Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Human Organs and Tissues > Digestive Tract > Flashcards

Digestive Tract Flashcards

1
Q

The digestive system includes which structures?

A
  1. Salivary glands
  2. Mouth/tongue
  3. Esophagus
  4. Stomach
  5. Liver
  6. Gallbladder
  7. Pancreas
  8. Small intestine
  9. Colon
  10. Rectum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the alimentary tract?

A

Tubular passage of mouth to anus

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

What is the small intestine/basic function?

A

upper part of the intestine where digestion is completed and nutrients absorbed

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

What are the large intestine components?

A

Cecum, appendix, colon, and rectum

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

What are the 4 fundamental layers of the digestive system? (inner to outer)

A
  1. Mucosa
  2. Submucosa
  3. Muscularis propria
  4. Outer layer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What 3 layers comprise the muscosa? (inner to outer)

A
  1. Epithelium
  2. Lamina propria
  3. Muscularis mucosae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What comprises the submucosa? what is another name for it?

A

aka the plexus

comprised of glands, blood vessels, and nerves

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

What two layers comprise the muscularis propria? what differentiates them

A
  1. Inner muscle layer (circular)
    - involuntary control/smooth muscle
  2. Outer muscle layer (longitudinal)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What makes up the outer layer?

A

the adventitia or serosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 4 types of papillae found on the tongue?

A
  1. Circumvallate papillae
  2. Filiform papillae
  3. Fungiform papillae
  4. Foliate papillae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which of the 4 types of papillae lack taste buds?

A

Filiform papillae

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

What is another name for circumvallate papillae? Where are they found? what shape do they have?

A

Aka the vallate papillae

Dome shaped, sunken structures
- contain TB

Found near the dorsal end of the tongue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What shape are the filiform papillae? where are they found?

A

small conical prominences on the lingual surface

** no taste buds **

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the shape of the fungiform papillae ? where are they found? Where are their taste buds?

A

Mushroom shaped projections on the surface among the filiform

  • mainly at the tip and lateral margins
  • taste bugs on the upper surface
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the shape of the foliate papillae? where are they found? where are their taste buds?

A

short vertical folds

on the lateral margins

Taste buds scattered over the surface

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

What drain into the folds of the foliate papillae to clean the taste buds?

A

serous glands

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

What are the 5 tastes that the taste buds can perceive?

A

salty, sour, sweet, bitter, umami

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

Papillae are among which type of epithelium?

A

stratified squamous non-keratinized epithelium

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

How many deciduous (primary) teeth do children have?

A

20

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

How many adult teeth should we have?

A

32 - 8 in each quadrant

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

What are the two main parts of the tooth?

A

Crown and root

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

What are the layers of the tooth from inner to outer?

A

Pulp –> dentin –> enamel

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

What are the layers of the gum around the tooth from inner to outer?

A

Periodontal ligament –> alveolar bone –> gingiva

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

What are the 3 types of salivary glands?

A
  1. Parotid
  2. Sublingual
  3. Submandibular
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What cells secrete amylase which digests starch into maltose?

A

serous cells

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

What are the 3 types of cells in salivary glands?

A
  1. Serous cells
  2. Intercalated duct cells
  3. Striated duct cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What do intercalated duct cells secrete? what do they absorb?

A

secrete bicarbonate, absorb Cl-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What do striated duct cells do?

A

modify saliva to be hypotonic with plasma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What kind of stimulation innervates salivary glands?

A

Parasympathetic stimuli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How many bacterial species have been isolated in culture from the oral cavity? How many do they think there are total (including ones that can’t be cultured?)

A

500 to 700

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What are 7 positive effects of host-microbiome symbiosis?

A
  1. Confers resistance to colonization
  2. Regulation of cardiovascular system
  3. Supports host defense functions
  4. Has anti-inflammatory properties
  5. Provides additional metabolic potential
  6. Has antioxidant activity
  7. Maintains a healthy digestive tract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are some common diseases of the oral cavity?

