Histo Of Small Intestine

Question 1

Mucosa of SI

Viewed with the naked eye, the lining of the small intestine shows a series of (temporary or permanent?) ____ or ____ shaped folds called _______

Answer 1

Permanent

circular or semilunar

plicae circulares

Question 2

Plicae circulares are composed of _____ and _____ layers

They are best developed in the _____

The entire mucosa is covered by (short or long?) outgrowths called ___

Answer 2

mucosa and submucosa

jejunum

Short

villi

Question 3

Intestinal villi

Are _____ outgrowths that project into the _____

Each villus has a core of (loose or dense?) connective tissue that extends from the ______

It contains:
______ , _____ and plasma cells, smooth muscle fibers, fenestrated capillaries and a ______

Answer 3

mucosal

lumen

Loose

lamina propria

Fibroblasts; lymphocytes

lacteal

Question 4

lacteal is a _______

Answer 4

central lymphatic

Question 5

Intestinal villi

In the duodenum, they are ___-shaped but gradually assume ___-like shapes moving towards the ileum

Answer 5

leaf

finger

Question 6

Intestinal villi

They are covered by a ______ epithelium of absorptive cells (______) and _____ cells

Answer 6

simple columnar

enterocytes

goblet

Question 7

Intestinal crypts

Between the villi are small openings of (short or long?) _____ glands called intestinal crypts or ________

Answer 7

Short

tubular

crypts of Lieberkükn

Question 8

The epithelium of each villus is discontinuous with that of the intervening glands

T/F

Answer 8

F

Question 9

The absorptive cells are ______ cells each with _____ nucleus in the (apical or basal?) half of the cell

Answer 9

tall columnar

an oval

Basal

Question 10

At the apex of each absorptive cell, is a homogeneous layer called the _______

Answer 10

striated /brush border

Question 11

When viewed with the electron microscope, the striated border is seen as a layer of (sparsely or densely?) packed ____ covered by ______

Answer 11

Densely

microvilli

glycocalyx

Question 12

Each absorptive cell is estimated to have an average of _____ microvilli

Answer 12

3000

Question 13

1 mm2 of mucosa contains about _______ microvilli

Answer 13

200 million

Question 14

Microvilli greatly ___ease the area of contact between the intestinal surface and the nutrients

This function is shared also by the _____ and the _____

Answer 14

Incr

plicae circulares and the villi

Question 15

It is estimated that plicae circulares increase the intestinal surface ___-fold, the villi increase it ____-fold, and the microvilli increase it ___-fold

Together, these processes are responsible for a ___-fold increase in the intestinal surface, resulting in a total absorptive area of ___ m2

Answer 15

three

10

20

600

200

Question 16

Absorptive cells absorb the nutrient molecules produced by digestion

T/F

Answer 16

T

Question 17

Goblet cells
Are interspersed between the ____ cells
They are (more or less?) abundant in the duodenum and (more or less?) numerous in the ileum
These cells produce _____ that are ____ to form _____

Answer 17

absorptivE

Less

More

glycoprotein mucins; hydrated;

mucus

Question 18

mucus function to ____ and ___ the lining of the small intestine

Answer 18

Protect and lubricate

Question 19

Paneth cells

Are (endocrine or exocrine?) cells with (small or large?) ___philic secretory granules
They are located in the (apical or basal?) portion of the intestinal crypts below the ___ cells

Answer 19

Exocrine

Large

eosino

Basal

stem

Question 20

Paneth cells

They undergo exocytosis to release _____,_______, and _____
These bind and breakdown membranes of _____ and ____ cell walls

Answer 20

lysozymes, phospholipase A2, and defensins

microorganisms

bacterial

Question 21

Paneth cells function:
———- _____
Regulates ______ of the intestinal crypts

Answer 21

Innate immunity

microenvironment

Question 22

Micro fold cells

Are specialized epithelial cells for _______ of ____ and _____

Located in the ____ overlying the ____________

M cells contain _____ and _____
They are important in the defense provided by mucosal immunity

Answer 22

transport of particles and microorganisms

ileum; lymphoid follicles of Peyer patches

macrophages and lymphocytes

Question 23

Lamina propria of the small intestine

It is composed of loose connective tissue containing extensive blood and lymph microvasculature, nerve fibers, smooth muscle cells and lymphoid tissue
The lamina propria penetrates the ____ of ______, bringing with it microvasculature, lymphatics, and nerves

Answer 23

core of each intestinal villus

Question 24

Lamina propria of the small intestine

Smooth muscle fibers inside the villi are responsible for their ______ which are important for _______

Contractions of the _____ also produce local movements of the plicae circulares that help propel lymph from the _____ into submucosal and mesenteric lymphatics

Answer 24

rhythmic movements

efficient absorption

muscularis mucosae

lacteals

Question 25

Submucosa of the small intestine Present in the (proximal or distal?) part of the duodenum are large clusters of (straight or branched?) _____ mucous glands, called the ________ glands

Answer 25

Proximal Branched tubular duodenal (Brunner)

Question 26

Brunners glands They possess (small or large?) excretory ducts opening among the intestinal crypts _____, which is the product of the glands is (alkaline or acidic ?) (pH __-___)

Answer 26

Small Mucus alkaline; 8.1-9.3

Question 27

Mucus from brunners gland ______ the mucous membrane Brings the intestinal contents to the optimum pH for _____ enzyme action Neutralizes chyme entering the _____ from the _____

Answer 27

Protects pancreatic duodenum pylorus

Question 28

In the ileum both the ____ and ___ contain the lymphoid nodule aggregates known as _______, an important component of the __________________

Answer 28

lamina propria and submucosa Peyer patches mucosa-associated lymphoid tissue (MALT)

Question 29

Muscularis of SI Composed of an internal _____ layer and an external _____ layer Between these muscle layers is the ____(——) nerve plexus (produce peristalsis) The serosa of SI Covered by a (thin or thick?) serosa

Answer 29

circular longitudinal myenteric (Auerbach) Thin

Question 30

Lacteals Lymph vessels of the intestine begin as (open or closed?) tubes in the ____ of ____ Lacteals run to the region of ______ above the _____, where they form a plexus From there they are directed to the ____ where they surround _____

Answer 30

Closed cores of villi lamina propria muscularis mucosae submucosa lymphoid nodules

Question 31

Lacteals anastomose repeatedly and leave the intestine along with the blood vessels T/F

Answer 31

T

Question 32

Lacteals are especially important for _____ absorption

Answer 32

lipid

Question 33

Celiac disease- disorder of small intestine’s ____ that causes _____ and can lead to damage or destruction of the ___

Answer 33

Mucosa malabsorption villi

Question 34

Leiomyomas- (benign or malignant?) tumors of smooth muscle cells.

Answer 34

benign

Question 35

Most common type of tumors in the stomach and small intestine is ????

Answer 35

Leimyomas

Question 36

Crohn disease- (acute or chronic?) ___________ disease that occurs most commonly in the _____ or _____. Causes excessive _____ activity and _____ in any or all the tract producing pain, localized bleeding, malabsorption and diarrhea

Answer 36

Chronic inflammatory bowel ileum or colon lymphocytic; inflammation