CH 26 Flashcards
(127 cards)
1
Q
digestive system
A
-ingested, mixes, transports, and breaks down food; absorbs digested nutrients and expels wastes
2
Q
bolus
A
-food mixed with saliva
3
Q
Chyme
A
-Stomach converts bolus into chyme
4
Q
digestive system 2 categories
A
-gastrointestinal (GI) tract
-accessory digestive organs
5
Q
gastrointestinal (GI) tract
A
-continuous tube including:
-Oral cavity
-pharynx
-esophagus
-stomach
-small intestine
-large intestine
-anus
6
Q
accessory
A
-connected to GI tract that includes:
-teeth
-tongue
-salivary glands
-liver
-gallbladder
-pancreas
7
Q
digestive system functions
A
-ingestion
-motility
-secretion
-digestion
-absorption
-elimination of wastes
8
Q
ingestion
A
-introduction of materials into the mouth
9
Q
motility
A
-involves voluntary and involuntary contraction that forces material to move further along the GI tract
-2 types
-Peristalsis
-Mixing
10
Q
peristalsis
A
-ripple-like wave of muscular contraction that forces material to move further along the GI tract
11
Q
mixing (segmentation)
A
-the name for the churning movement in small intestine that disperse ingested materials and combine them with digestive secretions
12
Q
oral cavity tissue
A
-lined by nonkeratinized stratified squamous epithelium
13
Q
oil cavity boundaries
A
-teeth and lips anteriorly; oropharynx posteriorly
-palate superiorly; mylohyoid muscle inferiorly
14
Q
2 regions of oral cavity
A
-vestibule
-oral cavity proper
15
Q
vestibule
A
-between cheeks or lips and gums
16
Q
oral cavity proper
A
-central to alveolar processes of jaw bones
17
Q
cheeks
A
-form the lateral walls of the oral cavity and are comprised mainly of the buccinator muscle
-the cheeks end anteriorly at the lips
18
Q
gingivae
A
-(gums) cover the alveolar processes of the teeth
-internal surfaces of the lips attach to gingivae with a thin, midline mucosa fold called the labial frenulum
19
Q
palate
A
-forms the roof of the oral cavity
-anterior 2-3rds of the palate is the hard palate
-posterior one-third of the palate is muscular and is called the soft palate
20
Q
hard palate
A
-formed by palatine processes of maxillae bones and palatine bones
-contains ridge called transverse palatine folds, which help tongue in manipulation of food
21
Q
soft palate
A
-extending posteriorly from soft palate in to uvula, which elevates during swallowing and closes off the posterior entrance to the nasopharynx
22
Q
fauces
A
-represent the opening from the oral cavity to the oropharynx
-Bound laterally paired muscular folds:
*palatoglossal arch (anterior)
*palatopharyngeal arch (posterior)
23
Q
palatine tonsils
A
housed between:
*palatoglossal arch (anterior)
*palatopharyngeal arch (posterior)
24
Q
tongue made of
A
-mostly of skeletal muscle
-superior surface has many papillae (small projections)
25
tongue function
-It manipulates and mixes ingested materials, helps compress them into a bolus and assists in swallowing
26
inferior surface of tongue
-attaches to floor of mouth by a thin, midline mucous membrane called the lingual frenulum
27
lingual tonsils
-found on posterior inferior surface of the tongue
28
salivary glands
-exocrine glands that produce and secrete saliva into the oral cavity
29
saliva function
-moistens ingested materials to become a slick bolus
-moistens, cleanses, and lubricates the structures of the oral cavity
-begins chemical digestion of carbohydrates with salivary amylase
-antibacterial action with lysozyme
-dissolve food so taste receptors on tongue can be stimulated
30
unicellular glands
-collectively known as intrinsic salivary glands
-produces a small amount of saliva within the mouth
-contains lingual lipase
31
lingual lipase
-breaks down lipids in the stomach
32
multicellular extrinsic salivary glands
-3 pairs
-make most saliva:
*parotid glands
*submandibular glands
*sublingual glands
33
parotid salivary glands
-are the largest salivary glands
-are located anterior and inferior to the ear
-secrete 25% to 30% of total saliva
-parotid ducts
34
Parotid ducts
-runs parallel to zygomatic arch and pierces the buccinator muscle before opening into mouth near second upper molar
35
submandibular salivary glands
-reside inferior to the body on the mandible
-produce majority of saliva (60% to 70%)
-submandibular duct opens through a papilla in the floor of the mouth next to lingual frenulum
36
sublingual salivary glands
-are inferior to the tongue
-contain multiple, time sublingual ducts that open onto the inferior surface of the oral cavity
-contribute 3% to 5% of total saliva
37
pharynx
-(throat)
-muscular tube used by digestive and respiratory systems
38
oropharynx and laryngealpharynx
-have nonkeratinized stratified squamous lining
39
pharyngeal constrictors
-superior middle and inferior pharyngeal constrictors within it's wall participate in swallowing
-CN X innervates most pharyngeal muscles
40
pharynx blood supply
-branches of external carotid arteries supply the pharynx
-internal jugular veins drain the pharynx
41
abdominal cavity
-lined with moist serous membranes
42
parietal peritoneum
