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Histology Tissues (copy)

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Tissues
Aggregate cells designed to perform one or more functions
Epithelium Tissue
Covers body surfaces, lines body cavities, + formas glands
Specific cell-cell adhesion (cell junctions)
Functional + morphological polarity
Attached to an underlying basement membrane
Connective Tissue
Extracellular matrix supports structurally + functionally
Includes bone and cartilage
Muscle Tissue
Functional porperties of contraction allow movement
Nerve Tissue
Neurons revieve, transmit, + integrate informatino to control body
What is blood tissue?
fluid connecticut tissue in the cardiovascular system
How much blood is in an adult human?
6 Liters
What is the function of blood?
transport nutrients
transport wastes
transport gases
deliver hormones
maintain homeostasis by a buffer system
What is hematocrit?
percentage of formed elements in blood based upon volume
What are the components of blood?
erythrocytes
leukocytes
thrombcytes
plasma
What is the percentage of plasma in blood?
55% plasma
45? formed elements
What is the hematocrit level for males and females?
male 39-50%
female 35-45%
What are the formed elements in the blood?
erythrocytes (red blood cells)
leukocytes (white blood cells)
thrombocytes (platelets)
How many erythrocytes are in 1 mm3 of blood?
4-5 millin/mm3
How many leukocytes are in 1 mm3 of blood?
6-9 million/mm3
How many thrombocytes are in 1 mm3 of blood?
200,000 -400,000/mm3
What are the components of plasma, %?
water 91-92%
proteins 7-8%
other components 1-2%
What proteins are in plasma?
albumin (maitain osmotic pressure)
globulin (immune system molecules)
firbinogen (fibrous net to prevent further blood loss)
What other components, besides protein and water, can be found in the plasma?
electrolytes (Na+, K+, Ca2+, HCO3-, etc.)
nitrogenous compound (urea, uric acid, creatine)
nutrients (glucose, AA, lipids)
gases (CO2, O2, N2)
regulatory substances (hormoes, enzymes)
What is the structure of an erythrocyte?
biconcave disk
elastic, deformable
7.8 um diameter
2.6 um edge
0.8 um center
What do erythrocytes stain with?
eosin
What is the lifespan of erythrocytes?
120 day lifespan
How are old erythrocytes removed?
90% phagocytosed by macrophages in spleen, bone marrow, and liver
10% break down intravascualarly
What are the integral membrane proteins of erythrocytes?
glycophorins
band 3 protein
What are the peripheral membrane proteins of erythrocytes?
actin, adducin, band 4.1, spectrin
What is the function of membrane proteins in erythrocytes?
network that laminates inner layer of membrane
junctional complexes stabilize prectrin tetramers
How is blood type recognized by erythrocytes?
sugar groups on peripheral proteins (type: A,B,O)
What is the structure and funciton of hemoglobin?
globulin alpha, beta, delta, and gamma
located on the large erythrocyte surface
iron-bound gas exchange
affinity for O2
What is a leukocyte?
digestive cell containning lysosomes
What are granulocytes?
leukocytes with specific granules
segmented nucleus
not dividing
short lives
What are the different types of granulocytes, %?
neutrophils 55-60%
eosinophils 2-5%
basophils 0-1%
What are agranulocytes?
leukocytes that lack specific granules
not segmented
actively dividing
long lives
What are the different types of arganulocytes, %?
lymphocytes 30-35%
monocytes 3-7%
What is the structure of a neutrophil?
