Digestive System Flashcards
(145 cards)
1
Q
Functions of the digestive system include..
A
- ingesting food
- transporting food
- breaking food into smaller absorbable components
- secretion of waste products
2
Q
The digestive system includes what two parts?
A
alimentary canal
accessory organs
3
Q
From mouth to anus, the tubular alimentary canal (or digestive tract) exhibits _______ and _________ muscles to keep food moving in one direction
A
circular and longitudinal
4
Q
The coordinated, rhythmic contractions of the gastrointestinal tract is called…
A
peristalsis
5
Q
Food is broken down…
A
mechanically and chemically (with enzymes)
6
Q
Mastication
A
chewing
7
Q
What are the primary muscles of mastication?
A
temporalis
masseter
pterygoids
8
Q
Where does the temporalis muscle originate?
A
lateral skull
9
Q
Where does the temporalis muscle insert?
A
coronoid process of mandible
10
Q
Function of the temporalis
A
elevates mandible
11
Q
Where does the masseter muscle originate?
A
zygomatic arch
12
Q
Where does the masseter insert?
A
lateral surface of mandible and angle
13
Q
Function of the masseter
A
elevates mandible
14
Q
Where do the medial and lateral pterygoids originate?
A
lateral pterygoid plate of pterygoid process
15
Q
Where does the lateral pterygoid insert?
A
disc of temporomandibular joint
16
Q
Where does the medial pterygoid insert?
A
angle of mandible
17
Q
Function of the pterygoid muscles
A
move mandible side-to-side for grinding
18
Q
The muscles of mastication are innervated by…
A
the mandibular division of the trigeminal nerve (V3)
19
Q
The oral cavity is the space…
A
inside the dental arches
20
Q
The space between the dental arches and lips/cheeks is called the…
A
vestibule
21
Q
What forms the roof of the oral cavity?
A
hard and soft palate
22
Q
The hard palate is formed by…
A
maxillary and palatine bones
23
Q
The soft palate is…
A
fibromuscular
24
Q
Function of the uvula
A
seals off nasopharynx during swallowing
25
Which muscles help move food to the pharynx with swallowing and form a "bed" for the palatine tonsil?
palatoglossus and palatopharyngeous
26
Superior Labial Frenulum
mucosal fold connected to upper lip
27
Inferior Labial Frenulum
mucosal fold connected to lower lip
28
Lingual Frenulum
mucosal fold connected to inferior surface of tongue
29
The tongue is convered by mucous membranes with specialized features called...
papillae
30
Which part of the tongue has lingual tonsil?
posterior 1/3
31
General sensation from the anterior 2/3 of the tongue is carried by which nerve?
mandibular division of the trigeminal nerve (V3)
32
Taste from the anterior 2/3 of tongue is carried by which nerve?
facial nerve (CN VII)
33
General sensation and taste from the posterior 1/3 of the tongue is carried by...
the glossopharyngeal nerve (CN IX)
34
The muscles of the tongue are innervated by...
hypoglossal nerve (CN XII)
35
Saliva assists with...
initial activities of digestion
36
What is the volume of daily secreted saliva estimated to be?
1-1.5 L
37
What percentage of saliva is water?
99.5%
38
What enzyme in saliva begins to break down carbohydrates?
Amylase
39
Saliva also contains...
antibodies and antibacterial substances
40
Parotid Glands
- largest of the salivary glands
| - near angle of mandible
41
Function of parotid glands
transport saliva to oral cavity by parotid duct
| - produces 25-30% of saliva
42
Where do the parotid glands get their parasympathetic innervation?
from glossopharyngeal nerve (CN IX)
43
Submandibular Glands
located in upper neck, under body of mandible
44
Function of submandibular glands
transport saliva to oral cavity by submandibular duct
| - produces 60-70% of saliva
45
Where do the submandibular glands get their parasympathetic innervation?
from facial nerve (CN VII)
46
Sublingual Glands
- located under the tongue in floor of oral cavity
- has multiple sublingual ducts under tongue
- produces 3-5% of saliva
47
Where do the sublingual glands get their parasympathetic innervation?
from facial nerve (CN VII)
48
Salivary glands have cells that produce...
mucus and serous fluid
49
Esophagus location
descends along posterior thorax
50
Function of Esophagus
transports food from pharynx to stomach
51
Does the esophagus absorb nutrients?
no
52
The esophagus passes through the diaphragm at the...
esophageal hiatus
53
Mucosa in the esophagus is composed of...
