Test 2 Part 2 Flashcards
CT wrapping of skeletal muscle
endomysium
perimysium
epimysium
thin filament
consist primarily of actin protein - G-Actin monomers that assemble to form a polymer - 2 G-actin polymers twist together to form double stranded helix = filamentous actin (F-actin)
F-Actin + troponin complex + tropomysoin alpha helices
troponins
TnT- attached to tropomyosin in actin groves
TnC - binds Ca ions
TnI - INHIBITS actin myosin interaction; binds troponin complex to actin molecules
tropomyosin
consists of two polypeptide chains that form an alpha-helix. the tropomysoin molecules line up in head to tail arrangement - each tropomyosin molecule rests on 7 G-actin molecules and COVERS their active sites for myosin
thick filaments
consist of myosin II protein about 200 quantity - cool.
myosin components
2 heavy chains (golf clubs)
4 light chains (flat-ish golf clubs)
myosin breakdown with trypsin
2 segments -
1) heavy meromyosin - 4 light, 2 glob heads, short twisted tail
2) light meromyosin - long twisted tail - two chains wrapped around each other in an alpha helix
heavy meromyosin break down with papain
TWO S1 moieties (S1 = 2 light chains +1 glob head) and ONE S2 segment (short twisted tail
organization of muscle
Overlapping of Thin Filaments + Thick Filaments form a –> Sarcomere –> Long cylindrical series of end-to-end sarcomeres form a–> Myofibril –> many parallel myofibrils are enclosed within a –> Muscle Fiber (Muscle Cell)
a-band
dark band - thick and thin fil - widest band
H–band
thick only - bisects a-band
z-line
attachment for thin filaments, contain alpha actinin= anchor, bisects the I-band
m-line
Consists of protein structures lying between thick filaments, holding them in register.
Creatine kinase is the major protein here. Bisects the H-band.
titin molecules
accessory protein - anchors thick fil to the Z-disks - 4 to each thick fil
alpha actinin
accessory protein - anchors thin fil to Z-disk- component of z-disk
nebulin
accessory protein - anchors thin fil to z-disk - 2 nebulins per - NON ELASTIC wrapped around
which three proteins create the orderly arrangement of striated muscle
titin, alpha actinin and nebulin
myomesin
secures thick filaments in register at the M-line.
c-protein
secures thick filaments in register at the M-line. (SAME AS MYOMESIN)
dystropin
cytoplasmic protein that binds actin (thin) filaments to laminin (a component of the external lamina surrounding the muscle fiber).
endomysium
surrounds each msucle fiber/cell - reticular fibers
perimysium
surrounds bundles of many muscle fibers = fascicles - collagenous CT derived from epimmysium
epimysium
many fascicles surrounded by this layer = envelopes the gross muscle - send septa within the muscle so that vessels and nerve fibers may reach deeper aspects of the muscles
transverse tubules (t-tubules)
invaginations of the cell membrane. Their lumen is continuous with the extracellular space, and contain extracellular fluid. Their function is to carry nerve impulses deep into the cell.at junction of A and I band
Sarcoplasmic reticulum
form a sleeve around each myofibril. - CA storage in terminal cisternae
Terminal cisternae
part of sarcoplasmic reticulum - store calcium here.
triads
1 t-tubule + 2 terminal cisternae of SR - at A-I junction
Satellite cells
regenerative cells that lie between the skeletal muscle cell and its external lamina. Following tissue injury they undergo proliferation. New myoblasts are derived from satellite cells.
motor end plate
one per muscle fiber/cell - has axon terminal- synaptic cleft - muscle cell sarcolema (post synaptic membrane)
Myasthenia Gravis
autoimmune disease causing muscle weakness
Ach receptors are detroyed via antibody-receptor complex
Muscular Dystrophy
genetic, degenerative disease, affecting striated muscles
gene for dystrophin is funky on X-chromosme
it is supposed to bind actin filaments
cardiac muscle
weakly striated - BRANCHED - contain glycogen deposits - lipid droplets for FA (major E source) - lipofuscin:aging pigment - artial granules: Lower BP by actin on kidney water loss - endomysium for capillaries to each muscle cell, intercallated disks: junctions - `
fascia adherens of cardiac muscle
transverse portion - anchor actin filaments of terminal sarcomere to plasma membrane
Maculae adherentes of cardiac muscl
transverse portion - spot desmosomes - bind cells together
gap junctions of cardiac muscl
lateral portion - for flow of ions SO THAT MUSCLE CONTRACTS AS A SYNCYTIUM!