10-12um diameter
multilobulated nucleus (2-4)
females have 'barr body' or drum stick appendage on lobe of 1 nucleus
What are the granules of neutrophils?
specific granules
azurophilic granules
tertiary granules
What is the function of specific granules in neutrophils?
release suring inflammatory response
nost numerous
What is the function of azurophilic granules in neutrophils?
larger, less numerous
similar to lysosomes (acid hydrolases)
defensins (form channel in bacteria wall)
contain myeloperoxidase (reactive bactericidal chlorines)
What is the function of tertiary granules in neutrophils?
contain enzymes secreted by cell
can insert ahesion molecules to cell membrane
What is the function of neutrophils?
first wave of defense, most numerous
active phagocytes at inflammatory site
How do neutophils kill bacteria?
migrate to site of action in connective tissue
specific and azurophilic granules fuse with phagosome membrane
kill bacteria
What is pus?
dead bacteria and dead neutophils
What is the structure of an eosinphil?
a leukocyte
10-12um diameter
refractile crystalloid bodies
What is the funtion of an eosinphil?
kill larval parasites
opperate with mast cells in allergic reactions
What is the structure of a basophil?
leukocytes
numerous large granules (stain with basic dyes)
heparin
histamine
acidic hydrolases
What is the funciton of a basophil?
similar to mast cells
bind antibodies
degranulate
What is the structure of lymphocyte?
a leukocyte
6-30um
90% are small
lymphatic immune cells
What are the different types of lymphcytes?
T cells (long life, cell mediated immunity)
B cells (produce circulatin antibodies)
NK cells (short life, kill certain virus infected cells)
What is the structure of a monocyte?
largest WBC
originate in bone marrow
indented cell nucleus is bean shaped
What is the function of a monocyte?
precursor of mononuclear phagocytotic cells
differentiate into macrophages, osteoclasts, etc.
What is the structure of a thrombocyte (platelet)?
2-3um diameter
disk shape
glycocalyx coat, receptors
microtubules (8-24), actin, myosin
fibrogren, coagulation factors
What is the funciton of a thrombocyte?
platelets derived from megakayoctes
survalence of blood vessels
blood clot formation
repair of injured tissue
What are the different types of T cells?
cytotoxic (recognize antigens)
helper (induction of immuse response)
supressor (downregulate T lymphocyte initiation)
What is the structure of bone marrow?
spongy bone in flat and long bones
sinusoid blood vessels covered by reticular tissue
vascualr and hemopoetic
What is the funciton of bone marrow?
to produce erythrocytes and thrombocytes
new blood cells penetrate endothelium to enter circulation
not active bone marrow is predominantely adipose (yellow)
Formaiton of erythrocytes
proerythroblast
basophilic erythroblast
polychromtophilic erythroblast
orthochromatophilic erythroblast
reticulocyte
erythroblast
erythrocyte
Formation of neutrophil
myeloblast
promyeloblast
neutrophilic myelocyte
neutrophilic metamyelocyte
neutrophil-band
neutrophil
Formaiton of eosinophil
myeloblast
promyeloblast
eosinophilic myelocyte
eosinophilic metamyelocyte
eosinophil
Formation of basophil
myeloblast
promyeloblast
basophilic myelocyte
basophilic metamyelocyte
basophil
Formation of platelets
multiple endimitoses
polyploidal cell (64n)
single lbulated nucleus
divided by membrane territory
easy release to proximal sinusoid
What is the funciton of myofilaments?
responsible for muscle cell contraction
What are the two types of myofilaments?
thin filaments
thick filaments
What is the structure of a thin filament?
6-8nm diameter
1um long
composed primarily of actin
fibrous actin (F-actin)
globular actin (G-actin)
What is the structure of a thick filament?
15nm diameter
1.5um long
composed of myosin II
200-300 myosin II molecules in one filamen
rod shaped tail
projecting heads
What is the single purpose muscle cells contain a large number of contractile filaments?
to produce mechanical work
What are the pincipal types of muscle?
striated (exhibit cross-striations)
smooth (do not exhibit cross-striations)
What are the types of muscle, based upon location?
skeletal
visceral
cardiac
What is the structure of skeletal muscle?
Where can it be found?
attach to bone
movement of axial and appendicular skeleton
maintinance of body position and posture
percise movement
Where can smooth muscle be found it be found?
Tongue, pharynx, upper esophogas
What is the structure of cardiac muscle?
