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Flashcards in Digestive System Deck (118)
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1
Q

What lines the oral cavity?

A

Oral mucosa

2
Q

What are the three types of oral mucosa?

A
  • Musculatory mucosa
  • Lining mucosa
  • Specialized mucosa
3
Q

Where is musculatory mucosa found?

A

Gingiva and hard palate

4
Q

Surface epithelium of musculatory mucosa?

A

Keratinized or parakeritinized stratified squamous epithelium

5
Q

Lamina propria of musculatory mucosa?

A
  • Papillary layer - think, loose CT (has blood vessels, nerves, sensory receptors, and some Meissner’s corpuscles)
  • Reticular layer - more dense CT
6
Q

Where is the lining mucosa found?

A

Soft palate, underside of tongue, floor of mouth, cheeks, and lips

7
Q

Surface epithelium of lining mucosa?

A

Nonkeratinized stratified squamous epithelium (thicker than keratinized areas)

Vermilion border and lips = keratinized stratified squamous epithelium

8
Q

Lamina propria of lining mucosa?

A

loose CT lined with blood vessels and nerves

9
Q

Submucosa of lining mucosa?

A

more dense CT

10
Q

Where is specialized mucosa found?

A

Dorsal surface of tongue

11
Q

Surface epithelium of specialized mucosa?

A
  • Keratinized stratified squamous epithelium on FILIFORM PAPILLAE
  • Stratified squamous epithelium on all other papillae
12
Q

General function of specialized mucosa?

A

Move food and TASTE

13
Q

Tongue mucosa location?

A

thicker dorsally; thinner and smoother posteriorly

14
Q

Surface epithelium of tongue mucosa?

A
  • includes PAPILLAE (fungiform, filiform, foliate, vallate)
  • Small salivary (von Ebner) glands associated with VALLATE PAPILLAE (produce serous fluid to cleanse taste buds)
  • taste buds located on all papillae EXCEPT filiform
15
Q

Lamina propria of tongue mucosa?

A

loose CT; adipose possible

16
Q

Submucosa of tongue mucosa?

A

contains lingual salivary glands

17
Q

Intrinsic tongue muscles

A
NO external attachment!!!
4 alternating muscles - change shape of tongue for phonation and movement of food
1) superior longitudinal m
2) vertical m
3) transverse m
4) inferior longitudinal m
18
Q

Layers of teeth listed outside to inside

A
  • ameloblasts
  • enamel
  • dentin
  • predentin
  • odontoblast
  • dental papilla
19
Q

Ameloblasts

A
  • polarized COLUMNAR cells
  • LOSE following tooth eruption
  • Produce ENAMEL
20
Q

Enamel

A
  • hardest substance in body

- cannot make more after tooth eruption

21
Q

Dentin

A
  • harder than bone

- contain thin dentinal tubules containing nerves and cell processes of ODONTOBLASTS

22
Q

Predentin

A

-precursor to dentin before mineralization

23
Q

Odontoblast

A
  • columnar cells lining pulp cavity
  • survive in adults
  • repair and produce DENTIN (maintain)
24
Q

Dental Papilla

A
  • aka, dental pulp
  • CT with many blood vessels and nerves
  • potential problem = excessive inflammation
25
Q

Types of salivary glands?

A
  • Parotid gland
  • Submandibular gland
  • Sublingual gland
26
Q

Parotid gland total salivay output?

A

~30%, but largest salivary gland

27
Q

Parotid gland facts

A
  • most affected by mumps
  • facial nerve passes through it
  • 100% serous producing
  • becomes infiltrated with adipose as one ages
28
Q

Products produced by parotid gland?

A
  • salivary amylase (alpha-amylase) - breaks down carbs
  • Lysosome
  • Secretory IgA
29
Q

Submandibular gland total salivary output?

A

~60%

30
Q

Submandibular gland facts

A
  • fatty infiltration by midlife possible
  • produces mucous AND serous products (~80-90% serous)
  • has serous DEMILUNES
31
Q

Sublingual gland total salivary output?

