Development and Regeneration of Muscle Tissu e Flashcards
(18 cards)
What is the primary origin of most muscle tissue in the body?
Embryonic mesoderm
Muscle tissue arises from mesoderm, specifically from paraxial mesodermal cells.
What are somites?
Blocks of cells formed by paraxial mesodermal cells
Somites are adjacent to the neural tube and give rise to myoblasts.
What is a myoblast?
A muscle-forming stem cell
Myoblasts migrate and fuse to form myotubes.
What do myoblasts fuse to form?
Myotubes
Myotubes are multinucleate structures formed from the fusion of myoblasts.
Why are skeletal muscle cells multinucleate?
They are formed from the fusion of multiple myoblasts
Each contributing myoblast’s nucleus remains intact in the mature skeletal muscle cell.
Do cardiac and smooth muscle cells have multiple nuclei?
No
Myoblasts that form cardiac and smooth muscle cells do not fuse.
What develops in cardiac and single-unit smooth muscle during early development?
Gap junctions
Gap junctions allow for communication between muscle cells.
What triggers the formation of motor end-plates and NMJs in skeletal muscles?
Spinal nerve innervation
The release of growth factors stimulates this formation.
What role do satellite cells play in skeletal muscle?
Repair skeletal muscle cells
Satellite cells are stem cells that facilitate protein synthesis needed for repair and growth.
What happens when muscle fibers are damaged beyond the repair capacity of satellite cells?
They are replaced by scar tissue
This process is called fibrosis, leading to loss of muscle strength.
What type of stem cell allows smooth muscle tissue to regenerate?
Pericyte
Pericytes are found in small blood vessels and aid in smooth muscle repair.
How does cardiac muscle tissue respond to damage?
It is replaced by scar tissue
Scar tissue does not contract, leading to loss of heart function.
What is the role of physical therapists regarding muscle atrophy?
To maintain muscle function and prevent loss
They prescribe and monitor exercises for muscles prone to atrophy.
What can lead to disuse atrophy?
Impaired muscle use after injury or surgery
Prolonged disuse can lead to long-term muscle weakness.
What is age-related muscle loss targeted by physical therapy?
Exercise to improve muscle function
Exercise can reduce the effects of age-related atrophy.
What factors do physiotherapists assess in patients?
Strength, balance, and endurance
These factors help design tailored exercise programs.
What is the goal of a physiotherapist?
To improve physical functioning and reduce impairments
This is achieved by assessing capabilities and designing enhancement programs.
What is the consequence of electrical stimulation in muscles?
Stimulates muscle contraction
It prevents protein loss when muscles are not used.