Where can it be found?
striated muscle
wall of the heart
base of large veins that empty into heart
What is characteristic about skeletal muscle?
multinucliated syncytium
"muscle fiber"
long
cylindrical
What connective tissues hold together muscle fibers?
endomysium
perimysium
epimysium
What is the structure and function of endomysium tissue?
delicate layer of reticular fibers that immediately surround individual muscle fibers
What is the structure and function of perimysium tissue?
thicker connective tissue that surround a bundle/fascicle of fibers
What is the structure and function of epimysium tissue?
a sheath of dense connective tissue that surrounds a collection of fascicles
What are the different types of skeletal muscle?
Type I, slow oxidative fibers(red)
Type IIa, fast oxidative glycolytic fibers (white)
Type IIb, fast glycolytic fibers (intermediate)
How are types of skeletal muscles distinguished?
color when dyed
speed of contraction and relaxation
What is the structure and function of Type I skeletal muscle?
intermediate fibers contain many mitochondria and large amounts of cytochrome complexes and myoglobin
slow-twitch fatigue-resistant motor units
(marathon runners)
What is the structure and function of Type IIa skeletal muscle?
many mitochondria and a high myoglobin content
capable of anaerobic glycolysis
fast-twitch fatigue-resistant motor units
longer distance sprinters
What is the structure and function of Type IIb skeletal muscle?
large fibers will less myoglobin and fewer mitochondria
low oxidative enzymes
high anaerobic enzyme activity on high amount of glycogen
fast-twitch fatigue-prone units
short distance sprinters, weightlifters
What is a myofibril?
the structural and functional subunit of a muscle fiber
composed of bundles of myofilaments
What are myofilaments?
inficifual filamentous polumers of myosin II, actin, and associated proteins
What are the structural levels of muscle fiber, magnification?
skeletal muscle
muscle fascicle
muscle fiber
myofibril
What are the different bands of a myofibril?
A band (actin, myosin, dark)
I band (unbound actin, light)
Z line (dark border)
H band (unbound myosin, light)
M line (most central line)
What is the basic contractile unit of striated muscle?
sacromere
What is the structure and function of a sacromere?
segment of myofibril between adjacent Z lines
resting 2-3um
stretched 4um
contracted 1um
What are the thin filament proteins?
F-actin
tropoyosin
tropnin
What are the thick filament proteins?
myosin II
What is the structure and function of tropomyosin?
double helix of two polypeptides
forms filaments that run between F-actin
when resting masks the myosin binding site on the actin molecule
What is the structure and function of trophin?
complex of three globular subunits
binds Ca2+ (essential step in the initiation of contraction)
inhibits myosin-actin interaction
What is the structure and function of myosin II?
two polypeptide heavy chains (small globular projections at right angles)
four light chains
rodshapped segments overlap
What are the names accesory porteins used in maintainning alighnment of thin and thick filaments?
titin
nebulin
desmin
dyomesin
C protein
dystrophin
What is the structure and function of the protein titin?
accesory protein in muscle fiber forms elastic lattice anchoring Z lines
two springlike portions
help stabalize
prevents excessive stretching
What is the structure and function of the protein nebulin?
accesory protein in muscle fiber helps anchor thin filaments to Z line
What is the structure and function of the protein desmin?
accesory protein in muscle fiber surrounds Z lines
stabilize cross-links between neighboring myofibrils
What is the structure and function of the protein myomesin?
accesory protein in muscle fiber
myosin-binding protein
holds thick filaments to M line
What is the structure and function of the protein C protein?
accesory protein in muscle fiber
myosin-binding protein
holds thick filaments to M line
What is the structure and function of the protein dystrophin?
accesory protein in muscle fiber
link laminin
What is the general contraciton cycle of skeletal muscle?
binding, hydrolysis, and release of ATP
What happens to the thin and thick filaments during contraction of a muscle?