-lines inside surface of the body wall
43
visceral peritoneum
-covers surface in internal organs within the cavity
44
peritoneal cavity
-between the 2 serous layers
45
intraperitoneal organs
-organs completely surrounded by visceral peritoneum (for example stomach)
46
retroperitoneal organs
-organs that lie against the posterior abdominal wall are only covered by peritoneum on their anterolateral surface
EX:pancreas, rectum
47
mesenteries
-are folds of peritoneum that support and stabilize intraperitoneal GI tract organs
-blood vessels, lymphatic vessels, and nerves are sanwhiched between the two folds and supply the digestive organs
-types:
*greater omentum
*lesser omentum
*mesentery proper
*mesocolon
48
greater omentum
-extends inferiorly like an apron from the greater curvature of stomach and covers most abdominal organs
49
lesser omentum
-connects the lesser curvature of the stomach and the proximal and of the duodenum to the liver
50
mesentery proper
-suspends most of the small intestines from the posterior abdominal wall
51
mesocolon
-peritoneal fold that attaches parts of the large intestine to the posterior abdominal wall
52
peritoneal ligament
-folds of peritoneum that connects structures
53
peritoneal ligament examples
-coronary ligament (liver to diaphragm)
-falciform ligament (liver to abdominal wall
-lienorenal ligament (spleen to kidney)
54
GI wall 4 tunic layers
-Deep to superficial
*mucosa
*submucosa
*muscularis
*adventitia or serosa
55
mucosa composed of
-an inner epithelium
-underlying areolar connective tissue layer called the lamina propria
-a thin layer of smooth muscle called the muscularis mucosae
56
submucosa is composed of
-areolar or dense irregular connective tissue
-lymphatic ducts
-mucin-secreting glands
-blood vessels
-nerves, including the submucosal nerve plexus, which is part of the enteric nervous system
57
muscular is composed of
-inner circular layer of smooth muscle
-outer longitudinal layer of smooth muscle
-myenteric nerve plexus
58
inner circular layer
-constricts the lumen and forms sphincters at some locations
59
outer longitudinal layer
-shortens the tube
60
myenteric nerve plexus
-nerve fibers and associated ganglia between the two layers of muscles
-also a component of the enteric nervous system
61
outer layer of GI tract
-adventitia or serosa
62
adventitia
is made of areolar connective tissue with collagen and elastic fibers
63
serosa
-same as adventitia but is covered by a visceral peritoneum
64
intraperitoneal/retroperitoneal organs
-intraperitoneal: have serosa
-retroperitoneal: primarily have and adventitia (covered only partially by visceral peritoneum)
65
esophagus
-tube that conducts ingested materials from the pharynx to the stomach
-courses anterior to the vertebral bodies
66
esophageal hiatus
-esophagus passes through this opening in the diaphragm just before it connects to the stomach
67
adult esophagus
-25 cm long
-most of it's length is in the thorax with the last 1.5 cm in the abdomen
-empty esophagus is flattened
68
esophageal mucosa
-stratified squamous epithelium
69
submucosa
-thick with many elastic fibers and mucous glands
70
muscular
-contains both skeletal and smooth muscle
-transitions from skeletal muscle (voluntary control of swallowing) superiorly to smooth muscle inferiorly
71
superior esophageal sphincter
-ring of skeletal muscle at the top of esophagus; closes during inhalation preventing air entry
72
inferior esophageal sphincter
ring of smooth muscle at the bottom of esophagus; prevents materials from regurgitating from stomach
73
stomach
-upper left quadrant of abdomen
-continues the mechanical and chemical digestion of the bolus
-bolus eventually is processed into chyme
74
4 stomach regions
-cardia
-fundus
-body
-pylorus
75
cardia
-entryway; meets esophagus at opening called cardiac orifice
76
fundus
-dome-shaped portion superior and lateral to cardiac orifice
77
body of stomach
-largest par; inferior to cardiac orifice and fundus
78
pylorus
-funnel-shaped terminal region
*includes wider pyloric antrum and narrower pyloric canal
*smooth muscle pyloric splinter controls opening to duodenum (pyloric orifice)
79
greater curvature
-inferior, convex border of stomach
80
lesser curvature
-superior, concave border
81
gastric folds (Rugae)
-internal surface of the stomach
*seen only when stomach is empty; allow for stomach to expand greatly when it fills
82
stomach lining
-simple columnar epithelium
83
gastric pits
-lining is indented by depressions
84
gastric glands
-at the base of each pit are openings to several branched tubular glands
85
five types of secretory cells form the gastric epithelium
-surface mucous cells
-mucous neck cells
-parietal cell
-chief cells
-enteroendocrine cells
86
surface mucous cells
-secrete alkaline fluid containing mucin
87
mucous neck cells
-secrete a less-alkaline fluid containing mucin
88
parietal cells
-secrete hydrochloric acid and intrinsic factor
89
chief cells
-secrete pepsinogen (converted into pepsin in stomach lumen)
90
enteroendocrine
