11 topics with brief reviews: definitions, key facts, and class questions.
Welcome to the section dedicated to the motor apparatus of our body—muscle tissue. Here, we thoroughly analyze its classification, development (histogenesis), and regenerative capacity.
You will study the organization of skeletal, cardiac, and smooth muscle, dissect the structure of a muscle as an organ, and take a deep dive inside the muscle fiber. We will examine in detail the organization of membrane systems, the histochemistry of various fiber types, and the fine molecular structure of the sarcomere.
During colloquia and exams, professors most frequently demand a thorough understanding of the muscle contraction mechanism (sliding filament theory) and the ability to confidently distinguish cardiac tissue from skeletal and smooth tissue under a microscope. Pay special attention to the intercalated discs of cardiomyocytes and the triads of skeletal muscle fibers—these are classic 'catch' questions used to test students.
What primary feature is used to divide muscle tissues into two large groups?
The basic classification is based on a morphological feature: the presence or absence of transverse striation (division into striated and smooth tissues).
What limits the sarcomere?
The sarcomere is located between two adjacent Z-lines (telophragms).
Why cannot nuclei in a muscle fiber divide?
Centrioles are completely absent in myosymplasts. As a result, nuclei lose the ability to divide both under normal conditions and during tissue regeneration.
From which embryonic structures does skeletal muscle tissue develop?
The source of skeletal muscle development is myotomes—specialized regions of the dorsal mesoderm.
How does a muscle as an organ differ from muscle tissue?
At the tissue level, muscle tissue is represented solely by the fibers themselves. A muscle as an organ additionally includes the stroma (endomysium, perimysium, epimysium), blood vessels, and nerves that ensure its function.
What is the difference between T-tubules and L-tubules?
T-tubules are transverse invaginations of the outer cell membrane (plasmalemma). L-tubules are elements of the internal smooth endoplasmic reticulum (sarcoplasmic reticulum) running longitudinally along myofibrils.
Master the entire topic in the "Histology" course
This is a summary. The course covers everything tested in classes and exams.
3,485 pages of study guides for all topics
Assignments and quizzes after every topic — just like in a colloquium