Histology Review Flashcards
How does collagen stain?
pink / eosinophilic
Irregular vs. regular connective tissue
Regular is much more uniformly arranged (you can easily tell difference)
Serous vs. mucinous acini
Serous stain much darker and more eosinophilic
Mucinous are light as their myoepithelial layer is smushed
What do all acini contain?
2 layers (luminal + myoepithelial)
can be harder to see layers with mucinous
Exocrine vs. endocrine glands
exocrine glands secrete into duct
endocrine glands secrete directly into blood vessels
Where are venous sinuses found? What are they?
in the red pulp of the spleen
barrel-shaped, dilated vascular spaces whose endothelial cells are separated by slits that filter RBCs
What is the pathway of blood flow through the spleen?
Splenic artery
Central artery
White pulp
Red pulp
Venous sinuses
Splenic vein
White pulp of spleen
looks like a germinal center
Red pulp of spleen
surrounds the germinal centers
What are branches of central artery that runs through spleen?
trabeculae
What is the muscularis externa in the gut?
smooth muscle
(not skeletal muscle)
Where are blood vessels found in the digestive tract?
in the submucosa
Where is adventita found? Specific structure
duodenum
*other portions of gut normally have serosa
Transitional epithelia
found in bladder
looks like stratified
umbrella cells at top can help you differentiate
What type of cells line blood vessels?
simple squamous
What type of cells line ducts?
simple cuboidal cells
Features of DCIS
luminal necrosis with no invasion through basement membrane
How can you tell the conducting passageway vs. respiratory passageway ?
conducting pathways are thicker (pseudostratified)
respiratory pathways are more single file
List the junctions as you move down cell
tight junction
adherens junction
desmosome
How can you tell a desmosome
normally at bottom of junction
thicker and has spider like projections
Intralobular stroma
surrounds the acini
Interlobular stroma
makes up most of breast
Where is adipose, lympathics and vessels of breast found?
in the interlobular stroma
Brunner’s glands (location + function)
only found in duodenum
gland in submucosa
secrete alkaline bicarb to neutralize stomach acid
Peyer’s patches
large, submucosal lymph nodes found in the ileum of small intestine
very hard to see
secrete lymphocytes
closely associated with M cells on epithelium
What are distinguishing features of the small intestine?
villi
finger-like projections
LARGE
What cell type makes up the villi?
simple columnar with microvilli brush border
lamina propria is inside the villi
Where are most (not all) Goblet cells found?
in the large intestine
How can you distinguish small from large intestine?
small intestine has large projections
large intestine may have some crypts, but not fingers (also has more goblet cells)
metaplasia
change in differentiate cell type
Where is metaplasia often seen?
in Barret’s esophagous
when simple columnar cells replace the normal simple stratified
Mast cells (location, function + appearance)
found in loose connective tissues
secrete histamines
very stipled with very basophilic nucleus
What makes up the submucosa ?
loose connective tissue
What are 2 routes for lymphocytes to access lymph nodes?
Afferent lymphatic vessels (within lymph)
HEVs (from the blood)
Where are HEVs found?
lymph nodes of tonsils
Macrophages in the lungs
referred to as dust cells
are often in the air space
Elastic fibers
important in the respiratory tract
provide recoil after each expansion of the alveoli from inhaled air to allow PASSIVE exhalation
What type of cells make up respiratory portion of lung?
pneumocytes (type I and type II)
pneumocyte type II
only one you can see on stain
secretes surfactant
Breakdown of pancreatic cell function
90% of function is exocrine (secretes alkaline bicarbonate sodium into duodenum)
other function is endocrine (insulin + glucagon)
What distinguishes the pancreas from the parotid gland?
Pancreas has islets of Langhorn
What do lymphocytes look like on stain?
small, basically a black dot
Distinguishing feature of macrophages on stain
large
kidney shaped nucleus
Distinguishing feature of neutrophils on stain
multi-lobed nuclei with pale pink cytoplasm
Distinguishing feature of eosinophils in cytoplasm
stain pink
bilobed nucleus
Distinguishing features of basophils
not often that you see them on smears
when you do, it looks like many blue stipples
What type of tissue / collagen is common in dermis of skin?
dense irregular connective tissue
type I collagen
What stains better brown or white adipose?
brown due to the eosinophilic mitochondria
Where do macrophages migrate to?
connective tissue
pleomorphic nuclei
sign of cancer
different size nuclei
Where is type 1 collagen?
strong places
tendons, bones and dermis of skin
Where is type II collagen?
cartilage
Where is type III collagen?
lymphoid organsq
Where is type IV collagen?
basement membrane
*can form sheets
Where is colloid stored?
in the follicle of thyroid
What does a healthy thyroid gland tissue look like?
good spacing of vessels
roughly equal sized follicles
Nodular goiter features
extreme variation in follicle size
band of connective tissue is too dense
hemorrhage of RBCs
Grave’s disease features
scalloped follicles with white border
hyperplasia also seen (do not focus on)
Hashimoto’s disease features
high density of cells with geminal center (lymphoid tissue)
Hurthle cells
Hurthle cell
seen in Hashimotos
dark cell
Thyroid papillary carcinoma features
can see trails (papillary like extensions of cancer)
orphan annie cells (bright nucleus)
can also see calcification (dark cells)
Parathyroid gland cell types (2)
chief cells and oxyphil cells
Chief cells
make parathyroid hormone and regulate Ca2+
Chief cells vs. oxyphil cells on stain
oxyphil are more eosinophilic
chief cells are more dense and whiter
oncocytic change
oxyphils can overtake the chief cells