-cells secrete hormones such as gastrin
91
small intestine
-finishes chemical digestion and is responsible for most nutrient absorption
-material spends 12 Hr until chemical digestion and absorption is complete
-about 6m (20ft) long in cadaver- shorter in living individual
92
3 segments for small intestine
-duodenum
-jejunum
-ileum
93
duodenum
-Is C-shaped
-Originates at pyloric sphincter
-Becomes continuous with jejunum at the duodenojejunal flexure
-Contains the major duodenal papilla, which is the site where bile and pancreatic secretions enter GI tract
-Minor duodenal papilla receives a small amount of pancreatic juice
94
jejunum
-is the middle portion of the small intestine
-is the primary region for chemical digestion and nutrient absorption
95
ileum
-is the last segment of the small intestine
-distal and terminates at the ileocecal valve, a sphincter that controls the entry of materials into the large intestine
96
circular folds (Plicae circularis)
-internally, the mucosal and submucosal tunics are thrown into folds called the circular folds
97
villi
-microscopic fingerlike projections called villi can be seen on the surface of the circular folds
98
microvilli
-microscopic fingerlike projections called microvilli can be seen on the surface of the villi
*collectively appear as a brush border
99
intestinal glands
-between villi are invaginations of mucosa that release hormones such as secretin, cholecystokinin and gastric inhibitory peptide
100
submucosal glands
-duodenum produce alkaline mucus
101
large intestine
-forms a 3-sided perimeter around the small intestine
-large diameter and shorter in length than the small intestine
-absorbs most of the remaining water, electrolytes, and vitamins from digested material
-compacts undigestible wastes and solidifies them into feces
-stores feces until defecation
102
cecum
-the first part of the large intestine
-it is a blind sac located in lower right quadrant of abdomen
-projecting from cecum is the vermiform appendix-a thin, hollow, fingerlike appendage with lymphoid nodules
103
ileocecal valve
-junction between small intestine and large intestine
104
ascending colon
-extends upward from cecum, along the right lateral border of the abdomen
-near the inferior border of the liver, it makes a 90 degree turn toward the left; this bend is the right colic flexure (hepatic flexure)
105
transverse colon
-originates at the right colic flexure and approaches the spleen in the upper left abdominal quadrant
-it is suspended by the transverse mesocolon
-it makes a 90 degree turn at the spleen; this bend is called the left colic flexure (splenic flexure)
106
descending colon
-originates at the left colic flexure and runs down the left side of the abdomen
-it terminates at the sigmoid colon
107
sigmoid colon
-shape resembles the letter s
-originates at the sigmoid flexure
-it turns inferomedially and is suspended by the sigmoid mesocolon
-it terminates at the rectum
108
rectum
-muscular tube that readily expands to store accumulated fecal material prior to defecation; terminates at the anal canal
-it has 3 thick, transverse folds, called rectal valves, that ensure fecal material is retained during the passage of gas
109
anal canal
-last few cm of the large intestine
-it passes through an opening in elevator ani muscles of the pelvic floor
110
anal columns
line the internal surface of the anal canal
111
anal sinuses
secrete music for lubrication during defecation
112
internal and external anal sphincters
relax during defecation
113
accessory digestive organs
-produce secretions that facilitate chemical digestive actions
-liver
-gallbladder
-pancreas
-biliary apparatus
114
liver
-located in the right upper quadrant of abdomen, immediately inferior to diaphragm
115
liver lobes
-right and left lobes are the major lobes
*seperated from each other anteriorly by falciform ligament
*right lobe is largest
-caudate lobe and quadrate lobe are subdivisions of right lobe
116
liver round ligament
is remnant of umbilical vein
117
gallbladder
-attached to inferior surface of the liver
-stores and concentrate bile
118
cystic duct
-connects the gallbladder to the common bile duct
119
3 region of gallbladder
-neck
-body
-fundus
120
military apparatus
-network of thin ducts that transport bile from the gall bladder to duodenum
121
right hepatic duct
left and right lobe drain into
122
common bile duct
cystic duct and common bile duct merge to form common bile duct, which descends toward duodenum
123
hepatopancreatic ampulla
common bile duct and main pancreatic duct merge
124
bile and pancreatic juice
mix in ampulla and empty into duodenum at major duodenal papilla
125
pancreas
-has both endocrine and exocrine functions
126
endocrine functions
-performed by pancreatic islets
127
exocrine functions
-involve acing cells (clusters into acini) secreting pancreatic juice (digestive enzymes, bicarbonate) into duodenum via the main pancreatic duct
*a smaller accessory pancreatic duct drains a small amount oof pancreatic juice into minor duodenal papilla in the duodenum
