Digestive System Flashcards
1
Q
6 basic processes of the digestive system:
A
- ingestion
- secretion
- mixing and propulsion
- digestion
- absorption
- defecation
2
Q
taking in food and liquid
A
ingestion
3
Q
______ of water, acid, buffers, and enzymes
A
secretion
4
Q
alternating contractions and relaxation of smooth muscle
A
mixing and propulsion
5
Q
mechanical and chemical processes to break down ingested food into small molecules
2 types: mechanical and chemical
A
digestion
6
Q
entrance of ingested and secreted fluids, ions, and products of digestion into epithelial cells lining the lumen of the GI tract
A
absorption
7
Q
Upper gastrointestinal (GI) tract consists of (4):
A
- mouth
- pharynx
- esophagus
- stomach
8
Q
Lower gastrointestinal (GI) tact consists of (2):
A
- small intestines
- large intestines
9
Q
accessory organs of the digestive system (7):
A
- salivary glands
- tongue
- teeth
- liver
- gallbladder
- pancreas
- vermiform appendix
10
Q
the 4 layers of GI tract tissues:
A
- an epithelial/mucous lining (innermost layer)
- a submucous layer of connective tissue (contains glands, parasympathetic nerves, and blood vessels)
- a muscular layer
- fibroserous layer (includes mesentery)
11
Q
a fold in the peritoneum that attaches the stomach, small intestine, pancreas, spleen, and other organs to the posterior wall of the abdomen
A
mesentery
12
Q
the stomach has # layers of smooth muscle in the muscular layer
A
3
13
Q
the small intestine has _____ in the inner-most mucosal layer, which function to increase surface area
A
villi
14
Q
the following 7 structures form the mouth:
A
- lips
- cheeks
- tongue
- hard palate
- soft palate: uvula
- salivary glands
- teeth
15
Q
3 functions of the lips:
A
- keep food in the mouth while being chewed
- help to sense temperature and texture of food before in enters the mouth
- needed to form many speech sounds
16
Q
3 functions of the cheeks:
A
- lateral boundaries of the oral cavity (keeps food between the teeth)
- lined by mucous membrane
- contain mucous-secreting glands
17
Q
the roof of the mouth
A
hard and soft palate
18
Q
the _______ consists of portions of 4 bones (2 maxillae and 2 palatines)
A
hard palate
19
Q
the ______ is composed of muscle arranged in the shape of an arch
A
soft palate
20
Q
hangs down from the soft palate arch in the midline; it rises during swallowing to close off the nasopharynx from the food
A
uvula
21
Q
the tongue consists of (4):
A
- extrinsic tongue muscles
- intrinsic muscles
- taste buds
- lingual glands that secrete lipase
22
Q
the 4 functions of the salivary glands:
A
- secrete saliva
- soften, moisten, and dissolves food
- cleanses the mouth
- salivary amylase splits starch into smaller fragments
23
Q
______ is the first of the digestive juices to contact food
A
saliva
24
Q
salivary glands located near the ear underlying the masseter muscle
A
parotid glands
25
salivary glands located on the floor of the mouth just under the mandibles
submandibular glands
26
salivary glands located on the floor of the mouth; ducts enter beneath the tongue
sublingual glands
27
teeth are made up of 4 types of connective tissue:
- pulp
- dentin
- cementum
- enamel
28
act of swallowing
- facilitated by saliva
- involves mouth, pharynx, and esophagus
- occurs in 3 stages: oral, pharyngeal, esophageal
deglutition
29
rounded mass of food is called a:
bolus
30
only the terminal part of the _____ is involved in digestion
pharynx
31
collapsible muscular tube about 25 cm long
begins at the inferior aspect of the neck and enters the mediastinum anterior to the vertebral column
pierces the diaphragm through an opening called the esophageal hiatus
esophagus
32
the esophagus contains 2 sphincters:
- upper esophageal sphincter: skeletal muscle
| - lower esophageal sphincter: smooth muscle
33
condition where the stomach protrudes up through the esophageal hiatus, above the diaphragm
effects 15% of population, but is usually asymptomatic
hiatal hernia
34
organ that lies just below the liver and disphragm
it is an enlargement of the GI tube
size varies according to several factors, and usually holds up to 1-1.5 liters
