Digestive System Flashcards
1
Q
What do organs of the digestive system contribute in? (3)
A
- ingestion and digestion of food
- absorption of nutrients
- elimination of indigestible materials
2
Q
What does the digestive system do?
A
provides nutrients for cells to be used as source of energy, or for growth and repair
3
Q
What is the digestive system divided into? (2)
A
- alimentary canal (gastrointestinal (GI) tract)
- accessory digestive organs
4
Q
What is the alimentary canal?
What are the main segments? (6)
A
muscular tube that starts from oral cavity, and ends at anus
oral cavity, pharynx, esophagus, stomach, small intestine, and large intestine
5
Q
What do accessory digestive organs do?
What are they? (6)
A
assist in ingestion and digestion of food
teeth, tongue, salivary glands, liver, gallbladder, and pancreas
6
Q
Oral Cavity
What is it bounded by?
A
- lips anteriorly
- oropharyngeal isthmus posteriorly
- palates superiorly
- muscular diaphragm and tongue inferiorly
- cheeks laterally
7
Q
Oral Cavity
What is the cavity divided into? (2)
A
vestibule
oral cavity proper
8
Q
Oral Cavity
What is the vestibule bounded by?
A
horseshoe-shaped space bounded by lips (anteriorly), cheeks (laterally), and dental arches (posteriorly and medially)
9
Q
Oral Cavity
What is the oral cavity proper bounded by?
A
bounded by dental arches (anteriorly and laterally), palates (superiorly), muscular diaphragm (mylohyoid muscle) and tongue (inferiorly)
10
Q
Oral Cavity
What are the lips?
A
2 muscular folds covered externally by skin, and internally by mucus membrane
11
Q
Oral Cavity
What does the orbicularis oris muscle do?
A
forms core of lips
12
Q
Oral Cavity
What is the frenulum?
A
midline mucosal fold that connects each lip to gum
13
Q
Oral Cavity
What are the cheeks formed by?
A
mainly formed by buccinator muscles covered internally by mucus membrane, and externally by skin
14
Q
Oral Cavity
What is the hard palate?
A
includes hard and soft palates
15
Q
Oral Cavity
What is the hard palate formed by?
A
has bony skeleton formed by maxillary and palatine bones covered by mucus membrane
16
Q
Oral Cavity
What does the hard palate form? (2)
A
- anterior part of roof of oral cavity proper
- floor of nasal cavities
17
Q
Oral Cavity
What does the soft palate form?
A
posterior part of roof of oral cavity proper, and separates it from nasopharynx superior to it
18
Q
Oral Cavity
What is the soft palate?
A
arch-shaped partition with fibro-muscular core covered by mucus membrane
19
Q
Oral Cavity
What is the uvula?
A
conical soft tissue projection that hangs from free posterior border of soft palate
20
Q
Oral Cavity
What are the palatoglossal and palatophrayngeal arches?
A
2 muscular folds or arches lateral to base of uvula, that run inferiorly and laterally
21
Q
Oral Cavity
What is the palatoglossal arch?
A
anterior fold that extends to side of root of tongue
22
Q
Oral Cavity
What is the palatopharyngeal arch?
A
posterior fold that extends to lateral wall of pharynx
23
Q
Oral Cavity
Where are the palatine tonsils?
A
in tonsillar fossa (shallow fossa) between the arches
24
Q
Oral Cavity
What is the oropharyngeal isthmus (fauces)?
What is it formed by?
A
passageway connecting oral cavity proper to oropharynx
formed by palatoglossal arches
25
Teeth
What are the 3 parts of a tooth?
crown
root
neck
26
Teeth
What is the crown?
part of tooth that projects from gingiva, and is visible in oral cavity
27
Teeth
What is the root?
part of tooth contained within alveolar processes of mandible and maxilla, and is attached to bony socket by periodontal ligament
28
Teeth
What is the neck?
narrow part of tooth connecting crown and root
29
Teeth
How are teeth classified?
What are the types of teeth?
based on shape of their crown
```
on each half of upper and lower jaws:
2 incisors
1 canine
2 premolars
2 molars
```
30
Teeth
What is the wisdom tooth?
third molar
31
Teeth
What is the core of the tooth composed of?
composed of dentine covered by enamel in crown, and cement (cementum) in root
32
Teeth
What does the pulp cavity contain? (3)
- tooth nerves
- blood vessels
- lymphatic vessels
33
Teeth
Where is the pulp cavity?
housed within dentine
34
Teeth
What is the root canal?
extension of pulp cavity into roots
35
Teeth
What are the 2 nerves that supply teeth?