A

~5%, smallest

32
Q

Sublingual gland facts

A
  • mucous AND serous production (~80% mucus)

- all serous from serous demilunes (no separate serous acini)

33
Q

Functions of saliva

A
  • lubricating and cleansing oral cavity
  • Antibacterial
  • Dissolve food materials for taste sensation
  • Initiate digestion (amylase, lipase)
  • Aid swallowing
  • wound healing (clotting factors, epidermal growth factor)
34
Q

Parasympathetic effect of saliva secretions

A

Increase amount of WATERY secretion

35
Q

Sympathetic effect of saliva secretions

A

Decrease amount of saliva with THICKER consistency (dryer oral cavity)

36
Q

Mucosa (general terminology)

A
  • surface epithelium
  • lamina propria
  • muscularis mucosae: SMOOTH muscle
37
Q

Submucosa (general terminology)

A
  • more dense CT
  • LARGER blood vessels
  • submucosal (Meissner) plexus
38
Q

Muscularis externa (general terminology)

A
  • Myenteric (Auerbach) plexus (found btwn circular and longitudinal m layers; influences musc. externa)
  • Typically smooth muscle
  • Normal fiber orientation = inner circular, outer longitudinal
39
Q

Serosa/Adventitia

A

Serosa - edge of simple squamous epithelium; serous producing

Adventitia - CT; seen with vertical organs

40
Q

Function of esophagus

A

Transfer bolus to stomach from oropharynx

41
Q

Mucosa - surface epithelium of esophagus

A

Stratified squamous

Contains LANGERHANS CELLS - an APC with some phagocytosis possible

42
Q

Mucosa - lamina propria of esophagus

A
  • loose areolar CT*
  • Can have esophageal cardiac glands - produce NEUTRAL mucus to protect epithelium
  • Location = near pharynx (1st inch) and near stomach (last inch)
43
Q

Mucosa - muscularis mucosae of esophagus

A
  • discontinuous layer of LONGITUDINAL muscle

- THINNER distally (by pharynx) and THICKER proximally (by stomach)

44
Q

Submucosa of esophagus

A

contains ESOPHAGEAL GLANDS - produce slightly acidic mucus to lubricate movement of food

45
Q

Muscularis externa of esophagus

A

Normal fiber pattern (inner circular, outer long.)

  • Upper 1/3 = all SKELETAL
  • Middle 1/3 = smooth and skeletal
  • Lower 1/3 = all SMOOTH
46
Q

Adventitia/serosa of esophagus

A

Primarily ADVENTITIA except last 1-2 inches are serosa (after diaphragm)

47
Q

Esophageal associated sphincters (2 physiological)

A

1) Pharyngoesophageal Sphincter - between oropharynx and esophagus
2) Gastroesophageal Sphincter - between esophagus and stomach (prone to problems; abrupt to change)

48
Q

Characteristics for physiological sphincters

A
  • NO THICKENING of circular muscle in muscularis externa

- Pressure gradient aids movement (muscle contraction and gravity)

49
Q

Function of the stomach

A
  • continue to digest CARBS
  • primary storage of food
  • SOME nutrient breakdown (primarily chemical)
50
Q

Mucosa - surface epithelium of stomach

A
  • simple columnar*

- CELLS = Surface mucosa and Regenerative cells

51
Q

Surface Mucosa Cells (stomach)

A

= surface lining

  • produce thick, visible mucus
  • secrete BICARBONATE IONS (buffering)
52
Q

Regenerative Cells (stomach)

A

Bases of pits

53
Q

Mucosa - lamina propria of stomach

A

loose, vascular CT present in small amounts between glands

54
Q

Mucosa - muscularis mucosae of stomach

A

smooth muscle layer (often 3 layers - well developed)