the stomach
35
the 3 divisions of the stomach:
- fundus: enlarged main upper portion
- body: the large middle portion
- pylorus: the lower part
36
_______ regulate passage of material at both stomach openings
controls outlets of pyloric portion of stomach into duodenum
pyloric sphincter
37
disease where the backward flow of stomach acid up through the lower esophageal sphincter and into the lower part of the esophagus
often causes a painful sensation called heartburn
gastroesophageal reflux disease (GERD)
38
4 layers of stomach wall tissue:
- mucosa
- submucosa
- muscularis
- serosa
39
thick stomach wall layer of simple columnar epithelium lining the stomach cavity
- designed for the production of digestive acids and enzymes
- epithelial lining has rugae marked by gastric pits (deep clefts increase the stomach's surface area)
- contains gastric glands that secrete most of the gastric juices
stomach wall layer: mucosa
40
cells that secrete enzymes of gastric juice
chief cells
41
cells that secrete hydrochloric acid and produce intrinsic factor needed for vitmin B12 absorption in small intestine
parietal cells
42
cells that secrete:
ghrelin, a hormone that stimulate the hypothalamus to secrete growth hormone and increase appetite
gastrin, influences digestive functions
endocrine cells
43
stomach wall layer comprised of fibrous connective tissue to support the mucosal layer
submucosa
44
stomach wall layer than contains 3 layers of smooth muscle arranged in a crisscrossing pattern
allows the stomach to contract at many angles
muscularis layer
45
the 3 smooth muscle layers of muscularis stomach wall:
- longitudinal layer
- circular layer
- oblique layer
46
similar to gyri of the brain
rugae
47
stomach wall layer that is the outer covering of the stomach
- secretes serous fluid
- contains blood vessels and nerve endings
serosa layer
48
6 functions of the stomach:
- food reservoir
- secretes gastric juices
- churns food
- secretes intrinsic factor
- performs limited amount of absorption
- produces gastrin and ghrelin
49
small bowel 1 inch in diameter and approx. 6-8 meters, fills most of the abdominal cavity
responsible for the major absorption of nutrients and water
small intestine
50
the small intestine consists of 3 divisions, beginning at the pylorus and ending at the ileocecal valve
- duodenum
- jejunum
- ileum
51
means "12 fingerbreadths" - refers to the short length
- uppermost division, attaches to the pyloric end of the stomach
duodenum
52
second part of small intestine, means "empty"; 8 ft long
jejunum
53
third part of the small intestine, means "twisted"; 12 feet long
ileum
54
wall of the _________:
- lining has circular plicae (folds) that have many tiny projections called villi
- villi are fingerlike projections of mucosa
- each villus contains an arteriole, venule, and lymph vessel
small intestine
55
the presence of _____ increases the surface area of the small intestine, making it the main site of digestion and absorption
villi
56
folds in the small intestine
plicae
57
5-6ft long and 2.5 in. diameter
designed only for absorption of water
extends from cecum to the rectum and has 3 divisions
large intestine (colon)
58
the 3 divisions of the large intestine:
- cecum
- colon
- rectum
59
1st 5-8 cm of large intestine
- blind pouch in lower right quadrant of abdomen
- receives chyme from terminal ileum
- guarded by a fold of mucosa called the ileocecal valve preventing fecal backflow into the small intestine
- vermiform appendix is attached to the tip of this part
cecum
60
semifluid mass of partly digested food that is expelled by the stomach into the duodenum and moves through the intestines during digestion
chyme
61
4 divisions of colon:
- ascending colon
- transverse colon
- descending colon
- sigmoid colon
62
- last 7-8 inches of the intestinal tube
- terminal inch is the anal canal with opening called the anus
- guarded by the anal sphincter
- these muscles prevent incontinence
rectum
63
external sphincter of the rectum is _____, an made up of skeletal muscle
voluntary
64
internal sphincter of the rectum is _____, comprised from smooth muscle under ANS control.
