Digestive System Flashcards

1
Q

Wall of Esophagus

A

From deep to superficial:

  1. Mucosa
  2. Submucosa
  3. Muscular Layer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Mucosa Layer of Esophagus

A

epithelium is nonkeratinized (mucosal) stratified squamous epithelium

abrasion-resistant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Muscularis Mucosae

A
  • thin/absent in pharynx
  • thickens to 200-400um in esophagus
  • found in submucosa layer
  • single layer of longitudinal smooth muscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Submucosal Glands

A

in digestive system, only found in Duodenum and Esophagus

simple, branched, tubular glands that produce mucous secretion that lubricated the bolus + protects epithelial surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Submucosa Layer of Esophagus

A

contains Muscularis Mucosae and Submucosal Glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Muscular Layer of Esophagus

A

-has inner + outer longitudinal layer; covered in Adventitia of connective tissue

  • in superior third, both contain mostly skeletal muscles
  • in middle third, even mixture of skeletal + smooth muscles
  • in inferior third, contains only smooth muscles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Adventitia of Esophagus

A

outside of muscular layer of esophagus

-anchors esophagus to posterior body wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

RetroPeritoneum of Esophagus

A

peritoneum covers anterior and left lateral surface

  • only found on esophagus that is between diaphragm and stomach
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Blood Vessels that supply Esophagus (7)

A
1 esophageal artery
2 thyrocervical trunk
3 external carotid arteries of neck
4 bronchial arteries
5 esophageal arteries of mediastinum
6 inferior phrenic artery
7 left gastric artery of abdomen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Intraperitoneal

A

Organs enveloped by visceral peritoneum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Retroperitoneal

A

Organs only covered by parietal peritoneum anteriorly

PRIMARY - organs that develop + remain outside of peritoneum

SECONDARY - organs originally intraperitoneal and then became retroperitoneal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

SAD PUCKER

mnemonic for retropineal organs

A
S = Suprarenal (adrenal) Glands
A = Aorta/IVC
D =Duodenum (except the proximal 2cm, the duodenal cap)
P = Pancreas (except the tail)
U = Ureters
C = Colon (ascending and descending parts)
K = Kidneys
E = (O)esophagus
R = Rectum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

MESENTERY

A

double layer of visceral peritoneum

  • usually connects intraperitoneal organs to posterior wall
  • provives pathway for nerves, vessels, lymphatics from body wall to viscera
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

4 Regions of the Stomach

A

1 CARDIA
2 FUNDUS
3 BODY
4 PLYORIC PART

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

CARDIA

A

most superior, medial portion of stomach

immediately surrounding the junction of the esophagus

Esophageal lumen opens into the Cardia of CArdiac Orifice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

FUNDUS

A

region that projects superior to the junction b/w esophagus and stomach

contracts the inferior + posterior portion of the diaphragm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

BODY of Stomach

A

area b/w Fundus and curve of J.

largest region of stomach

functions as a mixing tank for ingested food and gastric secretions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

PLYORIC PART

“gatekeeper”

A

b/w body of stomach and duodenum
3 parts:
1 PYLORIC ANTRUM - connected to body
2 PYLORUS - muscular tissue surrounding pyloric orifice
3 PYLORIC SPHINCTER - regulates the release chyme into the duodenum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

GASTRIC FOLDS

A

appears when stomach is empty of food and chime.

gradually flatens out until maximum distension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Blood Supply to Stomach

A

3 branches of the Celiac Trunk supply blood to the stomach:

1 Left gastric artery - supplies lesser curvature and cardia
2 Splenic artery - supplies fundus
3 Left gastro epiploic artery - supplies greater curvature
4 Common hepatic artery (branches into 4a right gastric artery, 4b right gastro epiploic artery, 4c gastroduodenal artery) - supplies greater + lesser curvatures at the plyrosus
5 Gastric vein + Gastro epiploic vein - drain blood intoHepatic portal vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Musculature of Stomach

