Histology Flashcards
1
Q
What are the four major layers of the alimentary canal?
A
mucosa, submucosa, muscularis externa, serosa/adventitia
2
Q
What is the muscularis mucosae made up of? and where is it found?
A
smooth muscle, found in mucosal layer
3
Q
Which layer of mucosa has increased leukocyte count and is made up of loose CT?
A
lamina propria
4
Q
What kind of tissue makes up submucosa? What plexus is there?
A
dense CT, Meissner’s plexus
5
Q
What tissue makes up the muscularis externa? What plexus is there?
A
smooth or skeletal muscle, Auerbach’s (myenteric) plexus
6
Q
Is serosa or adventitia found within the peritoneal cavity?
A
serosa
7
Q
The oral cavity lacks what two layers?
A
muscularis externa and serosa/adventitia
8
Q
Describe the mucosa of the oral cavity?
A
lacks muscularis mucosae, is non-keratinized stratified squamous
9
Q
What does the submucosa in the oral cavity have?
A
minor salivary galnds that are mucous secreting
10
Q
What are the four types of lingual papillae?
A
filiform, fungiform, circumvallate, and foliate
11
Q
Which papillae does not have taste buds?
A
filiform
12
Q
Which taste bud is located at the back of the tongue and are large and circular?
A
circumvallate
13
Q
What kind of ducts empty in the groove around circumvallate papillae?
A
serous lingual salivary glands/ von Ebners glands
14
Q
What papillae has a mushroom shape and are more prominent on the front of the tongue?
A
fungiform
15
Q
Which papillae has parallel low ridges ridges and are on the lateral part of the tongue?
A
foliate
16
Q
What two papillae are associated with von Ebners glands?
A
circumvallate and foliate
17
Q
What is the opening on the apical surface of a taste bud called?
A
taste pore
18
Q
What are the five major functions of saliva?
A
lubrication digest carbs antibacterial IgA calcium and phosphate ion source
19
Q
What are the three major components of extrinsic salivary glands?
A
stroma, secretory part, ductal system
20
Q
Describe the stroma of an extrinsic salivary gland?
A
dense CT, septa dives and divides into lobules, increased number of adipocytes
21
Q
Describe serous acinai
A
protein-secreting, euchromatic nuclei, basophilic (RER), spherical shape
22
Q
Describe mucous acinai
A
mucous-secreting, heterochromatic nuclei, mucous secretory granules staining lightly, columnar/tubular
23
Q
What is a feature of a mixed acini?
A
serous demilunes
24
Q
What are contractile cells in the basal part of acinar cells?
A
myoepithelial cells
25
What are two segments of intralobular ducts?
intercalated ducts and striated ducts
26
What are intercalated ducts?
segment of intralobular ducts that begin directly from secretory acini and drain to striated ducts, low cuboidal epithelium, basal nucleus
27
What are striated ducts?
second segment of intralobular ducts that connect intercalated ducts to interlobular ducts; simple columnar, numerous infoldings and longish mitochondria within, actively resorbing ions
28
Is saliva hypotonic or hypertonic? How does this occur?
hypotonic, striated ducts are actively transporting NaCl from saliva
29
What classification of cells make up interlobular ducts?
stratified columnar
30
What major salivary gland is deemed serous only and is the largest?
parotid
31
What major salivary gland is deemed a mixed gland but mostly mucous?
sublingual gland
32
What major salivary gland is deemed a mixed gland but mostly serous?
submandibular gland
33
What is the most common tumor derived from salivary glands?
pleomorphic adenoma, composed of ductal and myoepithelial cells
34
How is the mucosa in the esophagus classified?
non-keratinized stratified squamous
35
How is the muscularis mucosae different in the esophagus?
it has longitudinally oriented bundles of smooth muscle, not in a sheet
36
What types of glands are in the esophagus? Where are they?
mucosal glands (esophageal cardiac glands) in terminal esophagus and esophageal glands proper throughout
37
How does the muscularis externa change throughout the esophagus?
starts as skeletal muscle, then is mixed, then is smooth muscle closer to the stomach
38
Does the esophagus have serosa or adventitia?
adventitia covers most of the esophagus but the distal portion near the stomach has serosa
39
What cell type covers the gastric mucosa?
surface mucous cell, simple columnar
40
What does the surface mucous cell create?
insoluble mucous from mucinogen granules to protect from chyme
41
What three glands are within the lamina propria of the stomach?
fundic glands, cardiac glands, and pyloric glands
42
What are the five types of cells associated with fundic glands?
