Lecture 13- Digestive Tract Flashcards Preview

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Flashcards in Lecture 13- Digestive Tract Deck (75)
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1
Q
What makes up the Gastrointestinal system?
A
- digestive tract
- associated glands
2
Q
What makes up the digestive tract? (7)
A
1) oral cavity
2) esophagus
3) stomach
4) small intestine
5) large intestine
6) rectum
7) anus
3
Q
What makes up the associated glands? (3)
A
- salivary glands
- liver
- pancreas
4
Q
What is the general layout of the layers in the GI tract?
A
- lumen
- mucosa
- submucosa
- muscularis
- serosa or adventitia
5
Q
What makes up the mucosa in the GI tract?
A
- epithelial layer
- CT lamina propria
- muscularis mucosa
6
Q
What makes up the submucosa?
A
Connective tissue
7
Q
What makes up the muscularis?
A
Smooth muscle, exception is skeletal muscle in esophagus
8
Q
What makes up the serous or adventitia?
A
- Ct
- Epithelial layer (only in serous layers)
9
Q
What type of tissue is on the hard palate and gingiva made for abrasion and chewing food?
A
Stratified squamous epithelium, keratinized
10
Q
What type of epithelial layer is found in the cheek, floor of mouth, lips, and soft palate?
A
Stratified squamous epithelium, non-keratinized
11
Q
What underlies the epithelial layer in the hard palate and gingiva?
A
Lamina propria goes into the periosteum of bone
12
Q
What underlies the lips, cheek, soft palate, and floor of mouth?
A
Lamina propria, submucosa, striated or skeletal muscle
13
Q
What contributes to linea alba or thickening of the buccal mucosa?
A
keratinization of the epithelium- abrasion can cause keratinization
14
Q
What types of papillae make up the anterior or dorsal surface of the tongue?
A
Filiform and fungiform
15
Q
What are filiform papillae?
A
- most abundant
- rough, keratinized surface to help with food movement
- like "file"
16
Q
Where are taste buds found?
A
Everywhere but filiform. Fungiform, vallate, foliate
17
Q
Where are the vallate papillae found?
A
The V of the terminal sulcus
18
Q
What is the purpose of the serous fluid that is excreted by the papillae?
A
Helps wash away substances that cause taste so the next taste can be recognized.
19
Q
What is the purpose of the gustatory cell?
A
- contains taste receptors that are lined with microvilli to increase surface area
- transduction pathways send impulses to afferent sensory neuron
- Stem cells regenerate gustatory cells and support cells
20
Q
Where are taste buds found?
A
Inside the papillae
21
Q
What connects the nasal cavity to the larynx and the oral cavity to the esophagus?
A
The pharynx
22
Q
What type of epithelial tissue lines the nasopharynx?
A
Ciliated pseudostratified columnar
23
Q
What type of epithelial tissue lines the hypopharynx?
A
Stratified squamous, non-keratinized
24
Q
A disease in which layer of tissue would lead to the loss of peristalsis?
A
Muscularis
25
Q
What type of tissue makes up the mucosa of the esophagus?
A
Stratified squamous epithelium, non- keratinized
26
Q
What makes up the submucosa of the esophagus?
A
- Lamina propria (loose CT)
- Muscularis mucosa- smooth and skeletal
- Mucous glands
27
Q
How is the muscle tissue in the esophagus divided?
A
1/3s
- Top 1/3- striated muscle
- middle 1/3 mixed striated/smooth
- bottom 1/3 smooth muscle
28
Q
What are some of the functions of the stomach? (6)
A
1) accepts food from the esophagus
2 ) mixes food
3) makes gastric acid
4) starts protein, lipid digestion
5) absorbs very few substances from food
6) moves food (chime) into the intestine
29
Q
What are the four layers of the stomach?
A
1) mucosa- simple columnar epithelial
2) submucosa- CT
3) muscularis- 3 layers in different directions
4) serosa with an outer mesothelium layer
30
Q
How can you tell if a stomach is full or empty?
A
Evidence of folds or rugae.
31
Q
What type of cells are the surface mucous cells?
A
Simple columnar epithelial cells
32
Q
Why don't gastric contents normally injure the stomach mucosa?
A
Stomach mucosa is covered with mucus and bicarbonate that will neutralize acid
33
Q
What happens at the apical cup of mucinogen granules?
A
Mucus and bicarbonate are secreted
34
Q
What is the pH at the surface of mucosa and inside the stomach?
A
- Mucosa pH=7
- Stomach pH= 1
35
Q
What affect can aspirin have on the stomach?
A
It can deteriorate the surface mucosa leading to stomach ulcers.
