digestive sys Flashcards
1
Q
extends from the mouth to the anus through the ventral body cavity (approximately 9 m, or 30 ft.)
A
Alimentary canal:
2
Q
teeth, tongue, salivary glands, liver, gallbladder, and pancreas.
A
Accessory organs:
3
Q
Digestion (chemical and mechanical), ingestion, secretion, mixing and propulsion, defecation
A
absorbtion
4
Q
Role in metabolic processes
A
catabolism and anabolism
5
Q
:Larger molecules are broken into smaller molecules (mouth, stomach, duodenum).
◦ In the GI tract, this is called ____ and can occur by either mechanical or chemical means.
A
catabolism. Digestion
6
Q
: Smaller molecules are used as building blocks for larger molecules (liver).
A
anabolism
7
Q
all Movements that facilitate catabolic processes
Mastication
Mixing
◦ Increase contact of food with digestive chemicals
A
mechanical digestion
8
Q
Swallowing
Peristalsis
◦ Movement of muscles within the GI tract that facilitates movement of food
A
other movements
9
Q
:breaking large molecule into smaller ones, mainly through hydrolysis.
Fats -> fatty acids and glycerol.
Carbohydrates: polysaccharides -> monosaccharides.
Proteins-> polypeptides -> amino acids.
Requires ____
A
Chemical digestion. specific enzymes
10
Q
Four layers of tissues of GI tract
A
Mucosa (deepest), Submucosa, Muscularis Serosa/adventitia (superficial)
lumen is the inside of the tube.
11
Q
mucous membrane
A
moucosa
12
Q
(mouth, pharynx, esophagus, anus)
A
Epithelial tissue
Stratified squamous
13
Q
(stomach and intestines)
A
Epithelial tissue
Simple columnar
14
Q
Includes glandular cells that secrete mucus and fluid into the lumen
A
mucosa
15
Q
Mucosa
Areolar connective tissue
A
(lamina propria.)
16
Q
Mucosa
Smooth muscle
A
(muscularis mucosae)
17
Q
Lamina propria contains _____, mucosa-associated lymphatic tissue that protect against disease.
A
“MALT”
18
Q
creates folds in the lining of the stomach and small intestines
A
Muscularis mucosae:
19
Q
irregular connective tissue that binds the mucosa to the muscularis.
blood and lymphatic vessels (to receive absorbed substances)
submucosal plexus: a network of neurons
A
Submucosa
20
Q
mouth, pharynx, superior and middle parts of the esophagus, and anal sphincter contain skeletal muscle.
* Rest of the tract: smooth muscle
* Inner circular sheet
* Outer longitudinal sheets,
* myenteric nerve plexus between them.
A
Muscularis:
21
Q
is the outermost layer
A
Serosa/adventitia
22
Q
- fibrous connective tissue attached to surrounding tissues (e.g. esophagus).
A
adventitia
23
Q
- fibrous connective tissue in the peritoneal cavity, with a mesothelium surface layer
A
serosa
24
Q
Serosa covers the intra-abdominal organs as the
A
visceral peritoneum
25
the body’s largest serous membrane, wraps
around most abdominopelvic organs
Peritoneum
26
the serosa of the alimentary canal and covers other intra- abdominal organs.
visceral peritoneum
27
the abdominal wall, connects to visceral peritoneum.
Parietal peritoneum
28
five major peritoneal folds that bind the organs to one another and to the cavity walls
◦ greater omentum
◦ falciform ligament
◦ lesser omentum
◦ mesentery
◦ mesocolon
29
largest peritoneal fold.
* Connects the stomach to the transverse colon
* Drapes over the transverse colon and the anterior coils of the small intestine
Greater omentum :
30
____Contains: lymph nodes and a large amount of adipose tissue that can greatly expand
Greater omentum
31
attaches the liver to the anterior abdominal wall
and diaphragm.
Falciform ligament:
32
suspends the stomach and duodenum from the inferior edge of the liver.
pathway for blood vessels to enter the liver
contains the common bile duct.