filaments do not shorten but increase their overlap
thin filaments slide deep past thick filaments into the A band
I bands and H bands shorten as Z disks are drawn closer
What happens during the initiation of contraction of a muscle?
depolarization and Ca2+ release
sarcolemma is depolarized
T tubules convey the wave of membrane depolarization to myofibrils, DHP alter conformation
Ca2+ released into cystol A-I junctions via release channels
high Ca2+ lvls continues contraction cycle
What happens during the activation of actin in muscle fibers?
resting state-tropomyosin covers myosin binding sites
Ca2+ binding by troponin C results in conformational chnage, breaks TnI-actin bond
tropomyosin shifts and uncovers myosin-binging site
What happens during relaxation of a muscle?
low Ca2+ concentration
tropomyosin returns to resting state position
Ca2+ pump in SR membrane is bound
What is a motor unit of muscle cells?
neuron and innervating muscles
"all of none law"
unison
What are the types of innervations of skeletal muscle?
myoneural junction
muscle spindle (stretch receptor)
Golgi tendon organ
What are the structural components of the myoneural junction?
axon terminal lacks myelin, has Schwann cell
synaptic cleft
sarcolemmal incaginations (junctional folds)
postsynaptic membrane (acetylcholine receptors)
sarcoplasm (mitochondria, ribosomes, rER)
What is the sarcoplastic reliculum?
modified smooth endoplasmic reticulum
surrounds myofilaments
What happens in the conduction of nerve impulse across a myoneural junction?
presynaptic membrane is depolarized
voltafe-gates Ca2+ channels open
rise in cytosolic Ca2+ releases acetylcholine into synaptic cleft
acetylcholine binds to receptors of postsynaptic membrane results in a depolarization
degradation of acetylcholine ends the signal
recycling of acetylcholine
What is the structure of the muscle spindle (stretch receptor)?
fluid filled periaxial space is bound by connective tissue
contains 10 modified skeletal muscle fibers surrounded by norma skeletal muscles
What is the funciton of the muscle spindle (stretch receptor)?
stretching of a muscle-stretches the spindle
stimulates afferent nervve endings
response is dependent upon rate and duration or stretch
What is the structure and function of the Golgi tendon organ in the mucles cells?
collagen fibers sitmulated too strenuously on tendon
counteracts the effects of muscle spindles
What are the general features of cardiac muscle cells?
contract spontaneously
display rhythmic beat
branching connections
central nuclei
glycogen granules
doorly defined myofibrils
do not regenerate
What are the structural components of cardiac muscle cells?
T tubules are larger that skeletal muscle, lined by lamina
dyads-contain T tubule and SR
calcium ions
abundant mitochondria
atrial granules
intercalated disks
connective tissue elements
Purkinje fibers
How do calcium ions act in cardia muscle cells?
Ca2+ leaks into carcoplams at slow rate during relaxation (autonomic rhythm)
Ca2+ released from SR in response
contraction is dependent on concentratio of Ca2+
What are intercalated disks in muscle cells?
comples step-like junctions between adjacent cardiac muscle cells
What are Purkinje fibers?
modified cardiac muscle cells in bundle of His
conduction with a few myofibrils
What is the structure of smooth muscle?
nonstriated, fusiform cells
varriable lengths
regenerate
central nucleus (corkscrew shape when contracted)
mitochondris, RER, and Golgi concentrated at poles of nucleus
sarcolemmal vesicles (Ca2+ movement)
nexus gap junctions
What is the difference between skeletal and smooth muscle thick filaments?
skeletal-myosin molecules are opposite
smooth-myosin molecules all point in same direction
What happens in the contraction of smooth muscle?
slower and longer contraction
transient increase in Ca2+
inhibitory effect is eliminated in the presence of Ca2+
What happens in the initial contraction of smooth muscle?
vascular smooth muscle triggered by nerve impulse
visceral smooth muscle is triggered by stretching of muscle and spreading of signal
What nerves innervate the smooth muscle?