A

muscularis mucosae + muscular layer of stomach has extra layers of smooth muscle (normally it is just circular and longitudinal layers).
extra layers strengthen the stomach wall, assist in mixing + churning the chyme

muscularis mucosae contain an outer circular layer

muscular layer has inner oblique layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Omenta

A

mesenteries of the stomach
connects stomach to adjacent organts
Greater omentum - large pouch that is more inferior, attached to greater curvature
Lesser omentum - superior, attached to liver + first segment of duodenum, and lesser curvature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Layers of Stomach Wall

A

surface epithelium of gastric mucosa is simple columnar epithelium composed of mucous surface cells

produces layer of mucus that covers the luminal surface of somach
protects the epithelium against acids and enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Gastric Pits

A

shallow depressions that open onto gastric surface pit

the base of pits contains regenerative stem cells that actively replace the cells that are continuously sheding into chyme
also protects superficial epithelial cells if damaged from stomach acid or digestive enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

4 Gastric Secretory Cells

A

Mucous Neck Cells
Parietal Cells
Enteroendocrine Cells + G Cells
Chief Cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Gastric Juice

A

made by Parietal Cells + Chief Cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Mucous Neck Cells

A
  • found in call regions of stomach
  • columnar in shape
  • apical cytoplasm is filled w secretory product that is water-solulable + lubricates stomach contents
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Parietal Cells

A
  • large round/pyramid shaped
  • numerous in the proximal portion of gastric glands
  • secretes Intrinsic Factor + Hydrochloric Acid (HCl)
29
Q

Intrinsic Factor

A

glycoprotein that helps absorb vitamin B12 across intestinal lining

secreted by Parietal cells

30
Q

Hydrochloric Acid (HCl)

A

lowers the pH of gastric juice,
kills microorganisms,
breaks down plant cell walls, connective tissues in meat, + denatures protein

secreted by Parietal cells

31
Q

Enteroendocrine Cells + G Cells

A

Enteroendocrine - numerous in Fundus, occasionally found in Cardia + Pyloric Part
-scattered among chief cells + parietal cells

32
Q

G Cells

A
  • type of enteroendocrine cells found in Gastric Pits of Pyloric Part
  • secretes Gastrin when food enters stomach
33
Q

Gastrin

A

-secreted by G cells

  • stimulates the secretory activity of both parietal + chief cells
  • promotes smooth muscle activity in the stomach wall to enhance churning + mixing activity
34
Q

Chief Cells

A
  • found only in Funduss
  • most abundant in base of gastric gland
  • secretes Pepsinogen which turns into Pepsin

in newborns, produces Rennin + Gastric Lipase (enzymes vital for milk digestion)

35
Q

Pepsinogen

A
  • inactive proenzyme

- activated when come in contact w acid in the gastric lumen (turns into Pepsin)

36
Q

Pepsin

A
  • active proteolytic (protein digesting enzyme)

- functions most effectively in pH of 1.5-2.0

37
Q

Rennin + Gastric Lipase

A

Rennin coagulates milk protein

Gastric Lipase initiates digestion of milk fats

both produced by Chief cells in Fundus

38
Q

Regulation of Gastric Activity

A

directly by CNS - vagus nerve (sight/thought of food
triggers parasympathetic to innervate parietal, chief, + mucous cells of stomach); branches of celiac plexus (sympathetic inhibits)

indirectly by Local Hormones - small intestines release 2 hormones that inhibits gastric secretion:
Secretin
Cholecytokinin

39
Q

Secretin + Cholecytokinin

A

stimulate secretioin by both pancreas and liver

also depresses the gastric activity

40
Q

Small intestines

A
  • 90% of absorption
  • found in all abdominal regions except left hypochondriac + epigastric region
  • held by mesentaries attached to wall
41
Q