A
  1. Ulcers
  2. thrush
  3. Canker sores
  4. tooth decay
  5. grinding teeth in sleep
  6. gingivitis
  7. cancer
  8. congenital defects like cleft lip/palate
  9. trauma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What muscle controls the opening of the esophagus?

A

the inferior pharyngeal constrictor muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What covers the trachea to prevent food and fluids from entering the lung?

A

the trachea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What controls the movement of food from the esophagus into the stomach ?

A

Lower esophageal sphincter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

**refresh: what are the 4 layers of tissue?

A
  1. mucosa
  2. submucosa
  3. muscularis propria
  4. adventitia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What kind of epithelium make up the mucosa of the esophagus?

A

stratified squamous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What glads are present in the esophagus near the stomach ? What layer are they in and what do they secrete

A

Cardial glands

Found in the mucous layer and secrete mucous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is special about the upper third of the muscularis propria in the esophagus?

A

is it striated muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is Gastroesophageal reflux disease? (GERD)

A

Failure of the lower esophageal sphincter to close properly causing stomach contents to leak back

get frequent heartburn and potential ulcer formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What disease is characterized by inflammation/swelling of the esophagus due to large numbers of eosinophils?

A

Eosinophilic esophagitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

How do you diagnose eosinophilic esophagitis?

A

with an endoscopy and biopsy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is dysphagia? What can cause it?

A

difficulty swallowing due to stiffening or narrowing of the esophagus
- due to infiltration of large numbers of eosinophils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What main event happens in the stomach?

A

Denaturation of proteins and initiation of enzymatic breakdown by the action of pepsin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What 3 kinds of glands are there in the stomach?

A
  1. Cardiac glands
  2. Pyloric glands
  3. Gastric/fundic glands
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What allows for expansion of the stomach?

A

gastric rugae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What are the 4 sections of the stomach?

A
  1. Cardia
  2. Fundus
  3. Body
  4. Antrum or pylorus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What re the 4 types of cells in the stomach glands?

A
  1. Mucous cells
  2. Parietal/oxyntic cells
  3. Chief cells
  4. Enteroendocrine cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What cells secrete HCL and intrinsic factor into the stomach?

A

Parietal cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What is the purpose of intrinsic factor?

A

Used in vitamin B12 absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What happens if you don’t produce intrinsic factor?

A

you will develop pernicious anemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What cells produce pepsinogen?

A

Chief cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What do enteroendocrine cells release? where? what is an example?

A

secrete hormones

G cells specifically secrete gastrin into the lamina propria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What does gastrin do?

A

promotes the secretion of HCL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What cells secrete bicarbonate? where?

A

Parietal cells do into the lamina propria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What happens to the bicarbonate?

A

diffuses into capillaries and then back into the upper epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What two factors help the stomach not be harmed by the acid?

A

Mucous and bicarbonate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

The epithelium in the stomach is what type?

A

Simple columnar epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What is unique about the muscularis propria of the stomach?

A

it has 3 layers of muscle

and oblique muscle layer before the circular layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What is Barrett’s esophagus?

A

stratified squamous epithelium of the esophagus is replaced with simple columnar epithelium by goblet cells

at the gastroesophageal junction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

There is a strong connection between Barrett’s esophagus and….

A

esophageal adenocarcinoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What is an ulcer?

A

an open sore on an external or internal surface of the body caused by a break in the skin or mucous membrane that fails to heal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What is the leading cause of gastritis?

A

Helibobacter pylori

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What % of the worlds population harbour H. pylori in their GI tract?

A

more than 50%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What are two risks associated with having H. pylori in the stomach?

A

~10–20% of infected will ultimately develop gastric and duodenal ulcers.

associated with a 1–2% lifetime risk of stomach cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What is the product called from stomach digestion that enters into the small intestine?

A

chyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What causes the release of cholecystokinin and secretin? What does this accomplish?

A

the presence of fats in the duodenum

inhibits further gastric activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What is the order of segments in the small intestine?

A

Duodenum, jejunum, ileum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

How many litres of fluid pass through the small intestine every day? From that, how much goes on to the large intestine?