Lesser omentum:
33
______ (small) and _____ (large): attach intestine to posterior abdominal wall
Mesentery. Mesocolon
34
(Loose/ Tight) attachment so muscular contractions can mix and move the contents along the GI tract
loose
35
_____ organs are covered by visceral peritoneum only on their anterior surfaces. The portion of the organ that lies behind the peritoneum is said to be “xxx”
Retroperitoneal
36
Organs in the retroperitoneal space include:
The kidneys and ureters
Most of the pancreas
The adrenal glands
The aorta and inferior vena cava
37
Digestive activities are controlled in three overlapping phases:
1. The cephalic phase
2. The gastric phase
3. The intestinal phase
38
_____ :smell, sight, thought, or initial taste of food
* neural centers in the CNS to ___ for digestion.
stimulate secretion of saliva and gastric juice
cephalic phase. prepare.
39
:food enters the stomach.
Nervous and endocrine systems, ____ is a key hormone
Promotes secretion of gastric juice and gastric motility.
Gastric phase. gastrin
40
:acidic food enters the small intestine.
Neural response decreases gastric motility
Hormones (____) increases intestinal secretions and decreases gastric secretions and motility
Intestinal phase. secretin, CCK
41
: formed by the cheeks, hard and soft palates, and the tongue
oral or buccal cavity
42
mastication (chewing)
Saliva
◦ mixes with food to soften it so it can be easily swallowed
mechanical digestion
43
after mechanical digestion, starts the process of _____.
◦ _____: salivary amylase
◦ Fats: lingual lipase active in acidic stomach (limited activity)
Chemical digestion. Carbohydrates
44
Salivary regulation is under the control of the
ANS
45
promotes secretion
◦ This is enhanced by the cephalic phase
parasympathetic stimulation
46
decreases saliva secretions.
Sympathetic stimulation
47
located in sockets of the mandible and maxillae
teeth or dentes
48
- a dense fibrous connective tissue that anchors the teeth
Periodontal ligament
49
three major external regions of the mouth : the
crown, root, and neck
50
The neck of each tooth is covered by the____ , or gums, which extend slightly into each socket
gingivae
51
calcified connective tissue that forms most of the
tooth
dentin
52
harder-than-bone calcified non-living material, covers the crown
enamel
53
provides nutrition
pulp
54
___ dentitions as a child
___ as an adult
20. 32
55
The _____:
Moves food in the mouth for chewing and swallowing
(deglutition)
Provides a sense of taste
composed of _____
the tongue. skeletal muscle
56
swallowing food.
* Making sure food moves from the mouth through the pharynx to the esophagus and NOT the airway/nasal cavity.
degulation
57
3 stages of degulation
Voluntary, Pharyngeal, Esophageal
58
tongue pushing bolus of food into the pharynx,
Voluntary
59
palate rises and epiglottis lowers involuntarily due to presence of food
Pharyngeal
60
peristalsis moves the bolus down toward the stomach
Esophageal
61
a progression of coordinated contractions and
relaxations of the circular and longitudinal layers of the muscularis, push the bolus onward
Peristalsis
62
* Propulsion is only function (moving food into the stomach).
* Connects laryngopharynx to stomach posterior to the trachea. traverses the posterior mediastinum pierces the diaphragm
esophagus
63
The Esophagus
Mucosa:
nonkeratinzed stratified squamous epithelium
64
The Esophagus
Muscularis:
superior 1/3: skeletal muscle
intermediate 1/3: skeletal and smooth muscle
inferior 1/3: smooth muscle
65
Upper and lower esophageal sphincters (____) at each end of the tube.
UES and LES
66
The _____ regulates the movement of food from
the esophagus into the stomach.