thick, nonkeratinized stratified squamous epithelium
54
The submucosa of the esophagus has what kind of fibers to allow for distension during swallowing?
elastic fibers
55
The muscular layer of the esophagus has what components?
circular (inner) and longitudinal (outer)
56
Which part of the esophagus has voluntary skeletal muscle?
upper part
57
What part of the esophagus has involuntary smooth muscle?
lower part
58
The esophageal sphincter between the esophagus and stomach prevents...
movement of food from stomach into esophagus (if this happens, it is called reflux)
59
Cardia
entryway into stomach from esophagus
60
Fundus
dome of the stomach
61
Body (of the stomach)
large, middle region of stomach
62
Pylorus
funnel-shaped end of stomach with pyloric sphincter to control food leaving stomach
63
Lesser curvature (of the stomach)
small concavity of right side
64
Greater curvature (of the stomach)
large convexity of left side
65
Gastric Folds (rugae)
internal folds of stomach allowing for expansion
66
The stomach is lined with...
simple columnar epithelium with surface mucous cells that secrete alkaline fluid
67
Gastric pits receive secretions from...
gastric glands
68
Chief cells of gastric glands
secrete pepsinogen (which break down protein) and gastric lipases
69
Parietal cells of gastric glands
secrete intrinsic factor (binds vitamin B12) and hydrochloric acid
70
Mucous neck cells of gastric glands
secrete acid fluid containing mucin
71
Enteroendocrine cells of gastric glands
secrete gastrin into bloodstream to stimulate gastric secretions and muscle contractions
72
The small intestine is approximately how many feet long?
20 feet
73
Where are 90% of nutrients (and water) absorbed?
small intestine
74
The small intestine consists of the...
duodenum, jejunum, and ileum
75
Duodenum
- first part of small intestine
- about 10 inches long
- C-shaped and cradles the head of the pancreas
76
The duodenum receives...
secretions (bile) from the liver and gallbladder, as well as digestive enzymes from the pancreas
77
Jejunum
- second part of the small intestine
| - about 7.5 feet long
78
The jejunum is the main region of the small intestine for...
chemical digestion and nutrient absorption
79
Ileum
- 3rd and last part of the small intestine
| - about 10 feet long
80
The distal end of the ileum terminates at the ileocecal valve, which controls...
movement of materials into large intestine
81
In terms of histology, the small intestine has...
mucosa, muscular layer, and serosa (adventitia)
82
In the small intestine, mucosa is thrown into...
circular folds
83
Finger-like villi in the small intestine...
increase surface area for absorption and secretion
84
The endothelium in the small intestine consists of...
simple columnar epithelia (with microvilli) and goblet cells
85
The simple columnar epithelia cells, or enterocytes, of the small intestine do what?
absorb nutrients and water
86
What is in the center of each villus in the small intestine?
capillary network and lacteal (lymphatic vessel)
87
Intestinal glands contain...
unicellular gland cells and enteroendocrine cells
88
Enteroendocrine cells secrete...
hormones, some of which slow down movement of food out of the sotmach
89
Submucosal (Brunner) glands produce...
an alkaline mucus to protect the duodenum from acidic chyme
90
The muscular layer of the small intestine consists of...
inner layer of circular muscle and outer layer of longitudinal muscle
91
Large Intestine
- commonly referred to as large bowel
| - approximately 5 feet long
92
Main function of large intestine
absorb water and ions from remaining digested material
93
The large intestine consists of the...
cecum, ascending oclon, transverse colon descending colon, and sigmoid colon
94
Cecum
- first part of the large intestine
| - pouch-like structure extending inferiorly from ileocecal valve
95
What structure is attached to the cecum?
the appendix, which is a finger-like structure lined with lymphatic nodules
96
Ascending Colon
- second part of large intestine
- ascends from cecum to the area of the liver
- travels along right side of abdomen
- transitions into the transverse colon at the right colic (hepatic) flexure
97
Transverse Colon
- third part of large intestine
- originates at the right colic flexure and courses to the left, just inferior to the stomach
- as it approaches the spleen, it makes a turn inferiorly at the left colic (splenic) flexure to become the descending colon
98
Descending Colon
- fourth part of the large intestine
- descends along the left side of the abdomen from the left colic flexure to the ileum, where it transitions into te sigmoid colon
99
Sigmoid Colon
- S-shaped part of the large intestine
- it courses over the iliac fossa on the left and descends into the pelvis and transitions into the rectum (the rectum then terminates at the anus)
100
Teniae Coli
3 external longitudinal bands of smooth muscle visible throughout the length of the large intestine
101
Function of teniae coli
help to shorten the large intestine during peristalsis
102
The teniae coli muscles are shorter than the length of the large intestine, which causes the large intestine to form pouches called...