- CN V2 (trigeminal nerve, maxillary division)
| - CN V3 (trigeminal nerve, mandibular division)
36
Teeth
What does CN V2 (trigeminal nerve, maxillary division) supply?
teeth of upper jaws, adjacent gingiva, and palates
37
Teeth
What does CN V3 (trigeminal nerve, mandibular division) supply?
teeth of lower jaw, and adjacent gingiva
38
Teeth
What supplies blood for all teeth?
maxillary artery (branch of external carotid artery)
39
Tongue
What is the tongue?
muscular organ involved in swallowing, phonation, tasting, and chewing
40
Tongue
What are the 2 parts of the tongue?
- pharyngeal part or root
| - oral part or body
41
Tongue
What is the pharyngeal part or root?
posterior ⅓ of tongue attached to floor of oral cavity, and faces oropharynx
42
Tongue
What is the oral part or body?
anterior ⅔ of tongue that freely moves in oral cavity
43
Tongue
What is the terminal sulcus?
reverse V-shaped groove on superior surface of tongue that separates anterior and posterior parts of tongue
44
Tongue
What do skeletal muscles do?
mainly form core of anterior ⅔ of tongue
45
Tongue
What are lingual papillae?
mucosal elevations on superior surface of anterior ⅔ of tongue
named based on their shape
46
Tongue
What are the 4 types of lingual papillae?
- filiform papillae (thread-like)
- fungiform papillae (mushroom-like)
- foliate papillae (leaf-like)
- vallate papillae
47
Tongue
Which papillae carry taste buds?
- fungiform papillae
- foliate papillae
- vallate papillae
(all except filiform)
48
Tongue
Which nerves supply the tongue?
CN VII
CN V3
CN IX
49
Tongue
What does CN VII (facial nerve) do?
provides special sensation (taste)
50
Tongue
What does CN V3 (trigeminal nerve, mandibular division) do?
supplies general sensation of anterior ⅔ of tongue
51
Tongue
What are the paired lingual tonsils?
lymphoid tissue that forms core of posterior ⅔ of tongue
52
Tongue
What does CN IX (glossopharyngeal nerve) do?
```
formed by lymphoid tissue, which is organized as pair of lingual tonsils
CN IX (glossopharyngeal nerve) provides both special and general sensations of this part of tongue
```
53
Tongue
What is the lingual frenulum?
midline mucosal fold that attaches interior surface of tongue to floor of oral cavity
54
Tongue
What supplies blood for the tongue?
lingual branch of external carotid artery
55
What is the pharynx?
muscular tube that connects nasal cavities to larynx, and oral cavity to esophagus
56
Esophagus
What is the esophagus?
Where does it start and end?
muscular tube
start: laryngopharynx at level of vertebra CVI
end: stomach at level of vertebra TXI
57
Esophagus
What does the esophagus pass through to reach abdomen?
passes neck, superior and posterior mediastinum, and through esophageal hiatus (opening in diaphragm)
58
Esophagus
Where is the esophagus located?
in front of lower cervical and thoracic regions of vertebral column on its entire length
anteriorly related to trachea and left atrium of heart
59
Peritoneum
What is the perineum?
serous membrane
60
Peritoneum
What are the 2 parts of the peritoneum?
parietal peritoneum
| visceral peritoneum
61
Peritoneum
Where is the parietal peritoneum?
lines wall of abdominopelvic cavity
62
Peritoneum
Where is the visceral peritoneum?
covers surface of most of abdominal and pelvic viscera
63
Peritoneum
Where are retroperitoneal organs?
between parietal peritoneum and posterior abdominal wall
64
Peritoneum
What are intraperitoneal organs covered by?
completely covered by visceral perionteum
65
Peritoneum
What is the peritoneal cavity?
What does it contain?
slim space between parietal and visceral layers of peritoneum
contains few mL of serous fluid to lubricate surfaces of abdominal contents
66
Peritoneum
Where is the peritoneal cavity in males?
Where is the peritoneal cavity in females?
males: enclosed in sac
females: connected with exterior via cavity of uterine tubes, uterus, and vagina
67
Peritoneum
What are peritoneal reflections?
