CHAPTER 9: Muscle and Muscle tissue Flashcards
Skeletal muscle
-Attaches do bone and skin
-Longest fibres, striated
-Voluntary muscle/consciously controlled
Cardiac muscle
-Bulk of the heart
-Striated
-Involuntary
Smooth muscle
-In walls of hollow organs
-Non-striated
-Involuntary
-Visceral
4 characteristics of muscle tissue
- Excitability/responsiveness: ability to receive and respond to stimuli
- Contractibility: Ability to shorten forcibly when stimulated
- Extensibility: Ability to be stretched
4.Elasticity: Ability to recoil to resting length
4 muscular functions
- Produce movement
- Maintain posture/body position
- Stabilize joints
- Generate heat as they contract
Sacrolemma
Muscle fibre plasma membrane
What is sarcoplasm and what does it contain?
Muscle fibre cytoplasm
1. Glycosomes for glycogen stores
2. Myoglobin for oxygen storage
Myofibrils
Densely packed, rodlike elements
Striations, two types of bands
Striped formed from repeating series of dark/light bands
A bands: dark regions
I bands: lighter regions
Sacromere
-Smallest contractile unit of muscle fibre
-Area between Z-discs
-Align end to end along myofibril
Myofilaments
Orderly arranged within sarcomere (actin and myosin)
Actin myofilament
-Thin filament
-Anchored to z-disc
Myosin myofilament
-Thick filament
-Connected at M line
Tropomyosin/troponin
Regulatory proteins bound to actin
Sliding filament model
Thin filaments slide past thick filaments, causing actin/myosin to overlap more