Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
|
where is cardiac muscles
|
myocardium of heart
functional syncytium vs true syncytium |
|
|
Autonomic NS regulates but does NOT generate cardiac rhythm
|
cardiac rhythm is by SA AV AV nodes purkinjke fibers
|
|
|
Cardiac in light microscope
|
branch
intercalated discs capillaries mono-bi nucleate, centrally located fiber sizes vary but not as much as smooth muscle |
|
|
Cardiac Electron microscope
|
greatest amounts of mito
glycogen, but less than skeletal sarcomeres SR not as extensive, dyad intercalated discs step like |
|
|
telling the difference between atria and ventricle
|
atria: narrower
ventricle: large diam, wider T tubule at Z band |
|
|
Intercalated discs
|
where Z line would normally be
step like b/c not all myofibrils in a cardiac myocyte are equal length -longitudinal(gap junxns) -transverse(Fascia adherens-thin filaments (desomosomes-macula adherenns intermediate filaments) |
|
|
Components of the conduction system
|
SA -> AV -> purkinje fibers in bundle of his
|
|
|
characteristics of
SA/AV Purkinje |
SA/AV - smaller in diam, sep by CT, but attached in certain places by gap, oscillating mem pot
purkinje - larger diam, more glycogen(paler), branching bundles run under endocardium and make gap junxns with ventricular myocytes |
|
|
SMOOTH MUSCLE
|
the most recently evolved contractile tissue
|
|
|
Smooth muscle structure
|
spindle
central elongated nucleus CORKSCREW en passant boutan of autonomic NS axons SMALL diam |
|
|
smooth muscle ultrastructure
|
gap junxns(some sm muscle is innervated individually like iris for maximal control)
caveolae(t tubule) dense bodies(Z lines)alpha actinin and vimentin |
|
|
smooth muscle myosin II arrangement
|
sidepolar instead of bipolar
tail to tail but with heads pointing in opposite directiong |
|
|
describe ca influc in smooth muscle
|
main source is extracellular Ca
binds calmodulin(not tnC), activates MLCK --> P-myosin regulatory light chain deP'd by myosin phosphatase |
|
|
Thick filament smooth muscle
|
no bare zone
|
|
|
Smooth muscle oddities
|
can divide, makes collagen and elastin
Tubular - layers Sac like - interlacing bundles |
