Flashcards in Digestive System Deck (145):
1
Functions of Digestive System
Take in Food
Breakdown food
absorb digested molecules
provide nutrients
Eliminate waste
2
Two Main Divisions/Groups
Digestive/Gastrointestinal Tract/ Alimentary Canal
Accessory Digestive Organs
3
Alimentary Canal
mouth
pharynx
esophagus
stomach
small intestine
large intestive
anus
4
Accessory Organs
teeth
tongue
salivary glands
liver
pancreas
gallbladder
5
Basic Tissue layers/tunics of GIT
Mucosa
Submucosa
Muscularis
Serosa
6
innermost tunic
mucosa
7
3 layers of mucosa
mucous epithelium
lamina propria
muscularis mucosa
8
thick layer of loose connective tissue;nerves, blood vessels
submucosa
9
contains nerve plexus and submucosa plexus = enteric plexus
control movement and secretion of the tract
Muscularis
10
outermost layer
composed of peritoneum, underlying connective tissue
serosa
11
a double sac serous membrane that covers the wall of the abdominal cavity and abdominal organs
peritoneum
12
covers the organ
visceral peritoneum
13
lines the wall of the abdominal cavity
parietal peritoneum
14
connective tissues that are held in place many organs of the abdominal cavity
nerve and blood vessels enter peritoneal cavity
mesenteries
15
Organs of Alimentary Canal
Mouth/ Oral cavity
Pharynx
Esophagus
Stomach
Small Intestines
Large Intestines
16
first part of digestive tract bounded by lips and cheeks
mouth
17
Associated structures of mouth
lips
cheeks
hard palate
soft palate
tongue
teeth
18
muscular structure that is covered by the skin at the outer surface
lips
19
muscles in lips
orbicularis oris
20
forms the lateral walls of the oral cavity
cheeks
21
muscles in cheeks
buccinators
22
the bony roof of mouth; palatine rugae
hard palate
23
forms the posterior roof of the mouth composed of skeletal and connective tissue
closes nasopharynx when swallowing
soft palate
24
large, muscular organ that occupies most of the oral cavity
most powerful organ
aids in articulation
tongue
25
teeth consists of
crown
neck
root
26
parts of teeth
enamel
dentin
pulp cavity
cementum
27
protects tooth from abrasion and acid
enamel
28
living, cellular, bonelike tissue that surrounds the pulp cavity
dentin
29
conains blood vessels, nerves and connective tissue
pulp cavity
30
helps anchor the tooth
cementum
31
each quadrant contains
1 central incisor
1 lateral incisor
1 canine
fist and second premolars
3 molars
32
function of incisors
cutting
33
function of canine
tearing
34
function of premolars
crushing
35
function of molars
grinding
36
20 teeth that make up the first dentition which are shed and replaced by the permanent teeth
deciduous teeth
37
32 teeth that develop as the second dentition, replacing the deciduous teeth
premanent teeth
38
located in the lateral posterior walls of the oral cavity
tonsils
39
produce saliva which is a mixture of serous and mucus fluids
dissolve food chemicals so that they can be tasted
contains lysozymes and antibodies (IgA)
salivary glands
40
3 pairs of salivary glands
parotid, submandibular, sublingual
41
inflammation of parotid glands
mumps or parotidis
42
inflammation of testes
orchitis
43
passageway for both air and food, only the oropharynx and laryngopharynx transmit food
pharynx
44
muscular tube lined with moist stratified squamous epithelium that extends from the pharynx to the stomach
lies anterior to the vertebrae and posterior to the trachea
transport food by peristalsis to the stomach
esophagus
45
regulate movement of food into and out of the esophagus
esophageal sphincter
upper and lower cardiac sphincters
46
enlarged segment of the digestive tract in the left superior part of the abdomen
primarily for storage and mixing chamber for digested food
a sac
stomach
47
Parts of stomach
Cardiac region
fundus
body
pyloric opening
pyloric region
pyloric sphincter
muscular layer
rugae
48
region of the stomach around the cardiac opening
cardiac region
49
most superior part of the stomach
fundus
50
largest part of the stomach
body
51
opening from the stomach to the small intestine
pyloric opening
52
region of the stomach near the pyloric opening
pyloric region
53
thick ring of smooth muscle that guards the pyloric opening
pyloric sphincter
54