A

9 L to the small intestine

Only 1.5 L actually makes it to the large intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

While the architecture of the layers is the same in the small intestine, which layer is expanded? why?

A

the submucosa because of increased glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

What glands are located in the submucosa of the small intestine?

A

Brunner’s glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

What do Brunner’s glands secrete?

A 
Alkaline mucous (pH 8.1-9.3) 
- contains neutral and alkaline glycoproteins and bicarbonate ions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

What secretes carbohydrases, proteases, and lipases?

A

Crypts of Lieberkühn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

Where are the crypts of Lieberkühn located?

A

in the mucosa also

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What % of starches are digested by amylase in the stomach? what is the product?

A

about half are turned into maltose in the stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

What happens to the remainder of starches that reach the small intestine?

A

broken down into di and monosaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

What is the breakdown of proteins like in the small intestine?

A
  1. proteins are digested by pepsin and pancreatic enzymes

2. free amino acids are then broken down by carbxypeptidases on the villi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

What % of ingested protein is absorbed by the end of the jejunum?

A

70-80%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

What are the 4 principal epithelial cell types scattered along the crypts and villi?

A
  1. Enterocytes
  2. Paneth cells
  3. Goblet cells
  4. Enteroendocrine cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

What is the function of enterocytes?

A

absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

What do Paneth cells secrete?

A
  1. Lysozyme

2. Defensins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

What do goblet cells secrete?

A

mucous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

What do enteroendocrine cells of the small intestine secrete?

A

Hormones like secretin, Cholecystokinin, glycogen inhibitory peptide and others into the lamina propria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

What is the distribution of cells in the villi vs the crypts of the small intestine?

A

Paneth cells are most numerous at the bottom of the crypt = highest concentration of antimicrobial peptides in the bottom of the crypt

85
Q

What is Periodic-acid-Schiff?

A

a stain used to detect polysaccharides such as glycogen, glycoproteins, glycolipids, and mucins

86
Q

The epithelium of the small intestine is…

A

Simple columnar epithelium

87
Q

The small intestine replaces its epithelium completely every…

A

week

88
Q

What is the difference between endo and exo peptidases?

A

Endopeptidases cleave the polypeptide at interior peptide bonds

Exopeptidases cleave the terminal amino acid

89
Q

What are the two further subclassifications of exopeptidases?

A
  1. Aminopeptidases: cleave the terminal amino acid at the amine end of the chain
  2. Carboxypeptidases: cleave off the terminal amino acid at the carboxyl end of the chain
90
Q

What kind of peptidases can be intracellular?

A

di and tripeptidases

91
Q

What are the two key enzymes involved in carbohydrate digestion? which are found in the microvilli?

A

oligosaccharidases
disaccharidases

Both found in the microvilli!

92
Q

What are the 5 phases of fat digestion?

A
  1. emulsification
  2. Hydrolysis
  3. Micelle formation
  4. Absorption
  5. Chylomicron formation
93
Q

What is the function of colipase?

A

Binding to the lipidase during the emulsification step and enhances its activity

94
Q

How do amino acids and monosaccharides reach the capillaries?

A
  1. diffuse through the apical membrane
  2. diffuse across the cell
  3. Through the basolateral membrane either by diffusion or actively transported by carrier proteins
  4. Reach capillaries in the lamina propria
95
Q

How do lipids reach blood circulation?

A
  1. Processed into chylomicrons
  2. Enter lacteals (lymphatic capillaries) in lamina propria
  3. Travel to blood circulation via lymphatic vessels
96
Q

What is paracellular uptake?

A

uptake of materials by passing between cells

97
Q

Tights junctions are called __ and held together by ___

A

Zonula occludens

held together by occludins and claudins

98
Q

What are the proteins involved in adherens, intermediate, and belle desmosome junctions?

A

cadherins and catenins linked to cellular actin

99
Q

What is another name for macula adherens? what proteins are involved?

A

Desmosomes

Cadherins and demoplakin linked to intermediate filaments

100
Q

What is the glycocalyx?

A

acidic mucopolysaccharides and glycoprotein matrix on the apical surface, on the microvilli.

