The Muscular System

Yoga Teacher Training

Skeletal System Quiz

Muscular System Fundamentals

• 3 Types of Muscle: – Skeletal/ Voluntary muscle: attach to bone, responsible for

voluntary movement, composed of muscle fibers bundled together

– Smooth/ Involuntary muscle: important part of blood vessel walls and hollow organs (ex. Bladder, intestines & viscera)

– Cardiac Muscle

• 3 Functions of Skeletal Muscle:• 1. Movement• 2. Posture• 3. Heat Production

• Muscle fibers only contract in one direction.

• Most skeletal muscles attach to 2 bones with a moveable joint between them.

• Tendons attach muscle to bone.• The muscle’s attachment to the more

stationary bone is called the origin.• The muscle’s attachment to the more

moveable bone is called the insertion.• Knowing the origin & insertion help you

determine the purpose and direction of movement of a particular muscle.

• The Bursa is a small fluid filled sac that lies between some tendons and the bones beneath them making it easier for the tendon to slide over a bone.

• The Bursa is made from connective tissue and lined with a synovial membrane that secretes lubricating synovial fluid.

Movement: Muscles pull bones• Because the length of a skeletal muscle shortens as it’s fibers contract, the

bones to which the muscle attaches move closer together. • As a rule, only the insertion bone moves (there are exceptions to every

rule). A muscle’s insertion bone moves toward it’s origin bone.• Muscles work in coordinated groups.• Prime Mover: the muscle primarily responsible for movement within a

muscle group.• Synergists: the other muscles that assist in producing a movement• Antagonists: opposing muscles that relax as the prime mover & synergists

contract. When the antagonists contract they produce a movement opposite that of the prime mover. Ex. Biceps & Triceps

Fatigue & Oxygen Debt• Fatigue: Loss of muscle power/weakness; when muscle cells are

stimulated repeatedly without adequate rest then the strength of the contraction decreases. If this continues eventually the muscle loses it’s ability to contract

• Muscular movement is fueled by the breakdown of ATP stored in muscle cells. Formation of ATP requires oxygen.

• When oxygen supplies run low the body converts to anaerobic energy production (doesn’t require oxygen). This results in a build up of Lactic Acid. (lactic acid causes soreness and pain)

• Oxygen Debt describes the continued increased metabolism that must occur to remove excess lactic acid and replace depleted energy reserves (ATP). Hence the labored breathing after strenuous exercise. This is why we breath deep throughout yoga.

Types of Muscle Contractions• Each muscle fiber contracts completely

when stimulated. However every muscle is composed of many muscle fibers, each one with a different threshold stimulus. (threshold stimulus is the minimal level of stimulation required to cause a fiber to contract). This is how we control the strength of muscular contraction required for specific movements.

• Isotonic Contraction: produces movement at a joint; the muscle shortens and the insertion moves toward the origin.

• Repeated Isotonic contractions increase endurance.

• Isometric Contraction: the muscle does not shorten and no movement ocurs but tension is increased within the muscle.

• Repeated isometric contractions make a muscle grow larger and stronger.

Common Muscles You Should Know

Pectoralis Major Pectoralis Minor

Biceps Triceps

Muscles of the Rotator CuffSupraspinatus Infraspinatus

Teres Minor Subscapularis

Deltoid Trapezius

Latissimus Dorsi Rhomboids

Muscles of the core

External Obliques Internal Obliques

Transverse Abdominis Rectus Abdominis

Pelvic Floor

IlliopsoasPsoas Illiacus

Muscles of the Hips & LegsPirifomis Gluteus Maximus

I.T. Band & T.F.L. Adductors

Gastrocnemius Soleus

Diaphram