```
parietal cells
gastric chief cells
mucous neck cells
enteroendocrine cells
progenitor cells
```
43
What cell is found in the neck and secretes soluble mucous, has heterochromatic basal nucleus?
mucous neck cells
44
What cell secretes pepsinogen?
gastric chief cell
45
What cell produces HCl? What else does this cell secrete?
parietal cell; also secretes intrinsic factor
46
What cells are found in the isthmus and can replace both surface mucous cells and fundic gland cells?
progenitor cells
47
What cells are found in the base of the fundic glands and secrete their contents to the lamina propria?
enteroendocrine cells
48
Actively secreting parietal cells have what?
intracellular canaliculi with increased number of microvilli, making HCl
49
Resting parietal cells store the apical membrane where?
tubulovesicular system
50
A lack or deficiency of parietal cells can lead to what?
pernicious anemia
51
Where are cardiac glands found?
in the narrow ring around the esophageal orifice
52
What do cardiac glands lack, compared to fundic glands?
parietal and chief cells
53
How would you differentiate cardiac glands from pyloric glands?
cardiac glands have much shallower gastric pits than pyloric glands
54
How would you describe the shape of pyloric glands?
branched, coiled, tubular with deep gastric pits
55
Describe gastric muscularis mucosae
continuous sheet of smooth muscle, circular and longitudinal
56
Does the submucosa of the stomach have glands?
no glands
57
What are the layers of muscularis externa in the stomach?
inner oblique, middle circular, outer longitudinal
58
Where is Auerbach's plexus found?
between middle circular and outer longitudinal layers of muscularis externa
59
Describe the serosa of the stomach
mesothelium and thin layer of subserosal connective tissue
60
What are 5 functions of the small intestine?
digest
absorption
synthesis and secretion of digestive enzymes
control microbial growth
regulate system via enteroendocrine cells
61
What are permanent folds in the SI called that have a core of submucosa? Where are they found?
pilicae circulares found mostly in distal duodenum and proximal jejunum
62
What do pilicae circulares in the SI do?
increase surface area for absorption
63
Mucosa in the SI has what structure that is not found anywhere else in the canal?
villi, finger-like evaginations into the lumen
64
What is the core of a villus made of? What is the structures purpose?
loose CT of lamina propria, to increase surface area for absorption
65
What is the clinical concern if villi are destroyed?
gluten enteropathy/ celiac disease
66
What kind of cells make up the surface epithelium in the SI, including vill?
simple columnar
67
What is the predominant cell type in SI? What is its role?
enterocytes/intestinal absorptive cells; absorb nutrients and produce digestive enzymes
68
Where do the final stages of carb digestion occur?
in glycocalyx of enterocytes
69
Lipids diffuse through absorptive cell membranes. resynthesize, and go to SER, then Golgi to become what?
get a protein coat and become chylomicra
70
Why are intraepithelial lymphocytes different from other cells in the SI?
they are blood derived, providing mucosal immunity
71
Where are M cells found
only in epithelium overlying lymphoid follicles (peyers patches)
72
What do M cells do?
antigen-transporting cells - take from lumen to lymphoid follicle
73
What cell is tall and columnar, has numerous microvilli, making a brush border?
enterocytes
74
What cells function is the production of mucous, is unicellular, and interspersed throughout the SI?
goblet cells
75
The apical portion of enterocytes are intestine bound by what?
tight and anchoring junctions, establishing a barrier between intestinal lumen and epithelial intercellular
76
What cell is large and dome shaped, has a pocket with macrophages, dendritic cells, and lymphocytes?
