Microanatomy
Terms
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- What are the different parts of a nucleus?
- Pars Granulosa, Pars fibrosa, Nucleolonema, NOR(nuclear orgabizing region)
- Polysomes, free vs fixed and what type of proteins they secrete
-
Fixed - secretory prot, lysosomal and mem prot,
Free - remaining prot that are to be retained in the cell - Smooth ER, what are the three types of cells you will see this in abundance?
- Smooth - steroid synthesis, drug/toxin metab, calcium sequestration
-
Smooth ER:
Steroid Synthesizers
Drug metab
Calcium seq. -
Steroid - also have abundant mito w/ tubular cristae and numerous lipid droplets
Drug - longterm use of drugs induces increase in sER
Calcium - Sarcoplasmic reticulum pumps Ca from cytosol into it's lumen -
Mitochondria:
Stain eosin/acidophilic?
Basal Striations
(vs Canaliculi)
Ex of mitochondria rich cells -
Stain - acidophilic
Striations - mito's line up in folds of basal membrane
(canaliculi - invaginations fo the apical side)
ex) cardiac, ion pumping cells (parietal HCL cells, and duct cells of salivary glands) -
Lysosomes:
how do you best ID them
ex) -
ID - enz histochemistry : Acid Phosphatase
Ex) neutrophils and marcophages -
Golgi
if abundant, indicates produxn of?
ex of cells with abundance -
prod - lysosomes or secretory prot
Ex) pancreatic acinar and plasma -
Name the characteristics of an ion pumping cell
ex) -
Many mito, increased surface area of mem
ex) proximal tubule of kidneys, striated ducts of calivary glands, parietal cells - Characteristics of protein secreters
-
rER, well-developed golgi
regulated or constitutive - Characteristics of phagocytic cells
-
Lysosomes, well-developed golgi
note: look for autophagic lysosomes too(organelles inside a bag) -
Epithelium and Glands:
What are the four types of Tissues?
What is metaplasia
dysplasia? -
1)epithelium
2)CT
3)Muscle
4)nerve
metaplasia - the conversion of one type of tissue to another that is not typical (ie ciliated columnar in lungs of smoker b/cm squamous
Dysplasia - conversion to an abnormal type of tissue - What are the different parts of the basal mem?
-
Basal lamina: Lucida - lamanin
Densa - fibronectin, proteoglycans, and type IV collagen
Reticularis - types I and III collagen from CT pass into this layer where they are bound by fibrillin, fibronectin and type 7 collagen -
EP and G
Describe the parts of cilia
Stereocilia -
Cilia - MTs of 9+2 in the Axoneme(core), attached to basal bodies,
Stereo - long microvilli (actin) found in male repro tract and ear -
EP and G
Describe the Basal Plasma Membrane - Basal mem - bound to basemend membrane by hemidesmosomes (half a desmosome but composed of diff proteins), Can have many infoldings
-
Junctional complex
are found where?
how do we see them?
Consist of what components and in what order? -
Found - only in epithelia and at the apical end of the lateral plasma mem
See them as a terminal bar
From apical down:
Zonula occludens (tight) - encircles cell, freeze fracture shows intramembranous particles(lots or rows = very tight)separates apical and basolateral mem's as different
Zonula adherens - bundle of actin filaments on the inside of the cell completley encircle cell. The terminal web is anchored to this actin. The membranes are sep'd by space
Desmosomes - are not limited to junctional complex's or epithelial cells. Anchor cytokeratin interm. filaments to plasma mem, Dense adhesion plaques on inside surf and central density in the intracellular space -
EP and G
Gap junctions Are made of what?