sympathetic and parasympathetic nerves
What are some contractile nonmuscle cells?
moyepithelial cells
myofibroblasts
What is the general stuctrue of connective tissue?
tissue primarily of extracellular matrix (ground substance, fibers, fluid)
What is the general function of connective tissue?
supports
medium for exchange
protects
repairs
stores fat
What are the most common collagen types in connective tissue proper? What are they composed of?
type I
type III
tropocollagen
What are the different cell types associated with connective tissue? (resident/transient)?
fibroblasts (resident)
pericytes (resident)
adipose tissue (resident)
mast cells (resident)
macrophages (transient)
lypmhoid cells (transient)
plasma cells (transient)
granulocytes (transient)
What are the two different types of fibroblasts?
active fibroblasts
quiescent fibroblasts
From where are fibroblasts formed?
asire from mesenchymal cells
What is the structure of a fibroblast?
within connective tissue proper
two or more nuclei
oval nucleus
What is the structure and funtion of active fibroblasts?
spindle-shaped (fusiform)
well developed rER and Gogli
produce procollagen and other extracellular components
What is the structure and function of Quiescent fibroblasts?
small flattened cells
little rER
inactive
(except during wound healing)
From where are pericytes formed?
arise from embryonic mesenchymal cells
What is the structure of a pericyte?
small characterists of smooth muscle and endothelial cells
smaller than fibroblasts
located along capillaries with basil lamina
What is the function of a pericyte?
function as contractile cells that modify cappilary blood flow
differentiate into smooth muscle cells and endothelial during wound healing
From where are adipose cells formed?
arise from mesenchymal cells and fibroblasts
What is the function of an adipose cell?
synthesis, storage, and release of fat
What are the types of adipose tissue?
unilocular
multilocular
What is the structure and function of a unilocular adipose cell?
contain a single fat droplet
appear white
peripheral nucleus
receptors for insulin and other hormones
control uptake and release of free fatty acids and triglycerides
What is the structure of multilocular adipose cells?
contain many small fat droplets
appear brown
central spherical nucleus
What are mast cells formed from?
arise from myeloid stem cells during hemopiesis
What is the structure of a mast cell?
largest cell of connective tissue proper
central spherical nucleus
well developed Golgi
scant rER
What is the function of a mast cell?
contain secondary and primary mediators
mediate immediate hypersensitivity (allergic reactions)
degranulation occurs from second exposure and binding of IgE
What are macrophages formed from?
originate in bone marrow as monocytes
What is the principle function of macrophages?
phagocytosing cells
remove large particulate matter
assist in immune resopnse
What is the structure of a macrophage?
eccentric kidney-shape mucleus
vacuoles, lysosomes, residual bodies
What are lymphoid cells formed from?
arise from lymphoid stem cells during hemopoiesis
What are the different types of lymphoid cells?
T cells (cell mediated immune respone)
B cells (differentiate to plasma cells, body/humoral immune response)
NK cells (cytotoxic activity on tumor cells)
What are plasma cells formed from?
arise from activated B lymphocytes
What is the structure of a plasma cell?
clumps of heterochromatin in wheel spoke form
ovid cell
plae nucleus
abundant rER
What is the function of a plasma cell?
humoral immunity
anti-body manufacturing cells
What are the classifications of connective tissue?
embryonic
proper
What are the types of embryonic connective tissue?
muscous tissue (loose connective umbilical cord)
mesenchymal tissue (only in embryo, smorphous matrix)
What are the types of connective tissue proper?
loose conenective tissue (vascularized, flexible, fewer fibers, more abundant)
Dense connective tissue (irregular-dermis, organs; regular-tendons, ligaments)
What is the general structure of the extracellular matrix?
organized meshwork of macromolecules
ground substance
fibers
What are the different proteins in the ground substance?
