Unit 17 - Digestive System #1 Flashcards
1
Q
Not everything we eat is used by the body, such as cellulose and fiber.
These materials must be expelled from the body via a process called _____
A
“defecation”.
2
Q
The digestive system is composed of two separate categories of organs.
A
The digestive organs and accessory digestive organs
3
Q
The ______collectively make up the “gastrointestinal (GI) tract” or “alimentary (Latin for “relating to nourishment”) canal”.
A
digestive organs
4
Q
1) The GI tract organs include:
A
(a) Oral cavity
(b) Pharynx
(c) Esophagus
(d) Stomach
(e) Small intestine
(f) Large intestine
5
Q
The ______ do not form the long GI tube, but often develop as outgrowths from and are connected to the GI tract.
A
accessory digestive organs
6
Q
1) The accessory digestive organs include:
A
(a) Teeth
(b) Tongue
(c) Salivary glands
(d) Liver
(e) Gallbladder
(f) Pancreas
7
Q
The digestive system performs six main functions.
A
- Ingestion
- Digestion
- Propulsion
- Secretion
- Absorption
- Elimination
8
Q
the introduction of solid and liquid nutrients into the oral cavity.
A
Ingestion
9
Q
The breakdown of large food items into smaller structures and molecules.
A
Digestion
10
Q
Two types of digestion
A
Mechanical Digestion & Chemical Digestion
11
Q
physically breaks down ingested materials into smaller pieces.
A
Mechanical Digestion
12
Q
The first part of mechanical digestion is ______”, the chewing of ingested food by the teeth in the oral cavity.
A
Mastication
13
Q
breaks down ingested molecules into smaller molecules by using enzymes.
A
Chemical Digestion
14
Q
After the materials are swallowed, they move through the GI tract in a process termed ______
A
“propulsion”
15
Q
There are two types of movements involved in propulsion.
A
Peristalsis & Segmentation
16
Q
the process of muscular contraction
that forms ripples along part of the GI tract (much like pushing toothpaste out of a
tube) and causes material to move further along the tract
A
Peristalsis
17
Q
is churning and mixing movements in the small intestine which help dispense the material being digested and combine it with intestinal secretions
A
Segmentation
18
Q
the process of producing and releasing fluid products, such as acid, bile, digestive enzymes, and mucin
A
Secretion
When these fluids are secreted into the lumen of the GI tract, they facilitate chemical digestion and the passage of materials through the GI tract.
19
Q
involves either passive movement or active transport of electrolytes, digestion products, vitamins, and water across the GI tract epithelium and into GI tract blood and lymphatic vessels.
A
Absorption
20
Q
the final function of the digestive system.
A
Elimination
21
Q
All undigestible materials as well as the waste products secreted by the accessory organs into the GI tract are compacted into ______, or fecal material, and then eliminated from the GI tract by the process of “defecation”
A
“feces”
22
Q
The _____, or mouth, is the entrance to the GI tract.
A
“oral cavity”
23
Q
The _____ is the initial site of mechanical digestion (via mastication) and chemical digestion (via an enzyme in the saliva).
A
mouth
24
Q
The mouth is lined with ______ that protects against the abrasive activities associated with digestion.
A
stratified epithelium
This lining is continually moistened by the secretion of saliva.
25
The floor, or inferior surface, of the oral cavity contains the tongue as well as muscles covered with mucosa.
True
26
The oral cavity has two distinct regions:
1) The “vestibule” is the space between the cheeks or lips and the gums.
(a) This is where persons who chew tobacco hold the material after chewing.
2) The “oral cavity proper” lies central to the alveolar processes of the mandible and maxillae.
27
The “lips” have a reddish hue because of their abundant supply of superficial blood vessels and the reduced amount of _____ within their outer skin.
keratin
28
The ______ or “gums” are composed of dense regular connective tissue, with an overlying stratified epithelium that covers the alveolar processes of the upper and lower jaws and surrounds the necks of the teeth.
“gingivae”
29
The internal surfaces of the superior and inferior lips each are attached to the gingivae by a thin mucosal fold in the midline, called the ______
“labial frenulum”
30
The _____ forms the roof of the oral cavity and acts as a barrier to separate it from the nasal cavity.
“palate”
31
The _____, which makes up the anterior two-thirds, is formed by the palatine processes of the maxillae and the horizontal plates of the palatine bones.
“hard palate”
32
The Hard Palate exhibits prominent ______, to assist the tongue in manipulating ingested materials prior to swallowing.
“transverse palatine folds” or “friction ridges”
33
The arching _____ is primarily composed of skeletal muscle.
