THE MUSCULAR SYSTEM

MUSCULAR SYSTEM The muscular system has three major functions: Producing motion Providing stability Generating heat Muscles are not able to push. There are 600 different types of muscles Muscle cells are elongated. Contraction is due to movement of microfilaments

Occuli Facial Buccinators Sternomastoid Pectoralis Major Bicep Brachii Abdominals External Oblique Sartorius Quadriceps Extensor Digitorum Tibialis Anterior

Trapezius Deltoid Tricep Latissimus Dorsi Gluteus Maximus Hamstring Gastrocnemius

DIFFERENT TYPES OF MUSCLES Different Types of Muscles Diagram There are three different types of muscles: Skeletal Smooth Cardiac

Structure of a Skeletal Muscle SKELETAL MUSCLES About them… Structure of a Skeletal Muscle Skeletal muscles are voluntary and help you move. They are attached to your bones. They have the ability to contract (shorten) and thereby bring about movement. Skeletal muscle fibers contain numerous nuclei and mitochondria. Skeletal muscles make up 90% of your muscles. Under some conditions, skeletal muscles require no conscious thought. Skeletal muscles can be found in the tongue, pharynx, and some muscles of the eyes. Function: locomotion, posture, transport of blood/lymph, heat production. Skeletal muscles make up 85% of your body’s heat production.

SMOOTH MUSCLES About smooth muscles… Smooth muscles cells Smooth muscles include the muscles of internal organs and blood vessels. These muscles move involuntary. Their movement is controlled by the autonomic nervous system. They are found in your digestive organs. They make up 7-8% of your body. Smooth muscles are found in the internal walls of your digestive organs, trachea, gall bladder, blood vessels, urinary bladder, genital ducts and iris of eyes. Functions: propulsion, expulsion, regulation of openings and of blood vessels.

Diagram of a cardiac muscle CARDIAC MUSCLES About them… Diagram of a cardiac muscle Cardiac muscles are found only in the heart and also involuntary. They differ from skeletal muscles because their muscle fibers are laterally connected to each other. Cardiac muscles are also controlled by the sinus node which is influenced by the autonomic nervous system. Cardiac muscles make up to 3% of your muscles. Function: moves through heart and vessels.

MUSCLE MOVEMENT Involuntary- Automatically move without you knowing. Voluntary- Brain sends message to muscle. You control the movements.

MOVEMENT DEFINITIONS Abductor - moves a limb away from the midline Adductor - moves a limb towards the midline Extensor - increase the angle at a joint - extends a limb Flexor - decreases the angle at a joint - flexes a limb Pronator - turns a limb to face downwards Supinator - turns a limb to face upwards Rotator - rotates a limb Sphincter - closes an orifice of opening

MUSCLE TERMS Flexor  A muscle whose contraction bends a limb or other part of the body. Extensor  A muscle whose contraction extends or straightens a limb or other part of the body. Actin  A protein that forms (with myosin) the contractile filaments of muscle cells. Myosin  A fibrous protein that forms (together with actin) the contractile filaments of muscle cells and is also involved in motion Tendons  connects muscles to bones Sarcomeres  Basic compartments of myofilaments – functional unit

TYPES OF INJURIES Strain- Muscle “pull” or “strain” - Tearing a muscle fiber(s), followed by bleeding or swelling of muscle Muscle Cramp- Prolonged contraction of muscle, ion imbalance

Muscle Pairs Your muscles work in teams to move your body. An example of this is your Bicep and Tricep.

TERMINOLOGY -myo: muscle -mys: muscle -sarco: flesh

CHARACTERISTICS OF MUSCLE TISSUES Excitability  ability to receive and respond to stimulus Contractibility  ability to shorten and thicken Extensibility  ability to stretch Elasticity  ability to return to original shape

THANK YOU  Daniela, Erick & Jamila