Histology Flashcards
what do hematoxylin and eosin stain, respectively
hematoxylin (blue, basic) - nuclei acids in nuclei and ribosomes
eosin (pink, acidic) - cytoplasm, collagen, RBC
can you see plasma membrane with LM?
no
appears trilaminar in EM
how do ribosomes stain with H&E in LM
blue-purple
how does SER stain in LM
eosinophilic (pink)
can you see golgi with LM
no - need special prep
looks like stack of pancake membranes in EM
can you see secretory vesicles in LM
yes - dark pink granules
in EM look like dark membrane-bound vesicles of different sizes
can you see mitochondria with LM
no
CAN be seen with EM
can you see cytoskeleton with LM
no
can be seen with EM
microtubules largest, intermediate filaments, microfilaments (actin) smallest
how do microfilaments, microtubules, and intermediate filaments appear in EM
microfilaments (actin) - lines or dots - microvilli, stereocilia, cytokinesis
microtubules - tubes or open circles (depending on direction of cut) - cilia, flagella, centrioles, mitotic spindles, transport
intermediate filaments - lines
how does glycogen appear in LM
magenta/red (stained with PAS)
how do melanin, lipofuscin (aging pigment) and hemosiderin (RBC breakdown) appear in LM
shades of brown
can routine H&E depict glycogen or lipid
no - needs special prep
cells with lots of mitochondria stain more ___
eosinophilic (but can’t make out mitochondria on LM, need EM)
which germ layer does epithelia originate from
all 3
paracrine vs endocrine secretion
paracrine - neighboring cell
endocrine - through bloodstream to farther away
serous vs mucous secretion
serous: zymogen granules with enzymes, proteins, sweat, water
mucous: glycoproteins, lubrication, barrier
*note that some glands are mixed, and contain serous demilunes
what kind of gland secretion contains sweat
serous secretion
what kind of gland secretion is for lubrication and protection
mucous secretion
merocrine vs apocrine vs holocrine uses
merocrine: exocitosis (parotid, pancreas, eccrine sweat glands)
apocrine: axilla, lactating mammary
holocrine: oily sebum from sebaceous glands
what method of secretion is used to release oily sebum from sebaceous glands of skin
holocrine
what is most common form of gland secretion for exocytosis by parotid, pancreas, and eccrine sweat glands?
merocrine
what method of secretion is used by axilla and lactating mammary
apocrine
which stains darker with H&E, exocrine or endocrine tissue?
exocrine stains darker (dark pink)
endocrine is light pink
parenchyma
glandular epithelial cells of gland (connective tissue makes up stroma)
terminal bar seen in ___ = junctional complex seen in ____
LM - terminal bar
EM - junctional complex
(zonula occludins/ tight junctions, zonula adherens/ belt desmosomes, macula adherens/ spot desmosomes)
how are nutrients supplied to epithelia
diffusion - epithelia is AVASCULAR
carcinomas
malignant tumors of epithelia
functions of simple squamous epithelium (5)
diffusion, filtration, fluid transport, gas exchange, lubrication
what kind of tissue lines vessels (specifically)
simple squamous - referred to as endothelium in vessels
endothelial cel dysfunction plays a key role in atherosclerosis
what kind of tissue makes up mesothelium (serosa - pleura, pericardium, peritoneum)
simple squamous epithelium
mesothelium - lines organ cavities
serous fluid reduces friction
what type of tissue (specifically) makes up Bowman’s capsule and loop of Henle
simple squamous epithelium
what kind of tissue (specifically) makes up lung alveoli
simple squamous epithelium - for easy gas exchange
this type of tissue is found in small glandular ducts, kidney tubules, and follicular cells of thyroid
simple cuboidal epithelium - for secretion and absorption
hyperthyroidism exhibits tall follicular cells, hypothyroidism exhibits flat follicular cells
this type of tissue is found in large ducts of some glands, most of digestive tract, gallbladder, nasal sinuses and small bronchi, oviducts and uterus, and ductuli efferents of testis. what is?
simple columnar epithelium - function in absorption, secretion, protection, transportation
many have apical cell surface modifications (cilia, microvilli, stereocilia)
how do microvilli, stereocilia, cilia, and flagella appear in imaging
actin core:
microvilli - finger-like projections (brush-border)
stereocilia - long, immobile microvilli (whispy)
microtubule core:
cilia - hair-like exentsions (short hair)
flagella - single, long cilia
where are keratinized and nonkeratinzied stratified squamous epithelium found, respectively
keratinized - skin
nonkeratinized - mouth, epiglottis, vocal cords, esophagus, anal canal, vagina
*protection and prevents dehydration
where can you find stratified cuboidal epithelium
ducts of eccrine sweat glands and mammary glands
where can you find stratified columnar epithelium
large excretory ducts, parts of male urethra, pharynx, salivary glands, mammary glands (NOT ducts), conjunctiva of eye
*apical layer with differentiated cells, mitotic basal layer with nondifferentiated cells
the nasal cavity, trachea, primary bronchi,
auditory tube,
epididymus, ductus/vas deferens, and male urethra
are made of what type of tissue
psuedostratified columnar epithelium
*absorption, secretion, transportation via cilia, lubrication (via goblet cells), protection
where can transitional epithelium be found
aka uroepithelium - protection and distensibility
lines urinary system - renal calyces, ureters, bladder, urethra
*can be binucleated
on what cells will you find stereocilia?
psuedostratified columnar epithelium ONLY
what kind of cells will have basophilic cytoplasm?
cells actively synthesizing proteins for export (large amounts of RNA in their cytoplasm)
what is the diameter of an erythrocyte
7.7um
what kind of cells have multiple and larger nucleoli?
cells that are actively growing and dividing
nucleoli are involved in activation of oncogenes and tumor suppressors
cilia is made of a core of microtubules in what arrangement?
9 + 2 rule
9 doublets and 1 center doublet
(remember that centrioles are 9 triplets)
Type XVII collagen, laminin 5, and fibronectin can be found in what layer of the basal lamina?
lamina lucida
type IV collagen, laminin 1, and perclecan can be found in what layer of the basal lamina?
lamina densa
type I, III, and VII collagen, proteoglycans, and fibronectin can be found in what layer of the basal lamina?
lamina reticularis
T/F: you will never find cilia or stereocilia at the cell surface of stratified epithelium
TRUE
the core of microvilli is made of
actin
(also the core of stereocilia)
how can you distinguish cartilage and bone?
a. chondrocyte cytoplasmic extensions allow for communication within small channels in the matrix
b. cartilage matrix stains basophilic, bone matrix stains eosinophilic
c. all bone exhibits Haversian systems. Cartilage does not exhibit Haversian systems
b. cartilage stains basophilic, bone stains eosinophilic
cartilage is avascular, bone is vascular
mineralized matrix of bone is layered as lamellae with osteocytes in lacunae that communicate via canaliculi
both compact and spongy bone have lamellae and canaliculi BUT
only compact bone has Haversian systems
what granules do mast cells contain
heparin (anticoagulant), serotonin (vasoconstrictor), histamine (vasodilation and vascular leakage)
what kind of cartilage is found in symphyses, tendons insertion on bones, and articular discs in joints?
fibrocartilage
chondrocytes are arranged in rows with prominent bundles of type I collagen in between rows. NO perichondrium (because it is between hyaline cartilages)
in symphyses (pubic, sternal angle, and intervertebral discs) it is sandwiched between two layers of hyaline cartilage
