MUSCULAR
- "Mus" little mouse
- Shortening & Contraction (actin & myosin)
- Elongated
- Made up of muscle fibers
TYPES
1. Skeletal
- Striated, voluntary, CT
- Skeletal fibers - cigar shaped, multi nucleated, largest muscle fibers
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2. Cardiac
- Heart, striated, involuntary
- Intercalated disks
3. Smooth or Visceral
- Involuntary
- Hollow organs
- Peristalsis
Functions (M2RPC3)
Movement
Maintenance of posture
Respiration
Production of body heat
Communication
Constriction of organs and vessels
Contraction of the heart
SKELETAL MUSCLE (CEEE)
1. Contractility
2. Excitability
3. Extensibility
4. Elasticity
SKELETAL MUSCLE STRUCTURE
Ske-Fa-Fi
Epi-Peri-Endo
MUSCLE FIBER STRUCTURE
1. Sarcolemma
2. Transverse tubules
3. Sarcoplasmic reticulum
1|Muscular system
, 4. Sarcoplasm
5. Sarcomere
6. Muscle Fasciculi
7. Epimysium/Fascia
8. Perimysium
9. Myofibrils
2 major protein fibers
1. Actin Myofilaments
2. Myosin Myofilaments
Sarcomere
1. Z Disk Line
2. Light I band
3. Dark A Band
4. H Zone
5. M Line
3 Phases of Muscle Twitch
1. Lag phase
2. Contraction phase
3. Relaxation phase
2 ways in increasing the force of contraction:
1. Summation - force
2. Recruitment - number
PROVIDING ENERGY FOR MUSCLE CONTRACTION
1. Direct Phosphorylation of ADP by Creatine Phosphate
2. Aerobic Respiration
3. Anaerobic Respiration
Types of muscle contraction
1. Isomeric
2. Isotonic
3. Concentric
4. Eccentric
TRUNK MUSCLES
A. Vertebral Column
1. Erector Spinae (longissimus, spinalis, Iliocastalis)
2. Deep back muscles
2|Muscular system