Muscular Tissue - Histology Flashcards
What is the name of the plama membrane of a muscle fibre?
Sarcolemma.
What is the T triad in a muscle cell?
Where is it found?
Found near the A band in skeletal muscle.
Explain the sliding filament theory?
How does the contractile units actually shorten a muscle when it needs to contract?
The actin filaments are connected to the basal lamina through the dystrophin protein which means that it can act on the connective tissue.
what is the interaction between troponin and tropomyosin?
Calcium ions are released from the terminal cisternae which are on either sides of the T tubeule into the cytosol. They go and clear the troponin and tropomyosin complex which allows the interaction of the myosin head and actin causing the cross bridge and further shortening the sarcomere. The troponin binds the calcium, which causes a conformational change thereby displacing tropomyosin and therefore causing the binding site on the actin to be open and ready for activation.
What are the connective tissue layers of the muscle?
What are they covering?
What is the muscle spindle?
What connective tissue layer is covering it?
What are the different types of fibres which makes it up and their function?
What is a satellite cell?
- Sit between the sarcolemma and basil lamina, normally inactive.
- Can be a source of muscle fibre nuclei in adults or in hypertrophy.
- Play a role in repair of damaged muscle cells.
What are the two types of muscle fibre types, their colour and their type of metabolism?
What is an aponeurosis?
Tendon in a flattened shape
What type of connective tissue is tendons made out of?
What about ligaments?
Tendons: Regular DFCT.
Ligaments: Iregular DFCT (because it needs to withstand forces from many directions).
Explain the myotendinous junction?
Specalised proteins connect actin of the last sarcomere to the sarcolemma, basal lamina, and finally to the collagen of the tendons.
What is ethesis?
Collagen of the tendon slowly becomes fibrocartilagenous which then calcifies to become bone.
What is the outer covering of the tendon?
What are the cells of a tendon?
Epitendineum or synovial lining which allows free sliding.
Tendinocytes (few of them): Low metabolic rate, healing potential, cant regain original strength following injury.
