Skeletal Muscle Structure and Function Flashcards
What are the 4 main functions of muscle?
4 functions – Movement, Posture, Joint stability and Heat generation.
What are the 3 different arrangements of muscle?
3 different arrangements – circular such as sphincters, parallel (standard) and Pennate where the muscle branches off an aponeurosis.
What does compartment syndrome occur and how is it treated?
Muscles are compartmentalised in fascia this can result in compartment syndrome – treated with a fasciotomy and a skin graft.
What 5 different roles can muscles have?
Muscles can have 5 different roles, Agonists, Antagonists, Synergists (assist the movement of an agonist), Neutralisers (prevent unwanted movement) and Fixators (fix something in position whilst something else moves).
Define and describe the different ways in which muscles can contract
Muscles contract in different ways – Isotonic contraction involving length change (concentric and eccentric) and Isometric contraction involving no length change.
What are the 3 different types of muscle fibres?
3 type of muscle Slow oxidative (type I), Fast oxidative (Type IIA) and Fast glycolytic (type IIX).
How is proprioception achieved in muscle
Specialised intrafusal fibres covered in collagen fibres which are for proprioception by detecting the rate of change of muscle length and feeding this to the brain.
What order are different muscle types recruited in?
Order of recruitment of muscles = type I, type IIA then type IIX.
What is tetanus?
Tetanus is the limit at which action potentials going to a muscle collate together.
Do your muscles ever fully relax?
Healthy muscle always has tone, Hypotonia means no muscle tone and is normal in REM sleep.
What is special about the movement of Cl- across the membrane in muscle cells?
Skeletal muscle has lots of leaky Cl- channels so low resting potential which is important for repolarisation after the contraction.
What is Myotonia Congenita?
Myotonia Congenita is a disease of stiff muscle resulting from mutated Cl channels.
