small intestine pancreas

Question 1

Three main segments of the small intestine:

Answer 1

duodenum, jejunum and ileum

Question 2

The surface area of the small intestine are covered by VILLI, the villi are covered by the intestinal epithelial cells which are called ___

Answer 2

enterocytes

Question 3

The enterocytes further increase the surface area through the presence of ___ —- provides a great advantage for fast absorption of nutrients

Answer 3

microvilli

Question 4

There are also invaginations called ___, which function as a nursery and they contain the stem cells which constantly divide and differentiate.
they then travel up to the tip of the villus before they undergo programmed cell death or apoptosis, and shed to the lumen to be replaced by the newly differentiated epithelial cells. This takes about __ days.

Answer 4

crypts

3

Question 5

In the epithelial we have several cell types :

Answer 5

Absorptive epithelial cell
Enteroendocrine cells
Goblet cells

Question 6

enterocytes which specialize to absorb the nutrients

Answer 6

Absorptive epithelial cell

Question 7

this epithelial cell secrete various hormones into the blood

Answer 7

Enteroendocrine cell

Question 8

produce mucous, which has very important protective functions.

Answer 8

Goblet cells

Question 9

___ cells do not migrate up to the vilus but after differentiation they stay at the bottom of the crypt and it has been suggested that they function to protect the stem cells in the cypts against various bacterial toxins and viral factors

Answer 9

Paneth

Question 10

Each vilus is supplied by a arteriole which in turn branches in the vilus pore into capillary network. And then capillaries join to form the venules, which is away from the vilus. In addition, in each vilus pore we have lymphatic vessels which is called the ___ ___

Answer 10

central lacteal

Question 11

Most of the absorbed nutrients enter the capillary network and they enter blood circulation directly. However, the fats are too large to be absorbed directly into the capillary network, instead they first go into the ______ so the fats 1st enter the lymphatic circulation and then they join the venus circulation through the thoracic duct

Answer 11

lymphatic lacteal

Question 12

____ cells produce a large amount of mucous. The mucous covers the intestinal epithelium and protects it against shear stress and microbial damage

Answer 12

goblet cells

Question 13

one of the most important glycoproteins produced by the goblet cells is ____

Answer 13

Mucins MUC

Question 14

____ can bind to the potential pathogenic bacteria and it prevents the colonization of the intestinal lumen by the dangerous bacteria.

Answer 14

Mucin MUC

Question 15

____ ___ seal the space between epithelial cells and prevent the passage of substance via paracellular pathways between the cells

Most agents enter by crossing the epithelial cell membrane using the specialized membrane transporters

Answer 15

Tight junction

Question 16

refers to the collection of disorders and conditions idiopathic associated with chronic gastrointestinal tract inflammation.

Answer 16

Inflammatory Bowel Disease (IBD)

Question 17

The two major forms of inflammatory bowel disease are:

Answer 17

Ulcerative colitis

Crohn’s disease

Question 18

___ is confined to the colon. The inflammation is diffused and only affects the mucosal layer

____ can affect any area of the digestive tract; inflammation is also discontinuous, so we can have skipped lesion where one area has inflammation and the next to it there isn’t any inflammation–
. Inflammation is also more severe bc it not only affects the mucosal layer but the sub-mucosal layer

Answer 18

Ulcerative colitis

Crohn’s disease

Question 19

Common symptoms inflammatory bowel disease include:

Answer 19

abdominal pain, rectal bleeding, diarrhea, various nutritional deficiencies such as iron deficiency and weight loss
Patients can also have inflammation of the bile ducts (cholangitis) or arthritis or inflammatory conditions of the eyes

Question 20

When tight junctions are leaky some bacteria products and dietary antigen in the lumen can pass through the tight junctions and enter the \_\_\_\_ \_\_\_. ---- which initiates an immune respnse
The APC (antigen presenting cells)and dendritic cells can pick up various antigens which cause the differentiation of t cells and production of various pro-inflammatory \_\_\_

Answer 20

lamina propria

cytokines

Question 21

are two pro-inflammatory cytokines which have been suggested to be involved in the pathogenesis of IBD