What are its functions?
double layer peritoneal folds that either carry nerves, blood, and lymphatic vessels to supply abdominal organs, or attach abdominal organs to abdominal wall
68
Peritoneum
What are the 3 peritoneal reflections?
peritoneal ligaments
mesenteries
omenta
69
Peritoneum
What do peritoneal ligaments do?
connect abdominal viscera to abdominal walls or other organs
70
Peritoneum
What is the falciform ligament?
peritoneal ligament that connects liver to anterior abdominal wall and diaphragm
71
Peritoneum
What are the 4 types of mesenteries?
mesentery
transverse mesocolon
sigmoid mesocolon
mesoappendix
72
Peritoneum
What does the mesentery do?
connect small intestine (except duodenum) to posterior abdominal wall
73
Peritoneum
What does the transverse mesocolon do?
connect transverse colon to posterior abdominal wall
74
Peritoneum
What does the sigmoid mesocolon do?
connect sigmoid colon to posterior abdominal wall
75
Peritoneum
What does the mesoappendix do?
connect appendix to posterior abdominal wall
76
Peritoneum
Where is the omenta?
stretched between stomach and other organs
77
Peritoneum
What are the 2 types of omenta?
greater omentum
| lesser omentum
78
Peritoneum
What does the greater omentum do?
connects greater curvature of stomach to transverse mesocolon, and like an apron covers intestinal loops anteriorly
79
Peritoneum
What does the lesser omentum do?
connects liver to small curvature of stomach, and first part of duodenum
80
Peritoneum
What sensitizes visceral peritoneum?
afferent autonomic nerve fibers
81
Peritoneum
What sensitizes parietal peritoneum?
afferent somatic nerve fibers (mainly phrenic and lower intercostals)
82
Stomach
What is the stomach?
most dilated part of alimentary canal
J-shaped part of alimentary canal with 2 curvatures (greater and lesser), 2 surfaces (anterior and posterior), and 2 openings (cardiac and pyloric)
83
Stomach
Where is the stomach?
in left hypochondriac, epigastric, and umbilical regions
84
Stomach
What are the 3 regions?
fundus
body
pyloric part
85
Stomach
What is the fundus?
dome-shaped part of stomach, above level of cardiac opening
86
Stomach
What is the body?
funnel-shaped region located between fundus and pyloric part
87
Stomach
What is the pyloric part?
narrow region of stomach between body and pyloric opening
88
Stomach
What is the cardiac opening?
connects stomach to esophagus
89
Stomach
What is the pyloric opening?
connect stomach to duodenum
90
Stomach
What is the pyloric sphincter?
guards pyloric opening
91
Stomach
What are gastric rugae?
longitudinal folds that mucosal membrane lining interior of stomach is thrown into
disappear when stomach is full
92
Small Intestine
Where does the small intestine start and end?
starts: pyloric opening of stomach
end: ileocecal junction
93
Small Intestine
What are the 3 parts?
duodenum
jejunum
ileum
94
Small Intestine - Duodenum
What is the duodenum?
shortest, widest, and least mobile part of small intestine
C-shaped tube that surrounds head of pancreas
95
Small Intestine - Duodenum
Where does it start and end?
start: pyloric opening of stomach
end: merges with jejunum at duodenojejunal flexure
96
Small Intestine - Duodenum
What are the 4 parts?
superior, descending, horizontal, and ascending parts
97
Small Intestine - Duodenum
What is released into the second part of the duodenum?
exocrine secretions of pancreas and bile produced by liver
98
Small Intestine - Jejunum
Where is the jejunum?
Where does it start?
mainly located in umbilical region of abdomen
starts from duodenojejunal flexure
constitutes proximal ⅖ of small intestine (after duodenum)
99
Small Intestine - Ileum
Where is the ileum?
mostly located in hypogastric region of abdomen
100
Small Intestine - Ileum
What does the ileum form?
forms distal ⅗ of small intestine (after duodenum)
101
Small Intestine - Ileum
What does the ileum open into?
opens into large intestine at ileocecal junction, which is an opening guarded by ileocecal valve
102
Small Intestine
What type of organ are the jejunum and ileum?
intraperitoneal organs
attach to posterior abdominal wall by mesentery
103
Large Intestine
Where is the large intestine?
extends from ileocecal junction to anus, and almost complete frames small intestine
104
Large Intestine
What are the main characteristics of the large intestine? (4)
teniae coli
haustra coli
caliber
omental (epiploic) appendices
105
Large Intestine
What are teniae coli?
3 longitudinal bands of smooth muscle fibers visible on outer surface of colons
106
Large Intestine
What is the haustra coli?
series of pouches throughout length of colons produced by tonic contraction of teniae coli
107
Large Intestine
What is the caliber?
lumenal diameter is much larger than small intestine
108
Large Intestine
What is the omental (epiploic) appendices?
small, teardrop-shaped sacs of fat attached to surface of colons
109
Large Intestine
What are the 5 main parts of the large intestine?
