ACTION AND SUPPORT: THE MUSCLES AND THE SKELETONHow does movement work.

HOW DO MUSCLES WORK

- All muscular work requires that muscles alternately contract and length- The muscles only are active during the contraction phase- The lengthening that follows contraction is passive.

THREE MUSCLE TYPES

TYPE OF MUSCLES

Skeletal- It is used to move the skeleton, also called the striated muscle.- Most skeletal muscle is under voluntary or conscious control.-Muscular contractions can be quick as a blink (also twitches) to powerful sustained tension (carrying a textbook or a heavy lifts)

Cardiac- Cardiac Muscle is so named because it is only found in the heart.- It is spontaneously active initiating its own contractions- It is influenced by nerves (each cell has connection areas where every cell is stimulated by a branch of a motor neuron) and hormones.- cardiac muscle has gap junctions to allow action potentials travel to one cell to another making them synchronized.

Smooth- Smooth muscle lines the walls of blood vessels and most hollow organs including, uterus, bladder, digestive tract.- Smooth muscle lacks of the orderly striped appearance of the skeletal and cardiac muscle- it produces slow and sustained involuntary contractions, some cases is voluntary- It also has gap junctions to contract.- The movement starts from stretching commanded by hormones and nervous signals

MUSCLE CONTRACTION TYPES

• There are three ways a muscle fiber can be activated. Two allow for movement in the muscle and one simply creates tension, without joint movement. Those include:

• Concentric Muscle contraction (shortening)• Eccentric muscle contraction (lengthening) • Isometric Muscle contraction (static)Exercices That Cause Concentric ContractionsLifting phase of a bicep curl, a squat or a pull up. Running up hill or climbing stairs. Concentric contractions are common to many sports in which you need to generate a lot of power or explosive force.

Also Known As: Muscle shortening

• Concentric Muscle contraction (shortening) - In weight training, this is the lifting phase of an exercise.

• Eccentric muscle contraction (lengthening) - In weight training, this is the phase in which the muscle returns to the starting position of the exercise.

• Isometric Muscle contraction (static) - Isometric exercises are those that do not cause joint movement. An example is pushing against a wall.

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TAKE A LOOK OF HOW YOUR MUSCLES MOVE AND GROW IN THE GYM

Know Your Muscle, Grow Your Muscle

WHAT ABOUT GIRLS?

WHAT DOES THE SKELETON DO

• The Skeleton is a supportive framework of the body. It radically comes in three different forms.

• Hydrostatic: Fluid filled sac• Exoskeleton: Encase the bodies of

Arthropods• Endoskeleton: Inner Skeleton of

mammals, reptiles, etc.

FUNCTION OF THE SKELETAL SYSTEM

The bony endoskeleton system of most vertebrates have variety of functions.

1. Provides a rigid framework that supports the body and protect the internal organs.2. Locomotion, Although muscle contractions provides the power, the skeletal provides structure.3. Production of red blood cells.4. Storage site for calcium and phosphorus, release it when the body need it.5. Participating in sensory transduction. Hearing

WHICH TISSUES COMPOSE THE VERTEBRATE SKELETON

The skeleton is composed of two types of tissue that consist in Cartilage and bone. They are rigid tissue that consist of living cells embedded in a matrix of Collagen.

Osteoblast (Bone-forming-cells)Osteocytes (Mature bone cells)

Osteoclasts (Bone-dissolving cells)

Chondrocytes secrete flexible, elastic and non living collagen

Cartilage• Provides Flexible support and connections.• It covers the end of bones at joints• The nose the flexible part of the ears, connect

the ribs to the sternum, provides framework to the larynx, trachea and bronchi.

• Because it´s slow metabolic rate cartilage repair very slow, also has no capillaries inside the tissue and the waste must done in the collagen matrix.

Bone• Provides strong, rigid framework to the body• Is the most rigid form of connective tissue• The bones such as the long bones have an

outer shell of compact bone and a spongy tissue where the red marrow is located.

• Provides attachment to the muscles • Bone is well supplied with capillaries

SKELETAL SYSTEM DIVISION

The Axial Skeleton consist in 80 bones (Skull, Thorax, Vertebrate column)The Appendicular Skeleton consist in 126 bones (Shoulders, upper limbs, lower limbs, and pelvic girdle

SO, AFTER ANATOMY, LET'S FOCUS ON THE PHYSIOLOGY OF THE SKELETON; IN ORDER TO DO THAT WE WILL TALK ABOUT JOINTS.

JOINTS ARE THE MEETING PLACES BETWEEN TWO OR MORE BONESDid you know that we have more joints than Bones?

JOINTS ARE DIVIDED BY THEIR FUNCTION (WHAT THEY DO) AND THEIR STRUCTURE (WHAT ARE THEY MADE OF).

Synovial (diarthrosis):They are fully movable like the knee or elbow.They have both, fibrous connective tissue (Ligaments) and cartilage They have viscous synovial liquid in the middle of the bones to lubricate.

Fibrous connective tissue (synarthrodial) They can´t move at all, Eg, the joints of your

Cranium.

Cartilaginous (synchondroses (temporary) / sympheses): They move slightly, connection between the articulating bones is made up of cartilage for example between vertebrae in the spine.

Movement happens when the muscles contract across joints,

moving one bone toward another.

Hinge moves in one axis, the head of the bone adapts to the other allowing a very stable way.

Pivot: Allow rotation in one axis, cylindrical bone fits into a ring of bone and ligament.

Ball and Socket: The champ of the joints, Allows to move in all axis

Condylar(Ellipsoid): Similar to a ball and socket but the ligaments prevent rotation, still have the two axis for rotation.

Saddle: The rotation is similar to the bone shape one concave one convex, imagine a cowboy riding a horse.

Gliding (Plane): Two flat surfaces one over the other glide or rotate, they come in groups like carpals.

Hinge: Extension and Flexion, Knee Elbows

Pivot: Pronation and supination, Ulnar and radio

Ball and socket: All axis, Hips and elbows

Condylar: Flexion, extension, abduction, circular motion Wrist in the

radiocarpal joint

Saddle: Flexion, extension abduction adduction circumduction.

Plane: Some rotation, some gliding, acromioclavicular joint