composed of outer longitudinal layer, middle circular layer, inner oblique layer
muscular layer
55
submucosa and mucosa that are thrown into large folds when the stomach is empty and allows the stomach to stretch when the stomach is fille
rugae
56
the semi-fluid mixture formed by food that mixes with stomach secretions
chyme
57
regulation of stomach secretions: 3 phases
cephalic phase
gastric phase
intestinal phase
58
anticipatory and prepares stomach to receive food
sensations of taste, smell of food, stimulation of tactile receptors during chewing/swallowing, pleasant thoughts of food stimulate centers within medulla oblongata
cephalic phase
59
period of greatest gastric secretion
activated by the presence of food in stomach
gastric phase
60
inhibit gastric secretions
controlled by the entrance of acidic chyme into duodenum
intestinal phase
61
major site of digestion and absorption of food
final site of digestion
longest section of alimentary canal
small intestine
62
3 parts of small intestine
duodenum
jejunum
ileum
63
3 modifications that increase surface area (600 fold) of small intestine
circular folds
villi
microvilli
64
formed by mucosa and submucosa
circular folds
65
finger-like projections of the mucosa
villi
66
cytoplasmic extensions of the cells on the villi and contains blood capillary network and lymphatic capillary (lacteals)
microvilli
67
mucosa of liver is simple columnar epithelium with 4 major cell types
absorptive cells
goblet cells
granular cells (paneth's cells)
endocrine cells
68
within microvilli, produce digestive enzymes and absorb digested food
absorptive cells
69
produce a protective mucus
goblet cells
70
help protect the intestinal epithelium from bacteria
granular cells
71
produce regulatory hormones
endocrine cells
72
cluster of lymph nodules which help protect the intestinal tract from harmful microorganisms
payer's patches
73
junction between small intestine and large intestine
Ileocecal junction
74
secretions of small intestine
peptidases
disaccharidases
mucus
hormones
75
break peptide bonds in CHONS to form amino acid
peptidases
76
breaks down disaccharides into monosaccharides
disaccharidases
77
produced by duodenal glands and by goblet cells
mucus
78
stimulate liver and pancreatic secretions
hormones
79
parts of large intestine
cecum
colon
rectum
anal canal
80
proximal end of large intestine
cecum
81
where the small intestine and large intestine meet
sac that extends inferiorly about 6 cm past the ileocecal junction
located in the right lower quadrant newar the iliac fossa
Ileocecal junction
82
blind tube about 9 cm long that is attached to the cecum
appendix
83
about 1.5 - 1.8 meters long
colon
84
parts of colon
ascending colon
transverse colon
descending colon
sigmoid colon
85
extends superiorly from the cecum to the right colic flexure near the liver where it turns right
ascending colon
86
extends from the right colic flexure to the left colic flexure near the spleen where it turns inferiorly
transverse colon
87
extends from the left colic flexure to the pelvis where it becomes the sigmoid colon
descending colon
88
form an S-shaped tube that extends medially and then inferiorly into the pelvic cavity and ends at the rectum
sigmoid colon
89
straight, muscular tube that begins at the termination of the sigmoid colon and ends at the anal canal
rectum
90
begins at the inferior end of the rectum and ends at the anus
the last 2-3 cm of digestive tract
anal canal
91
anal canal contains
internal anal sphincter
external anal sphincter
92
made up of smooth muscle and found at the superior end of the canal
internal anal sphincter
93
made of skeletal muscle and found at the inferior end of the canal
external anal sphincter
94
introduction of fluid in anal canal and colon
enema
95
special lymphatic vessel where fats are absorbed
lacteals
96
milky fluid containing fat droplets
chyle
97
no IF is produced
pernicious anemia
98
IF + Vitamin B12=
RBC
99
Muscularis: inner - ________
outer- _______
circular
longitudinal
100
Functions of Large Intestine
converts chyme into feces by 3 processes:
1. absorption of water and salts
2. secretion of mucus
3. action of microorganisms
stores feces until defecation occurs
101
largest organ of the body
weighs 1.4 kg/ 3 lbs
