Muscle Histology Flashcards
Where are nuclei located in skeletal muscle?
At the periphery.
What colour are type I fibers?
Red
By what portion are sarcomeres formed?
By the portion between two Z disks.
Which protein is at the Z disc bound to actin?
Alpha-actinin
Which protein alineates the Z discs and connects the myofibrils to the cell organelles?
Desmin
Which protein binds thick filaments (myosin) to the Z disc?
Titin
Which protein binds actin to the cell membrane?
The cytoskeleton to the ECM.
Dystrophin
Which binding protein is elastic and acts as a coil?
Titin
Which protein is in charge of mantaining thick filament
cross-linking?
Myomesin
Located at the central part.
In what position is the T tubule respecting the myofibrils?
The T tubule is perpendicular (transverse) to the myofibrils.
Of what are the triads formed?
Of the T tubule and the terminal cisternae (dilations of the SER) at both sides.
Where are the triads located?
In the intersection between I and A bands.
What part of the muscle detects the degree of stretching?
The muscle spindle.
Where can we find satellite cells?
Inside the same basement membrane than muscle cells (and myofibirls…).
Can skeletal muscle divide?
No
But it can regenerate through satellite cells (progenitor cells).
Where are the nuclei in cardiac muscle located?
At the center.
How many nucleis does a cardiac muscel cell have?
1 or 2 nuclei.
True/False
In the cardiac muscle per each fiber there is one cell.
FALSE
One fiber is formed by many different cells.
Branching of the fibers.
Does the Sarcoplasmic Reticulum form terminal cisternae in the cardiac muscle?
NO
Is the cardiac or the skeletal muscle the one which has wider and less abundant T tubules?
The cardiac muscle.
Where do diads appear at the cardiac muscle?
At the Z lines
To what are Intercalated discs alligned?
To the Z discs.
What is the responsability of the intercalated discs?
To mechanically (transverse, fascia adherens and desmosomes) and electrically (lateral,gap juntions) coupling heart cells.
When does contraction in the cardiac muscle initiate?
After the contact of the Purjinke fibers with the Cardiac myocytes.