Define an exocrine vs endocrine gland -
Made of - connexons
Exocrine - prod dir on free surface of into ducts, has serous demilunes and myoepithelial cells, Endocrine release product into CT and therefore into caps ( they have no ducts!), can be independent organs, H production, less obviously polarized than exocrine, form cords/clumps or follicles(hollow spheres into which precursor H is stored) -
Ep and G
What does a serous cell look like? A mucous? -
Serous - round to oval nucleus apical region is not as pale as mucous
mucous - flattene nucleus b/c so many granules, very pale apical cytoplasm -
Ep and G
Decribe apocrine vs merocrine secretion -
Aprocrine - secreroty prod plus part of cell
Merocrine - only secretory product. -
EP and G
Simple
compound
branched
acinar
tubular gland -
Simple - non-branching duct
Compound - branching duct
Branched - branched secretory unit
Acinar - spherical secretory unit
Tubular - tubular secretory unit( tend to be mucous) -
EP and G -
What are lobes vs lobules
What are intercalated ducts vs striated ducts? -
Lobes - largest subdivision of a gland
Lobules - sep'd by CT called the septa in the lobes
Intercalated - smallest intralobular ducts, simple cuboidal
Striated - modify ionic composition of secretion, simple cuboidal, cells have infoldings of the basal mem with mito in them to cause eosinophilic streaks -
EP and G
What are the three major parts of the salivary glands and describe them ie serous or mucous, where located, acini/demilunes -
Parotid - serous, anterior to ears and cheeks, syn amylase and lysozmes, transport IgA to lumen of gland via TRANSCYTOSIS
Sublingual - serous/mucous, floor of oral cavity, demilunes
Submandibular - serous/mucous, beneath chin, acini and occasional demilune -
CT
Describe mesenchyme
Cell shape, any fibers,
derived from? - Mesenchyme - pluripotential precursor to CT derived mainly from mesoderm, stellate cells with reticular fiber and ground substance
-
CT
Collagen
MAde of? -
Made of
alpha chains(glycine every third aa)
Tropocollagen - three alpha chains
Fibrils - tropocollegen aggregation with periodic banding pattern
Fibers - fibril aggregates -
CT
Types of collagen - where located, produced by, thick or thin
I
II
III
IV -
I - most common prod by fibroblasts, acidophilic, striated fibrils combine into fibers
II - hyaline and elastic cartilage and eye, prod by chondrocytes, thin fibrils rather then fibers,
III - reticular fibers, prod by fibroblasts in loose CT, thin fibers form a delicate network, glycosylated so PAS positive/abs metallic silver,
IV - basal lamina (densa layer), form a mat of procollagen because propeptides are not removed
VII - lamina reticularis(connection b/w basal lamina and CT), forms anchoring fibrils -
CT
Elastic fibers
made of?
need special stains. ex?
location? 3 -
can stretch to 150% resting length
made of - core elastin with fibrillin glycoproteins on outside
stains - Aldehyde fuschin
Location - Loose CT long and slender
elastic ligaments 0 thick
Tunica media - arteries fenestrated sheets -
CT
What do proteoglycans do?(found in ground substance, not GAG) - filter macromolecules, negative charge attracts water, bind collagen crosslinking the ECM, bind signal molecules, can help anchor cell to ECM, attachment to hyaluronic acid makes a large complex called proteoglycan aggregate
-
CT
what do glycoproteins do in the ground substance?
ex's -
AKA adhesive glycoproteins, bind cell membrane and/or ECM. bind integrins (transmem prot linked to cytoskeleton) collagen and proteoglycans
ex) fibronectin lamanin chondronectin/osteonectin -
CT
Fibroblasts,
Fixed or transient
active vs inactive -
Fixed, active - spindle shaped, RER and golgi
inactive -less basophilic b/c less rER -
CT
Myofibroblasts - RER Golgi, and lack basal lamina like fibroblasts, but with actin filaments like smooth muscle, prominent in wound healing
-
CT
MAcrophages
description
functions -
-kupffer in liver, osteoclasts in bone, langerhans in epidermis
-irregular shape w/crap around edges
-phagocytosis (old RBC)
Ag presentation
cytokine production
development of RBCs in marrow
Enz production
can fuse to form foreign body giant cells -
CT
Mast Cells
describe, what do they do in the body -
Fixed
visible granules, metachromasia, resemble basophils
first Ag exposure sees IgE bound to receptors, second exposure leads to release of granules syn of leukotrienes : reult hay fever asthma and anaphylaxis -
CT
Plasma cells
Leukocytes -
Transient, derived from B lymphocytes, manufacture Ab
Leukocytes - diapedesis, include neutro, eosino, basophils, monocytes, lymphocytes -
CT
Loose connective tissue, what are three types? - Lamina Propis, Adipose and Reticular tissue (III collagen) are all Loose,
-
CT
Describe inflammation - respons of ct to damage or invasion, histamine release, neutrophils followed by monocytes
-
CT
Describe scurvy
ehlers danos
marfans -
scurvy - proline to hydroxproline(aa in collagen) needs vit C
Ehlers danos - heritable CT disorders, one form from lysyl hydroxylase causing abnormal tropocollagen crosslinks, skin exstensibility, fragility
MArfans - defect in fibrillin gene, abnormal elastiv fibers -
Integument
Morphology and function of
Keratinocytes
Melanocytes
Lagerhans
Merkel cell -
Keratin - structure protection, primary cell type
MElano - UV
LAngerhans - Ag presenting
Merkle -sensory receptor -
Integ
Name the layers of the epidermis starting with the closest to the dermis -
Basale ( keratinocyte stem cells divide bout every 19 days)
Spinosum,
granulosum,
lucidum,
corneum - Integ, classify thick vs thin skin
-
Thick - has all five layers, its the thickness of the corneum that usually differentiates, glabrous (hairless) skin, palms and soles of feet
Think - hair, no lucidum, -
Integ
Two layers of the dermis (lies on the hypodermis, not part of skin) -
Papillary - loose CT
Reticular layer - dense irregular -
Integ
Keratinization - makes "soft ketain"
3 major steps -
1) formation of tonofibrils, found in basale and spinosum (bundles of interm tonofilaments ade of keratins)
2) Formation of Keratohyalin Granules - prod in granulosum, not mem surrounded, basophilic proteins secreted from free polysomes that assoc with keratin
3) assoc of keratinhyalin granule proteins with tonofibrils, in lucidum -
Integ
What are MCG's? membrane coating granules? - membrane-bound organelles prod in spinosum. In stratum granulosum MCG's fuse with plasma mem and release lipid-like material into intercellular space. This acts as barrier for water ans foreign substance
-
Integ
Melanocytes
Location
Derived from
How to demonstrate through histochemistry
What are melanosomes/what do they do -
- basale
- neural crest (not ecto)
- histochem - contain tyrosinase
- Melanosomes - organelles hat migrate to ends of cytoplasmic processes, pinch off and are phago's by neighbor keratinocytes (which appear darker cause they eat up more than the melanocytes prod at any one time)
Ratio of melanocytes is constant ina given area but varies from region to region -
Integ
Langerhans
location
origin
function
Birbeck granules -
location - spinosum
origin - bone marrow
Function - Ag presenting to T cells
Birbeck - pingpong paddle shape, unique
Pale staining - elongated cell process -
Integ
Merkel Cell
Location
Origin
Merkel Disc
Function -
Loc - thick skin
Ori - epithelial
Disc - merkel cells lie in contact with expanded nerve ending called merkel disk
Function - touch receptor (finger) -
Integ -
Dermis
Connected to epidermis by?
Sensory nerves/receptors, two-ish types
NOTE: sebaceous glands dep on H stim not nerve stim for secretion
NO parasymp nerve in integ -
connection through - a basment mem of basal lamina and lamina reticularis and hemidesmosomes
NErves - sensory nerves (GSA) to hair follicles adn skin, postganglionic sympathetic(GVE) supplying bld vessels, arrector pili, eccrine and apocrine sweat glands -
Integ
Describe Meissners Corpuscles
Describe pacinian corpuscle -
Mei - in papillary layer of hairless skin, respond to low freq touch
Pac - located in deep dermis or hypodermis, respond to pressure or vib. -
Integ
What are the major cell types in inflamm respons?
in immune respons? -
inflamm - neutro, macro
Immune - lymphocytes -
Integ
Hypodermis - aka superficial fascia, loose CT and adipose binds loose to organs allowing skin to slide over, - A