- cecum
- appendix
- colon (ascending, transverse, descending, sigmoid)
- rectum
- anal canal
110
Large Intestine
What is the cecum?
initial part of large intestine located in right iliac region below ileocecal junction
111
Large Intestine
What is the appendix?
worm-like appendage that attaches to cecum inferomedial to ileocecal junction
112
Large Intestine
Where is the surface marking of the base of the appendix?
at junction of lateral ⅓ and medial ⅔ of line joining umbilicus to anterior superior iliac spine (ASIS)
113
Large Intestine
Where is the ascending colon?
starts from cecum, ascends in right lumbar region, reaches inferior surface of liver, and turns sharply to left to form right colic flexure (hepatic flexure)
114
Large Intestine
Where is the transverse colon?
located in right hypochondria, umbilical, and left hypochondriac regions
starts from right colic flexure (hepatic flexure), continues across abdomen to left side, and curves below spleen to form left colic flexure (splenic flexure)
115
Large Intestine
Where is the descending colon?
starts from left colic flexure, descends in left lumbar region, and ends to sigmoid colon in left iliac region
116
Large Intestine
Where is the sigmoid colon?
S-shaped
starts from end of descending colon in left iliac region, and terminates to rectum in true pelvis at level of vertebrae SIII
117
Large Intestine
Where does the rectum start and end?
start: level of vertebra SIII
passes through pelvic diaphragm
end: anal canal at anorectal junction (flexure)
118
Large Intestine
What is the rectal ampulla?
dilated distal part of rectum
119
Large Intestine
Where is the anal canal?
stretches between anorectal junction and anus
120
Large Intestine
What is the distal part of the anal canal guarded by?
two sphincters
- involuntary internal anal sphincter
- voluntary external anal sphincter
121
Large Intestine
What are the intraperitoneal organs? (3)
appendix
transverse
sigmoid colons
(suspended from posterior abdominal wall by their mesenteries)
122
Large Intestine
What are the retraperitoneal organs? (4)
cecum
ascending colon
descending colon
rectum
123
What supplies blood to the alimentary canal and its accessory digestive organs?
3 visceral branches of the abdominal aorta
- celiac trunk (artery)
- superior mesenteric artery
- inferior mesenteric artery
124
What does the celiac trunk (artery) divided into?
What does the celiac trunk (artery) supply?
divides into left gastric, common hepatic, and splenic branches
supply abdominal esophagus, stomach, liver, gallbladder, spleen, most of pancreas, and upper half of duodenum
125
What does the superior mesenteric artery supply?
lower half of duodenum, small part of pancreas, small intestine, cecum, appendix, ascending colon, and right ⅔ of transverse colon
126
What does the inferior mesenteric artery supply?
left ⅓ of transverse colon, descending colon, sigmoid colon, rectum, and upper part of anal canal
127
What are autonomic plexuses in the abdomen associated with?
autonomic ganglia that serves as synapse site for preganglionic sympathetic fibers
128
Where are abdominal autonomic plexuses?
surround abdominal aorta branches and use them as guide to distribute to target organs
129
What are abdominal autonomic plexuses named after?
arteries they surround (ie. celiac plexus, superior and inferior mesenteric plexuses)
130
What is the sympathetic input of abdominal autonomic plexuses provided by?
splanchnic nerves (greater, lesser, least, lumbar, and sacral)
131
What is the parasympathetic input of abdominal autonomic plexuses provided by?
CN X (vagus nerve) or pelvic splanchnic nerve
132
What forms the enteric system?
when outflow of abdominal autonomic plexuses reaches abdominal part of alimentary canal
133
What does the enteric system do?
regulates alimentary canal activities, including glandular secretion, motility (peristalsis), and blood flow
134
What are the 4 accessory glands of the digestive system?
salivary glands
liver
gallbladder
pancreas
135
Salivary Glands
What are the salivary glands?
