Lect. 17/18 - Digestive system Part 2 (from liver) Flashcards
1
Q
Heaviest gland in the body
A
Liver
2
Q
Second largest organ in the body
A
liver
3
Q
what divides the right and left lobes of the liver
A
falciform ligament
4
Q
name the 4 lobes of hte liver
A
right, left, quadrate, caudate
5
Q
functional cells of the liver
A
hepatocytes
6
Q
contain fixed phagocytes, which destroy worn out leukocytes, RBC, bacteria and other foreign matter from the GI tract venous blood
A
sinusoids
7
Q
bile is secreted by what
A
hepatocytes
8
Q
the bile enters the ___ ___ which empty into small ___ ___
A
bile canaliculi, bile ductules
9
Q
the ductules pass bile into ___ ___
A
bile ducts
10
Q
eventually merge into R/L __ ___
A
hepatic ducts
11
Q
R/L hepatic ducts unite to form the ___ ___ ___
A
common hepatic duct
12
Q
common hepatic duct joins the ___ and they form the ___ __ __
A
cystic duct, common bile duct
13
Q
ligaments of the liver (3)
A
falciform ligament
ligamentum teres (round)
R/L coronary ligaments
14
Q
is a remnant of the umbilical vein of the fetus
A
ligamentum teres (round ligament)
15
Q
suspends the liver from the diaphragm
A
R/L coronary ligaments
16
Q
blood supply of the liver
A
hepatic artery and hepatic portal vein
17
Q
what is the portal triad
A
hepatic portal vein, hepatic artery and bile duct
18
Q
liver - parasympathetic innervation
A
vagus nerve
19
Q
liver - sympathetic innervation
A
celiac ganglia
20
Q
pear shaped sac located in a depression on the posterior surface of the liver
A
Gall bladder
21
Q
3 parts of the gall bladder
A
fundus
body
neck
22
Q
function of the gallbladder
A
store and concentrate bile until it is needed by the S.I
23
Q
blood supply of gall bladder
A
cystic artery
24
Q
innervation of gallbladder
A
branches of the celiac plexus and vagus nerve
25
plays a key role in emulsification
bile salts
26
between meals, the __ ___ ___ closes off and bile flows into the gallbladder for storage
greater duodenal papillae
27
after a meal, _____ impulses along the vagus nerve stimulate the liver to ___ bile production
parasympathetic
| increase
28
fatty acids and amino-acids in chyme stimulate duodenal enteroendocrine cells to secrete ____ in the blood
cholecystokinin (CCK)
29
role of CCK (2)
- contraction of the gall bladder, squeezing stored bile into the cystic duct and through the common bile duct
- relaxation of the sphincter around the greater duodenal papilla allowing bile to flow into the duodenum
30
other vital functions of the liver (9)
- carbohydrate metabolism
- lipid metabolism
- protein metabolism
- processing drugs and hormones
- excretion of bilirubin
- synthesis of bile salts
- storage
- phagocytosis
- activation of vitamin D
31
where the majority of digestion and absorption occurs
Small intestine
32
S.I divided in three regions
duodenum
jejunum
ileum
33
permanent ridges in the mucosa
| being in the duodenum and end in the mid-portion of the ileum
circular folds
34
role of circular folds in the SI
enhance absorption by increasing surface area and causing chyme to spiral through the SI
35
arterial supply of SI
superior mesenteric and gastroduodenal
36
innervation of SI
superior mesenteric plexus and vagus nerve
37
two autonomic plexuses are found within the wall of the SI
1. myenteric plexus
| 2. meissner's plexus
38
layers of the small intestines
1. mucosa
2. submucosa
3. muscularis
4. serosa
39
greatly increase the SA of the epithelium available for absorption and digestion (in the mucosa)
villi
40
each villi contains 5 things
```
lamina propria
central lacteal
arteriole
venule
blood capillary
```
41
mucosa of SI - the epithelium consists of (4)
absorptive cells
goblet cells
enteroendocrine cells
paneth cells
42
mucosa of SI - digest and absorb nutrients
absorptive cells
43
mucosa of SI - secrete mucous
goblet cells
44
mucosa of SI - secrete secretin, CCK or GIP