36
Q
What are the for anatomical regions of the stomach?
A
1) cardia
2) fundus
3) body
4) pylorus
37
Q
What are the three histological regions of the stomach?
A
1) cardiac
2) fundus/body
3) pyloric
* differences in mucosa
38
Q
Describe the cardiac region of the stomach
A
- simple columnar epithelium
- cardiac glands present that secrete mucus
39
Q
What types of glands are present in the fundus/body?
A
Gastric glands
40
Q
What are the three parts of gastric glands and how does their size compare to cardiac glands?
A
- isthmus
- neck
- base
-much larger than cardiac glands
41
Q
What do surface mucus cells in gastric pit secrete?
A
Alkaline mucous and bicarbonate
42
Q
What do mucous neck cells secrete?
A
more neutral mucous
43
Q
What do parietal cells in the isthmus/neck secrete?
A
HCl and intrinsic factor
44
Q
What do chief cells in the base secrete?
A
Pepsinogen and gastric lipase
45
Q
How do parietal cells secrete acid?
A
They use a Hydrogen-Potassium ATPase pump
46
Q
What organelles have proton pumps in parietal cells?
A
-Tubulovesicles
- Canaliculi with microvilli
47
Q
What is the role of mitochondria in the parietal cells?
A
- Lots of ATP is needed to run the proton pump
48
Q
What happens when food is digested?
A
Tubulovesicles with the proton pump fuse with the canaliculi membrane
49
Q
Why is there acid in the stomach? (3)
A
- helps kill bacteria
- acid and intrinsic factor important for Vitamin B12 absorption
- acid converts pepsinogen to pepsin
50
Q
Where are the pyloric glands found?
A
The pylorous
51
Q
What types of cells are found in the plylorous?
A
- surface mucous cells
- mucous neck cells
- G cells
- Enteroendocrine cells
52
Q
What are the distinct features of pyloric glands?
A
- deeper pits
- shorter coiled pyloric glands
53
Q
What stimulates the release of gastrin?
A
Stomach distention
54
Q
What do enterochromaffin-like cells do?
A
Release histamine that releases acid
55
Q
What cells bind to enterochromaffin-like cells?
A
Gastrin and ACh from parasympathetic response
56
Q
Blocking the secretions of what kinds of cells would potentially treat gastroesophageal reflux disease?
A
- G cells (gastrin)
- Parietal cells (acid)
- enterochromaffin-like cells (histamine)
57
Q
What makes up the pyloric sphincter?
A
- Smooth muscles thickening the middle layers of the stomach muscularis
58
Q
Do the circular folds of the small intestine change shape during digestion?
A
No
59
Q
What is the main role of the small intestine?
A
Absorb nutrients and minerals from food
60
Q
What types of cells are found inside the lamina propria of the small intestine?
A
Lymphocytes
61
Q
Where do new intestinal cells come from?
A
stem cells
62
Q
What types of cells to stem cells from the intestinal crypt differentiate into?
A
- Enteroendochrine cells
- enterocytes
- paneth cells
63
Q
What is the function of paneth cells and where are they found?
A
- secrete antimicrobial peptide to protect against bacteria
- found at the bottom of the intestinal crypt
64
Q
What does not increase the surface area for absorption in the small intestine?
A
- intestinal crypts ( crypts of Lieberkuhn)
65
Q
Intestinal inflammation associated with inflammatory bowel disease would be associated with dysfunction in which type of cell?
A
Paneth Cells
66
Q
Where can peptic ulcers occur?
A
Stomach and duodenum
67
Q
How is the duodenum protected from gastric acid?
A
Brunner's or duodenal glands in produce alkaline mucus
68
Q
What helps with absorption of nutrients?
A
The rhythmic movement of villi mixes and facilitates absorption
69
Q
What helps with the absorption of amino acids and monosaccharides?
A
- venules, capillaries, and arterioles
70
Q
Where are the fatty acids and monoglyerides absorbed?
A
The lymphatic cappilaries of the lacteal
71
Q
What controls the activity of the gut?
A
Enteric nervous system
72
Q
What two plexus make up the enteric nervous system?
A
- submucosal (Meissner plexus)
- myenteric (Auerbach plexus) between smooth muscle layers
73
Q
What is the funtion of the large intestine? (3)
A
- absorption of water and electrolytes
- microbial fermentation
- storage of fecal materia
74
Q
What is unique about the muscularis externa layer of the large intestine?
A
- circular layer of muscularis externa
- 3 thin bands of longitudinal muscle making up the Tenia coli from cecum to rectum
75
Q
What is the main function of colonocytes?
A
Absorb water