Small and Large Intestine Flashcards
(106 cards)
1
Q
How long is the small intestine in humans?
A
4-6 meters
2
Q
What is the primary site of absorption and the compeltion of digestion?
A
small intestine
3
Q
Plicae circulares
valves of kerkring
A
valve-like fold/rings in the small intestine
4
Q
Plicae circulares increase
A
the surface area
5
Q
Plicae circulares contain
A
submucosal core
6
Q
the mucosal surface of the small intestine is made up of
A
villi
7
Q
Villi contain
A
a core of lamina propria
8
Q
How long are vili?
A
1mm
9
Q
What is the area between vili called
A
crypts of
Lieberkuhn
10
Q
Intestinal villi lined by
A
simple
columnar epithelium
11
Q
Celiac disease
A
gluten
enteropathy or allergy
to the wheat protein
gluten)
12
Q
Celiac disease causes
A
villus
blunting, atrophy and
loss
leads to malabsorption & weight loss
13
Q
What is the presence of lymphocytes
epithelial cells
A
Intraepithelial
lymphocytes
14
Q
What are the three functional zones in the epithelium of the small intestine?
A
- Villi
- Crypts
3.Neck – where the villi and crypts meet
15
Q
All Cells of the small instestine epithelium
A
- Enterocytes
- Mucous cells
- Paneth cells
- Endocrine cells
- Stem cells
16
Q
Mucosal cells of the small
intestine called
A
enterocytes
17
Q
enterocytes cover
A
surface of the villi
18
Q
enterocytes are
A
Tall columnar cells with
round/oval nuclei
19
Q
enterocytes apical surface
A
highly
folded, modified into 2-3000
microvilli
20
Q
microvilli =
A
striated or brush
border
21
Q
the surface of microvilli are coated with
A
protective
glycocalyx containing enzymes
important for digestion
22
Q
Enterocytes are separated from luminal surface by
A
desmosomes and tight junction
23
Q
Enterocytes Lateral walls have
A
complex interdigitations
24
Q
Muscous cells of the SI are Interspersed among enterocytes
and are
A
mucus secreting goblet cells
25
Mucous cells of the SI are usually found
in upper 2/3 of crypts
26
Mucous cells synthesize
mucinogen = mucus
| stored in membrane-bound
granule
27
Mucinogen
lubricates & protects
epithelium
28
Where are mucous cells least frequently found
doudenum
29
where are mucous cells most frequently found
ileum
30
Number of mucous cell increases from _______ to ______
doudeum, ileum
31
Where are paneth cells found
base of the crypts
| small intestine
32
paneth cell contain
large eosinophilic
granules
33
paneth cells produce
* defensins (antibacterial proteins)
* lysozyme
34
Where do you find enteroendocrine cell in the small intestine?
scattered throughout but mainly in the lower third of the cryp
35
enteroendocrine cells are
| SI
Pale-staining cytoplasm, broad
base & narrow at lumen
36
enteroendocrine cells examples
* s cell
* i cell
* a cell
* k cell
37
S cell secrete
secretin
38
secretin
stimulate release of
bicarbonate from pancreas
39
i cells secrete
cholecystekinin or CCK
40
cholecystekinin
| CCK
stimulates pancreatic seecretion & contraction of
gallbladder
41
A cell secrete
glucagon
42
glucagon
increases blood sugar
43
k cells secrete
GIP
| gastric inhibitory peptide
44
What cell secretes secretin?
S cell
45
WHat cell secretes cholecystekinin?
I cell
46
What cell secretes glucagon?
A cells
47
WHat cell secretes GIP?
K cell
48
Stem cells in the small intestine are located
at the base of the crypts
49
The small intestine epithelial lining is replaced
every 3 to 5 days
50
Stem cells migrate
up villus, mature, & are shed
51
Where can the lamina propria of the small intestine most clearlt be seen?
in core of villi but also surrounds and supports the glands’ crypts
52
lamina propria of the small intestine consists of
Collagen, reticular fibers, fibroblasts & GAGs
53
Lacteals
the lymphatic vessels of the small intestine which absorb digested fats.