“soft palate”
34
Extending inferiorly from the posterior part of the soft palate is a conical projection called the ____
“uvula”
When you swallow, the soft palate and the uvula elevate to close off the posterior entrance to the nasopharynx and prevent ingested materials from entering the nasal region.
35
The _____ are located toward the posterior lateral portions of the oral cavity and serve as an early line of defense as they monitor ingested food and drink for antigens.
palatine tonsils
They can initiate an immune response when necessary.
36
In addition, the tongue manipulates and mixes ingested materials during chewing and helps compress the partially digested materials against the hard palate to turn these materials into a _____, a globular mass of partially digested material.
“bolus”
37
The inferior surface of the tongue attaches to the floor of the oral cavity by a thin vertical mucous membrane, the _____
“lingual frenulum”
38
The salivary glands collectively produce and secrete ______, a fluid that assists in the initial activities of digestion or to keep the mouth moist.
“saliva”
39
The volume of saliva secreted daily ranges between _____.
1.0 and 1.5 liters
40
The salivary enzyme _____ begins chemical digestion by breaking down starch.
“amylase”
41
Saliva contains antibodies and an antibacterial substance called _____ that helps inhibit bacterial growth in the oral cavity.
“lysozyme”
42
It is a watery medium into which food molecules are dissolved so taste receptors can be stimulated.
Saliva
43
_____ pairs of multicellular salivary glands are located external to the oral cavity
What are they
Three
“parotid salivary glands”, “submandibular salivary glands”, “sublingual salivary glands”
44
the largest salivary glands.
“parotid salivary glands”
45
This gland becomes infected and swollen with mumps.
“parotid salivary glands”
46
Each _____ is located anterior and inferior to the ear, partially overlying the masseter muscle.
parotid gland
47
The “parotid duct”, which carries the saliva to the oral cavity, travels parallel to the _____ and opens into the vestibule of the oral cavity near the second upper molar
zygomatic arch
48
salivary glands that are inferior to the body of the mandible.
“submandibular salivary glands”
49
A “submandibular duct” opens from each gland in the floor of the mouth on the lateral sides of the _____.
These are the squirters used in “gleeking”!
lingual frenulum
50
The “______ glands” are inferior to the tongue and internal to the oral cavity mucosa.
sublingual salivary
51
Each sublingual salivary gland extends multiple tiny sublingual ducts that open onto the inferior surface of the oral cavity.
True
52
The salivary glands are primarily innervated by the _____ division of the autonomic nervous system.
parasympathetic
53
In particular, the ______ innervates the submandibular and sublingual glands, while the ______ innervates the parotid glands.
facial nerve (CN VII), glossopharyngeal nerve (CN IX)
54
Parasympathetic innervation stimulates salivary gland secretion, which is why your mouth waters when you see a delicious dinner in front of you.
Sympathetic stimulation inhibits normal secretion from these glands, which is why persons who are frightened experience the sensation of a dry mouth.
True
55
The “teeth” are collectively known as _____
“dentition”
56
A tooth has an exposed _____, a constricted “neck”, and one or more “roots” that anchor it to the jaw.
“crown”
57
The roots of the teeth fit tightly into _____, which are sockets within alveolar processes of both the maxillae and the mandible.
“dental alveoli”
58
There are two sets of teeth that develop and erupt during a normal lifetime.
In an infant, 20 “deciduous teeth”, also called “milk teeth”, erupt between 6 months and 30 months after birth.
These teeth are eventually lost and replaced by 32 “permanent teeth”.
59
The more anteriorly placed permanent teeth tend to appear first, followed by the posteriorly placed teeth (the major exception to this rule are the first molars, which appear at about age 6 and sometimes are referred to as the “6-year molars”).
True
60
The last teeth to erupt are the _____, often called “wisdom teeth”, in the late teens or early 20s.
third molars
61
The most anteriorly placed permanent teeth are called _____ and they are designed for slicing or cutting into food
“incisors”
62
Immediately posterolateral to the incisors are the _____, which have a pointed tip for puncturing and tearing food.
(a) They are also referred to as “eye teeth”.
“canines”
63
______ are located posterolateral to the canines and anterior to the molars.
“Premolars”, also referred to as “bicuspids”
64
(a) They have flat crowns with prominent ridges called “cusps” that are used to crush
and grind ingested materials.
(b) They have one or two roots.
“Premolars”, also referred to as “bicuspids”
65
The _____ are the thickest and most posteriorly placed teeth.
“molars”
66
(a) They have large, broad, flat crowns and distinctive cusps, and three or more roots.
(b) ______ are also adapted for grinding and crushing ingested materials.
“molars”
67
If the mouth is divided into quadrants, each quadrant contains the following number of permanent teeth:
(a) 2 incisors
(b) 1 canine
(c) 2 premolars
(d) 3 molars
68
The common space used by both the respiratory and digestive systems is the ____
“pharynx”.