1) inner longitudinal
2) outer longitudinal
3) outermost circular/oblique

55
Q

Submucosa of stomach

A
  • HIGHLY vascular
  • *location of AVA - function to shut down activity and secretion fast
  • Submucosal (Meissner’s) plexus - to influence MUCOSA
56
Q

Muscularis externa of stomach

A
  • 3 muscle layers possible (especially btwn CARDIAC REGION and GREATER CURVATURE)
    1) innermost oblique
    2) middle circular (well developed)
    3) outer longitudinal (thin)
  • normal pattern in other areas (inner circ, outer long)
  • Myenteric (Auerbach’s) plexus - stimulate muscularis externa
57
Q

Serosa of stomach

A

ALL serosa. no adventitia

58
Q

Three regions of the stomach

A

1) Cardiac region
2) Gastric region
3) Pyloric region

59
Q

Cardiac region of stomach

A

-shorter PITS - lead to cardiac glands with a coiled base
- cells =
Surface mucus (primarily)
Neck mucus
DNES and parietal cells (few)
*NO chief cells!
-smallest region; obtains much mucus

60
Q

Gastric region of stomach

A
aka, zymogenic gland
GASTRIC GLANDS
3 regions
1) Isthmus
2) Neck
3) Base
61
Q

ISTHMUS of gastric glands

A

Cells

1) Surface mucus
2) DNES cells

62
Q

Surface mucus cells (gastric glands; isthmus)

A
  • live 3-5 days
  • produce THICK, visible mucus that traps bicarbonate ions (alkaline)
  • Function = protect mucosa from auto-digestion and the rougher components of chyme
63
Q

DNES cells

A
-enteroendocrine cells
Types:
1) Type D
2) Type EC
3) Type G
64
Q

Type D; DNES cells (stomach)

A
  • produces SOMATOSTATIN
  • inhibits release of hormones by nearby DNES cells and HCL release
  • *DECREASES gastric acid
65
Q

Type EC; DNES cells (stomach)

A
  • produces SEROTONIN and SUBSTANCE P

- increases gut motility

66
Q

Type G; DNES cells (stomach)

A
  • produces GASTRIN
  • stimulates:
    1) HCL and pepsinogen secretion
    2) gastric motility
    3) regenerative cells in body of stomach
  • coffee, alcohol, AA’s all stimulate type G
67
Q

NECK of gastric glands

A

Cells:

1) Neck mucus cells
2) Regenerative cells - replace all cell types
3) Parietal (oxyntic) cells
4) DNES cells

68
Q

Neck mucus cells

A
  • live ~6 days
  • produce a soluble, less alkaline mucus (slightly acidic)
  • Function = to lubricate gastric contents
69
Q

Parietal (oxyntic) cells

A
  • live ~150-200 days
  • secretes or produces acid
  • add columnar cells with intracellular canaliculi
  • produce:
    1) very strong HCl; made at 0.8 pH and buffered immediately to 1-2 pH
    2) *Gastric intrinsic factor - enzyme; necessary for vit. B12 absorption
70
Q

Chronic Gastritis

A
  • can lead to PERNICIOUS ANEMIA
  • low number of PARIETAL cells can lead to low amounts of INTRINSIC FACTOR
  • will decrease vit. B12 absorption which is necessary for RBC maturation
  • stomach lining irritation –> INFLAMMATION
71
Q

BASE of gastric glands

A

Cells:

1) Chief (zymogenic) cells
2) Parietal cells
3) DNES cells (few)

72
Q

Chief (zymogenic) cells

A
  • live ~60-90 days
  • produce:
    1) Pepsinogen (primarily) - to break down proteins
    2) Gastric Lipase (some)
73
Q

Pyloric Region of stomach

A
  • deeper pits, very twisted and branched pyloric glands (shorter glands)
  • Cells:
    1) Surface mucus, DNES, parietal (primarily)
    2) Neck mucus that can produce some lysosome (some)
74
Q