Answer 21

Interferon gamma and TNF-alpha

Question 22

Signaling events triggered by IFNy and TNFa they cause further opening of the ___ ___, so they further compromise the tight junction barrier. As a result there’s more flux of the bacteria and various antigen from the lumen to the lamina propia which further amplifies the inflammatory response. (chronic inflammation is established)

Answer 22

tight junctions

Question 23

the disruption of the gastrointestinal barrier leads to the over aggressive immune response of ___ —happens mostly in individuals that are genetically pre-dispose

Answer 23

Tcells

Question 24

the combination of 3 factors are necessary for chronic inflammation in IBD

Answer 24

Genetic predisposition
Environmental triggers
Over aggressive immune response

Question 25

therapeutic options for IBD

Answer 25

``` Aminosalicylates Corticoidsteroid Immunomodulator Biologic agents Antibiotics ```

Question 26

1st line therapy for mild to moderate ulceraliphilits ; sometimes used to treat crohn’s disease; the exact mechanism of action is not well understood

Answer 26

Aminosalicylates

Question 27

been used to treat patients with IBD, however, they are not used to maintain remission bc corticoidsteroids are associated with severe side effects.

Answer 27

Corticoidsteroid

Question 28

were originally developed as immunosuppressant's for organ transplant therapy, and has been used as cytotoxic agent in cancer therapy, but are also being used to manage IBD; mostly used with patients that don’t respond to aminosalicylates

Answer 28

Immunomodulator

Question 29

specific pro-inflammatory cytokines which have been shown to be involved in IBD pathogenesis. targets are TNFa agent and a4 integrins

Answer 29

Biologic agents

Question 30

used for the manipulation of colonial bacteria seem to be beneficial for some patients. are mostly used to treat crohn’s disease in patients with mild and moderate symptoms

Answer 30

Antibiotics

Question 31

is the 1st line therapy for patients with mild to moderate ulcerative colitis as well as for management of patients with crohn’s disease.

Answer 31

Mesalamine (5ASA) (amino salicylate acid)

Question 32

agent of 5ASA which showed improvements of the gastrointestinal symptoms in the patients who also had ulcerative colitis

Answer 32

Sulfasalazine

Question 33

a good example oral administer drugs which is absorbed only in the distal gastrointestinal tract in the colon. it happens bc the chemical link between sulfapyridne and mesalamine prevents the absorption of ___ in the gastrointestinal tract, but then the colonic bacteria can breakdown this chemical link and then both components can be absorbed

Answer 33

Sulfasalazine | sulfasalazine

Question 34

there are delayed released mesalamine capsules called ___ , which importantly, it is released and absorbed at the whole length of the digestive tract starting in the stomach.

Answer 34

PENTASA

Question 35

There’s also the pH sensitive release tablet called _____, which is released and absorbed in the ileum

Answer 35

ASACOL / LIALDA

Question 36

Mesalamine is a salicylate like aspirin, but its therapeutic effects are not related to ____ inhibition. In fact aspirin and NSAIDs can aggravate the symptoms of IBD. In addition NSAIDs are not recommended to individuals with active gastro intestinal inflammation

Answer 36

cyclooxygenase

Question 37

____ seem to be the center of pro-inflamamtory cytokines, so when its released it further compromises the integrity of tight junction barrier , amplifying inflammation

Answer 37

TNFa

Question 38

The inhibition of ___ is an effective approach to reduce the inflammation in IBD patients

Answer 38

TNFa

Question 39

Current anti-TNFa available are: ---they are the monoclonal antibody against TNFa

Answer 39

infliximab, adalimumab, certolizumab

Question 40

Inflammation in IBD is also amplified by trafficking of ___ from the blood circulation into the gastro intestinal tract

Answer 40

lymphocytes

Question 41