54
Where is MALT located in the small intestine?
in lamina propria &
submucosa
55
The MALT of the small intestine have los of
* lymphocytes
* plasma cells
* eosinophils
* macrophages
* mast cells
56
MALT secretes
IgA
| by plasma cells within
57
MALT epithelium contains enlarged
M Cells
58
M Cells
| microfold
squamoid enterocytes modified for Ag
sampling and uptake of macromolecule
59
Peyer's patch
dome-shaped areas grossly visible
on surface of mucosa, project into
lumen
| found mainly in small intestine
60
Where do you find Brunner's Glands?
submucosa Duodenum
61
Brunner's gland secrete
* mucus
* zymogen ( unique
to duodenum)
62
What is the main function of the duodenum?
neutralize gastric acid & pepsin
63
the duodenum is assisted by
pancreas & gallbladder
64
Mucus secreted by Brunner's gland is
alkaline
(8.0-9.5)
65
Why is the mucus secreted by Brunner's gland alkaline
* may protect against acidic stomach contents
* brings closer to the pH at which pancreatic enzymes are most effective
66
Function of the large intestine
modifies fluid content of
feces
67
Cells of the large intestine
1. Columnar cells
2. Mucous cells
3. Endocrine cells
4. Stem cells
68
Jejunum
* no brunner's
* no peyers' patches
* plicae ciculares more extensive
69
What is including in the large intestine?
* cecum
* appendix
* ascending
* transverse
* descending
* sigmoid
* rectum
70
The large intestine lack
* villi
* plicae circulares
* brunner's
* peyer's
* lacteals
71
Colon Primary function
* H2O & electrolyte resorption
* produces mucus for elimination of undigested food & waste
72
In the colon there is a large number of
goblet cells in the epitthelium
73
In adult colon what is generally abesent
paneth cells
| found in kids
74
Columnar cells of the large intestine absorb
soluble salt and water
75
MALT in the large intestine ______ form domed peyer's patches
does not
76
In the large intestine how often does the epithelial cell get replaced
every 5 days
77
Commensal Bacteria
| coliforms
found in large numbers in the large intestine
78
In the large intestine the Outer longitudinal M layer in muscularis externa is
reduced or incomplete
79
The reduced M layer of the large intestine froms
3 longitudinal
strips
| taenia coli
80
taenia coli
three bands of longitudinal smooth muscle on the colon surface
81
taenia coli are responsible for
formation of haustra
82
Appendnix
* small, blind-ended sac
* 2-13cm in length
83
Where is the appendix located
distal
to ileo-cecal junction
84
Vestigial cecum
used for
bacterial digestion in
herbivores
85
The appendix contains
large amounts of
submucosal MALT
| active in chlidren
86
The appendix is most active in
children
87
Appednicitis
inflamed appendix
88
Removal of the appendix
appendectomy
89
Polys of the GI
| adenoma
Any mass arising from the wall of the colon that protrudes into the lumen
90
Polyps are Generall
* asymptomatic
* most common sign is rectal bleeding
91
what is the treatment for polyps in the GI
removal
92
Colon cancer
adenocarcinoma
93
what decreases Colon Cancer
increase in roughage and fiber and diet
| decreases the transit time and increase gut mobilit
94
What is treatment for color cancer?
Surgical removal; if extensive, may require resection of portion of colon
95
Rectum
Short, dilated, terminal portion of large intestine
96
Rectum Contains
* transverse rectal folds
* large # of mucus glands
97
What does the mucosa transtion to in the anal canal
from
simple columnar epithelium
to
stratified squamous epithelium
98
The longitudinal fold of the anal canal are called
anal columns
99
In the anal canal anal glands extend
into submucosa & muscularis
externa
100
Anal gland can be
branched, straight, tubular glands
| secrete mucus
101
The external sphincter is
* voluntary
* skeletal muscle
102
the internal sphincter is
* involuntary
* smooth muscle
103
What can lead to hemorrhoids
enlargement & irritation of submucosal vein in anal canal
104
Anus
external opening; exit of GI tract
105
Internal hemorrhoids
* pain follow autonomics
* difuse
106
External Hemorrhoids
* somatic pain
* sharp and localized