M cells
77
What are the mucosal glands in the SI called and what is their structure?
crypts of liberkuhn, simple tubular, invaginations of surface epithelium, open near base of vili
78
What two additional cells are found in mucosal glands?
paneth and progenitor cells
79
What cells are at the bottom of crypts and regulate bacterial growth?
paneth cells - have numerous large eosinophilic granules in apical protion, granules have antibacterial
80
How are progenitor cells recognized? What cell type can they not replace?
mitotic figures, cant replace intraepithelial lymphocytes
81
What layer of mucosa are lymphoid follicles found in? What is the barrier they form called?
lamina propria, GALT
82
Peyers patches are going to be in what section of SI?
ileum
83
Blood supply of SI is organized into what?
capillary loops
84
Each villus contains a central blind-ended lymphatic capillary called what?
lacteal
85
Where does a lacteal drain/what does it do?
drains into larger lymphatic vessels in submucosa, transports lipids in the form of chylomicra produced by enterocytes
86
Submucosal glands in the duodenum are called what?
Brunners glands
87
describe the glands found in the submucosa of the SI
mucous producing, branched tubular, proximal duodenum, alkaline secretions to neutralize acid containing chyme
88
What parts of SI are covered with serosa? adventitia?
serosa - jejunum and ileum, adventitia covers most of duodenum
89
Where will I find the most number of goblet cells and shorter vili?
ileum
90
What is the function of the LI?
reabsorb electrolytes and water; elimination of undigested food and waste
91
Why is the mucosa different in the LI? What cells are absent?
no villi in LI, Paneth cells are absent
92
What cells predominate here and what cells are more numerous here than SI?
enterocytes predominate, goblet cells are more numerous
93
Does the LI have crypts of Liberkuhn?
yes, with progenitor cells deep within
94
What is the most common and malignant tumor of the LI? What are risk factors for this?
adenocarcinoma
| RF: adenomatous polups or UC
95
In the muscularis externa of LI, the outer longitudinal layer forms 3 thickened bands called what?
teniae coli
96
Serosa of the LI contains small fatty progections visible on the outer intestinal surface called what?
omental or epiploic appendices
97
Where will the best expressed teniae coli be?
colon (transverse?)
98
Vermiform appendix has what within?
aggregated lymphatic follicles
99
the rectum, different from other areas, has what?
prominent transverse rectal folds
100
is the pancreas an exocrine or endocrine gland?
both
101
Describe the stroma of the pancreas.
thin, CT capsules, dives into the organ as septa, creating lobules
102
As an exocrine gland, is the pancreas serous or mucous?
serous, making digestive enzymes/proenzymes
103
Secretory acini of the pancreas are made of what type of cells? Describe them
pancreatic acinar cells, protein-secreting, round, euchromatic nucleus, basal RER, secretory granules, bulls eye appearance, pyramidal
104
Why are intralobular ducts in the pancreas special?
are within lobule and begin from within the acinus
105
What are the ductal cells found within secretory acinus called? What do they look like?
centroacinar cells, continuous with intercalated duct cells, squamous and light stain
106
What is a short portion of intralobular duct with low simple cuboidal cells called?
intercalated ducts
107
What does an intercalted duct in the pancreas do?
adds bicarb and H20 to exocrine secretion, drains to intralobular collecting ducts
108
What kind of cells line interlobular ducts of the pancreas? What do these ducts do?
lined with simple columar, drain directly into main pancreatic duct, hepatopancreatic ampulla of duodenum
109
What stimulates the secretion of enzymes from exocrine pancreas?
secretin, CCK, and hormones
110
Endocrine pancreas is formed by what? What is the primary role?
islets of langerhahns, secrete hormones that regulate blood glucose
111
How is endocrine pancreas arranged?
islets scattered throughout, more in tail; cells follow blood capillaries (clusters of pale surrounded by dark serous acini of exocrine)
112
What cells secrete insulin? What does insulin do?