GAGs (glycosaminoglycans)
proteoglycans
glycoproteins
fibronectin receptors
What is the structure of GAG proteins?
glycosaminoglycans
repeating disaccharide with one amino sugar
sulfated strong=negative charge
large volume
What are the types of GAG proteins?
hyaluronic acid (connective tissues, not sulfated)
chondoitin sulfate, dermatin sulfate (bone, cartilage; skin)
heparin, heparan sulfate (lungs)
keratan sulfate (nucleus pulposus)
What is the structure and function of proteroglycans?
core protein of GASs
binding sites for growth factors and signaling molecules
What are the different glycoproteins?
fibronectin (cell adhesion molecule)
laminin (basal laminae anchor)
entactin
tenascin
chondronectin
osteonectin
What are the different types of extracellular fibers?
collagen
elastic fibers
What are the steps in intracellular collagen synthesis?
preprocollagen synthesis (mRNA)
hydroxylation (rER)
attachement of sugars (glycosylation in rER)
procollagen formation (triple-helix, rER)
addition of carbohydrates (Golgi)
secretion of procollagen
What are the steps in extracellular collagen synthesis?
clevage of procollagen ends
self-assembly
covalent bond (cross-link)
What are the most common collagen fiber types?
I
II
III
IV
V
VII
What is the formation, location, and funciton of type I collagen?
fibroblast, osteoblast, odontoblast
dermin of skin, bone, tendon, ligaments, fibrocartilage
resists tension
What is the formation, location, and funciton of type II collagen?
chondroblasts
hyaline cartilage
resists intemittent pressure
What is the formation, location, and funciton of type III collagen?
fibroblast, schwann cell, hepatocyte, reticular cell
visceral organs
structural framework in expandable organs
What is the formation, location, and funciton of type IV collagen?
endothelial, epithelial
basal lamina
support and filtration

muscle, schwann
external lamina
scaffold for cell migration
What is the formation, location, and funciton of type V collagen?
mesenchymal cell
placenta
unknown
What is the formation, location, and funciton of type VII collagen?
keratinocyte
dermal-epidermal junction
secures lamina densa
What are the components of elastic fiber?
elastin
fibrillin
What is the structure of elastic fibers?
amorphous structural proteins
elasticity to matrix
composed of elastin and fibrillin
What are the structural divisions of nervous tissue?
central nerous sysytem (brain, spinal cord)
peripheral nervous system (nerves, ganglia)
What are the funcitonal divisions of nervous tissue?
sensory
motor (somatic, autonomic)
What types of cells are containned within nervous tissue?
neurons (conduct immpulases)
neruroglial (support)
What is the histogenesis of the nervous system?
neruoepithelium
neural plate thickens and differentiates
nerual groove
nerual tube (spinal cord, brain)
neural crest cells stem
What are the different morphological classificaitons of neurons?
unipolar (single process)
pseudounipolar (single branching process)
bipolar (single axon, dendrite)
multipolar (most common)
What are the functional classifications of nerurons?
sensory (to CNS)
interneurons (connect)
motor (from CNS)
What is the structure of the neruron?
cell body
dendrites (recieve stimuli)
axons (transmit away)
What are the characteristic components of neuronal cell bodies?
large central nucleus
nissl bodies (clumps of polysomes, rER)
Gogli close to nucleus
scattered mitochondria
neurofilaments, microtubules, microfilments
granules
What is the strucutre and funciton of dentrites?
arborized terminals
lack Golgi
abundant mitochondria
spines increase area
recieve stimuli, transmit to soma
What is the structure and function of axons?
contain collaterals (perpendicular branches)
can be long processes (100cm)
What are the functions of neuroglial cells?
support and protect neurons
What are the different types of neuroglial cells?
astrocytes
oligodendrocytes
schwann cells
microglia (phagocytic)
ependymal cells (epithelial cells)
What is the structure and function or astrocytes?
neuroglial cell that passess pedicles
protoplasmic (gray matter)
fibrous (white matter)
sealed barried
structural support
scar tissue
What is the structure and function of oligodendrdrocytes?