largest organ according to serface area
doesn't have capillaries
receives oxygenated and deoxygenated blood
located at RUQ tucked against the inferior of the diaphragm
divided into 2 major lobes: R and L lobe
liver
102
2 smaller lobes seen from the inferior view
caudate and quadrate
103
Functions of liver
produce bile
storage of nutrients
conversion of nutrients
detoxification of harmful chemicals
synthesis of new molecules
104
a thick, viscid, bitter-tasting fluid secreted by the liver
about 700 ml secreted by liver per day
plays a very important role in diluting and neutralizing stomach acid
emulsifies fats, breaking fat globules into smaller droplets
90% of bile salts are reabsorbed in the ileum and carried by blood to the liver
bile
105
pH of bile
7.6 - 8.6 (basic)
106
the gate through which blood vessels, ducts and nerves enter and exit the liver
porta
107
divisions of the liver containing portal triads at its corner
lobules
108
portal triads
hepatic artery
hepatic portal vein
hepatic duct
109
macrophages of the liver
aka stellate reticuloendothelial cells
breakdown of RBC
Kupffer cells
110
formed by platelike groups of cell called hepatocytes
hepatic cords
111
blood channels which separates hepatic cords from one another
consist of phagocytic cells that help remove foreign particles from the blood
hepatic sinusoids
112
brings oxygenated blood to liver
hepatic artery
113
carries oxygen-poor blood but rich in absorbed nutrients and other substances from the digestive tract to the liver
hepatic portal vein
114
where blood exits from the liver and empties into the IVC
hepatic vein
115
small sac on the inferior surface of the liver that stores and concentrates bile
gall bladder
116
organ composed of both endocrine and exocrine tissues
located retoperitoneal and posterior to the stomach in the inferior part of the LUQ
has a head located near the midline of the body and tail that extends to the left and touches the spleen
pancreas
117
endocrine part of pancreas
Islet of Langerhans (1%) that produces insulin and glucagon
118
exocrine part of pancreas
acini (99%) that produces digestive enzymes
119
join the common bile duct and empty into duodenum
pancreatic duct or duct of Wirsung
120
function of pancreas (exocrine)
Bicarbonate - neutralizes acidic chyme that enter the duodenum from the stomach
pancreatic enzyme - important for digestion of the major classes of food
121
continue protein digestion started in the stomach
proteolytic enzyme (protein-digesting enzyme)
122
continues polysaccharide digestion that began in oral cavity
pancreatic amylase
123
continue lipid digestion
pancreatic lipase
124
reduce DNA and RNA to their component nucleotides
nucleases
125
Hormones secreted by duodenum that control pancreatic secretion
secretin
cholecystokinin
126
initiates release of HCO3
secretin
127
stimulates pancreas to release an enzyme-rich solution
cholecystokinin
128
chewing of food by teeth
mastication
129
swallowing of food
deglutition
130
2 Types of movements in the stomach
mixing waves
peristaltic waves
131
weak contractions of the stomach
mix ingested food with stomach secretions to form chyme
mixing waves
132
stronger contractions
forced chyme toward and through the pyloric sphincter
peristaltic waves
133
movement of food in small intestines
peristaltic contraction
segmental contraction
134
cause chyme to move along the small intestine
peristaltic contraction
135
function to mix intestinal contents
segmental contraction
136
movement in large intestines
mass movement
137
large part of the colon undergo several strong contractions every 8-12 hours to propel colon contents a considerable distance toward the anus
mass movement
138
accessory duct
duct of santorini
139
neutralizes acidic chyme in duodenum
NaHCO3 ( pH 7.1 - 8.2)
140
breakdown of food to molecules that are small enough to be absorbed in the circulation
digestion
141
Types of Digestion
Mechanical
chemical
142
breaks large food particles to smaller ones
mechanical digestion
143
breaking of covalent chemical bonds in organic molecules by digestive enzymes
chemical digestion
144
examples of chemical digestion
CHO - monosaccharides
CHON - amino acids
Fats - fatty acid and glycerol
145