Different Types of Muscular Diseases
BIOSCI: Muscular Sys
- Lt. mus - little mouse
Body movement
Maintain posture
Generate heat
Stabilize joints
TYPES
SKELETAL
CARDIAC
SMOOTH
Elongated
Branching
Spindle-shpaed
Multiple Peripheral N
Single Central
Single Central
Nucleus
Visible
Visible
Wala Striations
Voluntary
Involuntary
Involuntary
Hierarchy
Bone → Tendon → Skeletal Muscle → Epimysium → Perimysium → Packs of Muscle Fibers → Endomysium → Muscle fibers → Sarcolemma → Myofibrils → Sarcomere → Actin & Mysoin myofilament
ARRANGMENT OF MYOFILAMENTS
A Bands
Dark areas, w/ thick filaments
I Bands
Light area, w/ thin filaments
Z Line
Within the I band
H Zone
Light, Middle of each A band
M Line
Within H zone, inside A band
Sarcomere
Between 2 Z lines
PARTS
MYOSIN
ACTIN
THICK
THIN
Tail
Troponin (displaces tropomyosin)
Heads
Actin
Flexible Hinge Region
Tropomyosin (covers head)
MOTOR UNIT
- single alpha motor neuron + muscle fibers that it innervate
- FINE: alpha motor neuron innervates FEW muscle fibers; GROSS: MANY muscle fibers
Muscle Depolarization and Contraction
1. Neuromuscular Junction
2. Release of ACh (Acetylcholine) molecules
3. Binding of ACh to receptor opens up Na/K
4. Concentration Gradient (K OUT, NA IN)
5. Depolarization of Sarcolemma
6. Action Potential down the T-Tubule
7. Sarcoplasmic Reticulum -> Ca pump
8. Influx of Calcium ions
9. Exposure of binding sites on Actin
10. Binding of Myosin head to Actin
11. Power stroke of cross bridge
12. Sliding of thin filaments
13. Binding of ATP
14. Disconnection of cross bridge
15. Hydrolysis of ATP -> reenergizing
16. Transport of Ca2+ back to Sarcoplasmic Reticulum (SMOOTH ER)
HOW MUSCLE CELLS SYNTHESIZE ATP
1. Hydrolysis of creatine phosphate
a) Creatine~P + ADP = ATP + Creatine
b) Direct Phosphorylation
c) Energy source: CP
d) No oxygen use
e) Produces 1 ATP per CP, creatine
f) Duration: 15 seconds
2. ANAEROBIC glycolysis
a) Glycolysis + Lactic Acid Formation
b) Energy source: Glucose
c) No oxygen use
d) 2 ATP per glucose, lactic
- Lt. mus - little mouse
Body movement
Maintain posture
Generate heat
Stabilize joints
TYPES
SKELETAL
CARDIAC
SMOOTH
Elongated
Branching
Spindle-shpaed
Multiple Peripheral N
Single Central
Single Central
Nucleus
Visible
Visible
Wala Striations
Voluntary
Involuntary
Involuntary
Hierarchy
Bone → Tendon → Skeletal Muscle → Epimysium → Perimysium → Packs of Muscle Fibers → Endomysium → Muscle fibers → Sarcolemma → Myofibrils → Sarcomere → Actin & Mysoin myofilament
ARRANGMENT OF MYOFILAMENTS
A Bands
Dark areas, w/ thick filaments
I Bands
Light area, w/ thin filaments
Z Line
Within the I band
H Zone
Light, Middle of each A band
M Line
Within H zone, inside A band
Sarcomere
Between 2 Z lines
PARTS
MYOSIN
ACTIN
THICK
THIN
Tail
Troponin (displaces tropomyosin)
Heads
Actin
Flexible Hinge Region
Tropomyosin (covers head)
MOTOR UNIT
- single alpha motor neuron + muscle fibers that it innervate
- FINE: alpha motor neuron innervates FEW muscle fibers; GROSS: MANY muscle fibers
Muscle Depolarization and Contraction
1. Neuromuscular Junction
2. Release of ACh (Acetylcholine) molecules
3. Binding of ACh to receptor opens up Na/K
4. Concentration Gradient (K OUT, NA IN)
5. Depolarization of Sarcolemma
6. Action Potential down the T-Tubule
7. Sarcoplasmic Reticulum -> Ca pump
8. Influx of Calcium ions
9. Exposure of binding sites on Actin
10. Binding of Myosin head to Actin
11. Power stroke of cross bridge
12. Sliding of thin filaments
13. Binding of ATP
14. Disconnection of cross bridge
15. Hydrolysis of ATP -> reenergizing
16. Transport of Ca2+ back to Sarcoplasmic Reticulum (SMOOTH ER)
HOW MUSCLE CELLS SYNTHESIZE ATP
1. Hydrolysis of creatine phosphate
a) Creatine~P + ADP = ATP + Creatine
b) Direct Phosphorylation
c) Energy source: CP
d) No oxygen use
e) Produces 1 ATP per CP, creatine
f) Duration: 15 seconds
2. ANAEROBIC glycolysis
a) Glycolysis + Lactic Acid Formation
b) Energy source: Glucose
c) No oxygen use
d) 2 ATP per glucose, lactic