
36
How many secondary or permanent teeth do we have?
32 total, 16 in each jaw
37
What are the 5 parts of teeth?
1. crown
2. root
3. enamel
4. dentim
5. pulp cavity
38
Where is the crown?
projects beyond the gum
39
What is the root?
part under the gums
40
What is enamel?
part that covers the crown
41
What is dentin?
bulk of the tooth, beneath enamel. Made of bone like substance, but harder
42
What is the pulp cavity?
contains blood vessels, nerves, and connective tissue
43
What do salivary glands do?
secrete saliva
44
What is the purpose of secreting saliva?
i. saliva moistens food, helps bind the particles, and begins chemical digestion of carbohydrates
ii. saliva is also a solvent, dissolving foods so that they can be tasted, and it helps cleanse the mouth and teeth
45
What are the 2 types of secretory cells?
serous cells and mucus cells
46
What do serous cells do?
Serous cells produce watery fluid with salivary amylase to split starch and glycogen into disaccharides
47
What do mucous cells do?
Mucus cells secrete thick mucus to bind food particles and lubricate the food during swallowing
48
What does the parasympathetic nerves have to do with this?
parasympathetic nerve impulses secrete watery saliva when you see, smell taste, or even think about appealing food
49
What are the major salivary glands?
parotid glands, submandibular glands, sublingual glands
50
Describe the parotid glands
inferior to the ear, secrete clear watery fluid with amylase (break down carbohydrates)
51
Describe the submandibular glands
located in the floor of the mouth along the jaw, secrete serous and mucus
52
Describe the sublingual glands
located on the floor of the mouth under the tongue, secrete mucus
53
What does the pharynx do?
connects nasal and oral cavities with the larynx and esophagus
54
What is the function of the nasopharynx?
passageway for air during breathing, auditory tubes connect pharynx with middle ears
55
What is the function of the oropharynx?
passageway for food moving downward and air moving to and from nasal cavity
56
What is the function of the laryngopharynx?
passageway to the esophagus
57
What occurs in the first stage of swallowing?
food is chewed and mixed with saliva. Tongue rolls mixture into a bolus and forces it into the oropharynx
58
What occurs in the second stage of swallowing?
food reaches oropharynx and stimulates swallowing reflex. A peristaltic wave of pharyngeal muscles forces food into the esophagus.
59
What occurs during the third stage of swallowing?
swallowing inhibits breathing momentarily as food is transported from esophagus to stomach
60
Describe the esophagus
straight collapsible tube about 25 cm long and it serves as a passageway from the pharynx to the stomach
61
What is the location of the esophagus?
penetrates diaphragm through the esophageal hiatus opening
62
What are scattered through the submucosa of the esophagus to moisten and lubricate the tubes inner lining
mucus glands
63
What prevents regurgitation?
lower esophageal sphincter or cardiac sphincter at the entrance of the stomach
64
Describe the stomach
a. J shaped, pouch like, holding 1 or more liters
b. thick folds (rugae) of mucosal and submucosal layers
65
What is the function of the stomach?
mixes food with gastric acid, initiates protein digestion, limited absorption and digestion, moves food to small intestine
66
What are the main parts of the stomach?
cardiac, fundus, body region, pyloric canal, pyloric sphincter
67
What is the cardia?
small area near the esophageal opening where cardiac sphincter is
68
What is the fundus?
storage area
69
What is the body region?
main area
70
What is the pyloric canal?
narrowing of pylorus as leads to small intestine
71
What is the pyloric sphincter?
muscular valve that controls gastric emptying
72
What is the opening of a gland to surface
gastric pit (located at the ends of tubular gastric glands)
73
Where are gastric glands found?
in mucous membrane that is the inner lining of the stomach
74
What are the 3 types of secretory cells whose collective secretions make up gastric juice?
mucous cells, chief cells, and partial cells
75
Characterize mucous cells
neck of the glands, near pit of stomach, give mucous
76
Characterize chief cells
deeper in the glands, secrete digestive enzymes
77
Characterize parietal cells
deeper in the glands, secrete a solution containing hydrochloric acid
78
What is the most important digestive enzyme?
pepsin
79
How is pepsin made?
by pepsinogen reacting with hydrochloric acid
80
What does pepsin do and where is it most active?
digest nearly all proteins down into polypeptides and it is most active in acidic conditions
81
What prevents the stomach from dissolving itself?
The inner lining of the stomach is coated by alkaline mucus secreted by mucous cells
82
What is secreted by parietal cells and helps the intestine absorb vitamin B12
intrinsic factor
83
Is gastric juice produced continually?
yes, but the rate varies
84
How is gastric juice secretion controlled?
It is controlled neurally and hormonally
85
How is gastric juice secretion inhibited?
As food enters the small intestine, acid triggers sympathetic nerves to inhibit gastric juice secretion. Simultaneously, proteins and fats in this region trigger release of the peptide hormone, cholecystokinin, which acts to decrease gastric motility
85
describe the process of when we experience food from our senses and what happens with gastric juice secretion
taste, smell, sight of food, or food entering the stomach causes a message to be sent from vagus nerves which stimulate the release of acetylcholine from nerve endings which causes gastric glands to secrete gastric juice which stimulate the stomach to release peptide hormone gastrin and this stimulates glands to release more gastric juice
86
What all does the stomach absorb?
The stomach absorbs small volumes of water and certain salts and some lipid soluble drugs
87
Where is alcohol absorbed?
stomach and small intestine
88
What is chyme?
mix of food and gastric juice in the stomach
89
As food moves to the small intestine, liquids move more quickly than solids. What moves the slowest and quickest?
fats or lipids move the slowest taking 3-6 hours, proteins are faster, and carbohydrates move the quickest
90
What happens with accessory organs when food enters the duodenum of the small intestine?
secretions come from the accessory organs-pancreas, liver, and gallbladder
91
Describe the structure of the pancreas.
pancreatic acinar cells make up the bulk of the pancreas and secrete pancreatic juice
92
Where do both the pancreatic duct and the bile duct from the liver and gallbladder join
duodenum
93
94
94
95
96