101
Q

Does the large intestine have villi?

A

no, has crypts only

102
Q

What are 5 important features that increase the surface area of the intestine?

A
  1. Long length
  2. Plicae circulares
  3. Villi
  4. Crypts
  5. Brushborder/microvilli
103
Q

What cells secrete Cholecystokinin? where? where does it act on?

A

L cells in the epithelium of the small intestine

acts on the pancreas and gallbladder

104
Q

What does cholecystokinin do? (6 things)

A

mediates digestion by:

  1. inhibiting gastric emptying
  2. inhibiting gastric acid secretion
  3. Stimulating acinar cells of the pancreas to release digestive proenzymes
  4. Increased production of bile
  5. Contraction of the gall bladder
  6. relaxation of the sphincter permitting delivery of bile into the duodenum
105
Q

What cells release gastric inhibitory peptide (GIP)?

A

K cells of the small intestine

106
Q

What is another name for GIP?

A

glucose-dependent insulinotropic peptide

107
Q

What 2 things does GIP do? where does it act on

A
  1. Induces insulin secretion
  2. Inhibits gastric secretion and motility

acts on the stomach and the pancreas

108
Q

What main event occurs in the large intestine?

A

complete absorption of food and formation of feces

109
Q

What are haustra?

A

pouches formed by the taenia coli

110
Q

What are the taniae coli?

A

3 independent long ribbons of smooth muscle just below the serosa, along the colon length (condensations of the longitudinal muscle layer)

111
Q

What is the histology of the large intestine compared to the small intestine?

A

layers are identical but only have the crypts of Lieberkühn

112
Q

What are the levels of goblet cells like in the large intestine?

A

abundant

113
Q

What glands are noticeably absent from the large intestine?

A

Brunner’s glands

in fact there are no submucosal glands in the large intestine

114
Q

What is the smooth muscle layer like in the large intestine?

A

thin and longitudinal

115
Q

What does the adventitia of the large intestine form?

A

Small pouches (appendices epiploicae) filled with fatty tissue along length, though mainly on ascending and transverse colon

116
Q

What is the shape of the cecum? what controls the contents?

A

• sac-like, controlled contents

through the ileocecal valve

117
Q

What are 5 functions of the cecum?

A
  1. Reservoir
  2. Churning activity
  3. Salt recovery
  4. Lubrication of solid waste
  5. Bacterial digestion of cellulose
118
Q

What is the appendix?

A

Small blind ended pouch (diverticulum) of the cecum

119
Q

What is the histology of the appendix like?

A
  1. Thickened walls due to lymphoid tissue

2. Longitudinal smooth muscle layer that does not aggregate into the taenia coli

120
Q

What is the rectum a continuation of?

A

the sigmoid colon

121
Q

What is noticeably lacking from the rectum?

A

taenia coli

122
Q

What occurs when there is expansion of the rectum?

A

nerves send signals to the brain that you need to have a bowel movement*. Muscles around the anal canal control the action

123
Q

What happens at the recto anal junction ?

A

transition between epithelium types

124
Q

What are the 4 epithelium types that exist and where between the lower rectum and the anal canal?

A
  1. simple columnar epithelium in the upper zone
  2. Stratified squamous epithelium in the middle and lower zones
  3. Simple columnar epithelium of the anal glands
  4. Stratified columnar epithelium of the anal sinuses, crypts, and ducts of anal glands
125
Q

Besides water resorption, what are some roles of the large intestine? what is produced

A
  1. Fermentation of carbohydrates by bacteria and further protein decomposition
    - products: organic acids, carbon dioxide, methane, hydrogen sulfide
    - toxic products: phenol, skatole, indole, cresol
  2. Cellulose split by microbial fermentation
  3. vitamins, amino acids, electrolytes, and glucose produced by microbes and absorbed
126
Q

What are the 2 plexi of the enteric nervous system?

A
  1. Myenteric plexus (aka Auerbach’s plexus)

2. Submucosal plexus (aka Meissner’s plexus)

127
Q

What is the role of the Myenteric plexus?