diads in cardiac muscles
one T-tubule and one Sr form Diad a z-disk
Purkinje fibers
specialized (modified) cardiac muscle cells, located in the endocardium. have glycogen deposits
relay electrical impulse to cardiac muscle fibers
troponin test
blood test that is ordered when a patient complains of chest pain. This is one of several blood tests that will help the physician diagnose a heart attack or if the patient has suffered other heart injury (ranging from mild to severe). elevated troponin levels are a problem.. durp
smooth muscle
form sheets and no striations; NO TROPONIN; ONE NUCLEUS; dense bodies form at points of myofilament criss-cross (attachment for thin fil and intermediate fil); NO T-TUBULES; SR NOT WELL DEVELOPED; have caleolae for Ca release;
unitary (visceral) smooth muscle
One innervates a few muscle cells - intestines, uterus, ureters - many gap junctions
calveolae
pinocytotic vessicles that form bubble-like structures on inner surgace of the cell membrane - release CA
multiunit smooth muscle
each muscle fiber has its own nerve supply - sphincter and pupullae muscle
Gray matter
consists of nerve cell bodies and neuroglia arranged into 1) cerebral cortex: multiple layers of nerve cell bodies that form a folded sheet on brain surface 2) cerebellar cortex: same as above but dif location 3) nuclei:collections of nerve cell bodies and neuroglia embedded deep within the brain
white matter
consists mostly of myelinated nerve cell axons with some unmyelinated axons and neuroglia. Axons may be short = 1 mm and reside within the brain; or may be long = up to 1m. Long axons leave the brain and descend to the spinal cord.
neuroglia
support cells in nerve tissue (brain spine etc)
collection of nerve cell bodies in the CNS=
called a nucleus
collection of nerve cell bodies in the PNS=
called a ganglion
axodendritic/axosomatic
nerve synapse onto a dentrite
axoaxonic
nerve synapse onto another nerve synapse
electrical synapse
found in brainstem, cerebral cortex, and retina
uses gap junctions - RAPID
choroid plexus
located in ventricles of brain.
pia mater w/ simple cuboidal epithelium (ependymal cells-type of neuroglia) held together by tight junctions -zona occludentes.
fenestrated (leaky) capillaries
produces CSF-fills ventricles,central canal of spinal cord and subarachnoid space
nerve injury and regeneration occurs where?
in the peripheral nervous system
anterograde changes (regeneration)
distal to site of injury - include axonal degeneration and elimination of debris
1) segment of axon distal to injury degenerates (wallerian degeneration)
2) phagocytotic cells derived from schwann cells and monocytes clean up
3) schwann cells proliferate and form tubes with their external lamina
retrograde reaction and regeneration
proximal to site of injury
1) cell body swells
2) chromatolysis - nissl bodies move to periphery of soma
3) nucleus moves away from cell center
4) free robosomes formed and protein synthesis
5) axon grows
6) schwann cells guide axon growth toward target cell
7) growing axon grows into endoneurium
Essential for growth: macrophages, fibroblasts, basal lamina, and schwann cells
layers of the eye
1) outer-fibrous=corneoscleral coat
2) intermediate-vascular layer=uvea:blood supply, contains chorioid
3) inner-retina:visual aspect - anterior aspect is iris: non visual part
corneoscleral coat
outermost layer of eye - has the cornea and the sclera
uvea
vascular intermediate coat: has the choriod, cilary body, and iris
retinal layer
visual and non visual parts - neural - retinal pigment epithelium (RPE)
chambers of the eye
anterior and posterior separated by the lens. the lens is part of the anterior.
anterior segment of the anterior eye
infront of the iris
posterior segment of the anterior eye
behind the iris
contents of the anterior chamber
aqueous humor iris cilary body and muscle lens cornea anterior sclera
posterior chamber contents
vitreous humor - gel like visual retina RPE posterior sclera uvea
vitreous humor
gel like content of the posterior chamber
gets more fluid like as we age - may detatch retina or something
cornea
anterior 1/6 of the eyeball -it is transparent and refractive! need to let light through to the lens
2/3s of the reflractive power
5 layers - 1) corneal epithelium 2)bowmans membran 3) corneal stroma 4) desceents membrane 5) corneal endothelium
corneal epithelium
1 -Continuation of the conjunctiva
- Stratified squamous (non-keratinized) epithelium attached via desmosomes
- Mitotic activity is high to replace injured epithelium
- Apex of cells have microvilli to help retain tears secreted, prevents corneal drying
- Cells have ferritin to protect DNA from damage to UV light since melanin is absent
- Innervated by Ophthalmic division of CN V, corneal blink reflex, very sensitive
bowmans membrane
2 - Acellular specialized basement membrane
- Does not regenerate
- Terminates at Corneoscleral limbus
- Contributes to strength and stability of cornea
- Acts as a barrier to prevent spread of infections
