A&PII Lab 11: The Digestive System - Anatomy Flashcards
(139 cards)
1
Q
Digestive System
A
system that converts food into a form that the body can use for energy, growth, and repair
2
Q
Gastrointestinal (GI) tract
A
sequence of organs forming a single, continuous tube extending from the mouth to the anus; AKA alimentary canal
3
Q
Accessory organs
A
organs that support digestion by the secretion of enzymes and other substances into the GI tract
4
Q
Mucosa
A
deepest layer of the GI tract; composed of a lining epithelium kept moist by the secretion of mucus, a connective layer (lamina propia), and a thin layer of smooth muscle (muscularis mucosae)
5
Q
Submucosa
A
external to the mucosa; composed of loose connective tissue
6
Q
Muscularis
A
layer external to the submucosa; composed of 2 layers in all GI tract organs except the stomach; inner layer = circular arrangement of smooth muscle; outer layer = longitudinal arrangement of smooth muscle; stomach has 3rd layer (innermost layer of smooth muscle fibers extending in an oblique direction)
7
Q
Serosa (visceral peritoneum)
A
external to the muscularis is this serous membrane; contains a layer of epithelium and a layer of connective tissue
8
Q
Peritoneum
A
most extensive serous membrane of the body; combination of simple squamous epithelium with underlying connective tissue; associated with most digestive organs that reside within the abdominopelvic cavity, including the stomach, small intestine, large intestine, and liver
9
Q
Parietal peritoneum
A
outer layer; lines the inner wall of the abdominopelvic cavity
10
Q
Visceral peritoneum
A
inner layer; attached to the outer wall of most organs within the abdominopelvic cavity to form the serosa
11
Q
Peritoneal cavity
A
space between the parietal and visceral peritoneum
12
Q
Mesentery
A
fold that attaches the coils of the small intestine to the posterior abdominal wall
13
Q
Mesocolon
A
fold that attaches the large intestine
14
Q
Falciform ligament
A
fold that attaches the liver to the anterior abdominal wall; can be observed between the right and left lobes of the liver
15
Q
Ligamentum teres
A
vestigial structure which served as the umbilical vein that brought maternal blood from the placenta to the liver of the fetus
16
Q
Greater omentum
A
largest peritoneal fold; begins from the greater curvature of the stomach and folds back to attach to the large intestine; in most people, it hangs like an apron over most of the anterior abdomen, and is filled with fat and lymph nodes
17
Q
Lesser omentum
A
extends between the lesser curvature of the stomach and the liver
18
Q
Mouth
A
point of entry of food into the GI tract
19
Q
Oral cavity
A
AKA buccal cavity
20
Q
Lips
A
opening of the mouth is marked by these fleshy structures
21
Q
Fauces
A
opening into the oropharynx; throat
22
Q
Cheeks
A
lateral borders of the mouth
23
Q
Tongue
A
at the floor of the mouth
24
Q
Hard palate
A
bony structure forming the anterior part of the roof of the mouth
25
Soft palate
posterior part of the roof of the mouth
26
Gingivae
gums; anchor the teeth
27
Vestibule
narrow space between the teeth and gingivae
28
Labial frenulum
bridge of mucous membrane connecting the superior lip and gingivae across the vestibule
29
Palatoglossal arch, palatopharnygeal arch
bordering the fauces are these 2 arches
30
Palatine tonsil
between the arches on each side is a slight depression housing this tonsil
31
Uvula
visible at the back of the mouth; extends from the soft palate to hang downward
32
Pharynx
when you swallow, movements of the soft palate and tongue push food into this next organ of the GI ; muscular chamber lined with mucous membrane, divided into 3 segments
33
Nasopharynx
superior segment of the pharynx that receives air from the internal nares, & includes the single pharyngeal tonsil and openings into the auditory tubes
34
Oropharynx
middle segment of the pharynx; posterior to the fauces of the mouth; common chamber for food, water, and air (due to its location)
35
Laryngopharynx
inferior to the oropharynx; extends to the glottis of the larynx
36
Esophagus
when it's not transporting food, this "gullet" is a flattened tube with muscular walls and a slippery mucosa that stretches open to accommodate swallowed food
37
Peristalsis
the esophagus propels food by this action, in which the circular and longitudinal muscles in its walls contract sequentially to form a wavelike pattern
38
Esophageal hiatus
at its distal end, the esophagus passes from the thoracic cavity into the abdominal cavity through this opening in the diaphragm
39
Lower esophageal sphincter (LES)
near its union with the stomach, the esophageal muscles thicken to form this structure, which opens to allow food into the stomach
40
Stomach
J-shaped organ immediately inferior to the diaphragm on the left side of the abdominal cavity
41
Cardia
part that receives the esophagus (in the superior part of the stomach)
42
Fundus
dome-shaped holding area for food that forms the superior part of the stomach
43
Body
large, central portion of the stomach
44
Pylorus
small area to the left of the body of the stomach; the "gatekeeper"
45
Pyloric valve (pyloric sphincter)
the pylorus unites with the small intestine at this thickening of the stomach wall; opens to allow stomach contents into the small intestine
46
Pyloric antrum
part of the pylorus adjacent to the body of the stomach
47
Pyloric canal
part of the pylorus near the pyloric valve
48