A

Major role in motility and passing food through the digestive tract

128
Q

What is the role of the submucosal plexus? what is it formed from?

A

Secondary plexus derived from and formed by branches having perforated the circular muscle

Innervates the epithelial layer and the muscularis mucosae

129
Q

What is celiac disease? symptom?

A

genetic predisposition of an autoimmune crossreactive reaction to gluten

pale, loose, and greasy stool affecting absorption

130
Q

What is the cause of lactose intolerance? what is the result?

A

lack of lactase enzyme to cleave lactose into glucose and galactose

results in high concentrations of lactose reaching the colon and affecting the osmotic state

  • water gets drawn passively into the lumen
  • not a hypersensitivity or inflammatory disease
131
Q

What is colitis? symptoms?

A

inflammation of the colon due to multiple causes

results in abdominal pain and diarrhea

132
Q

What are two inflammatory bowel diseases?

A

Crohn’s disease: inflammation affects the alimentary tract.

Ulcerative colitis: inflammation affects colon and rectum.

133
Q

What is irritable bowel syndrome?

A

A non-inflammatory, symptom based diagnosis with chronic abdominal pain, discomfort, bloating and diarrhea/constipation

134
Q

What is diverticulosis?

A

small weak areas in the colon wall allow the mucosa to protrude forming diverticuli (pouches)

Usually not a problem but can bleed, become inflamed or infected

135
Q

What are 3 common causes of diarrhea?

A
  1. Salmonellosis: food contamination, diarrhea and stomach cramps, which resolve without treatment.
  2. Shigellosis: food contamination, invaded the colon. Fever, stomach cramps and diarrhea, which may be bloody.
  3. Travelers’ diarrhea: Many different bacteria or protozoa (Giardia) may contaminate water or food.
136
Q

What are colon polyps?

A

small growths where some may develop into cancer over a long period of time

137
Q

Blood in the spleen, stomach, pancreas, gallbladder and intestines passes through and collects in the…

A

hepatic portal vein

138
Q

Where does blood leaving the liver collect? where does it travel?

A

collects into the hepatic veins then goes to into the vena cava to the heart

139
Q

cells of the liver are organized into lobules around…?

A

the central vein, and the hepatic artery/bile duct/portal vein triad

lymph vessels are also present

140
Q

What are the low pressure channels that receive blood from terminal branches of the hepatic artery and portal vein? Where do they deliver it to?

A

Sinusoids

Deliver it into the central veins

141
Q

What are the sinusoids lined with? Flanked with? populated with?

A

Fenestrated endothelial cells

Flanked by hepatocytes

Populated with numerous Kupffer cells

142
Q

What is the space of Disse?

A

the space between the endothelium and hepatocytes

143
Q

What are Kupffer cells?

A

liver macrophages

144
Q

Hepatocytes make bile which is dumped into __ between the cells?

A

Bile canaliculi

145
Q

Hepatocytes are bathed in plasma derived party from…

A

venous blood from the small intestine

146
Q

Plasma which collected in the space of Disse flows back towards the …

A

portal tracts and collects in lymphatic vessels

147
Q

what % of bile is reabsorbed by hepatocytes vs. what % is newly produced bile?

A

10% new bile that is produced and 90% reabsorbed

148
Q

What are 5 functions of hepatocytes?

A
  1. Bile production/uptake/transport
  2. Lipid uptake & metabolism
  3. Glycogen synthesis
  4. Detoxification by p450 enzymes
  5. Protein synthesis
149
Q

What kinds of proteins are synthesized by hepatocytes?

A

Albumin, complement, fibrinogen, lipoproteins

150
Q

Are all hepatocytes carrying out the same functions at the same time?

A

no there is a division of labour between the hepatocytes at different locations in the lobule

151
Q

What do Kupffer cells do?

A

Eliminate foreign particles and gut endotoxins

152
Q

Where are stellate cells located? What do they produce?

A

Found in the space of Disse

Produce collagen fibrils and extracellular matrix materials

153
Q

What is bile a mixture of?

A

Water, bile salts, cholesterol, bilirubin

154
Q

What happens to bilirubin in the intestine?