- If damaged creates an opaque scar, which can impair vision
corneal stroma
3 -90% of corneal thickness: A) Collagen fibrils arranged in lamellae. Adjacent lamellae are arranged at right angles to each other, this maintains the transparency of the cornea B) Proteoglycans and Collagen V are responsible for the precise spacing of the collagen fibrils
-Disruption of the lamellar arrangement results in an opaque cornea
descemets membrane
4 -Basement membrane of the cornea endothelium (Next layer)
- Regenerates after injury
- Thickens with age
- Interwoven meshwork of fibers and pores
- Helps maintain, through connections with the sclera and ciliary muscle, the normal curvature of the cornea
corneal endothelium
5 -Faces the anterior chamber of the eyeball
- Simple squamous epithelium joined by zonula adherens, zonula occludens and desmosomes
- Limited proliferative ability
- Injury results in corneal opacity
- Responsible for virtually all of the metabolic exchanges of the cornea
sclera
- posterior 5/6 of the eye - WHITE of the eye
- tough fibrous CT (collagen and elastic fibers) to maintain shape of eye
- Tenon’s capsule-fascial sheath over the surface of the sclera in which the extraocular muscles insert
- pierced by the optic nerve, blood vessels, and other nerves
corneaoscleral limbus
- contains stem cells for the corneal epithelium
- location of iridocorneal angle- trabecular meshwork, formation of the canal for schlemm (scleral venous sinus), apparatus for the outflow of the aqueous humor
uvea
iris, cilary body, and choroid make it up
cilary body
make up uvea –area ant to the ora serrata - area that defines the ant limit of the retina of choroid and the posterior limit of the cilary body
-lined by two layer of simple columnar epithelium separated by a basement membrane:INNER LAYER (adjacent to aqueous humor, non pigmented, fluid-transporting epithelium, complex cell-to-cell junctions, well developed zona occludens AND OUTER LAYER (pigmented, rich in melanin, less developed cell-tocell junctions, cilary channels
iris
make up uvea – most anterior portion, pupil, ant and post pigment epithelium, contractile diaphragm in front of the lens:dilator pupillae and phincter pupillae
choroid
make up of uvea – dark-brown (MELANOCYTES) vascular sheet - prevents felection of light waves entering
- lies between the sclera and retina
- choriocapillary layer: inner vascular layer, richer in small fenestrated blood vessels, provides nutrients to retina
- Bruch’s membrane (lamina vitrea): thin and amorphous hyaline membrane, innermost layer of the choroid
five layers formed from choroid and a retinal layer (bruchs membrane)
1) basal lamina of endothelial cells of choriocapilary layer
2) Collagen fibers
3) Elastic fibers
4) collagen fibers
5) Basal lamina of the retinal epithelial cells
dialator pupillae
radially arranged smooth muscle fibers, sympathetic - of the iris - opening pupil
sphincter pupillae
circular arranged smooth muscle fibers, parasympathetic - CN III - of the iris - closing pupil
non visual part of the retina
ora serrata
cilary processes
75 radial ridges that secrete and anchor zonule fibers to lens
produce aqueous humor
blood-aqueous barrier
flow of aqueous humor
posterior chamber –> pupil –> anterior chamber –> trabecular meshwork –> canal of schlemm –> venous system
cilary muscle
- longitudinal (meridional) fibers stretch choroid
- radial fibers flattern lens= distal vision
- circular fibers reduces tension on lens=near vision
open angle glaucoma
angle is open but reabsorption into cnanl of schlemm in to venous system is not happening= increase in pressure - slow onset
trabecular meshwork to canal is preventing flow
angle closure glaucoma
angle closed and immediate buildup bc cants get to drainage canal (schlemm)
choriocapilary membrane (bruchs membrane
supplies retina with blood
retina
- –non-photosensitive region - anterior to ora serrata-lines the inner aspect of the cilary body and posterior surface of the iris
- –photosensitive region- posterior to ora serrata, pierced by the optic nerve
- –optic disk (papilla) - site where optic nerve joins retina - no photo receptors= blind spot
- –macula lutea and fovea centralis= only CONES= greatest visual acuity here
ora serata
change from non-visual to visual of retina
fovea centralis
only contains cones - photoreceptors = point of best visual acuity
1 on 1 relationshp bw cone and bipolar cell
RPE
FIRST LAYER -Attached through Bruch’s membrane to the choriocapillary layer of the choroid
- Mechanical separation occurring at this junction = “detached retina”
- pigmented - dark - phagocytic = recycling of rods and cones
- controls what gets sent to retina
detached retina
bw RPE and layer of rods and cones
rods and cones
conducting neurons. connected to biopolar cells to ganglions and axons of ganglions = optic nerve
apical portion embedded into RPE
rods - DEPOLARIZATIONG MORE NUMEROUS - black white gray - rhodopsin pigment - iodopsin pigment
cones - HYPERPOLARIZATION colors - red blue green - high intensity
