Muscular System Flashcards
Main Functions of the muscular system
Create movement.
Maintain Posture.
Maintain bodily functions.
Types of Muscle Tissue
Skeletal: Bone Attached, moves body.
Smooth: Autonomic bodily function organs.
Cardiac: Specialized autonomic heart muscles
Roles of Skeletal Muscle Tissue
Produces movement.
Maintain posture.
Stabilize joints.
Generate Heat.
Properties of Skeletal Muscle
Contractility
Extensibility
Excitability
Elasticity
Increasing number of muscle fibres
Hyperplasia.
Increasing number of muscle fibres
Hyperplasia.
Muscle cell name.
Muscle Fibres
Role of Synergists
Assist Prime mover with additional force.
Including acting as fixators.
Role of Synergists
Assist Prime mover with additional force.
Including acting as fixators.
Origin def
End of the muscle attaching to the non moving bone
Insertion
End of muscle attaching to moving bone
Belly
Muscle tissue between tendons of origin and insertion
Origin of rectus femoris
anterior iliac crest
Insertion of rectus femoris
Proximal tibia via the patella
Isotonic movements
Muscle produces force while lengthening or shortening
Types of contractions
Concentric,
Eccentric,
Isometric
Types of contractions
Concentric,
Eccentric,
Isometric
All properties of type 1 fibre
Red/Slow Fatigue Resistant. Most of postural/tonic muscles. Highly adapted for aerobic metabolism. Recruited first. Many mitochondria. High concentration of myoglobin. Small Motor Neurone.
All properties of type 2 fibre
Fatigue Easily. Most of phasic muscles. Adapted for anaerobic metabolism. Recruited after type 1. Low Mitochondria. Low/nil myoglobin. High creatine. Large motor neurone.
Type 2A fibre
Transitional, can improve aerobic function with training stimulus.
Type 2B Fibre
Classic white, cannot improve aerobic function.
Motor Unit
Motor neuron and and all muscle fibres it innervates.
Gross muscle function
High ratio of muscle fibres to one nerve.
Fine muscle function
Low ratio of fibres to one nerve
Postural Muscles
Support the body when sitting, standing or lying. Also called tonic. Strong muscles that usually require preferential stretching. (High % Red fibre)
Phasic Muscles
Generate & maintain movement. Work in association with postural muscles. Require strengthening, especially with age. (High % White fibre)
Muscle structure hierachy
Muscle Fascicle Myofibre Myofibril Myofilaments
How muscles fire
Nerve impulse via motor nerve.
Chemical messenger causes release of calcium from sarcoplasmic reticulum.
presence of calcium allows myosin and actin cross bridging. allowing them to slide past, shortening the sarcomere.
Breakdown of ATP to ADP +P release energy for cross bridging.
