Histo Of Small Intestine Flashcards

1
Q

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 _______

A

Permanent

circular or semilunar

plicae circulares

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2
Q

Plicae circulares are composed of _____ and _____ layers

They are best developed in the _____

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

A

mucosa and submucosa

jejunum

Short

villi

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3
Q

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 ______

A

mucosal

lumen

Loose

lamina propria

Fibroblasts; lymphocytes

lacteal

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4
Q

lacteal is a _______

A

central lymphatic

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5
Q

Intestinal villi

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

A

leaf

finger

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6
Q

Intestinal villi

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

A

simple columnar

enterocytes

goblet

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7
Q

Intestinal crypts

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

A

Short

tubular

crypts of Lieberkükn

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8
Q

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

T/F

A

F

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9
Q

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

A

tall columnar

an oval

Basal

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10
Q

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

A

striated /brush border

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11
Q

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

A

Densely

microvilli

glycocalyx

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12
Q

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

A

3000

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13
Q

1 mm2 of mucosa contains about _______ microvilli

A

200 million

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14
Q

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

This function is shared also by the _____ and the _____

A

Incr

plicae circulares and the villi

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15
Q

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

A

three

10

20

600

200

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16
Q

Absorptive cells absorb the nutrient molecules produced by digestion

T/F

A

T

17
Q

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 _____

A

absorptivE

Less

More

glycoprotein mucins; hydrated;

mucus

18
Q

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

A

Protect and lubricate

19
Q

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

A

Exocrine

Large

eosino

Basal

stem

20
Q

Paneth cells

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

A

lysozymes, phospholipase A2, and defensins

microorganisms

bacterial

21
Q

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

A

Innate immunity

microenvironment

22
Q

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

A

transport of particles and microorganisms

ileum; lymphoid follicles of Peyer patches

macrophages and lymphocytes

23
Q

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

A

core of each intestinal villus

24
Q

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

A

rhythmic movements

efficient absorption

muscularis mucosae

lacteals

25
Q

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

A

Proximal

Branched

tubular

duodenal (Brunner)

26
Q

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 __-___)

A

Small

Mucus

alkaline; 8.1-9.3

27
Q

Mucus from brunners gland

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

A

Protects

pancreatic

duodenum

pylorus

28
Q

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

A

lamina propria and submucosa

Peyer patches

mucosa-associated lymphoid tissue (MALT)

29
Q

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

A

circular

longitudinal

myenteric (Auerbach)

Thin

30
Q

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 _____

A

Closed
cores of villi

lamina propria

muscularis mucosae

submucosa

lymphoid nodules

31
Q

Lacteals anastomose repeatedly and leave the intestine along with the blood vessels

T/F

A

T

32
Q

Lacteals are especially important for _____ absorption

A

lipid

33
Q

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

A

Mucosa

malabsorption

villi

34
Q

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

A

benign

35
Q

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

A

Leimyomas

36
Q

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

A

Chronic

inflammatory bowel

ileum or colon

lymphocytic; inflammation