mullers cells
support cells for rods and cones - packing material - manage metabolites coming to and from rods and cones area
Layers of the retina
INNER MOST - 1) Retinal pigment epithelium
2) layer of rods and cones - photoreceptors
3) outer limiting membrane - end of muller cells( anchoring membrane)
4) outer nuclear layer - cell bodeis of rods and cones
5) outer plexiform layer - CONDUCTING LAYER connection to bipolar cells
6) inner nuclear layer - biopolar nuclei
7) inner plexiform layer - bipolars meet the ganglia cells
8) ganglion cell layer - these are the ganglions
9) layer of optic nerve fibers - head to the optic disc to form optic nerve
10) inner limiting membrane -
crystalline lens
-biconvex
-focuses light rays on retina
-avascular
-not innervated
3 parts: lens capsule (basal lamina and type IV collagen w/ proteoglycans; subcapsular epithelium (cubiodal layer of cells only on anterior surface of lens (connected by gap junctions and gives rise to lens fibers at the equator);lens fibers (produced throughout life, rate dec with age,has crystallins-lens protein-cells with no organelles or nuclei, cataracts=loss of transparency), fibers stiffen and enlarge with age = presyopia-loss of accomodation)
diabetes on eye
glucose gunks up capilaries = bleeds and immune response = swelling, new growth of vessels to make bv which block up cones and rods from light. , cones separate from RPE
macular degeneration
multifactorial disease - fovea centralis is damages - central vision affected
drusen
yellow pigment - under bruchs membrane macular edema - intra retinal bleeding separates retina from RPE
WET AMD
new bv grow in retina
DRY AMD
drusen - protein lipid that occurs in aging - breakdown of RPE cells
catarcts
oldness of chrystalins - plaques accumulate over life - cloud up
vitreous body
pressure of this gel fluid pushes the retina against the RPE and choroid - stagnant not replaced - beomces more watery over time and pressure dexcreases and separation
eye lids
tarsal plates - fibrous plates for shape
stye of the eye
glands of Zeis infection
external ear
cerumen from ceruminous glands (too much = conduction hear loss); tympanic membrane
middle ear
tympanic cavity, simple cuboidal, CNIX, mastoid air cells posterior, auditory tube anterior, ossicles (maleus, incus, stapes) with synovial joints, muscles: stapedius m (dulls stapes) and tensor tympani (dulls of maleus)
internal ear
membraneous labrynth, series of sacs and tubules suspended in a bony labrynth; endolymph, perilymph, and cortilymph
tympanic membrane compostion
outer: simple squamous epithelium (of external auditory epithelium auriculotemporal)
middle: collagen fibers with elastic fibers circularly arranged. Fibroblasts
inner: simple cuboidal (can be squamous) all along tympanic cavity (CNIX)
auditory tube
simple cuboidal changes into respiritory epithelium= pseudostratified with goblet cells; equalizes pressure bw middle ear and nasopharynx
perilymph
fills tube bone to membrane; high in NA low K
endolymph
fills membraneous part inside tube; high K low NA
bony labrynth
filled with perilymph; semicircular canals, vertibule and cochlea, series of tunnels within the petrous part of temporal bone
creating an electrical signal
hair bundle (sterocillia) - next to kinocilia - in the fluid so as the fluid moves the steroecilia will move toward the kinocilia or away - movement = the electrical potential
cristae ampullaris
located in the ampulla of the semicircular duct and canal; toward base of semicircular canal - little swelling;sits perp to longitudianl axis in endolymph; cupula - gelatinous structure that embeds the hair cells at apical portion - if you move it it moves the hair which are connected to the nerve - senses angular, rotational movement of the head
macula
speicalized sensory in the utricle and saccule - sits at roof in horiz plane of utricle and verticle plane of saccule - in endolymph - straight side to side or up down movement - gel membrane with bony structures on the gel (otoliths) - Otolithic membrane - they do not move - help with gravity info - movement of gel shifts hairs - uses bipolar cells to move info back vestibular ganglion
stria vascularis
produces endolymph- later wall of cochlear duct - next to bone - vascular.
basilar membrane
floor of scalia media, holds the organ of corti (special hair cells for sound)
outer hair cells and inner hair cells - hair cells go to tectorial membrane n okinocilium. moves whcih causes the tectorial membrane to shift the movement moves the hair cells. dentrites go to ganglion. deflection bw basilar and tectorial = signal
tectorial membrane
gel membrane- colalgen II, V, IX, glycoproteins
vestibular membrane
preserves the gradient - tight junctions bw scala vestibuli (perilymph) and scala media (endolymph) . simple squamous
phalangeal cells
support for the hair cells - contain cortilymph - help for cotritunnel - cortilymph
cortilymph
high in NA low K
i-band
thin filaments only. bisected by z-line