69
Three skeletal muscle pairs form the wall of the pharynx.
(a) “Superior pharyngeal constrictors”
(b) “Middle pharyngeal constrictors”
(c) “Inferior pharyngeal constrictors”
70
The _____ innervate most of the pharyngeal muscles.
vagus nerves (CN X)
71
As the pharyngeal constrictors work, the epiglottis of the larynx closes over the laryngeal opening to prevent ingested materials from entering the larynx and trachea.
True
72
The abdominal organs of the GI tract are supported by serous membranes, and the walls of these organs have specific layers called ______
tunics.
73
The portion of the serous membrane that lines the inside surface of the body wall of the abdominopelvic cavity is called the _____
“parietal peritoneum”
74
The portion of the serous membrane that reflects and covers the surface of the internal organs is called the _____
“visceral peritoneum”.
75
The space between these two layers is a potential space called the _______ where the facing peritoneal layers secrete a lubricating serous fluid.
“peritoneal cavity”
76
Within the abdomen, organs that are completely surrounded by visceral peritoneum are called _____
“intraperitoneal organs”.
77
intraperitoneal organs include the:
1) Stomach
2) Jejunum and ileum of the small intestine
3) Cecum
4) Appendix
5) Most of the large intestine
78
Abdominal organs that lie behind the parietal peritoneum are called _____
“retroperitioneal organs”.
79
Retroperitioneal organs include the:
1) Most of the duodenum
2) Pancreas
3) Kidneys
4) Ascendingcolon
5) Descendingcolon
6) Rectum
80
The ______are double-layered folds of peritoneum that support and stabilize the intraperitoneal GI tract organs.
“mesenteries”
Blood vessels, lymphatic vessels, and nerves are sandwiched between the two folds and travel to the digestive organs.
81
There are several different types of mesenteries:
Greater Omentum, Lesser Omentum, Mesentery Proper, Mesocolon, Peritoneal Ligament
82
extends inferiorly like an apron from the greater curvature of the stomach and covers most of the abdominal organs
Greater Omentum
83
connects the lesser curvature of the stomach and the proximal end of the duodenum to the liver.
Lesser Omentum
84
a fan-shaped fold of peritoneum that suspends most of the small intestine from the internal surface of the posterior abdominal wall
“mesentery proper”
85
The fold in the peritoneum that attaches parts of the large intestine to the internal surface of the posterior abdominal wall is called the
Mesocolon
86
a type of mesentery that attaches one organ to another organ, or attaches an organ to the anterior or lateral abdominal wall.
Peritoneal Ligament
87
attaches the liver to the anterior internal abdominal wall.
“falciform ligament”
88
The GI tract from the esophagus through the large intestine is a tube composed of four concentric layers, called ____
tunics.
89
From deep to superficial, the four tunics are
1. Mucosa (Mucous Membrane), 2. Submucosa, 3. Muscularis, 4. Adventitia or Serosa
90
The “mucosa”, or “mucous membrane”, that has absorptive and secretory functions and which contains:
(a) Superficial epithelium
(b) Connective tissue
(c) Thin layer of smooth muscle
91
The “submucosa” is a dense irregular connective tissue and which contains:
(a) Accumulations of lymphatic tissue
(b) Mucin-secreting glands
(c) Many large blood vessels and lymphatic vessels
(d) Nerve plexuses
92
The “muscularis”, which typically contains two layers of muscle:
an inner circular layer and an outer longitudinal layer.
93
It is these muscular layers which are responsible for peristaltic movements throughout the GI tract.
an inner circular layer and an outer longitudinal layer of muscularis
94
At specific locations along the GI tract, the inner circular layer is greatly thickened to form a _____
“sphincter”.
95
An “adventitia” is composed of loose connective tissue with dispersed collagen and connective tissue with dispersed collagen and elastic fibers.
- The _____ of the duodenum is covered with adventitia
retroperitioneal portion
96
A “serosa” has the same components as the adventitia, but is covered by a visceral peritoneum.
- ______ (i.e. - stomach) are covered with serosa.
Intraperitoneal organs
97
1) _____ innervation promotes digestive system activity by stimulating GI gland secretions and peristalsis, and by relaxing GI sphincters.
2) ______ innervation inhibits digestive system activity, and it tends to do the opposite of parasympathetic innervation.
Parasympathetic
Sympathetic
98
The ______ is a tubular passageway for swallowing materials being conducted from the pharynx to the stomach.
“esophagus”
99
The inferior region of the esophagus connects to the stomach by passing through an opening in the diaphragm called the _____
“esophageal hiatus”.
