Characteristics & Functions of Muscle

Morphological Classification of Muscle

Muscle Type and Activity

picture of skeletal muscles

Shapes of Skeletal Muscle

Skeletal Muscle Action

Question: Are skeletal muscle an orgarn?

Architecture of Skeletal Muscle

Architecture of Skeletal Muscle

Architecture of Skeletal Muscle

Structure of Skeletal Myofiber1

Structure of Skeletal Myofiber2

Structure of Skeletal Myofiber3

Architecture of Skeletal Muscle

Thick Filament1

Thick Filament2

Question: Do thick filaments connect to Z-line?

Thick Filament3

Thin Filament1

Thin Filament2

Structure of Sarcomere1

Structure of Sarcomere2

If we did cross-section of skeletal muscles, which area can be seen the following:1. Thick filaments only H zone2. Thin filaments only I band3. Both thick and thin filaments C zone

Architecture of Skeletal Muscle

Summary: Architecture of Skeletal Muscle

Video

Sensory Receptors of Skeletal M.

Structure of M. Spindle

Structure of M. Spindle

Structure of M. Spindle

Question: How to maintain the sensitivity of afferent (sensory) nerve

Sensitivity Modulation(α-γ Coactivation)

Skeletal Muscle Repair

Architecture of Skeletal Muscle

Sliding Filaments

Example Question

Example Question

Example Question

Video

Phases of M. Contraction

Process of Skeletal Muscle Contraction

Process of Skeletal Muscle Contraction

Neuromuscular Junction1

Neuromuscular Junction2

Question: Why injection of Botulinum toxin (肉毒桿菌素) can reduce facial wrinkles?

Cosmetic Aesthetic Medicine

Question: What is the purpose of converting electrical signal to chemical signal?

Neuromuscular Junction3

Neuromuscular Junction4

Neuromuscular Junction5

Neuromuscular Junction6

Question: How to prolong the function of Acetylcholine at neuromuscular junction?

Neuromuscular Junction Disease

Process of Skeletal Muscle Contraction

Events of M. Contraction

Events of M. Contraction

Molecular Mechanisms of Contraction

Crossbridge Cycle1

Crossbridge Cycle2

Summary of Crossbridge Cycle

Animation

Summary: Process of Skeletal Muscle Contraction

Process of Skeletal Muscle Relaxation

Muscle Cramps

Question: Can voluntary muscles produce involuntary movement?

Skeletal Muscle Reflexes

Monosynaptic Stretch Reflex

The response of skeletal m. is always excitatory. How to inhibit the response of skeletal muscle?Reduce the excitability of neuronActivation of antagonist

Disynaptic Reflex

Reciprocal Innervation

Types of Muscle Contraction

Isotonic Contraction With Different Loads

Load-Velocity Relation

Question: Are all-or-none law applied for muscle fibers?

Different Response of M. Fiber vs. Whole Muscle

Motor Unit1

Motor Unit2

Motor Unit3

Muscle Tone

Frequency-Tension Relation1

Frequency-Tension Relation2

Muscle Force1

Muscle Force2

Length-Tension Relation1

Question: Why the active tension decreased when the muscle length is shorter than the normal resting length?

Length-Tension Relation2

Muscle Fatigue

Causes of Muscular Fatigue

Question: What are the energy sources of skeletal muscle contraction?

Energy for Contraction1

Energy for Contraction2

Question: What does ATP do for providing energy in skeletal muscle contraction?

Functions of ATP in Skeletal-Muscle Contraction

Energy Sources in Working M.

Types of Skeletal Muscle Fiber1

Types of Skeletal Muscle Fiber2

Question: Why can skeletal muscles be divided into red muscles and white muscles?

Types of Skeletal Muscle Fiber2

Exercise Training on Adaptation of Muscle Fibers

Exercise Training on Adaptation of Muscle Fibers

Myofascial Pain

Smooth Muscle

Structural Characteristics of Smooth M1

Structural Characteristics of Smooth M2

Structural Characteristics of Smooth M3

Structural Characteristics of Smooth M4

Structural Characteristics of Smooth M5

Structural Characteristics of Smooth M4

Structural Characteristics of Smooth M5

Voltage-Gated Channels in Smooth M.

Single Muscle Twitch

Smooth Muscle Contraction

Mechanisms of Smooth M. Relaxation1

Mechanisms of Smooth M. Relaxation2

Smooth M. Latch State

Unique Mechanical Properties

Difference in Contraction Mechanism Between Smooth M. & Striated M.

Classification of Smooth Muscle

Single-Unit Smooth Muscle1

Single-Unit Smooth Muscle2

Single-Unit Smooth Muscle3

Multiunit Smooth Muscle1

Multiunit Smooth Muscle2

Cardiac Muscle

Cardiac Muscle

Characteristics of the Cardiac M.

Automaticity (Chronotropic effect)

Conductivity (Dromotropic effect)

Action Potentials of contractile cardiac cellsPhase 0: Rapid depolarization (Na+ channels open, Na+ in)Phase 1: Rapid, partial early repolarization (Na+ channels close)Phase 2: Prolonged period of slow repolarization (Ca2+ channels open, Ca2+ in; fast K+

Excitability

Contractility (Inotropic effect)

Contractility

Contractility

Contractility

Contractility

Mechanism of Cardiac Muscle Excitation, Contraction, & Relaxation (Lusitropic effect)

Question: If a drug has a positive inotropic effect on heart, which means this drug can increase heart’s heart rate conductivity contractility relaxation excitability

Excitation Contraction: Cardiac vs. Skeletal M.