live symbiotically with neurons
gray and white matter
produce myelin
What is the structure and function of Schwann cells?
few mitochondria
create myelin sheath around an axon
What are nerve synapses?
functional appositions for transmitting signals
What are the different classifications of synapses?
axodendritic
axosomatic
axoaxonic
sendrodendritic
What are the different methods of synapse signal transmission?
chemical synapses
electrical synapses
What are the characteristcs of chemical synapses?
most common neruon-neruon synapse
only neruon muscle synapse
slight delay
contain neurotransmitters (acetylchoiline)
What are the characteristics of electrical synapses?
movement of ions between neurons via gap junctions
almost instantaneous
What are neurotransmitters?
diffusing chemical substances in synapse
produced, stored, and released by presynaptic neurons
What is the structure of a synapse?
acon terminals
preynaptic membrane (voltage-gated Ca2+)
postsynaptic membrane (receptors)
synaptic cleft (20-30nm wide space)
synaptic vesicles (transport neurotransmitters to membranes)
What are the types of nerve fibers?
myelin sheath
nodes of ranvier
internodes
What is the structure and function of the myelin sheath fibers?
produced by oligodendrocytes and Schwann cells
spiral layers of plasma membrane
present in lenght of axon
What are the nodes of ranvier?
regions along axons that lack myelin
discontinuities between adjacent Schwann cells
What are the connective tissues that surrond nerves?
epineurium (external coat)
perineurium (surrond bundle/fascicle, tight junctions)
endoneurium (thing reticular fibers)
What are ganglia, types?
aggregations of neruonal cell bodies
autonomic ganglia (motor)
craniospinal ganglia (sensory, dorsal root, pseudounipolar)
What is the distophysiology of nervous tissue?
resting membrane potential
action potential
axonal transport
What are the characteristics of resting membrane potential in neurons?
exists across plasma membrane
maintained by K+ leak channels and Na+-K+ pump
no net movement of K+ ions
How is the action portential in neurons generated?
stimulus creates depolarization
threshold reached-voltage gated Na+ channels allow Na+ to enter cell
reversal of resting potential
voltage-gated K+ channels triggered by depolarization to repolarize (open longer)
How is the action potential in neurons propogated?
longitudial diffusion of Na+ ions depolarizes adjacent membranes
most rapid in myeliniated fibers
What are the two types of axonal transports?
anteroretrograde transport (away from soma)
retrograde transport (toward soma for recycling)
What is the structe and function of the somatic nervous system?
contains sensory fibers
innervate skeletal muscle
propogate voluntary movement
What is the structure and function of the autonomic nerous system?
regulate smooth muscle, cardiac muscle, and glands
maintain homeostasis
sympathetic and parasympathetic systems function antagonistically
What are the types of autonomic nerves?
pregangionic fibers to autonomic ganglion of CNS
postganglionic fibers to effector organ
What is the function of the sympathetic system?
vasoconstriction
increase HR, BP, and respiration
What is the funciton of the parasympathetic system?
secretomotor
decreases HR, BP, and respiration
What is the structure of the CNS?
white matter (myelinated nerve fibers, neuroglial cells)
gray matter (unmelinated neuronal bodies)
meninges
cerebrospinal fluid
What is the structure of gray matter in the spinal cord?
appears in the shape of a central 'H'
central canal
dorsal horns (sensory)
ventral horns (motor, multipolar)
What is the structure of the gray matter in the brain?
peripheral (cortex)
purkinjie cell layer
excitatrory and inhibitory impulasis
basal ganglia in cerebrum
What are the meninges?
membranous coverings of the brain and spinal cord in the CNS
(dura mater, arachnoid mater, pia mater)
What is the structure and function of the cerebrospinal fluid?
choroid plesus
water, ions, protein
nouraishes brain and spinal cord
What is characteristic about nerve tissue's degeneration and regeneration?