B cells; decrease blood glucose
113
What cells secrete glucagon? What does glucagon do?
A cells; increase blood glucose, stimulates synthesis of glucose from metabolites and release of glucose into blood
114
What cells secrete somatostatin? What does somatostatin do?
D cells; role unclear, possibly inhibits release of both insulin and glucagon
115
What are the contents and functions of bile in the liver?
water, bile salts to emulsify fats, bilirubin end product of hemoglobin break down, electrolytes establish and maintain bile as isotonic fluid
116
What plasma proteins does the liver synthesize?
albumin, prothrombin, fibrinogen, non-immune alpha and beta globulins
117
What does the liver release lipids as?
VLDL into blood
118
What form of glucose does the liver store and what metabolic process takes place here?
glycogen, glycogenolysis
119
What vitamins and other things are stored or converted in the liver?
storage Vit A
converts Vit D to circulating form
Vit K from SI to liver by chylomicra (partially used and secreted with VLDL)
storage-meteabolism- homeostasis of iron
120
What structures aid in detoxificiation?
SER and peroxisomes
121
What are organized plates of hepatocytes that are 1 cell thick and separated by sinusoidal capillaries?
parenchyma
122
What is the connective tissue covering of the liver called?
Glisson's capsule
123
Lobules are built around what in classic form of the liver?
around vasculature
124
What blood supply has more nutrients than it does oxygen? What forms this vascular structure?
portal vein created by joining of SMV and splenic vein
125
Where does the hepatic artery come from?
celiac trunk
126
Outflow from hepatic lobules eventually drains where?
into hepatic vein and IVC
127
Within the liver, portal vein and hepatic a form what?
conducting branches to interlobular spaces
128
Interlobular branches of portal vein and hepatic artery are located within interlobular spaces and constitute part of what?
portal triad
129
Terminal branches deliver blood to where? What are the next few steps?
to hepatic sinusoids - large discontinuous capillaries - to central vein - to sublobular veins to collecting tributaries of hepatic veins
130
What has thicker CT, central vein or sublobular vein?
sublobular vein (central veins drain into these)
131
What organelles are found in hepatocytes?
binucleated euchromatic nucleus, lots of mito, good RER and Golgi, lots of SER and peroxisomes, large number of glycogen particles, lysozymes
132
What are the blood derived monocytes in the liver called? Where do they reside?
Kupffer cells in hepatic sinusoids
133
Where are the fat-storing cells located? What do they store? What are they derived from?
space of Disse, store Vit A, derived from fibroblasts
134
What goes through the center of the classic hepatic lobule?
central vein
135
Plates of hepatocytes are separated by what?
hepatic sinusoids
136
What is the narrow space between hepatocytes and the basement membrane of sinusoids called?
space of disse
137
What do portal canals do?
bring blood to the lobule and collect bile from the lobule, contain portal triad and loose CT
138
What direction does blood flow in hepatocyte lobules? bile flow?
blood flows from periphery to central vein, bile flows from center lobule to periphery
139
Describe a portal lobule
emphasizes the exocrine function of the liver and production of bile.
centered on portal triad, so the duct is located in the middle of the lobule, more like in most exocrine glands; outer margins are imaginary lines drawn bt the 3 closest central veins
140
What is a liver acinus structure centered around?
centered on terminal branches of portal vein/hepatic artery and on canals of Hering
141
What does liver acinus structure emphasize? How is it organized?
different O2 and nutrient contents of blood present; zones 1-3
142
What zone will die first bc of decreased circulation?
zone 3
143
What zone would be the last to die but the first to regenerate?
zone 1
144
What is the smallest branch of the biliary tree?
bile canaliculus
145
What are the steps for bile exiting?
to bile ductules (low cuboidal), to interlobular bile ducts (within portal triad), to L and R hepatic ducts, to common hepatic duct
146
What layer of mucosa does the GB not have?
muscularis mucosae
147
Muscularis externa of the GB is made of what in order to do what function?
smooth muscle and collagen in order to contract
