Musculoskeletal system

Question 1

what are the functions of the musculoskeletal system?

Answer 1

there are 6 main functions:

1. movement
2. posture
3. thermogenesis
4. organ protection
5. venous return
6. protein metabolism

Question 2

describe skeletal muscle contraction.

Answer 2

the sliding filament theory: 4 main steps

1. excitation: action potential in nerve fibres leads to action potential in muscle fibres
2. excitation-contraction coupling: events that link the action potential on the sarcolemma to the activation of the myofilaments
3. contraction: muscle fibres get tense due to cross bridge cycling
4. recovery: muscle fibres relax and return to resting length

Question 3

describe the structure of skeletal muscle?

Answer 3

• attached to 2 bones via tendons
• 3 layers of connective tissue: epimysium, perimysium and endomysium
• fascicles with muscle fibres
• muscle fibres have myofibrils, with myofilaments

Question 4

what are the organelles in muscle fibre cells?

Answer 4

sarcoplasma
sarcolemma
multiple nuclei
sarcoplasmic reticulum
T tubules
myofibrils