Muscular system

Objectives To identify the types of muscles To identify the types of muscles Understand terms related to muscles Understand terms related to muscles To know how are the muscles named To know how are the muscles named

Types of the muscle Skeletal:striated, and voluntary. Skeletal:striated, and voluntary. Smooth:nonstiated, and involuntary. Smooth:nonstiated, and involuntary. Cardiac:striated, and involuntary. Cardiac:striated, and involuntary.

Are effectors which enable movement to be carried out Muscles

Types of connective tissues wrappings of skeletal muscle

Endomysium : a delicate connective tissue sheath surrounds muscle fibre. Endomysium : a delicate connective tissue sheath surrounds muscle fibre. Perimysium : a coarser fibrous membrane surrounds several sheathed muscle fibers to form bundle of fibers called a fascicle. Perimysium : a coarser fibrous membrane surrounds several sheathed muscle fibers to form bundle of fibers called a fascicle. Epimysium : a tougher overcoat of connective tissue surrounds many fascicles. Epimysium : a tougher overcoat of connective tissue surrounds many fascicles.

The epimysia blend into the strong, cord- like tendons, or into sheet-like aponeurosis. The epimysia blend into the strong, cord- like tendons, or into sheet-like aponeurosis. Function: Function: 1-Attaching the muscle to bone…. 2-Providing durability 3-Conserving space

Muscles & the Skeleton Skeletal muscles cause the skeleton to move at joints Skeletal muscles cause the skeleton to move at joints They are attached to skeleton by tendons. They are attached to skeleton by tendons. Tendons transmit muscle force to the bone. Tendons transmit muscle force to the bone. Tendons are made of collagen fibres & are very strong & stiff Tendons are made of collagen fibres & are very strong & stiff

Muscle function Providing movement Providing movement Maintaining posture Maintaining posture Stabilizing joint Stabilizing joint Generating heat Generating heat

Skeletal Muscle Functions of Skeletal Muscle –Produce Movement –Maintain posture –Stabilize joints –Generate Heat Sites of Muscle Attachment –Bones –Cartilage –Connective tissue coverings Muscle Fibers blend into a connective tissue attachment –Tendon—cordlike structure –Aponeurosis—sheet-like structure Properties of Muscle –Irritability – ability to receive and respond to a stimulus –Contractibility – ability to shorten when an adequate stimulus is received –Extensibility – ability to lengthen when an adequate stimulus is received –Elasticity – ability to return to normal shape

Muscles: Muscles: Are responsible for almost all the movements in animals

Origin : is the point where the muscle is attached to immovable or less movable bone. Origin : is the point where the muscle is attached to immovable or less movable bone. Insertion : is the point where the muscle attached to movable bone. Insertion : is the point where the muscle attached to movable bone.

Prime mover : the muscle that has the major responsibility for causing a movement. Prime mover : the muscle that has the major responsibility for causing a movement. Antagonist : the muscle that reverse a movement. Antagonist : the muscle that reverse a movement.

Antagonistic Muscle Action Muscles are either contracted or relaxed Muscles are either contracted or relaxed When contracted the muscle exerts a pulling force, causing it to shorten When contracted the muscle exerts a pulling force, causing it to shorten Since muscles can only pull (not push), they work in pairs called antagonistic muscles Since muscles can only pull (not push), they work in pairs called antagonistic muscles The muscle that bends the joint is called the flexor muscle The muscle that bends the joint is called the flexor muscle The muscle that straightens the joint is called the extensor muscle The muscle that straightens the joint is called the extensor muscle

Elbow Joint The best known example of antagonistic muscles are the biceps & triceps muscles The best known example of antagonistic muscles are the biceps & triceps muscles

Naming Skeletal muscles Direction of the muscle fibers: Orbicularis oris, Occuli Direction of the muscle fibers: Orbicularis oris, Occuli Relative size of the muscle: Gluteus maximus, medius, minimus…Major, minor. Relative size of the muscle: Gluteus maximus, medius, minimus…Major, minor. Location of the muscle:Obturator internus Location of the muscle:Obturator internus Number of the origin:Biceps, Triceps Number of the origin:Biceps, Triceps Location of the muscle’s origin and insertion: Occipitofrontalis Location of the muscle’s origin and insertion: Occipitofrontalis Shape of the muscle:Deltoid Shape of the muscle:Deltoid Action of the muscle:Pronator Quadratus Action of the muscle:Pronator Quadratus

Types of body movements Flexion&extension Flexion&extension in sagittal plane in sagittal plane angle of the joint angle of the joint

Rotation Rotation It is the movement of a bone around its long axis It is the movement of a bone around its long axis atlas around the dens of axis atlas around the dens of axis

Abduction &adduction Abduction &adduction moving the limb away or toward the midline of the body moving the limb away or toward the midline of the body

Circumduction is a combination of Circumduction is a combination of flexion,extension,abduction and adduction flexion,extension,abduction and adduction

Special movement Dosiflexion&planter flexion Dosiflexion&planter flexion Inversion and evasion Inversion and evasion Supination and pronation Supination and pronation opposition opposition

Head muscles Facial Muscles (Frontalis, Orbicularis oculi Orbicularis oris, Buccinator,Zygomaticus). Facial Muscles (Frontalis, Orbicularis oculi Orbicularis oris, Buccinator,Zygomaticus). Chewing Muscle (Buccinator,Masseter, Temporalis). Chewing Muscle (Buccinator,Masseter, Temporalis).

