By muscle contraction the length of the I-discus is diminished whereas the A-discus is unchanged.
"Sacromere" is a concept designated to the part of the myofibril between two Z-lines.
Leiomyofibril is the cell specific for the striated muscle tissue.
The intercalated discs are localized in the cardiac muscle tissue.
Z-Line (telophragma) is in the middle of the I-discus of the myofibril.
The loose connective tissue plays a role of inter-cellular substance for the muscle tissue.
The myofibril is:
Specialized cell organelle
Cell
Syncytium
Symplast
Under electron microscope in H - band of myofibril are observed:
Thin myofilaments
Thick myofilaments
Thin and thick myofilaments
No myofilaments
The nuclei of the striated myofibre are localized:
In the central part of the cytoplasm
Sublemmal (under the plasma membrane)
Without strictly localization
Along the bundles of myofibrils
The intercalated discs between the cardiomyocytes are localized:
Step-like
Under the plasma membrane
Along the bundles of cardiomyofibrils
Under electron microscope in I-disc of the myofibril are observed:
The cardiomyocytes bind together through:
Interdigitation ("zipper" interlocking)
Intercalated discs
Hemi-desmosomes
Basal lamina
Under electron microscope in A-disc of the myofibril are observed:
The cardiomyofibrils in the cells of impulse-conductive muscle tissue:
Are scanty and centrally placed in the cell
Fill the whole cell cytoplasm
Are scanty and peripherally placed in the cell
Are lacking
The sacrosomes in the muscle tissue cells are:
Phagesomes
Mitochondria
Lysosomes
Cell inclusions
Myoepithelial cells are localized
In the wall of some acini
In the blood vessels wall
In the skeletal muscles
In the wall of the semi-niferous tubules
The most specific features of the muscles tissue are:
Abundant intercellular substance
Numerous blood vessels and nerve endings
Lack of proper intercellular substance
Presence of three types of microscopic organisation
Presence of tonofibrils
Which of the following is specific for the striated skeletal muscle tissue:
Presence of striated myofibrils
Presence of smooth myofibrils
Symplast type of organisation
Syncytial type of organisation
Origin from the mesoblast
Which of the following is specific for the smooth muscle tissue:
Cellular type of organisation
Origin from the mesenchyme
Origin of the mesoblast
The intercalated discs of the cardiac muscle tissue consists of:
"Zipper" interlocking (interdigitatio)
Gap junctions (nexus)
Tight junctions (zonula occludens)
Desmosomes