Lesser curvature
medial border of the stomach forms this concave curve
49
Greater curvature
lateral border of the stomach forms this convex curve
50
Rugae
ridges of the mucosa on the internal surface of the stomach; provide an additional surface area that permits stretching of the stomach wall to accommodate a large volume of food
51
Gastric juice
within the stomach, food is mixed and churned with these secretions of the stomach wall
52
Pepsin
enzyme within gastric juice; performs the chemical digestion of protein molecules
53
Small intestine
long tube-shaped organ that extends from its union with the stomach to the large intestine, dominating the abdominopelvic cavity; 10 feet long, 1 inch in diameter in an average healthy adult; composed of 3 segments
54
Duodenum
proximal segment of the small intestine; name derived from its length of "12 finger-widths" (~10 inches); wall of this segment contains glands that secrete mucus, which protect its lining from the acidic material arriving from the stomach; receives enzymes from the pancreas, bile from the liver & gallbladder, and produces its own digestive enzymes
55
Jejunum
middle segment of the small intestine; measures about 3 feet long; derives its name from early human dissections, during which it was usually found "empty" of any contents
56
Ileum
distal segment of the small intestine; longest portion at about 6 feet in length; named after peristaltic waves were observed to "roll" through it
57
Ileocecal valve
the ileum terminates at this valve, where it unites with the large intestine
58
Plicae circulares
absorption is aided by the presence of these internal circular folds, along with villi and microvilli
59
Villi
fingerlike projections of the mucosa; aids absorption along with plicae circulares and microvilli
60
Microvilli
cellular processes that aids absorption along with plicae circulares and villi
61
Large intestine
5 feet, 3 inches wide; consists of 3 main segments (cecum, colon, rectum)
62
Cecum
blind pouch arising from the ileocecal valve and extending 2-3 inches before it ends
63
Appendix
slender appendage that extends from the medial wall of the cecum about 2 inches
64
Colon
at the level of the ileocecal valve, this portion of the large intestine begins its ascent toward the liver on the right side of the abdominopelvic cavity
65
Ascending colon
begins its ascent toward the liver on the right side of the abdominopelvic cavity to form this
66
Right Colic Flexure
colon takes this 90 degree turn just beneath the liver
67
Transverse colon
part of the colon that extends transversely to the left side of the abdominopelvic cavity
68
Left Colic Flexure
near the spleen, the colon turns 90 degrees inferiorly
69
Descending Colon
part of the colon continuing downward along the left side until it turns to form an S-shaped segment (sigmoid colon)
70
Sigmoid Colon
S-shaped segment of the colon at the level of the iliac crest
71
Taenia coli
all 4 portions of the colon contain these 3 longitudinal bands of smooth muscle
72
Haustra
contractions of taenia coli gather the colon into these pouches, which can be observed externally
73
Epiploic appendages
numerous fat-filled pouches of visceral peritoneum; hang from the taenia coli
74
Rectum
final segment of the large intestine; about 6 inches long; lacks the taenia coli, haustra, and epiploic appendages of the colon
75
Anal canal
terminal 2 inches of the rectum
76
Anal columns
anal canal contains these folds along the inner wall
77
Anus
rectum opens to the exterior at this structure
78
Internal & external sphincters
anus is bordered by these smooth muscles and skeletal muscles
79
Teeth
provide mechanical digestion by breaking up food particles in the mouth
80
Crown
visible area of teeth above the gum line
81
Root
submerged area of teeth below the gum line; embedded into an alveolar socket of the mandible or maxilla
82
Periodontal ligament
root of teeth anchored in place by this ligament which lines the socket
83
Dentin
most of a tooth is composed of this calcified connective tissue
84
Enamel
harder than dentin; = compact bone; forms a covering over the crown of a tooth
85
Cementum
in the root of a tooth, this adhesive connective tissue adheres the dentin to the periodontal ligament
86
Pulp cavity
the center of the crown of the tooth is this small chamber; filled with pulp, which contains blood vessels, nerves, and lymphatics
87
Root canal
the pulp cavity and pulp continues into the root as this slender channel
88
Incisors
teeth with narrow edges for cutting during a bite
89
Canines (cuspids)
teeth with a pointed edge for tearing food
90
Premolars
teeth with 2 flat surfaces (cusps) for grinding
91
Molars
teeth with broad/rounded cusps for additional food grinding
92
Deciduous teeth
in a child, teeth begin forming several months after birth to eventually form these teeth; AKA primary or milk teeth; temporary with very small roots, lost between the ages of 6-12 years; 20 teeth = 2 incisors, 1 canine, 0 premolars, 2 molars on upper and lower (x 2)
93
Permanent teeth
32 teeth = 2 incisors, 1 canine, 2 premolars, 3 molars on upper and lower (x 2)
94
Salivary glands
exocrine glands that secrete saliva
95
Saliva
watery substance secreted by exocrine glands that lubricates food in the mouth to assist in swallowing; its enzymes begin the process of carbohydrate digestion in the mouth
96
Parotid glands