A

Intestinal bacteria further convert it into the brown pigment stercobilin

155
Q

The bile/hepatic ducts join with the ___ which brings bile to and from the gall bladder?

A

cystic duct

156
Q

The gallbladder is ___ and the mucosa has ___

A

stretchable and has folds

157
Q

What is the epithelial lining of the gallbladder like? what does this do?

A

lined with high columnar epithelium

modifies bile, largely by absorbing water

also acts as a way to remove toxins

158
Q

What is bilirubin a product of?

A

the digestion by Kupffer cells of expired rbc, makes bile green

159
Q

What is the name of the vessels collecting bile from the canaliculli?

A

Hering’s canals

160
Q

What collect bile from the Hering’s canals? where do they lie?

A

the bile ducts

lie parallel to the hepatic arteries and portal veins

161
Q

What collects bile from the bile ducts?

A

hepatic ducts

162
Q

What does the common hepatic duct do? what does it branch into?

A

collects bile from the hepatic ducts

branches into the cystic duct and then the common bile duct

163
Q

Where does the common bile duct empty into?

A

the duodenum

164
Q

What causes Jaundice?

A

increased bilirubin in the blood

165
Q

What is cirrhosis?

A

When normal liver cells are replaced by scar tissue due to chronic liver disease

166
Q

What is the most common cause of liver disease in North America

A

alcohol abuse

167
Q

What is Steatosis ?

A

fatty liver disease

- where cholesterol/triglycerides accumulate in the liver

168
Q

What causes gall stones?

A

accretion of bile, blockage and then inflammation

169
Q

the pancreas has both __ and ___ functions

A

endocrine and exocrine functions

170
Q

what are the two types f exocrine cells in the pancreas?

A
  1. Acinar cells

2. Ductal cells

171
Q

What do acinar cells do?

A

secrete digestive enzymes

172
Q

How many types of ductal cells are there? What do they secrete?

A

4 types

- intercalated duct cells secrete bicarbonate

173
Q

What are the 3 main types of endocrine cells in the pancreas? what do they secrete?

A
  1. Alpha cells - glucagon
  2. beta cells - insulin
  3. Delta cells - somatostatin
174
Q

What is the purpose of the bicarbonate secreted by ductal cells of the pancreas?

A

to neutralize the acid pH of the chyme in the duodenum

175
Q

What 5 precursor enzymes are released from the acinar cells?

A
  1. Trypsinogen
  2. Chymotrypsinogen
  3. Proelastase
  4. Procarboxydase A
  5. Procarboxydase B
176
Q

What acts as an activator for all the pancreatic zymogens? which one is different?

A

tyrpsin for all of them

Enteropeptidase and trypsin will activate trypsinogen

177
Q

What activates enteropeptidase?

A

duodenase

178
Q

what is the effect of glucagon on blood glucose levels? what cell types does it act on?

A

raises blood glucose levels by stimulating the liver to metabolize glycogen into glucose and release it into the blood

stimulates adipose tissue to metabolize triglycerides into glucose and release them into the blood

179
Q

What is the effect of insulin on blood glucose levels? what cell types does it act on?

A

lowers blood glucose by stimulating absorption of glucose by the liver, muscle, and adipose tissues

triggers formation of glycogen in the muscles and liver and triglycerides in adipose to store the absorbed glucose

180
Q

What does somatostatin do?

A

reduces smooth muscle contractions in the tract and gall bladder

181
Q

What is a common cause of acute pancreatitis (inflammation)

A

alcohol abuse

182
Q

What are 3 common diseases of the pancreas (besides inflammation)

A
  1. Cancer
  2. Pancreatic insufficiency
  3. Cystic Fibrosis
183
Q

What happens to patients with pancreatic insufficiency?

A

Lose of about 90% of their ability to secrete digestive enzymes

Patients are unable to digest food –> results in malabsorption of nutrients/malnutrition

184
Q

What happens in terms of pancreatic function in patients with CF?