LES
67
* J shaped sac with Rugae (folds in the mucosa) that allow stretching
* Third layer of muscularis (oblique)
* position and size varies as the diaphragm moves
stomach
68
Function of the _____:
* Store food, regulate delivery to small intestine
* Finish mechanical digestion
* Start chemical digestion of proteins
* minimal chemical digestion of fats
stomach
69
The stomach has four main regions:
cardia
fundus
body
pylorus
70
Simple columnar epithelial cells secrete a
protective mucous. (in stomach)
mucosa
71
gastric glands down in the lamina propria connecting to narrow channels called
gastric pits.
72
Exocrine glands secrete:
Mucus, Gastric juice (◦ HCl, ◦ pepsinogen, ◦ gastric lipase, ◦ intrinsic factor), Enteroendocrine (gastrin)
73
§ kills many microbes,
§ partially denatures proteins in food
§ converts pepsinogen into pepsin.
HCI
74
digests proteins.
pepsin
75
(and lingual lipase) digest triglycerides.
Gastric lipase
76
needed for absorption of vitamin B12 in the terminal ileum.
Intrinsic factor (IF)
77
1–3 mm layer of alkaline _____ protects the stomach from acidic gastric juice
mucus
78
______ (gentle, rippling, peristaltic movements) pass over the stomach a few times a minute.
mixing waves
79
mixing waves reduce food and gastric juice to
chyme
80
Small, Regulated amounts of chyme pass through the pyloric sphincter and enter the _____
duodenum
81
the small intestine Finishes ______ of food and ____ the vast majority of food
chemical digestion, Absorbs
82
_____ regulates food supply into the small intestine receives chyme and secretions from the pancreas and liver/gallbladder
Duodenum
83
lipid-rich food spends more time in the _____ for more chemical digestion
duodenum
84
oblong gland located posterior to the stomach in the retroperitoneal space.
connected to the duodenum by the hepatopancreatic ampulla and accessory ducts.
pancreas
85
Function of what _____: (exocrine)
secretes enzymes (chemical digestion)
sodium bicarbonate (buffer acidic chyme)
pancreas
86
Pancreatic _____ (~99% of glandular clusters) exocrine 1% (pancreatic ____) endocrine function
acini. islets
87
* NaHCO3 : neutralize acid
* Digestive enzymes
* Carbohydrates
* Proteins
* Lipids
Pancreatic juice:
88
* Produced by the liver
* Stored in the gallbladder
* Secreted into the duodenum
* Alkaline: water, bile salts, cholesterol, and bile pigments.
* digestive secretion and excretory product
bile
89
______ and absorption of lipids.
◦ Without bile salts, most of the lipids in food would be passed out in feces, undigested.
The dark pigment (bilirubin) from red blood cells.
(bile)
Emulsification
90
Bile produced by the liver exits in the
common hepatic duct.
91
joins the ____ from the gallbladder to form
the common bile duct (CBD).
(bile the Liver and Gallbladder)
cystic duct
92
The CBD joins the pancreatic duct to form the _______, enters through the ______ just proximal to the second part of the duodenum to deliver its contents.
hepatopancreatic ampulla. duodenal papilla
93
Bile “backs-up” into the ____ where it is stored and concentrated up to ten-fold through the absorption of water and ions
gall bladder
94
_____, causes the gallbladder to
release stored bile
cholecystokinin (CCK)
95
the small intestine is divided into 3 regions
The duodenum (10 in)
The jejunum (8 ft)
The ileum (12 ft)
96
In the small intestine, ____ continues,
____ begins.
digestion. absorption
97
Absorption Structures of the small intestine
Plicae circulares, Villi, Microvilli
98
Chemical Digestion structures of the small intestine
Pancreatic juice, Bile, Intestinal juice, Brush border enzymes
99
_____ finger-like projections that are covered with a simple columnar epithelium
Villi
100
microscopic folds in the apical surface of the
plasma membrane on each simple columnar cell (about 200 million/mm2)
microvilli
101
passage of digested nutrients into the blood or
lymph: 90% occurs in the small intestine.
absorbtion
102
Active transport/facilitated diffusion into blood
capillaries
Proteins (amino acids),
nucleic acids,
sugars (monosaccharides)
Lipids (Triglycerides /fats)
103
Lipids (Triglycerides /fats) aggregated globules coated with proteins called _____. Enter lacteals (lymphatic system) by simple diffusion
chylomicrons
104
intestinal glands in intestinal mucosa secrete
Intestinal juice
105
Contains digestive enzymes.