3 pairs of glands that secrete ~1 L of saliva per day
136
Salivary Glands
What are the 3 salivary glands?
parotid gland
submandibular gland
sublingual gland
137
Salivary Glands - Parotid Gland
What is the parotid gland
largest salivary gland located in front and below ear, and partially covers masseter muscle
138
Salivary Glands - Parotid Gland
What does the parotid duct do?
drains secretions of gland into vestibule of oral cavity opposite to second upper molar tooth
139
Salivary Glands - Parotid Gland
What regulates secretion of saliva of the parotid gland?
parasympathetic fibers of CN IX (glossopharyngeal nerve)
140
Salivary Glands - Submandibular Gland
Where is this gland?
related to medial surface of body of mandible
141
Salivary Glands - Submandibular Gland
What does the submandibular duct do?
carries secretions of gland to floor of oral cavity, and opens lateral to lingual frenulum
142
Salivary Glands - Sublingual Gland
What is the sublingual gland?
almond-shaped gland located underneath mucosal membrane of floor of oral cavity
143
Salivary Glands - Sublingual Gland
What is the secretion of this gland drained by?
several short ducts to floor of oral cavity at summit of sublingual fold
144
Salivary Glands - Sublingual Gland
What regulates the secretion of saliva of this gland?
parasympathetic fibres of CN VII (facial nerve)
145
Salivary Glands - Submandibular Gland
What regulates the secretion of saliva of this gland?
parasympathetic fibres of CN VII (facial nerve)
146
Liver
What is the liver?
largest gland of body
147
Liver
Where is the liver?
below diaphragm in right hypochondriac, epigastric, and left hypochondriac regions
148
Liver
What is the liver covered by?
mostly covered by peritoneum
149
Liver
What is the liver connected by peritoneal reflections to?
stomach via lesser omentum
anterior abdominal wall via falciform ligament
150
Liver
What are the 5 surfaces and 1 border?
surfaces: anterior, posterior, superior, inferior, and right
border: inferior
151
Liver
What is the visceral surface?
inferior surface
related to abdominal viscera (such as stomach, duodenum, and right kidney)
152
Liver
What is the diaphragmatic surface?
anterior, posterior, superior, and right surfaces
related to diaphragm
153
Liver
What is the porta hepatis?
transverse fissure near centre of visceral surface of liver that serves as passageway for hepatic arteries, hepatic portal vein, hepatic (bile) ducts, hepatic nerve plexus, and lymphatic vessels
154
Liver
What are the 4 lobes?
Where are they?
right, left, caudate, and quadrate
on visceral surface
155
Liver
What are the lobes separated by?
2 impressions
2 grooves
porta hepatis
156
Liver
What are impressions occupied by?
inferior vena cava and gallbladder
157
Liver
What do grooves contain?
2 ligaments that are remnants of fetal blood vessels
- round ligament of liver (ligamentum teres hepatis)
- ligamentum venosum
158
Liver
Where is the porta hepatis?
horizontally located between grooves (on the left) and impressions (on the right)
159
Gallbladder
What is the gallbladder?
small pear-shaped sac located on inferior surface of liver
160
Gallbladder
What are the 3 parts of the gallbladder?
fundus
body
neck
161
Gallbladder
What is the fundus?
round, protrudes from inferior border of liver, and is completely covered by peritoneum
162
Gallbladder
What is the body?
closely related to visceral surface of liver
163
Gallbladder
What is the neck?
aligned with body, and is continuous with S-shaped cystic duct that joins common hepatic duct to form common bile duct
164
What provides sympathetic and parasympathetic fibers to the liver and gallbladder?
greater splanchnic and vagus nerves (CN X) provide sympathetic and parasympathetic fibers to liver and gallbladder via celiac plexus
165
What supplies blood to the liver and gallbladder?
common hepatic branch of celiac artery
166
Pancreas
What is the pancreas?
soft lobulated exocrine/endocrine gland located behind stomach on posterior abdominal wall
167
Pancreas
What type of organ is the pancreas?
almost entirely retroperitoneal
168
Pancreas
What are the 3 parts?
head, neck, body, and tail (from right to left)
169
Pancreas
What is the head surrounded by?
duodenum
170
Pancreas
What is the tail related to?
hilum of spleen
171
Pancreas
What collects secretions of exocrine part of pancreas?
main and accessory pancreatic ducts
172
Pancreas
What does the main pancreatic duct do?
joins common bile duct to form hepatopancreatic ampulla (of Vater) that opens into descending (second) part of duodenum at major duodenal papilla (summit of a mucosal fold)
173
Pancreas
Where is the accessory pancreatic duct?
What does it do?
lies in head of pancreas
either drains into main pancreatic duct or directly drains into descending part of duodenum at minor duodenal papilla (summit of a mucosal fold)
174
Pancreas
What provides sympathetic and parasympathetic fibres to pancreas?
greater splanchnic and vagus nerves (CN X) provide sympathetic and parasympathetic fibres to pancreas via celiac and superior mesenteric plexuses
175
Pancreas
What supplies blood to pancreas?
- common hepatic and splenic branches of celiac artery
| - superior mesenteric artery
