Muscles 1 Flashcards
3 types of muscle?
- Skeletal
- Cardiac
- Smooth
2 examples of skeletal muscle?
- Voluntary muscles
- Diaphragm
2 examples of places in the body you would find smooth muscle?
- Blood vessels
- Sphincters
- Airways
Another name for a skeletal muscle cell?
Muscle fibre
What are skeletal muscle cells formed from in utero?
Myoblasts
How do you identify skeletal muscle in histology?
- Striated
- Multinucleate
- Nuclei pushed to edges of the cell
Are skeletal muscles able to repair?
Not well at all
Myoblasts do not replace damaged muscle
What 2 ways can skeletal muscle try to repair itself?
- Satellite cells replace damaged ones to form new muscle fibres
- Surrounding muscle fibres undergo hypertrophy
How does smooth muscle repair?
Can divide very easily
What encircles muscle fibres?
Areolar connective tissue
How are muscles attached to bone?
Tendons
How does blood reach the muscle in the centre of the muscle?
Deep penetrating vessels
What is the Z line
Border between one repeating unit (sarcomere) and another
What does titin ensure?
Myosin is always surrounded by actin on six sides
How is myosin energised to allow quick on demand contraction?
ATP constantly hydrolysed to ADP and Pi on the myosin head
What proteins are attached to actin?
Troponin
Tropomyosin
What does tropomyosin do?
Blocks myosin binding sites
What does troponin do?
Holds tropomyosin in place
How does calcium reveal myosin binding sites?
- Binds to troponin
- Troponin twists and moves the tropomyosin
Where is calcium stored in the muscle fibre
Sarcoplasmic reticulum
Role of transverse tubes in muscle?
Propegating electrical signals into muscle core
What do transverse tubes allow the muscle to do?
Uniform contraction
What is the combination of a nerve and a muscle called?
Motor unit
If a motor unit is damaged why don’t you lose the function of the muscle?
There are multiple motor units for a single muscle