neurons of CNS cannot divide
regeneration or proximal axonal segment
What are the classifications of epithelia based upon?
number of cell layers
shaper of superficial layer
What is the shape and location of simple squamous cells?
flattened, single layer
lining of blood vessels (endothelium, mesothelium)
What is the shape and location of simple cuboidal cells?
cuboidal, single layer
lining of kidney, ovary, ducts
What is the shape and location of simple comlumnar cells?
columnar, single layer
lining of intestine, stomach, excretory glands
What is the shape and location of pseudostratified cells?
falsely stratified, single basal layer (all attached to basal lamina, not all reach lumen)
lining of trachea, bronchi, nasal cavity
What is the shape and location of stratified squamous cells (nonkeratinized)?
flattened, multiple layers
lining of esophagus, vagina, mouth
What is the shape and location of stratified squamous (kerateinized)?
flattened (no nuclei), multiple layers
epidermis of skin
What is the shape and location of stratified cuboidal cells?
cuboidal, multiple layers
lining of ducts in sweat glands
What is the shape and location of stratified columnar cells?
columnar, multiple layers
lining of large excretory ducts
What is the shape and location of transitional cells?
dome-shaped to flattened
lining of urinary passages
What are the functions of epithelial cells?
transcellular transport (diffusion of gases, carrier protein and vesicle mediated transport)
absorption
secretion
selective permeability
protection
What are the different types of lateral and basal junctions? (from apex to base)
tight junctions
intermediate junctions
desmosomes
gap junctions
hemidesmosomes
What is the structure and function of tight junctions?
zonula occludens
surrounds apical perimeter
fusion of outer leaflets
integral membrane proteins
What is the structure and function of intermediate junctions?
zonula adherens
surround the entire perimeter
actin filaments
E-cadherin
ribbon adhesion zone
What is the structure and function of desomsomes?
macula aherens
dense plaque (desmoplakins)
keratin filaments
glycoproteins
What is the structure and function of gap junctions?
communicating junctions
couple adjacent cells metabolically and electrically
ordered 12 subunits of connexons (open and closed conformation)
What is the structure of the basal lamina?
extracellular supportive structure
type IV collagen (some I, III), laminin, entactin, proteoglycans
lamina lucida
lamina densa
What is the structure and funciton of hemidesmosomes?
adhesion of basal cells
dense cytoplasmic plaque
link to extracellular matrix
What is the structure and function of basal plasma-membrane infoldings?
ion-transporting epithlia
deep invaginations that compartmentalize
increase SA
bring ion pumps close to mitochondria
What is the structure of the apical epithelial surface?
microvilli
seriocilia
cilia
What is the structure and function of microvilli?
projections of epithelia
nine triplets
extend into a lumen increasse SA
glycocalyx
actin filaments with terminal web connection
brush border in kidney (proximal tube cells)
striated border of intestine (absorptive cells)
What is the structure and function of sterocilia?
very long mucrovilli
epididymis and vas deferend of male reproductive tract
What is the structure and function of cilia axoneme?
actively motile propel substances (effective and resting stroke)
longitudinal microtubules
9 doublets+2 configuration (ciliary dynein arms, radial spokes, central sheath, and nexin)
without central microtubules cilia would only spin
What is the structure and function of cilia basal body?
base of each cilium
(9+0) configuration
9 triplet microtubules
What are the classifications of multicellular exocine glands?
duct branching (simple, compound)
shape of secretory unit (alveolar-sac/flask, tubular)
What are the types of glands?
exocrine (secrete into a duct or surface)
endocrine (secrete into bloodstream, no duct)
paracrine (secrete into extracellular space)
What do multicellular exocrine glands secrete?
mucus
serous secretions (water, enzymes)
mixed secretions
What are the different mechanisms for multicelluar exocrine secretion?
merocrine (parotid-releases just contents)
apocrine (marramry-part of apical cytoplasm released with contents)
holocrine (sebaceous-entire cell with contents released)

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