Pyloric Sphincter

A

-ANATOMICAL sphincter between the pylorus of the stomach and the duodenum

75
Q

Characteristic of an anatomical sphincter

A
  • well developed inner circular layer or muscle in the ME

- inner circular layer in ME can be independently controlled

76
Q

General function of Small Intestine

A
  • digestion
  • absorb nutrients
  • produce intestinal hormones (using DNES cells)
77
Q

Surface adaptations of Small Intestine

A
  • PLICA CIRCULARES (valves of Kerckring) - permanent folds of mucosa and submucosa; found throughout duodenum, jejunum, and proximal ileum
  • VILLI
  • MICROVILLI - on luminal cell surface
78
Q

Mucosa - surface epithelium of small intestine

A
  • simple columnar
  • Cells:
    1) Enterocytes
    2) Goblet cells
    3) DNES cells (~11 types in SI)
    4) Regenerative cells (crypts)
    5) Paneth cells
    6) M (microfold) cells
79
Q

Enterocytes

A

aka, surface absorptive cells: contain MICROVILLI

  • Functions
    1) absorb water and nutrients
    2) terminal digestion in GLYCOCALYX; cells produce the enzymes and absord the monosaccharides and peptides created
80
Q

Goblet Cells

A

Fewest in duodenum and most in ILEUM

81
Q

DNES cells (SI)

A

~11 types in SI

1) Type I
2) Type K
3) Type S

82
Q

DNES; Type I (SI)

A
  • produces CCK
  • CCK stimulates
    1) gallbladder contraction
    2) pancreatic secretion of enzymes from SEROUS ACINI
83
Q

DNES; Type K (SI)

A
  • produces GIP

- Inhibits HCl release

84
Q

DNES; Type S (SI)

A
  • produces SECRETIN
  • *stimulates pancreas secretion of bicarbonate from the pancreatic ducts
  • inhibits HCl release and movement of chyme into SI
85
Q

Paneth cells

A
  • long lived (~20 days)
  • location = base of CRYPTS (intestinal glands)
  • function = produce LYSOZYME
86
Q

M (microfold) cells

A
  • location = ileum over PEYER’S PATCHES
  • contain large intracellular pockets that are fairly open to the LP; sample foreign antigens in gut lumen and transfer antigens to lymphocytes and dendritic cells that have entered the M cell pockets
  • function = promote HUMORAL IMMUNITY
    • Important in maintaining GUT FLORA
87
Q

Mucosa - lamina propria of SI

A
  • loose areolar CT*
  • found in VILLUS CORE
  • **LACTEALS - lymphocyte capillaries (lipid absorption)
  • smaller blood vessels
  • some longitudinal smooth m
  • borders intestinal glands (=crypts of Lieberkuhn)
88
Q

Mucosa - muscularis mucosae of SI

A

thin but present, connects to smooth muscle in villi

89
Q

Submucosa of SI

A
  • dense fibroelastic CT

- VERY vascular; larger blood vessels

90
Q

Submucosa of SI (duodenum)

A
  • Duodenal (Brunner) glands - seromucus glands
  • products produced:
    1) Alkaline mucus; to neutralize chyme
    2) Urogastrone; inhibits HCl secretion and increase mitosis of epithelial cells
91
Q

Submucosa of SI (Jejunum)

A

NO structures of significance

92
Q

Submucosa of SI (Ileum)

A
  • location of PEYER’S PATCHES - groups of regularly occuring large lymph nodules
  • Submucosal (Meissner’s) plexus - PARASYMP. innervation; influences mucosa
93
Q

Muscularis externa of SI

A
  • normal pattern (inner circ, outer long)