3 Subdivisions of Small Intestines

A

1 Duodenum
2 Jejunum
3 Ileum

42
Q

Duodenum

A
  • shortest + widest
  • connected to Pylorus of Stomach
  • mixing bowl of chyme fr stomach, + digestive secretions of liver + pancreas
  • ring of smooth muscle regulates movement of chyme
43
Q

Jejunum

A
  • second segment starts at Duodenojejunal flexure
  • re-enters the peritoneal cavity becoming intraperitoneal
  • bulk of digestion + nutrient absorption
  • typically found in umbilical region
44
Q

Ileum

A
  • longest segment of small intestine that is intraperitoneal proximally, then secondary retroperitoneal in the rest
  • typically in hypogastric region
  • mesentary has more fat, is thicker
45
Q

Mesentery Proper

A
  • fan shaped mesentary that covers jejunum and ileum
46
Q

Histology of Digestive Tract

A
Mucosa
Muscularis Mucosae
Submucosa
Muscular layer
Serosa
47
Q

Intestinal Epithelium

A

1 Circular Folds -large flaps in mucosa
2 Intestinal Villi - fingerlike projection of mucosa
3 Microvilli - the columnar cells that cover the Intestinal Villi

increases the surface area of small intestines
increases the surface

48
Q

Intestinal Gland

A
  • glandular pockets that extend deep into underlying lamina propria
  • at the base, stem cells continuously divide to produce new epithelial cells (old cells turn into intracellular chyme)
49
Q

Paneth Cells

A
  • at base of intestinal glands

- secretes DEFENSINS + LYSOZYME for innate (nonspecific) immunity (kills some bacteria but ignores good bacteria)

50
Q

Lamina Propria of Intestinal Villi

A

loose areolar connection tissue located within the core of each villi

contains lymphatic cells, ocassional lymphoid nodules, extensive network of capillaries, LACTEAL,

51
Q

Lacteal

A

found w/in Lamina Propria

lymphatic vessel that transports materials that cannot enter blood capillaries

52
Q

Terminal Ileum

A

contains ileocecal sphincter - controls flow of chyme into large intestines

53
Q

longest portion of intestinal segement

A

Ileum

54
Q

second intestitnal segment

A

jejunum

55
Q

connection between pharynx and stomach

A

esophagus

56
Q

function of chief cells

A

secretes pepsinogen (which turns into pepsin a protein digesting enzyme)

57
Q

function of parietal cells

A

secretes glycoprotein that helps absorb vitamin B12

secreted HYDROCHLORIC ACID which lowers pH, kills microorganisms, helps break down plant walls and connective tissues of meat, denatures protein

58
Q

terminal portion of small intestines

A

ileocecal valve

59
Q

Lining of Intestinal Tract

inside to out

A
mucosa
muscularis mucosa
submucosa
muscular layer
serosa
60
Q

Salivary Glands

A

parotid gland
submandibular gland
sublingual gland

61
Q

Large intestine parts

A
Cecum 
Ascending Colon
Transverse Colon
Descending Colon
Sigmoid Colon
Rectum
62
Q

Hausta

A
individual pouch of the large intestines
looks like 
(    ) - 1 hausta
(    ) - 2 haustra
(    ) - 3 haustra
63
Q

Teniae Coli

A

runs along outer surface of colon just deep to the serosa

-contracts lengthwise and what makes the folds that creates the Haustra

64
Q

Teniae Coli

A

runs along outer surface of colon just deep to the serosa

-contracts lengthwise and what makes the folds that creates the Haustra

65
Q

Bile

A

synthesized int he liver, stored in the gallbladder, and released into the lumen of duodenum

breaks down lipids in chyme to make fatty acids absorbable

66
Q

Blood flow from Intestines to Liver

A

Blood drains from stomach, large + small intestines, to HEPATIC PORTAL SYSTEM, to LIVER.

Liver extracts nutrients, + toxins from blood before returning to Heart

67
Q

Gallbladder

A

stores and concentrates bile before it is released into small intestines

68
Q

Wall of gallbladder

A

mucosa
lamina propria
muscular layer
serosa