____ are a family of signaling molecules which are located on the membrane of leukocytes and where it can bind to specific integrin receptors on the membrane of the endothelial cells of the blood vessels, and migrate from the blood circulation into the surrounding tissue to the site of inflammation

Answer 41

Integrins

Question 42

inhibition of ___ signaling can prevent the migration of lympocytes

Answer 42

integrins

Question 43

an anti-integrin monoclonal antibody, which targets several integrins on the lymphocyte membrane. However, during clinical trials patients taking this drug developed a severe disease called multilocal leukoencephalopathy After further review, it was brought back, and its approved and used for the treatment of moderate to severe ___ disease

Answer 43

Natalizumab | crohn’s

Question 44

multilocal leukoencephalopathy

Answer 44

fatal viral disease of the white matter of the brain

Question 45

___ induces the differentiation of Tcells and initiation of the whole flammatory signaling This is why suppresion and inhibition of ____ is an effective strategy to reduce inflammation in IBD patients

Answer 45

Interleuin12 | interleukin12

Question 46

Some anti-IL12 developed are

Answer 46

ustekinumab, briakinumab, apilimod

Question 47

___ therapy remains the most effective biological therapy for management of IBD --- however due to high risk of infection, -it is mainly used on patients that have no responds to other treatment

Answer 47

TNFa

Question 48

After the meal, there are two major spasms of motility

Answer 48

segmentation contraction and peristalsis contraction

Question 49

Between meals, “housekeeping” contractions, also called ____ propagate from the stomach through the entire small intestine, sweeping it clear of debris

Answer 49

migrating motor complex

Question 50

the ___ has both endo and exocrine part-

Answer 50

pancreas

Question 51

The endocrine part of the pancreas, which is the isle of langerhans produces

Answer 51

insulin and glucagon

Question 52

The exocrine cells of pancreas are ___ cells connected to the system of the ducts and they eventually form the pancreatic duct and empty into the duodenum.

Answer 52

acinar

Question 53

___ cells produces pancreatic juices which is rich in digestive enzymes. The pancreatic digestive enzymes they can breakdown and digest virtually all nutrients present in our food

Answer 53

acinar

Question 54

pancreatic duct cells they secrete the ___ juice which is rich in bicarbonate. This ___ help neutralize the acid in the duodenum that s coming from the stomach

Answer 54

alkaline | alkaline

Question 55

The main pancreatic duct joins the common bile duct to form a common excretory duct, which is guarded by the sphincter of ___. 

Answer 55

Oddi

Question 56

Exocrine pancreatic secretions and bile enter the __ when the sphincter of Oddi is relaxed.~1–2 L of pancreatic juice is secreted per day. both pass through hepato-pancreatic ampula also known as ampula of vater before they enter the __

Answer 56

duodenum | duodenum

Question 57

The enzymes produced by the acinar cells are synthesized in the inactive form as precursors and are called ___ which are stored in specific granules in the apical domain of the cell and they are just waiting for a specific signal to be released

Answer 57

zymogens

Question 58

are secretagogues that stimulate exocytosis of zymogens into the acinar lumen (act by causing an increase in cytosolic Ca 2+).

Answer 58

Acetylcholine (ACh) and cholecystokinin (CCK)

Question 59

a gastro intestinal hormones produced by the enteroendocrine cells of the small intestine

Answer 59

cholecystokinin CCK

Question 60

One of the most important zymogens produced by the pancreatic asinar cell is

Answer 60

trypsinogen

Question 61

is converted into its active form tyrpsin by brush border enteropeptidases Once actived the trypsin can convert all other zymogens into their active form

Answer 61

Trypsinogen

Question 62

the most important pancreatic enzymes are

Answer 62