- Myenteric (Auerbach) plexus - stimulates ME for peristalsis

94
Q

Serosa/Adventitia of SI`

A

Serosa - all of JEJUNUM and ILEUM; first and last 1-2 cms duodenum

Adventitia - vertical (descending) portion of DUODENUM

**only one with BOTH serosa and adventitia!!

95
Q

Ileocecal Valve

A
  • found btwn ileum and cecum of colon

- a physiological AND anatomical sphincter

96
Q

Appendix

A

aka, vermiform appendix

-a blind pouch, on the right, extending from the CECUM

97
Q

Mucosa of appendix

A

SE - simple columnar with surface absorptive cells, goblets, regenerative, and DNES

LP - yes

MM - poorly developed

  • short crypts,
  • NO VILLI
  • no to infrequent Paneth cells
98
Q

Submucosa of appendix

A
  • thick layer with large blood vessels

- numerous lymph nodules

99
Q

Muscularis externa of appendix

A

Normal pattern, but thin

Also, just serosa

100
Q

Function of appendix

A
  • humoral immunity

- reservoir for good bacteria

101
Q

General functions of the colon

A
  • primary = absorption of water
  • compaction, lubrication, and elimination of feces
  • production of some vitamins
102
Q

Mucosa of colon

A

SE - simple columnar with many GOBLET cells and surface absorptive cells, some regenerative and few DNES cells

LP - typical and has intestinal glands (crypts)

MM - normal

-lacks: VILLI and PANETH CELLS

103
Q

Submucosa of colon

A

typical

104
Q

Muscularis Externa of colon

A
  • *NOT NORMAL PATTERN
  • Outer longitudinal m is gathered into bands called TENIAE COLI and is discontinuous
  • constant tonus of teniae coli results in sacculations called HAUSTRA
105
Q

Serosa/Adventitia of colon

A

Serosa - transverse and sigmoid colon

Adventitia - ascending and descending colon

106
Q

General function of rectum

A

store fecal material

107
Q

Surface epithelium of rectum

A
  • simple columnar*
  • similar to colon EXCEPT
    1) Transverse rectal folds (luminal wall folds)
    2) NO teniae coli in ME; more complete long. m’s
    3) *luminal wall covering includes ADVENTITIA
108
Q

Surface epithelium of anal canal

A

-transitions to stratified squamous

109
Q

Glands of anal canal

A
  • ANAL GLANDS extend into SM and produce mucus to lubricate lumen
  • CIRCUMANAL GLANDS (apocrine glands) in skin surrounding anus
110
Q

Mucosa and submucosa of anal canal

A
  • contain LONGITUDINAL FOLDS creating anal columns

* NO muscularis mucosae in anal canal

111
Q

Internal anal sphincter

A

a think circular layer of smooth m within the muscularis externa
-stay CONTRACTED until triggered to relax; NOT anatomical

112
Q

External anal sphincter

A

a STRIATED (voluntary) muscle from the pelvic floor

113
Q

Luminal wall covering of anal canal

A

ADVENTITIA (just like the rectum)

114
Q

Peptic Ulcer Disease

A

2 causes:

1) Insufficient protection from HCL and PEPSIN - damaged mucus coat, too much HCL and pepsin
2) Helicobacter pylori

-if luminal acidity is decreased, damaged tissues can repair in 1-2 months

115
Q

Gastroesophageal (esophageal) reflux

A
  • cause = stomach chyme backing up into the lower esophagus (common)
  • contributing factors = chronic gastritis, hiatal hernia, pregnancy, incompetent lower esophageal sphincter, subluxations
116
Q

Barrett’s Esophagus

A
  • precancerous condition
  • stratified squamous epithelium is replaced by MUCUS-SECRETING SIMPLE COLUMNAR EPITHELIUM in lower esophagus (metaplasia)
117
Q

Parasympathetic Stimulation in general

A

From VAGUS NERVE

  • EXCEPT decending colon and rectum from SACRAL N’s
  • STIMULATE peristalsis
  • INHIBIT sphincters
  • ACTIVATES secretion
118
Q

Sympathetic Stimulation in general

A

from SPLANCHNIC NERVES

  • INHIBITS peristalsis
  • CONTRACTS sphincters
  • control blood flow to gut