HBT Muscle tissue Flashcards
How do you classify muscle tissue?
- Smooth- (non-striated)
- Skeletal- (striated)
- Cardiac- (striated)
Describe smooth muscle
- No striations and involuntary- ANS
- Walls of blood vessels, tubes and hollow organs
- Cells can easily regenerate
- Myocytes
Describe skeletal muscle
- Striated and generally voluntary- SNS
- Muscles of locomotor system and visceral muscles (e.g. tongue, oesophagus and diaphragm)
- Limited regeneration capacity
–> repair with fibrous tissue - Myofibres
Fibre –> fibril (packed in sarcoplasm) –> filaments (actin and myosin)
What does the sacra-tubular system comprise of?
- Network of membranes found in skeletal muscle fibre
- Sarcoplasmic reticulum
- Transverse tubular system
- Muscle triad
What is the sarcoplasmic reticulum?
Network of tubules and cisternae (flattened sacs) that store intracellular calcium ions
- Similar to endoplasmic reticulum
Where is the transverse tubular system found?
Sarcolemma at actin and myosin
What does the muscle triad comprise of?
2 terminal cisternae and transverse tubular system
What is endomysium?
Loose CT, surrounds individual muscle cells
What is perimysium?
Dense CT, segregates muscles into bundles of cells
What is epimysium?
Dense CT, sheath of deep fascia
What does direct attachment to bone involve?
Collagen of epi/peri/endomysium merge with collagen of bone ECM
What does indirect attachment to the bone involve?
Tendon/muscle interface (myotendinous junction) is highly interdigitated
What is a neuromuscular junction?
Contact between motor neuron and myofibre
What is a motor unit?
- Made up of a motor neuron and skeletal fibres innervated by the axon terminals of that motor neuron
- Myofibres innervated by a single motor unit
Describe cardiac muscle
Striated, only in heart, involuntary- ANS
- Some cells modified into conducting cells
- no regeneration
- no satellite cells