involuntary
65
the wall of the large intestine does not contain _____, as in the small intestine
villi
66
_______ produce lubricating mucus that coats feces as they are formed
intestinal mucous glands
67
a wormlike, tubular organ 3-4 inches in length, found just behind the cecum
- functions are not fully understood
vermiform appendix
68
large continuous sheet of serous membrane
- lines the walls of the entire abdominal cavity and forms the serous outer coat of the organs
- forms the mesentery
- includes greater and lesser omentum
peritoneum
69
the largest gland in the body
- weighs 3-4 pounds and lies under diaphragm
- consists of 2 lobes: L and R
liver
70
the anatomical units of the liver, are tiny hexogonal or pentagonal cylinders
hepatic lobules
71
the 6 functions of the liver:
- detoxification of certain substances
- breaks down and removes old red blood cells, recycling the iron from hemaglobin
- secretes about on pint of bile per day
- important role in metabolism of proteins, fats, and carbs
- storage of iron, vitamin A, vitamin B12, and Vitamin D
- produces important plasma proteins and serves as a site for blood cell production during fetal deelopment
72
a pear shaped sac 3-4 inches long that lies on the undersurface of the liver
- stores bile that enters by way of hepatic and cystic ducts
- concentrates bile (5-10x)
- during digestion, contracts and ejects bile into duodenum
gallbladder
73
gallstones may form causing inflammation of the gallbladder =
cholecystitis
74
results when bile is obstructed from entering the duodenum, bile is store in the blood and a yellow hue enters the blood and is stored in tissues
jaundice
75
a grayish-pink colored gland 6-9 inches in length located in C shaped curve of duodenum
composed of 2 different types of glandular tissue: exocrine and endocrine
pancreas
76
between exocrine units in the pancreas lie clusters of endocrine cells called ________.
pancreatic islets
77
3 functions of the pancreas:
- secretes digestive enzymes
- beta cells secrete insulin, a hormone that exerts a major control over carbohydrate metabolism
- alpha cells secrete glucagon
78
primary function of the digestive system
bring essential nutrients into internal environment so nutrients are available to each cell of the body
79
______ digestion:
- change ingested food from large particles into minute particles, facilitating chemical digestion
- churn contents of GI lumen to mix with digestive juices and come in contact with the surface of the intestinal mucosa, facilitating absorption
- propel food along the alimentary tract, ultimately eliminating digestive waste from the body
mechanical digestion
80
3 processes that aid in mechanical digestion:
- mastication
- deglutition
- peristalsis and segmentation
81
2 main types of motility produced by smooth muscle of GI tract; can occur together, in an alternating fashion
peristalsis and segmentation
82
wavelike ripple of the muscle layer of a hollow organ; progressive motility that produces forward movement of matter along the GI tract
peristalsis
83
mixing movement
| - digestive reflexes cause a forward and backward movement with a single segment of the GI tract
segmentation
84
regulation of motility: emptying the stomach takes _#_-_#_ hours
chyme is ejected about every _#_ seconds into duodenum
2-6 hours
20 seconds
85
_______ includes both peristalsis and segmentation
- mixes chyme with digestive juice from pancreas, liver, and intestinal mucosa
- chyme takes about 5-6 hours to pass through small intestine
intestinal motility
86
________ digestion:
- changes in chemical composition of food as it travels through the digestive tract
- hydrolysis
- numerous enzymes in the various digestive juice catalyze the hydrolysis of foods
chemical digestion
87
a chemical process in which a compound unites with water and then splits into simpler compounds
hydrolysis
88
undigested compounds, bacteria, pigments, water, and mucus
feces