Facial muscles Frontalis : It covers the frontal bone Frontalis : It covers the frontal bone It raise the eyebrows It raise the eyebrows It wrinkle the forehead It wrinkle the forehead Orbicularis oculi : It has fibres that run in circles around the eyes. Orbicularis oculi : It has fibres that run in circles around the eyes. It closes the eyes, squint, blink. It closes the eyes, squint, blink.

Orbicularis oris : it is a circular muscle of the lips. Orbicularis oris : it is a circular muscle of the lips. It closes the mouth It closes the mouth It protrude the lips It protrude the lips Buccinator : it runs horizontally across the cheek and inserts into orbicularis oris. Buccinator : it runs horizontally across the cheek and inserts into orbicularis oris. It flatten the cheek. It flatten the cheek.

Zygomaticus Zygomaticus It extends from the corner of the mouth to the cheekbone. It extends from the corner of the mouth to the cheekbone.

Chewing Muscle Buccinator Buccinator Masseter : it covers the angle of lower jaw Masseter : it covers the angle of lower jaw It closes the jaw by elevating the mandible It closes the jaw by elevating the mandible Temporalis : it is a fan shaped muscle overlying temporal bone Temporalis : it is a fan shaped muscle overlying temporal bone It is synergist of the masseter in closing the jaw. It is synergist of the masseter in closing the jaw.

Neck muscles Sternocleidomastoid : it is a paired muscles with two headed muscles, one from each side of the neck. Sternocleidomastoid : it is a paired muscles with two headed muscles, one from each side of the neck. platysma platysma

Trunk muscles Anterior muscles Anterior muscles Muscles of the abdominal wall Muscles of the abdominal wall Posterior muscles (Post. Antigravity muscles) Posterior muscles (Post. Antigravity muscles)

Anterior muscles : Anterior muscles : Pectoralis major : a large fan shaped muscle covering the upper part of the chest. It adduct and flex the arm. It forms the anterior wall of the axilla Pectoralis major : a large fan shaped muscle covering the upper part of the chest. It adduct and flex the arm. It forms the anterior wall of the axilla Intercostal muscles Intercostal muscles

Muscles of the abdominal wall : Muscles of the abdominal wall : Rectus abdominis Rectus abdominis External oblique External oblique Internal oblique Internal oblique Transversus abdominis Transversus abdominis

Posterior muscles : Posterior muscles : Trapezius : It is the most superficial muscles of posterior neck and upper trunk. Trapezius : It is the most superficial muscles of posterior neck and upper trunk. Diamond –shaped. Diamond –shaped. Extend the head &antagonist sternocleidomastoid. Extend the head &antagonist sternocleidomastoid. Also,it can elevate, depress, adduct, and stabilize the scapula. Also,it can elevate, depress, adduct, and stabilize the scapula.

Latissmus Dorsi Latissmus Dorsi Large, flat muscle pair that cover the lower back. Large, flat muscle pair that cover the lower back. Extends and adducts the humerus. Extends and adducts the humerus. Erector spinae Erector spinae Prime mover of back extention Paired muscles Paired muscles Deep muscles of the back. Deep muscles of the back. Spasm of these muscles lead to lower back pain. Spasm of these muscles lead to lower back pain.

Deltoid Deltoid Fleshy, triangle-shaped muscles Favorite injection Prime movers of arm abduction.

Muscle of the upper limb The first group include muscles that arise from the shoulder girdle and cross the shoulder joint to insert into the humerus (pectoralis major, latissimus dorsi, and deltoid). The first group include muscles that arise from the shoulder girdle and cross the shoulder joint to insert into the humerus (pectoralis major, latissimus dorsi, and deltoid).

The second group causes movement at the elbow joint (Biceps brachii,brachialis,brachioradialis, and triceps brachii) The second group causes movement at the elbow joint (Biceps brachii,brachialis,brachioradialis, and triceps brachii)

The third group causes movement at the wrist joint (flexor carpi and flexor digitorum) The third group causes movement at the wrist joint (flexor carpi and flexor digitorum) (extensor carpi and extensor digitorum) (extensor carpi and extensor digitorum)

Muscles of lower limb Muscles causing movement at the hip joint Muscles causing movement at the hip joint Muscles causing movement at the knee joint Muscles causing movement at the knee joint Muscles causing movement at the ankle and foot joint Muscles causing movement at the ankle and foot joint

Muscles causing movement at the hip joint (gluteus maximus,gluteus medius,illiopsoas,adductor muscles) Muscles causing movement at the hip joint (gluteus maximus,gluteus medius,illiopsoas,adductor muscles)

Muscles causing movement at the knee joint (hamstring group,sartorius,quadriceps group) Muscles causing movement at the knee joint (hamstring group,sartorius,quadriceps group)

Muscles causing movement at the ankle and foot joint (tibialis anterior,extensor digitorum longus,fibularis muscles,gastrocnemius,soles) Muscles causing movement at the ankle and foot joint (tibialis anterior,extensor digitorum longus,fibularis muscles,gastrocnemius,soles)