Activates pancreatic enzymes :ie Trypsin
intestinal juice
106
* enzymes on the villi Finish chemical
digestion.
* Protiens->single amino acids
* Carbohydrates->monosacchrides
* Fats->glycerol+fatty acids
brush border
107
Minimal mechanical digestion:
segmentations
108
are circular folds/ridges that encourage turbulent flow of chyme.
pilacea circulares
109
Food is absorbed into the blood in the
small intestine
110
That food absorbed blood all goes to the
liver
111
body’s largest gland and second largest organ
liver
112
Liver:
2 main lobes (right and left – divided by the _____)
falciform ligament
113
the liver is made up of repeating functional units
called
liver lobules
114
are the major functional cells of the liver. "chemical factories"
hepatocytes
115
* Digestive Functions
* Synthesis, transformation, and storage of proteins, fats, carbs
* Detoxification, modification, and excretion of a variety of Substances
* Production of bile The Liver
just read
116
Non-digestive liver functions include
Phagocytosis of old or worn-out cells
Making heparin (anticoagulant) and other plasma proteins (prothrombin, fibrinogen, and albumin)
Modifying vitamin D to its active form
117
Outer margin of liver lobules: the ____
triad
118
Liver lobules
Blood goes through _____ (a specialized
capillary) towards the _____.
sinusoids. central vein.
119
(liver macrophages) destroy red cells, white
cells, and bacteria in blood draining from the GI tract
Kupffer cells
120
Remove/transform toxins, And transform/store excess nutrients from the materials absorbed in the small intestine
hepatocytes
121
Function of what :
Absorb water
Absorb some other minerals and
vitamins
Eliminate waste
the large intestine
122
Large intestine is about 5 feet in length. 4 parts:
The cecum
The colon
◦ ascending
◦ transverse
◦ descending
◦ sigmoid
The rectum
The anal canal
123
has no circular folds or villi, The mucosa is mostly an absorptive epithelium (mainly for
water), Plentiful microvilli, Interspersed cells produce mucous, but no digestive
enzymes
the large intestine
124
The Large Intestine is attached to the posterior abdominal wall by ______ peritoneal membrane.
mesocolon
125
longitudinal ribbons of smooth muscle that run
the length of the colon:
Teniae coli
126
Segment the colon into small pouches called
haustra
127
Ascending & descending colon (are/ are not) retroperitoneal. Transverse & sigmoid colon
(are/are not)
are. are not
128
small pouch inferior to the ileocecal valve
cecum
129
is a 3 in coiled tube attached to the cecum
appendix
130
last 8 in of the GI tract, anterior to the sacrum and coccyx.
rectum
131
last 1 in of the rectum
mucous membrane in longitudinal folds called anal columns
anal canal
132
The opening of the anal canal to the exterior is called the
anus
133
~____ liters/day of fluid enter the small intestine (ingestion+secretion)
9
134
~___ liters/day absorbed by Small intestine; the remainder passes into the large intestine, where most of the rest of it is also absorbed.
8
135
Only ~____ mL/d of water is excreted in the feces
100
136
______ make up most of the flora (microbes) in the colon and about 60% of the dry mass of feces
Bacteria
137
As these bacteria digest/ferment left-over food, they secrete beneficial chemicals such as _____, _____ (a B vitamin), and some _____ (they are our main source of some of these nutrients.)
vitamin K, biotin, amino acids
138
The ______:
haustral churning and peristalsis
mechanical events
139
Two autonomic nervous system
reflexes: __________
◦ Both reflexes occur with distension of the stomach.
◦ food moved from small intestine to large intestine and from large intestine to rectum
gastroileal and gastrocolic reflexes
