5.5.14 Mammalian Muscle Structure (learning) Flashcards
1
Q
Types of muscle in animals
A
- Skeletal
- Smooth
- Cardiac
1
Q
What is skeletal muscle
A
- Attached to skeleton
- Striated muscle fibres (contractile proteins with lots of nuclei)
2
Q
What are the parts of muscle fibres called?
A
Cell surface membrane = Sarcolemma
Cytoplasm = Sarcoplasm
Endoplasmic Reticulum = Sarcoplasmic Reticulum (SR)
3
Q
What does the sarcolemma do?
A
- T tubules fold in from outer surface
- Run close to the Sarcoplasmic Reticulum
4
Q
What does the sarcoplasm do?
A
- Mitochondria and myofibrils
- ATP for muscle contraction
- Myofibrils are bundles of actin and myosin filaments that slide past each other during muscle contraction
5
Q
What does the sarcoplasmic reticulum do?
A
- Membrane contains protein pumps
- Transporting calcium ions into lumen of SR
6
Q
What is the structure of myofibrils?
A
- In sarcoplasm
- 2 types of protein filament
- Thick filament of myosin
- Thin filament of actin
7
Q
Cardiac Muscle
A
- Only in heart
- Myogenic (initiates its own contraction)
- Does not tire of fatigue
- Fibres connected via intercalated disks
- lots of mitochondria in muscle fibres
7
Q
Smooth Muscle
A
- Unconscious control of body parts
- Contains myosin and actin but no banding or striation
- Gut walls
- Blood vessel walls
- 1 nucleus