largest of the salivary glands are these paired glands; located anterior and inferior to the ear, between the masseter muscles of the jaw and the skin
97
Parotid ducts
parotid glands secrete saliva into these chambers, which carry it into the mouth near the 2nd molar of the upper jaw
98
Submandibular glands
paired glands that may be found in the posterior floor of the mouth medial to the mandible
99
Submandibular ducts
submandibular glands secrete saliva into these ducts, which open into the mouth near the lingual frenulum beneath the tongue
100
Sublingual glands
paired salivary glands located beneath the tongue in a location medial and superior to the submandibular glands
101
Lesser sublingual ducts
sublingual glands secrete saliva into these ducts, which open into the floor of the mouth beneath the tongue
102
Tongue
when relaxed, it lies flat on the floor of the mouth
103
Lingual frenulum
ventral surface of the tongue contains an extension of mucous membrane called this, which anchors the tongue to the actual floor of the mouth
104
Papillae
the tongue is covered with a thick mucous membrane and these that are distributed along its dorsal and lateral surfaces
105
Extrinsic muscles
muscles that attach the tongue to the hyoid bone
106
Intrinsic muscles
tongue muscles not attached to bone; skeletal muscle fibers that move the tongue during chewing, speech, and swallowing
107
Pancreas
organ located within the abdominal cavity posterior to the body and pylorus of the stomach and the proximal end of the duodenum; soft glandular organ in 3 parts
108
Head
expanded portion of the pancreas located posterior to the duodenum
109
Body
central part of the pancreas behind the pylorus of the stomach
110
Tail
narrow part of the pancreas located behind the body of the stomach
111
Pancreatic acinar cells
internally, the pancreas consists of these enzyme-secreteing cells, which dominate its landscape; produce pancreatic juice
112
Pancreatic juice
produced by pancreatic acinar cells; empties into the duodenum
113
Pancreatic islets
portion of the pancreas secreting hormones
114
Pancreatic duct
most acinar cells deliver their secretions into this central duct; extends from the tail to the head of the pancreas
115
Hepatopancreatic ampulla
within the head, the pancreatic duct joins the bile duct to form this structure, which opens at the duodenum
116
Accessory pancreatic duct
some acinar cells empty their secretions into this duct, which is a division of the pancreatic duct; also opens into the duodenum
117
Liver
large, soft organ in the right side of the abdominal cavity that presses against the diaphragm; suspended from the diaphragm and the anterior abdominal wall by the falciform ligament; consists of 4 lobes
118
Right lobe
largest lobe of the liver
119
Left lobe
separated from the right lobe by the falciform ligament
120
Caudate lobe
visible from the posterior view only; superior lobe of the liver; posterior to the right lobe
121
Quadrate lobe
visible from the posterior view only; inferior lobe of the liver; posterior to the right lobe
122
Right and left hepatic ducts
bile produced by liver cells is transported by small ducts that eventually unite to form these ducts
123
Common Hepatic Duct
soon after emerging from the liver tissue, the right and left hepatic ducts converge to form this duct; bile may flow through this to the duodenum where it can be used for lipid digestion or it may flow through the cystic duct to be temporarily stored in the gallbladder
124
Cystic duct
bile may flow through the common hepatic duct to the duodenum where it can be used for lipid digestion, or it may flow through this duct to be temporarily stored in the gallbladder
125
Gallbladder
hollow organ with smooth muscle walls; visible as a green-colored sac on the posterior side of the liver, located between the right lobe and the quadrate lobe; receives bile from the liver by way of the cystic duct, and stores it until a meal is consumed
126
Gastric glands and gastric pits
part of the mucosa of the stomach
127
Chief (zymogenic) cells
blue-stained cells lining the gastric pit; secrete pepsinogen (acidic environment is necessary to activate pepsinogen into its protein-cleaving form, pepsin)
128
Parietal cells
red-stained cells within the gastric pit; secrete HCl
129
Brush border
faint pink line along the surface of the simple columnar cells of the small intestine; indicates presence of microvilli
130
Goblet cells
cells in the lining epithelium of the small intestine; secrete mucus
131
Intestinal glands
crypts of Lieberkuhn; produce hormones that participate in digestion
132
Duodenal glands
Brunner's glands; embedded in the submucosa of the small intestine; produce mucus to protect the intestinal lining from acid arriving from the stomach
133
Peyer's Patches
round clusters of dark-staining cells (lymphocytes and macrophages)
134
Lobules
microscopic sections of the liver
135
Hepatocytes
each lobule of the liver is a cylindrical arrangement of these cells that radiate from a central vein
136
Portal triad
the sectioned lobule contains 6 corners, each of which includes this that is formed by a branch of the hepatic artery, a branch of the hepatic portal vein, and a bile duct
137
Sinusoids
between the rows of hepatocytes are these blood-filled channels which carry blood through the liver as hepatocytes
138
Kupffer cells
remove unwanted substances
139
Bile canaliculi
running parallel to the sinusoids are these, which carry newly formed bile toward the bile duct