A

Decreased production of sodium bicarbonate makes secretions dehydrated, thickened, which blocks the ducts

Pancreas continues to make enzymes which accumulate and damage the pancreas and lead to fibrosis

185
Q

At what age does breast feeding history cease to impact gut microbiome profile?

A

18-36 months

186
Q

What are some innate barrier properties of the immune system that contribute to protection of the digestive system?

A
  1. Low pH in the stomach
  2. Alkaline mucous of Brunner’s glands
  3. Lubricating & protective mucous of goblet cells
  4. Tight junctions between enterocytes
  5. Steady epithelial replacement and capacity for regeneration
  6. Diarrhea, peristalsis
  7. Commensal microbiota
187
Q

What are 2 secretions of paneth cells that contribute to innate immunity in the digestive system?

A

lysozyme and secretory phospholipase A2

188
Q

What are α and β defensins?

A

ancient, evolutionarily conserved class of antimicrobial peptides made by many eukaryotes, including mammals, insects, and plants

189
Q

What are histadins? what secretes them? where are they made?

A

epithelial cells of the digestive system

made in the salivary glands

Have antifungal properties

190
Q

What are some receptors the innate immune system uses to detect pathogens?

A

MAMPS which include TLRs, and formyl-peptide receptors (FPR)

191
Q

What are some humoral components of innate immunity ?

A

Immunoglobulin and complement

192
Q

What are some cellular components of innate immunity in the digestive system?

A

epithelial cells, granulocytes (macrophages, eosinophils, meutrophils, basophils, mast cells and DCs)

193
Q

What is GALT and what can it be subdivided into?

A

Gut associated lymphoid tissue for T and B cells

  1. IEL populations
  2. Highly organized lymphoid aggregates
194
Q

What are 5 “highly organized lymphoid aggregates” of GALT

A
  1. Pharyngeal tonsils
  2. Peyer’s patches
  3. Mesenteric Lymph nodes
  4. Cryptopatches
  5. Isolated lymphoid follicles
195
Q

What are peyer’s patches? Where are they?

A

The mucosal inductive site where cells become stimulated

located throughout the jejunum, ileum, with few in the colon

196
Q

What is FAE in the Peyer’s patches? What kind of cells does it contain?

A

FAE = follicle-associated epithelium

contains M (mother or membranous) cells

197
Q

What are M cells? What do they do?

A

Cytoplasmic extensions that surround T and B cells in an apparent “pocket”

Transport and present luminal antigens

198
Q

What are M cells the route of entry for?

A

Lymphocyte entry into the lumen and also for some infectious agents to gain entry

199
Q

What do T and B cells exposed to antigen in the intestines do?

A

they will leave, circulate, and then home back to the intestine due to expression of certain adhesion molecules and chemotactic molecules

200
Q

What is the distribution of T and B cells within the epithelium/lamina propria?

A

Lamina propria: mostly CD4 T cells and scattered B cells secreting IgA

Epithelia: Mainly CD8 cells (many gamma δ)

201
Q

What are intraepithelial lymphocytes thought to do? What properties do they have?

A

Function is not entirely clear..

Thought to play a role in detecting pathogens or reacting to infected/damaged epithelial cells

Have cytotoxic properties that allow them to kill abnormal cells

202
Q

What is the most abundant immunoglobulin in the mucosa?

A

IgA

203
Q

What receptors do epithelial cells have for IgA?

A

polymeric IgA receptors

204
Q

What are Innate Lymphoid cells and how many groups are there?

A

Cells seemingly highly excited by commensal microbes and involved in modulating the tone of gut inflammation

There are 3 groups

205
Q

What plays a large role in the tolerance of the digestive system to the wide variety of foreign molecules it is exposed to?

A

the stimulation of regulatory T cells

206
Q

What is the state of tolerance of the gut called?

A

oral tolerance

207
Q

What can induce oral tolerance?

A

can be purposely induced to a foreign molecule with a suitable exposure to the molecule, typically ingesting very high or very low amounts.

208
Q

What is one example of loss of regulation of tolerance resulting in disease?

A

Loss of IL-10 resulting in colitis

Human Organs and Tissues (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions