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Histo Exam 1
Muscle, Nervous, Cardio, Blood, Connective, Lymphoid, Skin, Resp
384
Histology
Professional
02/06/2014

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Term
tight junction
Definition
zonula occludens
joins epithelial cells, particularly in sheet formation
separates two parts of epithelial cell
pathway inbetween epithelial cells to pass from one compartment to another
Term
belt desmosome
Definition
zonula adherens
runs all the way around the cell just beneath the tight junction
neighboring cells are close, but do not touch
actin microfilaments support from intracell
Term
spot desmosome
Definition
macula adherens, keratin
can exist anywhere along the sides of cells
Term
hemidesmosomes
Definition
holds cells to underlying substrate
Term
gap junction
Definition
nexus, connexons
places where the gap between cells is narrow, fixed and even
pore
no cytoskeleton association
regulated by each cell's internal Ca conc
poore allows small molecules to flow back and forth
Term
microvilli
Definition
brush or striated border
small, highly organized projection on an epithelial cell surface
actin is central structural component
form on apical surface
Term
glycocalyx
Definition
sugars at the surface of the membrane proteins that usually stick out on the membrane in brush borders
faint residual coming off the microvilli
Term
microplicae
Definition
another way to increase surface area of cell
ridges at the surface of a cell
actin is central structural component
form on apical surface
Term
stereocilia
Definition
larger, finger-like projections from a cell surface
actin is central structural component
form on apical surface
located on hair cells in ear
Term
basal foldings
Definition
greatly increase surface area of cell
Term
axoneme
Definition
propulsive structure
motor that allows cilia and flageela to move
Term
motile cilia
Definition
9+2 arrangement
reproductive system
Term
primary cilia
Definition
9+0 arrangement, single cilia sticking up on surface of epithelium
plays role in cell signaling
respiratory system
Term
apical surface
Definition
luminal, mucosal
side the mucus exits on
Term
basolateral surface
Definition
abluminal, serosal
sides or base of cell
Term
absorption (epithelial)
Definition
lumen (apical surface) --> basal surface
Term
secretion (epithelial)
Definition
basal surface --> luminal surface
Term
merocrine
Definition
membrane-bound material that was produced in cell getting released
mucus secretion by epithelial cells, hormones by peptide secreting cells
Term
apocrine
Definition
things are eliminated from cell but part of the cell surface membrane goes with it
i.e. fatty substances
Term
holocrine
Definition
entire cell is degraded to form secretion
Term
constitutive secretion
Definition
typically into blood (sometimes lumen)
cells can do it all the time
ex: albumin in liver cells
continuous
Term
regulated secretion
Definition
more common
contents get stored in epithelial cells and are released upon a stimulus
Term
serous cells
Definition
opposite of mucous cells; secrete watery materal
ex: tongue, releases saliva enzymes
Term
neuroendocrine cells
Definition
form as part of neural crest cells that leave early in embryo and end up in all kinds of organs
release contents on basolateral side
Term
mucous cells
Definition
granule full of mucin, water can't be pumped out
nucleus squished at bottom
Term
goblet cell
Definition
mucous cell that is all by itself
Term
steroid cell
Definition
lots of SER
mitochondria with tubular cristae
contain fat droplets for used in steroid synthesis
products leave cell by diffusion b/c steroids can't be packaged
Term
myoepithelial cells
Definition
contractile cells that are part of the epithelium
Term
lamina articularis
Definition
no longer considered part of basement membrane
made of fibrilar collagens and other proteins
Term
basement membrane
Definition
extracellular structure
located right beneath an epithelial cell, muscle cell and peripheral nerve cell
made of type IV collagen, laminin and heparin sulfate
looks felt-like filter
serves as anchoring substrate, signaling for differentiation, filter for molecules and cells
Term
diapedesis
Definition
process that cells can move through basement membrane
in tumor progression, takes 3 BMs crossed for metastasis
Term
cuboidal epithelium
Definition
about as wide as is tal
round central nucleus
Term
columnar epithelium
Definition
taller than it is wide
elongated nucleus
Term
squamous epithelium
Definition
very flat, almost no visible cytoplasm
squished nucleus
Term
simple epithelium
Definition
single layer
ex: simple squamous lines blood vessels
Term
stratified epithelium
Definition
multiple layers
type is determined by the surface cell type
Term
transitional epithelium
Definition
stretches and changes shape
not really cuboidal, squamous or columnar
ex: in bladder
Term
pseudostratified epithelium
Definition
jumbled looking nuclei
not stack of cells, just nuclei at different levels
Term
skeletal muscle cell (fiber)
Definition
very long, striated, multinucleated with nuclei at periphery
contain contractile strands called myofibrils surrounded by sarcoplasmic reticulum
scaroplasm = cytoplasm
sarcolemma = plasma membrane
all or none contraction
Term
endomysium
Definition
connectiv3e tissue surrounding each skeletal muscle cell
looks thin, wispy and delicate between cells
surrounds and fills space between cells
Term
fascicle
Definition
several skeletal muscle cells bundled together surrounded by perimysium
Term
perimysium
Definition
connective tissue layer surround skeletal muscle fascicles
desnser than endomysium
Term
epimysium
Definition
thick, tough layer covering groups of fascicle
usually surrounds the named muscle groups
Term
organization of muscle
Definition
muscle --> fascicle --> myofiber (cell) --> myofibril
Term
sarcomere
Definition
contractile unit of myofibril
composed of thick and thin filaments arranged in a highly-ordered manner
Term
I-band
Definition
region of sarcomere with only thin filaments
does not alter the rotation of polarized light = isotropic
Term
A-band
Definition
region of sarcomere with thick and thin filaments
alters the rotation of polarized light = anisotropic
Term
Z-line
Definition
where thin filaments are anchored
sarcomeres connect at Z-lines
Term
M-line
Definition
located at center of sarcomere
where thick filaments are anchored
Term
H-zone
Definition
areas in sarcomere of non-overlapping surrounding the M-line
area of only thick filaments
Term
thin myofilament
Definition
composed mainly of actin (filamentous), some troponin and tropomyosin
troponin and tropomyosin are involved in control of contraction
Term
thick myofilament
Definition
composed of myosin
has ATPase sites and actin-binding parts
Term
troponin
Definition
regulatory molecule associated with thin myofilaments
consists of Ca-binding, inhibitory, and tropomyosin-binding units
helps to regulate muscle contraction by sensing calcium levels and exposing the actin's myosin-binding site when levels are high
Term
transverse tubules
Definition
invaginations of the sarcolemma
from an anastomosing network around the sarcomere around the A-I band junction
associate with terminal cisternae of the SR to form triads
Term
terminal cisternae
Definition
blind-ended sacs of the SR that associate with the transverse tubules
Term
motor unit
Definition
combination of a motor axon and the myofiber(s) that it innervates
1:1 fine control
1:160 coarser motions
Term
cardiac muscle
Definition
branched cells joined physically and electrically
nuclei are centrally located and mitochyondria are prevalent
very aerobic
sarcomeres are highly organized
have t-tubules that carry electrical signal in from the outside (has diad at end)
Term
intercalated disks
Definition
structures joining cardiac muscle cells together
made of fascia adherens, macula adherens and gap junctions
gap = electrical connections
Term
atrial natriuretic peptide
Definition
released by cells of the atria
involved in regulation of body fluid volume
Term
fascia adherens (cardiac)
Definition
connects Z-lines to one another between cardiac muscle cells
Term
smooth muscle
Definition
spindle-shaped cells with centrally located nuclei and no striations
thick and think myofilaments connected to intermediate filaments, less organized
contraction is partially regulated by assemble/disassemble of thick filaments
also regulated by proteins on thin filaments
capable of mitosis to replace injured tissue (can regenerate by dedifferentiating, dividing and redifferentiating)
Term
smooth muscle intermediate filaments
Definition
vimentin and desmin
Term
cytoplasmic dense bodies
Definition
linking between thin filaments and intermediate filaments in smooth muscle cells
Term
membrane dense bodies
Definition
linking between cell membrane and thin filaments in smooth muscle cell
Term
unitary smooth muscle
Definition
cells have gap junctions and function in syncytium
cells contract together
Term
multi-unit smooth muscle
Definition
richly innervatred group of non-gap-junction-connected of cells
allows for very fine gradations of contraction
ex: iris of the eye
Term
satellite cells (muscle)
Definition
long, slender cells that reside just beneath the basement membrane next to each myofiber
less differentiated cells in skeletal muscle that can undergo division and form new muscle cells
Term
regeneration of skeletal muscle
Definition
satellite cell --> myoblast --> myotubes --> myofibrillogenesis --> myofiber
Term
myofibrillogenesis
Definition
process that myotubes undergo to produce filaments and myofibrils to become myofibers
Term
myoblasts
Definition
step past satellite cells
do not look like muscle cells but express muscle proteins
Term
myotubes
Definition
formed by fusion of myoblasts
long cells with multiple nuclei
Term
gray matter
Definition
location of cell bodies in the central nervous system
some specific areas = nuclei
Term
white matter
Definition
area of nerve fiber tract in central nervous system
Term
ganglia
Definition
clusters of neuron cell bodies outside of the central nervous system
Term
neuron classification by # processes
Definition
multipolar, bipolar, pseudounipolar
Term
neuron classification by function
Definition
excitatory, inhibitor, modulatory, sensory, motor, interneurons
Term
neuron classification by transmitter
Definition
gluatmergic (excitatory), GABAergic (inhibitory), dopaminergic (modulatory)
Term
neuron classification other
Definition
projection, interneurons, pyramidal, granule
Term
Nissl substances
Definition
RER in a histological stain
Term
lipofuscin
Definition
finely granular yellow-brown pigment granules composed of lipid-containing residues of lysosomal digestion
Term
neurofilaments
Definition
intermediate filaments of the neurons
Term
dendrites
Definition
receive inputs from other neurons
exhibit repeated branching, taper off
have dendritic spines
multiple per neuron possible (multipolar)
Term
dendritic spine
Definition
receiving portion of the dendrite
small membranous protrusion from a neuron's dendrite
bulbous head (the spine head), and a thin neck that connects the head of the spine to the shaft of the dendrite
Term
axon
Definition
sends out information to other neurons
one per neuron, bifurcate and branch with consistent diameter
Term
axon hillock
Definition
initial segment of axon coming from the cell body
Term
anterograde axonal transport
Definition
from cell body to peripheral
motor protein = kinesin
Term
retrograde axonal transport
Definition
from peripheral to cell body
motor protein = dynein
Term
synapse
Definition
site of communication between two neurons
Term
electrical synapse
Definition
formed by gap junctions
few in the mammalian brain
no modulation which is not good for us
Term
chemical synapse
Definition
specialized junctions through which neurons signal to each other and to non-neuronal cells
Term
presynaptic neuron
Definition
has lots of vesicles containing neurotransmitters
Term
postsynaptic neuron
Definition
surface has many receptors and associated proteins
Term
synaptic cleft
Definition
space between presynaptic terminal and postsynaptic surface
usually contain enzymes to regulate neurotransmitters
Term
glial cells
Definition
oligodendrocytes, Schwann cells, astrocytes, microglia, pericytes
Term
oligodendrocytes
Definition
produce myelin for the CNS axons
Term
Schwann cells
Definition
produce myelin for PNS axons
Term
myelin
Definition
lipoprotein complex, "insultation"
allows for fast velocity conductance
salutatory conductance
Term
Node of Ranvier
Definition
gap between myelin sheaths on a myelinated nerve fiber
Term
internode
Definition
one schwann cell per segment
one oligodendrocyte envelops many segments
Term
astrocytes
Definition
most numerous glial cell
fibrous in the white matter
protoplasmic in gray matter
have end feet
function as physical support, maintaining homeostasis, releasing neurotrophic factors and neurotransmission
increase and change morphology after ischemia
Term
end feet of astrocytes
Definition
extended processes that link to endothelial cells of capillaries or present at the external surface of the CNS
Term
injection of Schwann cells
Definition
used to treat spinal cord injuries
bridge the gap of the injured spinal cord
guide regenerating axons
limit scar tissue formation
enable factors to accumulate
offer environment that can be modified
facilitate tracing
Term
blood-brain barrier
Definition
functional barrier that restricts exchange of substances between brain and blood
endothelial cells connected by occluding junctions, low transcytotic activity
basement membrane
pericytes
end feet of astrocytes
Term
microglia
Definition
macrophage in the CNS derived mainly from bone marrow
facilitate immune response in pathological conditions
Term
multiple sclerosis
Definition
autoimmune disease characterized by myelin degeneration
microglia give wrong signal to lymphocytes, saying myelin is foreign
symptoms disappear and come back, cycling
eventually damage is irreversible
Term
central canal
Definition
tunnel in middle of spinal cord
lined by ependymal cells
Term
ependymal cell
Definition
ciliated cuboidal epithelium that lines the brain ventricles and the central canal of the spinal cord
Term
neuropil
Definition
any area in the nervous system composed of mostly unmyelinated axons, dendrites and glial cell processes that forms a synaptically dense region containing a relatively low number of cell bodies
Term
satellite cells (neuron)
Definition
surround the pseudounipolar neurons in the sensory ganglia of the PNS
surround the multipolar neurons in the autonomic ganglia
Term
sensory ganglia
(examples, cell types)
Definition
cranial ganglia, DRG
composed of pseudounipolar neurons that bifurcate and satellite cells
Term
autonomic ganglia
(example, types of cells)
Definition
intramural ganglia
composed of multipolar neurons and satellite cells
Term
epineurium
Definition
connective tissue around larger group of nerve fibers
Term
perineurium
Definition
connective tissue around small groups of nerve fibers
Term
endoneurium
Definition
connective tissue around individual axons
Term
somatic nerve
Definition
sensory/motor
Term
somatic sensory nerve
Definition
conducting sensory signals from peripheral terminals to CNS
passing through DRG and dorsal horn
precise
Term
somatic motor nerve
Definition
conducting movement signals CNS to skeletal muscle
passes through ventral horn
fast, precise
Term
visceral nerve
Definition
controls smooth muscle, glands, cardiac rhythm and maintains body homeostasis
Term
visceral sensory nerve
Definition
conducint sensory signals from internal organs to CNS
travels through DRG
diffuse, vague, referred pain
Term
visceral sympathetic motor nerve
Definition
preganglionic from thoracolumbar division, relases acetylcholine at sympathetic ganglia
postsynaptic from ganglia to effector tissue, releases norepinephrine
mobilizes body for activity
Term
visceral parasympathetic motor nerve
Definition
preganglionic from craniosacral division, releases acetylcholine at ganglia
postganglionic from ganglia to effector tissue, releases acetylcholine
singals body to go into low energy, saving energy mode
Term
skin functions
Definition
forms physical, protective barrier (part of immune response)
regulates body temperature and water loss
conveys sensory information about external environement
participates in homeostasis (hormone, cytokine, and growth factor secretions and converting vitamin D to active form)
excretion through exocrine secretion, sweat, sebaceous and apocrine glands (elimination of toxins)
Term
epidermis
Definition
external layer of skin
keratinized stratified squamous epithelium of ectodermal origin
Term
dermis
Definition
inner layer of skin
formed by connective tissue of mesodermal origin
supports the epidermis and binds it to the subcutaneous tissue
Term
stratum basale (germinativum)
Definition
deepest layer of epidermis
single layer of basophilic columnar or cuboidal cells
mitotically active
attached to GM
Term
stratum spinosum
Definition
layer of epidermis deep to granulosum and superficial to basale
several layers of cells that exhibit numerous cytoplasmic processes/spines
connect to each other by desmosomes
Term
stratum granulosum
Definition
layer of epidermis deep to lucidum or corneum but superficial to spinosum
3-5 layers of flattened polygonal cells that contain coarse basophilic granules
less developed in thin skin than thick skin
contain keratohyaline granules and lamellar bodies
Term
stratum lucidum
Definition
layer of epidermis found only in thick skin; deep to corneum and superficial to granulosum
single layer of extremely flattened eosinophilic epidermal cells
cells start to lose nucleus and organells
still have keratohyaline granules
Term
stratum corneum
Definition
superficial-most layer of epidermis
15-20 layers of flattened, non-nucleated keratinized cells
Term
keratohylaine granules
Definition
found in the stratum granulosum and lucidum of epidermis
contain proteins that attach to keratin in tonofibrils
Term
lamellar bodies
Definition
found in stratum granulosum of epidermis
lipids enclosed in membrane and released into extracellular media
Term
epidermal barrier
Definition
formed by the release of lipids from lamellar bodies in the stratum granulosum
forms a lipid layer that protects the skin from dehydration
Term
thick skin
Definition
present in palsm of hands and soles of feet
hairless
think areas of high abrasion
has stratum lucidum, thicker corneum and granulosum
Term
thin skin
Definition
present everywhere but palms and soles of feet
in most cases, has hair
does not have stratum lucidum, less corneum and granulosum
Term
keratinocytes
Definition
predominant cell type in epidermis
produce keratin
participate in formation of epidermal water barrier
Term
keratin
Definition
major structural protein of epidermis
produced by keratinocytes
Term
melanocytes
Definition
derived from neural crest
round cells with cytoplasmic projections that are scattered among cells of stratum basale
produces and secrete pigment melanin
Term
melanin
Definition
produced by melanocytes from tyrosine
transferred via cytocrine secretion to keratinocytes
protects against the damaging effects of non-ionizing UV radiation
Term
Langerhans' cells
Definition
derived from bone marrow
star-shaped cells present mainly in the stratum spinosum
bind, process, and present antigens to T-cells (mediate immune response)
Term
Merkel's cells
Definition
modified epidermal cells located in stratum basale
present in thick skin, where sensory perception is acute
contain dense-cored neurosecretory granules
closely associates with expanded terminal bulb of afferent nerve fibers
Term
Merkel's corpuscle
Definition
a mechanoreceptor
formed by close association of terminal buble of afferent myelinated nerve and a Merkel's cell
Term
tyrosinase
Definition
enzyme involved in synthesis of melanin from tyrosine
absent in albinos
Term
papillary dermal layer
Definition
most superficial layer formed by loose connective tissue
network of delicate type I and II collagen and elastic fibers
anchoring fibrils (type IV) insert into basal lamina and bind the dermis to epidermis
contains nerve processes and blood vessels that supply (not penetrate) epidermis
Term
reticular dermal layer
Definition
deepest layer of demis
thickness varies by part of body
always thick and less cellular than papillary layer
formed by type I collagen and elastic fibers that are regularly oriented (form lines of tension)
Term
Langer's lines
Definition
lines of tension created by type I collagen and elastic fibers in the reticular dermal layer
incisions along these lines heal better and leave less of a scar
Term
fingerprints
Definition
caused by epidermis following the same shapes of blood vessels and dermal papillae
Term
glomus body
Definition
structure in dermis
formed by arteries and veins and surrounded by connective tissue
Term
cutaneous plexus
Definition
between dermis and hypodermis
artery, vein and lymphatics
Term
papillary plexus
Definition
between papillary and reticular dermal layers
artery vein and lymphatcis
Term
free nerve endings (skin)
Definition
terminate in stratum granulosum of epidermis
allow multiple sensation including touch, heat and cold
Term
pacinian corpuscles
Definition
large ovoid structure in deeper dermis and hypodermis
composed of myelinated nerve ending surrounded b y capsule
response to pressure and vibration
formed by modified Schwann cell, concentric layers around unmyelinated fiber
Term
meissner's corpuscles
Definition
tapered cylinders oriented perpendicular to skin surface in papillary layer of hairless skin
respond to touch, and low-frequency stimuli
formed by modified Schwann cell
Term
ruffini's corpuscles
Definition
elongated fusiform structures that function as mechanoreceptors
Term
hair follicle
Definition
epidermal invagination responsible for production and growth of a hair
acellular hyaline layer formed by thickened BM separates hair from dermis
always associated with a subaceous gland
surrounded by internal and external root sheaths
Term
hair bulb
Definition
terminal dilation of hair follicle during growing period
Term
dermal papilla
Definition
at the base of a hair bulb
contains a capillary network that irrigates the hair follicle
Term
sebasceous glands
Definition
associate with hair follicles
release sebum into the canal around the hair
die by apoptosis as they become filled with sebum (holocrine secretion)
acinal glands
Term
hair
Definition
elongated keratinized filamentous structures with 3 layers
Term
hair medulla
Definition
central part of shaft contain large vacuolated and moderately keratinized cells
Term
hair cortex
Definition
located peripheral to medulla
contain cuboidal cells that undergo differentiation into keratin-filled cells
Term
hair cuticle
Definition
outermost layer of hair that contains squamous cells
Term
root sheaths
Definition
external and internal surround hair follicle
made of epithelial cells that are continuous with epidermis and surround hair
Term
anagen
Definition
growth stage of hair
hair bulb more developed and producing hair cells and cells that make it grow
Term
arrector pili muscle
Definition
small bundle of smooth muscle that controls movement of hair
contraction --> raise hair --> goose bump
Term
catagen
Definition
transitional stage of hair
hair stops growing
root is dimished and dermal papilla breaks away and rests below
Term
telogen
Definition
stage during which hair is entirely inactive
Term
nails
Definition
flexible, hard plates of keratinized cells containing hard keratin
located on dorsal side of phalanges
Term
nail root
Definition
proximal part of nail; hidden in nail groove
constant addition of cells and keratinization --> nail growth
Term
nail matrix
Definition
formed by dividing cells thaqt eventually cornify forming nail root
variety of cells: stem, melanocytes, keratinocytes, Merkel's cells and Langerhan's cells
Term
nail plate
Definition
"the nail" itself
highly specialized stratum corneum
cells contain hard keratin that does not desquamate
Term
nail bed
Definition
area of skin where nail rests
formed by stratum basale and stratum spinosum
Term
hyponychium
Definition
area of skin right below nail where it becomes free and separates from skin
Term
sebum
Definition
produced and released by sebaceous glands
coats hair and skin
oily substance
Term
sweat glands
Definition
classified on basis of their secretion method: merocrine or apocrin
Term
merocrine sweat glands
Definition
(eccrine)
simple tubular glands with ducts opening at the skin surface over the entire body (except lips and ext. genitalia)
embedded in dermis
composed of dark cells and clear cells that are surrounded by myoepithelial cells that help with secretion
ducts are formed by two layers of cuboidal cells
innervated by cholinergic fibers
merocrine secretion method
Term
dark merocrine cells
Definition
contain secretory granules of merocrine sweat glands
granules contain glycoproteins
Term
clear merocrine cells
Definition
devoid of secretory granules
produce watery component of sweat
Term
apocrine sweat glands
Definition
large-lumen, tubular glands associated with hair follicles in axilla, areolaa and anus
embedded in dermis and hypodermis
innervated by adrenergic nerves
merocrine secretion method
Term
acinal gland
Definition
release products into a small duct that will carry product directly onto end of hair follicle or onto epidermal surface
Term
acini
Definition
formed by layer of epithelial cells that surround them
start to accumulate lipids and form vacuole cells called sebocytes
Term
merocrine secretion
Definition
organelle in cello that has the secretion product is released by exocytosis
Term
dermal repair
Definition
removal of damaged collagen fibers by macrophages
proliferation of fibroblasts and subsequent production of collagen and other ECM components
Term
epidermis repair
Definition
proliferation of basal keratinocytes of undamaged skin around wound
cover of wound by scab
migration of proliferating keratinocytes beneath scab
proliferation and differentiation to restore the multi-epidermis layers
detachment of scab and desquamating keratinized cells
Term
malpighian layer
Definition
basale and spinosum b/c contain stem cells that allow the renewal of epidermal cells
can be culture to produce ectodermal, endodermal or mesodermal tissues
Term
bullous penphigoid
Definition
blistering skin disease
abnormalities in dermal-epidermal junction
due to presence of antibodies against the BM
Term
pemphigus
Definition
blistering skin disease
loss of intercellular junctions among keratinocytes
due to antibodies against desmosome proteins
big skin lesions, like on fire
Term
psoriasis
Definition
increase in number of proliferating cells in stratum basale and spinosum
decrease in the cycle time
greater epidermal thickness and more rapid renewal
Term
basal cell carcinoma
Definition
type of skin cancer
tumor cells originate from basal cells of epidermis or epidermal appendages
Term
squamous cello carcinoma
Definition
type of skin cancer
tumor cells originate from squamous cells of the stratum spinosum
Term
malignant melanoma
Definition
type of skin cancer
tumor cells originate from melanocytes
most aggressive form
Term
parakeratosis
Definition
abnormal presence of nuclei in stratum corneum
seen in psoriasis due to decrease cycle time not allowing proper differentiation of epidermal cells
Term
Griscelli Syndrome
Definition
silver baby
autosomal dominant
hypocoloration and discoloration
hair appears silvery and have accumulation of pigment in hair
immune problems
accumulation of melansomes around nucleus that are not released
Rab27a defective protein that is involved in transport of melansomes
Term
air conduction
Definition
warming of air before it gets deep into lung
Term
air filtration
Definition
done by nasal hairs, mucus from secretory units and goblet cells in respiratory epithelium
Term
conducting portion of respiratory system
Definition
nasal cavity to terminal bronchioles
function to condition inspired air (conduction and filtration)
Term
respiratory portion of respiratory system
Definition
respiratory bronchioles to alveoli
function for gas exchange
Term
respiratory epithelium
Definition
majority of epithelium in resp system
ciliated pseudostratified columnar (unique)
looks stratified bu all touch basement membrane
Term
ciliated respiratory cells
Definition
most abundant cell
long cilia at apical end
mucus transport
Term
goblet respiratory cells
Definition
mucus production
number increase during chronic irritation
Term
brush respiratory cells
Definition
microvilli
free nerve endings (interface with NS)
Term
basal respiratory cells
Definition
stem cells
can differentiated into any of other respiratory cells
located close to GM
Term
small respiratory granule cells
Definition
neuroendocrine function
secrete catecholamines that regulate airway diameter
contained within and release from secretory granules
Term
olfactory epithelium
Definition
specialized epithelium that allows sense of smell
located on superior concha
pseudostratified
Term
metaplasia
Definition
transformation of epithelium from respiratory to stratified squamous
occurs with chronic insult by turbulent flow (chronic cough, bronchitis or smoking)
no goblet cells or cilia
Term
olfactory cells
Definition
bipolar neurons, ciliated
cilia project into the lumen and have receptors for odorant
Term
supporting cells (of olfactory epithelium)
Definition
microvilli, apical nucleus
interspersed between ciliated cells
Term
basal cells (of olfactory epithelium)
Definition
single layer at epithelium base, stem cells
Term
Bowman's gland
Definition
aka olfactory gland
serous glands in lamina propria
secretions contain odorant-binding protein
Term
odorant-binding proteins
Definition
secreted from Bowman's glands
binds to odorants and carires them to receptors on olfactory cell cilia
Term
swell bodies
Definition
venous plexus in lamina propria of olfactory epithelium
Term
nasal cavity lamina propria
Definition
highly vascular to help warm inspired air
Term
nasal cavity
Definition
paired chamgers separted by a septum
comprised of vestibule and nasal fossae
functions to trap particles and begin warming the are
Term
nasal vestibule
Definition
contains vibrissae
transition from keratinized stratified squamous epithelium from skin to respiratory epithelium
contains sebaceous glands
Term
vibrissae
Definition
nasal hairs that are in the nasal vestibule
function to begin trapping particles
seen at nonkeratinzed stratified squamous but disappear before respiratory epithelium begins
Term
nasal fossae
Definition
three conchae, superior containing olfactory epithelium
middle and inferior have respiratory
function to produce turbulent flow
highly vascularized
Term
nasal conchae
Definition
increase surface area of region (more particle collection and air warming)
create turbulence in air flow (more particle collecting)
Term
paranasal sinuses
Definition
cavities in facial bones
mucus travels to nasal cavity
prone to infections
covered in respiratory epithelium (bit thinner)
Term
pharynx
Definition
connects nasal cavity to larynx
naso and oralpharynx sections
oral = nonkeratinzied stratified squamous
naso = respiratory epithelium (pseduostratified columnar)
Term
larynx
Definition
connects pharynx to trachea
irregular shapes of cartilage (hyaline and elastic)
vocal cords contained within
respiratory epithelium
Term
vocal cords
Definition
two mucosal folds projecting into lumen of larynx
each contains a supporting ligament and skeletal muscle
covered by stratified squamous epithelium (better for resisting abrasion of speaking)
Term
trachea
Definition
from base of larynx to start of bronchial tree
hyaline cartilage rings in "C" shaped, closed off by trachealis muscle
Term
perichrondrium
Definition
dense, fibrous tissue on top of cartilage rings in trachea
serves to contract lumen of trachea
Term
bronchial tree
Definition
bronchi to terminal bronchioles
progressive transition to smaller diameter
segmental branching deep into lungs
Term
primary bronchus
Definition
two
come off the trachea
enters each lung at the hilum
have glands and cartilage
Term
bronchioles
Definition
NO glands or cartilage
still have smooth muscle, some goblet cells
progressive transition from ciliated pseudostratified columnar to ciliated simple columnar to cuboidal
Term
clara cells
Definition
secrete alveolar fluid which serves as the aqueous phase of surfactant
bulge out into the lumen of tubes
have prominent granules that secrete
Term
bronchi
Definition
one for each lobe of the lung (two in left and three in right)
irregular cartilage plates which decrease in size/number as tube gets smaller
contains circular layer of smooth muscle
abundant mucous and serous glands
Term
surfactant
Definition
lowers surface tension to prevent alveoli from collapsing
Term
terminal bronchiole
Definition
fairly simple epithelium that is NOT DISRUPTED
Term
respiratory bronchiole
Definition
fairly simple epithelium that is DISRUPTED by alveoli pockets
two or more arise from each terminal bronchiole
clara cells can be present
Term
alveolar ducts
Definition
region of tube at which respiratory bronchiole contals only alveoli
lined by squamous alveolar cells
contains smooth muscle, elastic, and reticular fibers
Term
alveolar sacs
Definition
collection of alveoli at end of alveolar duct
like a cul-de-sac of alveoli
Term
alveoli
Definition
sac-like evaginations of respiratory structure
O2 and CO2 exchange
lined by simple squamous epithelium (type I) and cuboidal (type II)
Term
intraalveolar septum
Definition
wall separating two adjacent alveoli
comprised of two layers of squamous epithelium between which are capillaries, CT, leukoctyes
alveolar pores connect adjacent alveoli
Term
emphysema
Definition
damage is in the respiratory portion (distal to terminal bronchioles)
permanent enlargement and wall destruction of air spaces
due primarily to loss of elasticity (elastic fibers) via elastase (from PMNs)
smoking is major cause
Term
pneumonia
Definition
bacterial infection in alveoli leading to inflammation and fluid accumulation
lots of lymphocytes and fluid accumulation in respiratory portion
Term
type I (squamous alveolar) cells
Definition
flat (very thin) that line majority of alveolar surface
provide minimum thickness barrier for gas exchange
connect via both desmosomes and occluding junctions
form the sac-like nature of alveolus
Term
type II (great alveolar) cells
Definition
much larger cuboidal cells located in corners of alveoli (group of 2-3)
contain lamellar bodies that secrete pulmonary surfactant
can differentiated to replace injured type I cells
can be connected with occluding junctions to type I alveolar cells
Term
alveolar macrophage (dust cell)
Definition
in alveolar septum and alveolar spaces
remove degraded surfactant and other debris
either migrate up the bronchial tree or remain in alveoli for life
Term
endothelial cells of respiratory capillaries
Definition
thin, no fenestrations
express angiotension-converting enzyme
Term
neonatal RDS
Definition
surfactant deficiency in premature infants (production begins at 35th week of gestation)
results in collapse of alveolar walls
tx: corticosteroids (which stimulate synthesis of surfactant) or artificial surfactant
Term
blood-air barrier
Definition
separates air in alveoli from blood in capillaires (0.1-1.5u thick)
surface lining and cytoplasm in alveolar cells
fused BM of the alveolar and endothelial cells
cytoplasm of endothelial cell
facilitates exchange of gas
Term
pleura
Definition
serous membrane coving the lung that serves to facilitate sliding during respiration
parietal and visceral layers
normally pleural cavity has thin film of liquid (pathologies lead to accumulation of fluid)
Term
hydrothorax/pleural effusion
Definition
general accumulation of fluid in pleural cavity
Term
hemothorax
Definition
accumulation of blood in pleural cavity
Term
pneomothorax
Definition
accumulation of air in pleural cavity
Term
primary lymphoid organ
Definition
site are primary source of lymphocytes
where lymphocytes undergo antigen-independent differentiation
bone marrow and thymus
Term
secondary lymphoid organ
Definition
peripheral
lymphocytes can react with foreign antigens and undergo antigen-dependent differentiation
MALT, lymph nodes, and spleen
Term
bone marrow
Definition
primary lymphoid organ
site of origin for Bcells, NK, dendritic cells and precursors to T cells
Term
thymus
Definition
primary lymphoid organ
bilateral organ located in mediastinum
site of maturation of T cells
encapsulated
Term
diffused lymphoid tissue
Definition
contains numerous lymphocytes without apparent organization
usually associated with mucous membrane (GI, resp, urinary)
close to areas that can be entry point of pathogens
Term
nodular lymphoid tissue
Definition
lymphocytes are arranged as spherical masses called nodules (or follicles)
contain mainly B cells
Term
germinal center
Definition
present in activated lymphoid nodules
contains actively dividing cells that have more cytoplasm than mature lymphocytes
disappear after completion of initial immune response
Term
reticular cells (lymphoid)
Definition
produce reticular fibers that provide support to cell in most lymphoid tissue (except thymus)
fibers composed of type III collagen
density of fibers determines the mobility of cells in tissue
Term
dendritic cells
Definition
most potent antigen presenting cells
derived from bone marrow
Term
lymphocytes
Definition
white blood cells responsible for specificity of adaptive immune response
can be classified as B, T or NK cells
Term
plasma cells
Definition
secrete IgA
B-cell derived antibody secreting cells
Term
IgA
Definition
secreted by plasma cells
contain secretory component that gives it resistance to enzymes (remains active in enzyme-rich secretions)
confers resistance to microorganism
serum monomer, dimer, J chain, and secretory component
Term
thymus cortex
Definition
T lymphoblasts or thmocytes (immature T cells) and macrophages in stroma of epithelial reticular cells
Term
thymus medulla
Definition
T lymphocytes, epithelial reticular cells and reticular fibrocytes
Hassal's corpuscles
Term
Hassal's corpuscle
Definition
contains debris from dead cells with connective tissue around
function-unknown (marker of aging?)
Term
thymic selection
Definition
cortex: positive selection - thymocyte that bind self MHC
medulla: negative selection - thymocytes that bind strongly MHC (potential for auto-immune response)
Term
post-capillary venules (high endothelial capillaries)
Definition
located at cortico-medullary junction in thymus
where cells leave thymus
endothelial cells are not flat as they typically are for capillaries
Term
thymus cortex capillary (thymus blood barrier)
Definition
lined by continuous endothelial cells that are surrounded by type I epithelial reticular cells that attach to each other by desmosomes
prevents immature T cells from escaping thymus prematurely
Term
severe combined immunodeficiency disease (SCID)
Definition
severe defect in both T, B and NK cells
mutations in gene that encodes IL-2 receptor gamma chain
bubble boy syndrome
Term
MALT
Definition
mucosa associated lymphoid tissue
Peyer's pathes and tonsils
accounts for total mass of lymphoid tissue in GI, resp, and GU tracts
composed of diffused lymphoid tissue and non-encapsulated or partially-encapsulated aggregations
Term
tonsils
Definition
only connective tissue on inside border that blocks entrance of pathogens from that area
partially encapsulated MALT
Term
lymph nodes
Definition
secondary lymphoid tissue
bean-shaped structure distributed through the body along the course of the lymphatic vessels
Term
lymph node cortex
Definition
reticular cells, macrophages, APCs, and B cells
lymphoid nodules w/o germinal centers
sub-capsular sinsues and cortical sinuses
Term
sub-capsular lymph node sinuses
Definition
immediately beneath the capsule on cortex
formed by reticular fiber meshes
Term
cortical sinuses
Definition
run between the lymphoid nodules in cortex
communicate with sub-capsular sinsues
Term
lymph node paracortex
Definition
T lymphocytes (no B cells)
post-capillary venules lined by tall endothelial cells
Term
lymph node medulla
Definition
medullary cords - B cells, plasama cells and macrophages
medullary sinsues - spaces that contain lymph, lymphocytes, and macrophages
Term
spleen
Definition
secondary lymphoid organ, ecncapsulated
filtration of blood
destruction of aged erythrocytes
production of antibodies and activated lymphocytes
pulp - reticular tissue containing reticular cells, lymphocytes, macrophages, and APCs
Term
white pulp
Definition
lymphoid nodules
periarteriolar lymphoid sheaths (PALS)
densely populated by T and B cells
Term
red pulp
Definition
splenic cords (Cords of Bilroth)
venous sinusoids
Term
periarteriolar lymphoids sheaths (PALS)
Definition
found in white pulp of spleen
populated largely by T cells and surround central arteries within the spleen
Term
splenic cords (cords of Billroth)
Definition
between the sinusoids, consisting of fibrils and connective tissue cells with a large population of monocytes and macrophages
Term
tunica intima
Definition
layer of blood vessel next to blood
Term
tunica adventitia
Definition
outside layer of blood vessel
made mostly of CT
Term
tunica media
Definition
middle layer of blood vessel containing smooth muscle
Term
vasa vasorum
Definition
smaller blood vessels in the walls of large blood vessels
Term
capillaries
Definition
about 7-10um in diameter
consist of endothelium and occasionally a pericytes
Term
pericytes
Definition
found adjacent to blood vessels
visible with EM
capable of undergoing division and differentiation
Term
continuous capillary
Definition
tightest junction of capillaries
located in muscle, nerve, CT and exocrine glands
have tight junctions, often pinocytotic vesicles, no fenestrate and a basement membrane
Term
fenestrated capillary w/ diaphragm
Definition
more leaky form of capillaries
located in kidney, gut and endocrine glands
have tight junctions, some pinocyototic vesicles, fenestrae, diaphragms, and basement membrane
Term
fenestrated capillary w/ diaphragm
Definition
more leaky than w/o diaphragm
located in renal glomerulus
have tight junctions, some pinocytotic vesicles, fenestrae, no diaphragms and a basement membrane
Term
sinusoidal capillary
Definition
leakest of capillary types
located in bone marrow, lymphoid, liver (due to large amount of protein/ceolls moving across these capillaries)
have some tight junctions, no pinocytotic vesicles, fenestrae, no diaphragms, and some basement membrane
Term
PV1
Definition
major protein that is part of fenestral diaphragm
Term
precapillary sphincter
Definition
ring of smooth muscle at the entrance to capillary bed
where blood flow can be controlled
Term
diapedesis
Definition
process characterized by movement of some cells across the endothelium of capillary
Term
large elastic artery
Definition
tunica intima = endothelium
tunica media = smooth mm, elastic laminae (many throughout)
tunica adventitia = present
Term
medium muscular artery
Definition
tunica intima = endothelium
tunica media = sm and elastic laminae (internal and external lining)
tunica adventitia = present
Term
arteriole
Definition
intima = endothelium
media = smooth muscdle
adventitia = present
Term
capillary
Definition
intima = endothelium
media = none
adventitia = none
Term
venule
Definition
intima = endothelium
media = none
adventitia = present
Term
medium vein
Definition
intima = endothelium
media = smooth muscle
adventitia = present
Term
large vein
Definition
intima = endothelium, CT, muscle
media = smooth muscle
adventitia = CT and longitudinal smooth muscle
Term
arterovenous anastomoses
Definition
direct communication of smaller arteries and veins
if these are open then blood will be shunted from capillary beds
Term
endocardium
Definition
atrium - endothelium and CT
ventricle - endothelium only
Term
myocardium
Definition
atrium - muscle
ventricle - muscle
Term
epicardium
Definition
atrium - CT and mesothelium
ventricle - CT, vessels, and mesothelium
Term
lymphatic capillaries
Definition
have blind ends
endothelial cells with no fenestrae, incomplete tight junctions and very little BM
anchored via direct attachment of collagen fibrils to endothelial cells
capillaries fuse to form larger vessels which have thinner walls of similar size
Term
hematocrit
Definition
percentage of blood volume that is erythrocytes
40-50% in men
35-45% in women
Term
leukocytes
Definition
"buffy coat"
~1% of blood volume
Term
serum
Definition
fluid remaining when blood clots
Term
plasmna
Definition
water, plasma proteins, inorganic salts, organic compounds
Term
anemia
Definition
low hematocrit
common causes are blood loss, reduced production of RBCs or accelerated destruction of RBCs
Term
polycythemia
Definition
increased number of RBCs
ex: low oxygen environment, dehydration, myeloproliferative disorders
reactive (due to less plasma) and true (more RBCs)
Term
erythrocytes (RBC)
Definition
fully mature form
anucleate w/o organelles
biconcave disks that are extremely flexible (facilitating travel in capillary)
7-8um in diameter
120 day lifespan, then phagocytosed by macrophage in spleen
Term
granulocytes
Definition
neutrophils, eosinophils and basophils
nuclei with 2+ lobes
specific granules with enzymes
contain azurophilic granules (mostly lysosomes)
Term
agranulocytes
Definition
lymphocytes and monocytes
have azurophilic granules but no granules
Term
neutrophils (PMNs)
Definition
polymorphonuclear leukocytes
60-70% of leukocytes
multi-lobe (2-5) nucleus linked by chromatin (# is indicative of age)
1-4 day lifespan
express P-selectin ligands
enter CT at post-capillary venules via diapediesis
acts as defense against bacteria
Term
band form
Definition
very young neutrophil characterized by horseshoe shaped nucleus
Term
Barr body
Definition
drumstick-like appendage of nucleus in neutrophils of females
Term
P-selectin
Definition
expressed on neutrophils on cell surface
serve to interact with vasculatoure to slow travel of neutrophil and attract it to sites of damge
Term
neutrophil development
Definition
formation in medulla of bone marrow - 7 days
storage in medulla - 4 days
circulating and marginating - 6-7 hours
connective tissue doing their job - 1-4 days
die via apoptosis
Term
eosinophils
Definition
2-4% of leukocytes
bilobed nucleus
large specific granules (highly eosinophilic)
key protein = major basic protein, kills parasites
high concentration of these in sites of potential inflammation (i.e. GI)
Term
basophils
Definition
~0.5% of leukocytes
irregularly lobed nucleus that is often masked by granules
key protein = heparin and histamine
functions like mast cell (mediator of inflammation)
Term
monocyte
Definition
originate in bone marrow as monoblast ->promonocyte -> monocyte and enter circulation as mature cell
circulate for ~8hrs and then go into CT and become macrophage specific to that tissue
nucleus I oval, horseshoe, or kidney shaped; eccentric
Term
lymphocytes
Definition
~28% leukocytes
originate form bone marrow as blast and prolymphocyte
B cells fully diff in marrow and then migrate to peripheral organs to multiply
T cells immature from marrow go to thymus to mature
T-cell = cell-mediated immunity, B-cell = recognizes antigens, NK cells = attack virus-infected cells and some tumor cells
Term
thrombocytes
Definition
platelets
dissociate from megakaryocytes w/in marrow
no nucleus
functional regions: hyalomere and granulomere
Term
hyalomere
Definition
site of function for platelets
at periphery of the cell
contains two membrane systems that facilitate uptake (open canilicular system) and release (dense tubular) of factors
Term
granulomere
Definition
area of activity for platelets
in central region of cell
contains granules (alpha, delta, and lambda) filled with clotting factors (fibrinogen, PGF)
Term
colony forming units (CFUs)
Definition
collections of each type of blood progenitor cells
influenced by colony stimulating factors
each produces one cell lineage (except CFU-GM)
progenitor -> unipotent or bipotent (blasts, histo differentiation possible) -> terminal cell lineage
Term
red marrow
Definition
hematogenous
100% of marrow in new borns, transition to yellow with age
Term
stroma of red marrow
Definition
network of reticular cells and fibers, type I and II collagen, hemonectin
Term
hemonectin
Definition
located in stroma of red marrow
plays a role in keeping everything together
Term
hematopoietic cords
Definition
found in red marrow
site of blood cell formation containing the CFUs
Term
sinusoidal capillaries in red marrow
Definition
formed by endothelial cells, allows for mature cells to enter circulation
Term
yellow marrow
Definition
fatty
inactive
majority of marrow in adults
made of adipocytes
reversion to red possible
Term
erythroblastic islands
Definition
macrophages in medullary cords of bone marrow promote RBC differentiation
erythropoietin stimulates macrophages to increase RBC production
Term
RBC differentiation
Definition
proerythroblast - large with clearly visible nuclei
basophilic erythroblast - basophilic cytoplasm, condensed nucleus, mitotic cell
polychromatophilic erythroblast - mitotic cell
orthochromatophilic erythroblast - non mitotic, still has nucleus
reticulocytes - no nucleus, some polyribosomes
erythrocyte
Term
granulopoiesis
Definition
*accumulation of protein and packaging into granules
azurophilic granules made first then specific
stages: myeloblast, promyeloblast, myelocyte, metamyelocyte
Term
myeloblast
Definition
most immature cell that is recognizable in granulopoiesis
no cytoplasmic granules yet
Term
promyeloblast
Definition
multi-potential stem cell
has azurophilic granules
Term
myelocyte
Definition
precursor for each lineage, acquires specific granules
Term
metamyelocyte
Definition
prominent granulation
Golgi apparatus volume is reduced with lessening production of proteins and granules
Term
thrombopoiesis
Definition
maturation of megakaryoblasts to megakaryocytes
large cells, lobulated nucleus
dermarcqation of membrane w/in are invaginations of PM that serve as reservoir for growing platelets
Term
proplatelets
Definition
cytoplasm processes that extend from megakaryocyte body
penetrate into sinusoidal capillaries
ends are pinched off to form platelets
Term
connective tissue proper (primary)
Definition
surrounds and invests epithelium, muscle, and nerve tissue
classified as loose or dense depending on fiber content and organization within the ECM
Term
specialized CT
Definition
adipose, cartilage, elements of blood, myeloid and bone
Term
functions of CT
Definition
structure, defense, transport, storage, repair
Term
degradation of CT
Definition
rate increases with age
genetics affects
lifestyle affects (smoking, sunlight, diet, exercise)
disease
Term
aging effects on CT
Definition
elastosis (wrinkles)
change in fat distribution
thinning of bones (osteopenia or osteoporosis)
attenuation of joint mobility (cartilage degradation)
weakening of immune system (wound healing less efficient)
Term
components of CT
Definition
ground substance of ECM
Term
ground substance
Definition
glycosaminoglycans and structural glycoproteins
fills connective tissue space not occupied by fibers and cells
Term
chondroitin 6-sulfate
Definition
glycosaminoglycans
found in bone, cartilage, skin, and vessels
core proteins = versican or aggrecan
Term
kertan sulfate
Definition
glycosaminoglycan
found only in cartilage
Term
herparin
Definition
glycosaminoglycan
found only in mast cells
core protein = syndecan
Term
dermatan sulfate
Definition
glycosaminoglycan
found in skin, tendon and vessels
Term
hyaluronate
Definition
glycosaminoglycan
found in cartilage and synovial fluid
Term
laminin
Definition
structural glycoprotein of ground substance
binds to cells, collagens, GAGs, proteoglycans, and other glycoproteins
Term
fibronectin
Definition
structural glycoprotein of ground substance
binds to cells, collagens, GAGs, proteoglycans, and other glycoproteins
Term
collagen
Definition
most abundant protein in body (30% dry weight)
large segments of Gly-X-Y
left-handed helical structure
3 helicies form right-handing super-triple-helix = tropocollagen
fibers are inelastic and have high tensile strength
fibrils only visible on EM
Term
collagen type I
Definition
two alpha-1(I) chains and one alpha-2(I) chain
most numerous in CT
forms fibrils and fibers
skin, tendon, bone, dentin
Term
collagen type II
Definition
forms fibrils
cartilage, vitreous body
Term
collagen type III
Definition
forms fibrils and fibers
skin, muscle, blood vessels, frequently with type I
Term
collagen fibril formation
Definition
outside cell
tropocollagen line up head-to-tail
lines of that associated and form covalent cross-links by lysyl oxidase between lysines on the tropos
periodicity of striations = 67nm
Term
collagen type IV
Definition
forms 2D cross-linked network
found in all BMs
made up of 3 of one of the 6 collagen gene products
small globular domain at N-term and larger at C-term
triple helix has interruptions that give flexibility
form dimers and tetramers to yield a sheet-like network
Term
fibril-associated collagens
Definition
types VI and IX
link the fibrillar collagens to one another or the other ECM components
Term
sheet-forming and anchoring collagens
Definition
types IV, VII, XV
form 2D networks in BMs and connect BMs in skin to underlying connective tissue
Term
transmembrane collagens
Definition
types XII, XVII
function as adhesion receptors
Term
host defense collagens
Definition
collectins, C1q
help body recognize and eliminate pathogens
Term
Good Pasture Syndrome
Definition
diffuse alveolar hemorrhage, acute glomerulonerphritis
related to type IV collagen mutations with auto-antibodies attacking it (1* in kidney)
Term
Ehlers-Danlos Syndrome
Definition
diseases resulting from defects in collagen
Term
Ehlers-Danlos Type IV
Definition
vascular type
inherited CT disorder
characteristic facial features (acrogeria), translucent skin with highly visible subcutaneous vessels, easy bruising, severe arterial digestive and uterine problems
autosomal dominant, mutations in COL3A1 gene for type III procollagen
die in 40s
type II is main component of reticulocytes!
Term
reticular fibers
Definition
composed 1* of type III collagen
high content of glycoproteins associate
extremely thin, 0.5-2um diameter
stain with silver salts = black fibers
present in smooth muscle, endoneurium, and framework of hematopoietic organs (spleen, lymph node, red marrow)
Term
elastic fibers
Definition
oxytalan fibers -> elaumin -> elastic fibers
3rd stage
elastin deposition increases, occupying center of microfibril scaffold and is primary protein of fiber system
found in dermis and blood vessels
Term
elastosis
Definition
degenerative changes in dermal CT with increased amounts of elastotic material
wrinkles
Term
oxytalan fibers
Definition
first stage of elastic fibers
organize scaffold
found in dermis and zonule fiber of eye
very resistant to pulling
Term
elaunin
Definition
second stage of elastic fibers
irregular deposition of elastin appears in oxytalan microfibrils
found in dermis and sweat glands
located around oxytalan fibers and more stretchy than oxytalan
Term
cutis laxa
Definition
characterized by sagging and inelastic skin (extremely wrinkled in certain areas)
disease affects CT in many places of body
different forms distinguished by inheritance mode
Term
mesenchymal cells
Definition
wispy, small amount of cytoplasm extends as multiple thin processes away from oval nucleus
give rise to cells of connective tissue
Term
fibroblasts
Definition
connective tissue cells derived from mesenchymal or hematopoietic stem cells
most common cell of CT
produce fibers and ground substance of CT
typically found next to collagen fibers
oblong shaped
Term
adiopocytes
Definition
white/yellow fat in H&E looks like chicken wire
stains black with osmium
nucleus is on the periphery
Term
brown fat
Definition
less prevalent
small lipid droplets, more cytoplasm
cells stain darker
nucleus is centrally located
Term
macrophage (CT)
Definition
derived from monocytes
part of innate immune system
phagocytize bacteria, dead cells, etc.
Term
mast cells
Definition
connective tissue cell that contains numerous basophilic granules with heparin (or chondroitin sulfate), histamines, and other chemical mediators of inflammation
surface is covered with IgE receptors (some antibodies stick to) --> granule reslease
function: anaphylactic hypersensitivity, inflammation, cytotoxicity, and immunoregulation
Term
plasma cells
Definition
derived from B cells
pump out tons of antibodies
secrete immunoglobulins
basophilic cytoplasm
eccentric nucleus
Term
loose connective tissue (areolar)
Definition
delicate consistency, flexible, well vascularized
fibroblasts, macrophages, lymphocytes, plasma cells
collagen, elastic and reticular rfibers
significant ground substance
supports epithelial tissue, in serosal linings of peritoneal and pleural cavities
Term
dense irregular CT
Definition
fewer cells, clear predominance of collagen fibers
less ground substance
Term
dense regular CT
Definition
i.e. tendon
long, parallel bundles of collagen fibers
fibroblasts in longitudinal rows
Term
elastic fibers
Definition
thin, delicate (compared to collagen)
best observed with orcein stain
found in loose CT or in blood vessels
associated with vessels as laminae and fibers
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