100
Only the last ______ of the esophagus is located in the abdomen.
1.5 centimeters
101
The esophageal wall is thick and composed of concentric tunics that are continuous superiorly with those of the pharynx and inferiorly with those of the stomach.
True
102
The empty esophagus is flattened; thus, there is no luminal space except when a passing bolus of food slightly expands the esophagus.
1) Recall that such a bolus can cause anterior bulging of the trachealis muscle into the trachea
True
103
there are two sphincters associated with the esophagus
“superior esophageal sphincter”,
“inferior esophageal sphincter”.
104
At the superior end of the esophagus there is the ______, a thickened ring of circular skeletal muscle marking the area where the esophagus and the pharynx meet.
“superior esophageal sphincter”
105
This sphincter is closed during inhalation of air, so air won’t enter the esophagus and instead enter the larynx and trachea.
“superior esophageal sphincter”
106
The orifice between the esophagus and the stomach is bounded by a thin band of circular smooth muscle, the _______
“inferior esophageal sphincter”.
107
The inferior esophageal sphincter isn’t strong enough alone to prevent materials from refluxing back into
the esophagus; instead, the ______ acts as strong support to prevent materials from regurgitating from the stomach into the esophagus.
esophageal opening of the diaphragm
108
Sometimes acidic chyme refluxes into the esophagus, causing the burning pain and irritation of ______
Because the pain is felt posterior to the sternum and can be so intense that it is mistaken for a heart attack, this condition is commonly known as heartburn
reflux esophagitis
109
in which a portion of the stomach protrudes through the diaphragm into the thoracic cavity.
hiatal hernias
110
Chronic reflux esophagitis can lead to ______
Frequent gastric reflux erodes the esophageal tissue in this condition, so over time scar tissue builds up in the esophagus, leading to narrowing of the esophageal lumen.
gastroesophageal reflux disease (GERD).
111
In more advanced cases, the esophageal epithelium may change from stratified squamous to a simple columnar epithelium, a condition known as ______.
Barrett esophagus
112
“Swallowing”, also called _______, is the process of moving ingested materials from the oral cavity to the stomach.
“deglutition”
113
The _____ is a muscular, J-shaped sac that occupies the left upper quadrant of the abdomen, immediately inferior to the diaphragm.
“stomach”
It mechanically and chemically digests the food bolus.
114
After the semidigested bolus has been completely processed in the stomach, it is called ____ which has the consistency of a paste-like soup.
“chyme”
115
The stomach facilitates mechanical digestion by the contractions of its thick _____, which churns and mixes the bolus and the gastric secretions.
muscularis layer
116
The stomach is composed of four regions.
The Cardia, Fundus, Body, Pylorus
117
The internal opening where the cardia meets the esophagus is called the ______
“cardiac orifice”
118
a small, narrow, superior entryway into the stomach lumen from the esophagus.
Cardia
119
the dome-shaped region lateral and superior to the esophageal connection with the stomach.
Fundus
Its superior surface contacts the diaphragm.
120
the largest region of the stomach; it is Inferior to the cardiac orifice and the fundus.
Body
121
a narrow, medially directed, funnel-shaped pouch that forms the terminal region of the stomach.
Pylorus
122
The Pylorus's opening with the duodenum of the small intestine is called the ______
“pyloric orifice”.
123
Surrounding the pyloric orifice is a thick ring of circular smooth muscle called the ______.
“pyloric sphincter”
124
The pyloric sphincter regulates material entering the small intestine by closing upon sympathetic innervation and opening upon _______.
parasympathetic innervation
125
The inferior convex border of the stomach is the _____, while the superior concave border forms the “lesser curvature”.
“greater curvature
126
The greater omentum attaches to the ______ edge of the stomach and the lesser omentum extends between the _______.
greater curvature
lesser curvature and the liver
127
Internally, the stomach lining is composed of numerous “gastric folds”, or “_____
gastric rugae”
128
These gastric folds, which are only observed when the stomach is empty, allow
the stomach to expand greatly when it fills, and then return to its normal J-shape
when it empties.
gastric rugae”
129
a chronic, solitary erosion of a portion of the lining of either the stomach or the duodenum.
peptic ulcer
130
peptic ulcers that occur in the stomach
Gastric Ulcers
131
peptic ulcers in the superior part of the duodenum, the first segment of the small intestine
duodenal ulcers
132
If left untreated, an ulcer may erode the entire organ wall and cause ______, which is a medical emergency.
perforation
133
the major player in peptic ulcer formation is a bacterium called
H. Pylori
134
Irritation of the gastric mucosa, ______, has been linked to many cases of peptic ulcers
(gastritis)