enteroendocrine cells
45
mucosa of SI - secrete the bacterial enzyme lysozyme and has some phagocytotic functions
paneth cells
46
mucosa of SI - lamina propria has many MALT (2)
solitary lymphatic nodules (distal ileum)
| peyer's patches (distal ileum)
47
submucosa of SI content
duodenal glands (Brunner's)
48
role of Brunner's gland (duodenal)
secrete an alkaline mucous which helps neutralize gastric acid in chyme
49
why is Brunner's gland role important
because the gastric juice is acidic but the farther you go down the GI tract, the less mucous you need as it is less and less acidic
50
muscularis layer of SI (2)
longitudinal and circular layers
51
serosa layer of SI
most superficial
52
slightly alkaline
contains mucous and water
aids with the absorption of substances as they come in contact with the villi
clear yellow fluid (1-2L/day)
intestinal juice
53
absorptive epithelial cells synthesize many digestive enzymes and insert them into the microvilli
brush-border enzymes
54
two types of movement occur in the small intestine
segmentation
| migrating motility complex (a form of peristalsis)
55
localized, mixing contractions that occur in portions occupied by large volumes of chyme
mixes chyme with digestive juices
brings food particles in contact with the mucosa for absorption
Segmentation
56
segmentation starts with the contraction of what
circular muscle
57
where does MMC begins
lower portion of the stomach
58
when does absorption occurs in the SI
once food has been changed into forms that can pass through the epithelial cells lining the mucous into blood and lymphatic vessels
59
about __% of the absorption occurs in the SI
90%
60
10% of absorption occurs in __ and ___
stomach and large intestine
61
terminal portion of the GI tract
large intestine
62
LI is divided into 4 main regions
cecum
colon
rectum
anal canal
63
functions of the large intestine (4)
complete absorption, produce certain vitamins, form feces, and expulse feces from the body
64
attached to posterior wall by the mesocolon
large intestine
65
LI - hangs from ileocecal sphincter
cecum
66
LI - twisted, coiled tube attached to the cecum
appendix
67
divisions of the colon
ascending, descending, transvers and sigmoid
68
LI - abrupt turn inferior to the liver
right colic flexure
69
LI - abrupt turn inferior to the spleen
left colic flexure
70
LI - begins near L. iliac crest and ends at the level of 3rd sacral vertebrae
sigmoid
71
LI - guarded by an internal sphincter of smooth muscle and an external sphincter of skeletal muscle
anus
72
arterial supply of LI
sup/inf mesenteric aa.
| sup, middle, and inf. rectal aa.
73
sympathetic innervation of large intestine
celiac, superior and inferior mesenteric ganglia
74
parasympathetic innervation of large intestine
vagus and pelvic splanchnic nerves
75
t/f there are villi and circular folds in the large intestine
false
76
layers of large intestine
mucosa, submucosa, muscularis, serosa
77
muscularis layer of LI - some portions of the longitudinal muscle are thickened forming 3 bands called
taenia coli
78
muscularis layer of LI - tonic contractions of the bands form a series of pouches called
haustrae
79
passage of chyme from the ileum into the cecum is controlled by what
ileocecal sphincter
80
what is haustral churning
haustrae remain relaxed until they fill up
| after a certain distension, the wall contracts and pushes the contents into the next haustrae
81
2 functions of the LI
peristalsis and mass peristalsis
82
t/f peristalsis occurs at a slow rate
true
83
mass peristalsis
strong peristaltic wave that begins in the middle of the transverse colon and rapidly drives the contents into the rectum
84
the final stage of digestion occurs through the activity of bacteria in the lumen
anything remaining after will not be absorbed (sent to urine for excretion)