``` trypsin, chymotrypsin carboxypeptidase lipase amylase ribonuclease deoxyribonuclease ```

Question 63

regulates the function of many other zymogens

Answer 63

trypsin

Question 64

are proteolytic enzyme so it digest the proteins, breaks the peptide bonds and converts the protein into a very small peptide to two or three amino acids

Answer 64

Trypsin and chymotrypsin

Question 65

it digests the complex carbohydrate into disacharrides or monosacharrides

Answer 65

pancreatic amylase

Question 66

Ribonuclease and deoxyribonuclease digest

Answer 66

RNA and DNA

Question 67

its almost the only enzyme that is secreted through the digestive tract which is able to efficiently digest fat

Answer 67

Pancreatic Lipase

Question 68

when ph in the duodenum falls due to the chyme, this acidic chyme stimulates specific entero endocrine cells which release the hormone ___

Answer 68

SECRETIN

Question 69

The secretin released in the duodenum is released into the blood circulation and then it reaches the pancreatic ducts cells where it stimulates them to produce the high amount of ___ __ rich juices. When this juice is emptied into the duodenum, it helps to increase the pH

Answer 69

alkaline bicarbonate

Question 70

Then the presence of the fatty and protein rich chyme stimulates another type of enteroendocrine cell to release the hormone ____

Answer 70

CCK cholecystokinin

Question 71

CCK is released into circulation and then with the blood flow it reaches the pancreatic __ cells and it stimulates them to produce high amounts of juice in the digestive enzymes so that the fat and protein in the duodenum can be digested as soon as and as effectively as possible

Answer 71

acinar

Question 72

common cause of pancreatitis is

Answer 72

gallstones

Question 73

Both the bile and pancreatic juices, they pass through the common ___ ___ (ampoule) before they enter the duodenum. So if gallstones block this duct, it blocks not only the bile flow but also the flow of pancreatic juice. The pancreatic juice can reflux back along with bile to the pancreas and causes the damage of pancreatic cells and the release of pancreatic enzymes which causes the ___ of the pancreatic and the surrounding tissue

Answer 73

secretory duct | auto-digestion

Question 74

small amounts of pancreatic enzymes leave into the circulation due to blockage by gallstones In ___ ___ the blood levels of pancreatic amylase and pancreatic lipase increase substantially, this is why increased plasma levels of pancreatic enzymes can be used to diagnose acute pancreatitis

Answer 74

acute pancreatitis

Question 75

The release of pancreatic lipase in the surrounding fat tissue can cause __ __

Answer 75

fat necrosis

Question 76

__ ___ can be very painful and is characterize by pain in the middle abdominal region which can radiate to the back. This pain can be alleviated by leaning forward

Answer 76

Acute pancreatitis

Question 77

Two major causes of pancreatitis is ___ and __

Answer 77

gallstones | alcohol

Question 78

can change the composition of the pancreatic juice and make it more viscous so the protein flux can form within the pancreatic ducts causing the rupture of the pancreatic ducts and subsequent development of pancreatitis It also changes the normal motility of the sphincter of Oddi

Answer 78

Alcohol

Question 79

Endocrine dysfunction can lead to the development of ___ ____ Exocrine dysfunction can lead to pancreatic exocrine insufficiency __ (deficiency in pancreatic digestive enzyme)

Answer 79

pancreatic diabetes | PEI

Question 80

Nutrients are not absorbed and this leads to malnutrition, gradual weight loss, and steatorrhea (fat in stool) ---- managed by lowfat diet as well as the pancreatic enzyme replacement therapy PERT

Answer 80

Exocrine dysfunction PEI

Question 81

3 major pancreatic enzymes

Answer 81

amylase, lipase, proteases

Question 82

Pancreatic __ is the most sensitive to acidic environment and degradation, this is why fat mal-absorption occurs earlier in patients with exocrine insufficiency

Answer 82

lipase

Question 83

3 drugs associated with the highest risk of pancreatitis

Answer 83

Azathioprine Mesalamine/Olsalazine Simvastin (lowers cholesterol)

Question 84

an immuno-modulating agent. Acts by inhibition of proliferation and activation of lymphocytes, so its used as an immunosuppresant in organ transplant therapy, also used in cancer patients, and manage patients with IBD

Answer 84

Azathioprine

Question 85

Groups of patients at risk of drug induced pancreatitis

Answer 85

``` Pediatric Elderly Females HIV Patients with Inflammatory Bowel Disease ```

Question 86

is the hormone that’s release by the entero-endocrine cells of the small intestine in response to a meal. can stimulate the beta cells of the pancreas which secrete insulin and inhibits the function of alpha cells which secrete glucagon, therefore increasing the insulin production and accordingly decreases the blood glucose levels which is beneficial for patients with diabetes

Answer 86

Glucagon-Like Peptide-1 (therapy for type 2 diabetes)

Question 87

GLP1 degraded by enzyme ____ enzymes

Answer 87

DPP4

Question 88

enhance of β-cell proliferation, inhibit of β-cell apoptosis and promote differentiation of adult stem cells in the ductal pancreatic epithelium.

Answer 88

GLP-1–induced pathways

Question 89

Chronic GLP-1 receptor activation induces expansion of pancreatic duct glands in rats and accelerates formation of dysplastic __ and chronic pancreatitis

Answer 89

lesions