Muscle Structure and Function Part 1 W4 Flashcards
What are the functions of skeletal muscle?
Force production for locomotion and breathing
Force production for postural support
Heat production during cold stress
Act as an endocrine organ
What are flexors muscle actions?
Decreases joint angles
What are extensors muscle actions?
Increases joint angles
What is the sarcolemma?
Muscle cell membrane
What is the basement membrane?
Just below endomysium
What is the endomysium?
Surrounds muscle fibres
What is the perimysium?
Surrounds fascicles
What is the epimysium?
Surrounds entire muscle
What is the microstructure of myofibrils?
Contains contractile proteins:
- Actin (thin filament)
- Myosin (thick filament)
What is the microstructure of the sarcomere?
Z line
M line
H zone
A band
I band
What is the sarcoplasmic reticulum?
Storage sites for calcium
Terminal cisternae
What is the transverse tubules?
Extend from sarcolemma to sarcoplasmic reticulum
How does satellite cells play a key role in muscle growth and repair?
They increase the number of nuclei in mature muscle fibres
What is the myonuclear domain?
Volume of sarcoplasm surrounding each nucleus
Each nucleus can support a limited myonuclear domain
What is myonuclei and muscle hypertrophy relationship?
Increased myonuclei