haustra
103
Anus
- terminal part of the large intestine
| - has internal and external sphincter
104
Internal Sphincter of Anus
made of smooth muscle, under the control of the autonomic nervous system
105
External Sphincter of Anus
skeletal muscle, under the control of the somatic motor system
106
The mucosa of the large intestine is lined with...
simple columnar epithelium and goblet cells
107
The simple columnar cells of the large intestine absorb...
water and nutrients
108
Goblet cells of the large intestine secrete...
mucous to lubricate the undigested material
109
Does the mucosa of the large intestine have villi?
no
110
The submucosa of the large intestine containes...
many lymphatic nodules
111
The large intestine's muscular layer has..
inner circular layer and outer longitudinal layer (in the form of taniae coli)
112
When the rectum is storing feces, the wall is ________ while the internal anal sphincter is _________; this is under the control of sympathetics
relaxed ; contracted
113
When stool builds up in the rectum, _______ _________ send signals up to the defecation reflex center of the brain
stretch receptors
114
The reflex center in the brain activates parasympathetics, which causes....
the internal anal sphincter to relax and the wall of the rectum to contract (DEFECATION REFLEX)
115
To override the defecation reflex, the __________ ______ __________ must contract to hold feces until it is convenient to defecate.
external anal sphincter
116
Polyps
outgrowths of the colon mucosa into the lumen
| - can give rise to cancer
117
Hiatal hernia
part of the stomach protrudes through the diaphragm into the thorax
118
Diverticulosis
out-pocketing of the intestinal wall (usually the large intestine)
119
Peptic Ulcer
erosion of the lining of the stomach or duodenum
120
The liver is located in which quadrant?
upper right quadrant of the abdomen
121
The superior surface of the liver is fused to what?
the diaphragm
122
The liver consists of how many lobes?
4
123
What are the two major lobes of the liver?
right and left
124
What are the two minor lobes of the liver?
caudate and quadrate
125
What is the name of the connective tissue structure located between the right and left lobe that attaches the liver to the anterior abdominal wall?
falciform ligaments
126
At the inferior aspect of the falciform ligament, there is a dense cord of tissue called the...
round ligament of the liver
127
During fetal development, what was the round ligament?
a functional blood vessel (umbilical vein) that carried oxygenated blood from the placenta to the heart
128
The liver has many functions. What is an important one?
removes harmful substances from the substances being absorbed by the gastrointestinal tract (in hepatic portal vein)
129
The cells of the liver (hepatocytes) form...
wheel-like hepatic lobules - branches of the hepatic portal vein pass from the periphery to the center of the lobules, past the cells which detoxify the blood
130
Another function of the liver is to produce ______ to break down fats in the digestive tract
bile
131
Bile is transported to the duodenum by the...
bile duct
132
What does the gall bladder do?
stores bile produced by the liver until needed by the digestive tract
133
Why is the liver considered to be an exocrine gland?
it uses a duct to transport its secretions
134
Liver secretes bile into the...
hepatic duct
135
The gall bladder secretes bile into the...
cystic duct
136
The hepatic duct and cystic ducts join to form the...
common bile duct
137
The pancreatic duct joins the common bile duct to empty into the...
duodenum
138
Why is the pancreas considered a mixed gland?
it has both exocrine and endocrine functions
139
What does the exocrine part of the pancreas consist of and do?
consists of acinar cells which synthesize and secrete pancreatic juice to help with digestion
140
What does pancreatic juice consist of?
mucin and digestive enzymes (transported by the pancreatic duct, which joins with the common bile duct)
141
What does the endocrine part of the pancreas consist of and do?
consists of islet cells which produce insulin
142
The serous membrane that lines the abdominal cavity is called the...
peritoneum
| - as the abdominal organs grow into the abdominal cavity, they acquire a covering of this peritoneum
143
When peritoneum is found on the surface of an abdominal organ, it is called...
visceral peritoneum
144
Where peritoneum is found on the inner wall of the abdominal cavity, it is called...
parietal peritoneum
145
When the peritoneum sandwiches the neurovascular supply of "intraperitoneal" organs, it is called...
mesentery
- certain parts of the digestive tract (small intestine, transverse colon, sigmoid colon) grow into the abdominal cavity such that the peritoneum behind them "collapses" on the nerves and blood vessels traveling to them
