Muscular System Karina Espinosa Per.7

Major Functions of Muscular System

Names of Muscles

Bodymovement Terminology

3 Muscle Tissues and their Functions

Structure and Organizational Levels of Skeletal Muscle

Muscle Contraction (Sliding Filament Theory)

1: Gives us posture

2: Allows us to have movement

3: Thermogenesis = Heat production

There are fourteen types of body movement including :

Flexion: Movement that decreases angle of joint

Extension: Movement that increases angle of joint

Hyperextension: Extension beyond 180º

Rotation: Movement of a bone around a longitudinal axis

Abduction: Movement of limb away from midline

Adduction: Movement of limb toward the midline

Circumduction: Proximal end of a limb is stationary and the distal end moves in a circle

Plantar Flexión: Pointing toe

Dorsiflexion: Lifting superior surface of foot towards shin

Inversion: Turn sole of foot medially

Eversion: Turn sole of foot laterally

Supination: Forearm rotates laterally so palm faces anterioly

Pronation: Forearm rotates medially so palm faces posterioly

Oppisition: Movement of thumb to touch tips of other fingers

Cardiac Muscle

Smooth Muscle

Skeletal Muscle

It is subject to conscious control and it makes up approximately 40-50% of body weight.

They form the heart’s walls and it allows blood to circulate around the heart.

This muscle controls movements inside internal organs. For example, digestive tracts, blood vessels urinary and reproductive organs.

1) The nerve impulse travels down the sacrolemma and into the T-tubules. It causes sacroplasmic rectilium to release Ca++ into the sacrolasm.

2) Ca++ binds to actin myofilaments which exposes the myosin binding site.

3) The myosin head attaches to the actin, forming actin/ myosin crossbridges.

4) The myosin head moves towards the M line of sacromere, pulling actin filaments past myosin.

5) That process is repeated many times and it is powered by ATP.

6) Z lines get closer together as actin and myosin filaments slide past each other, and sacromeres shorten. This shortens the entire myofibril.

Epicranius (L: Head)

Gastrocemius (L: Lower Leg)

Deltoid (L: Shoulder)

Gluteus Maximus (L: Butt)

Orbicularis (L: Eyes)

Llitibial Tract (L: Outer Thigh)

Rectus Abdominis (L: Abs)

Tensor Fascla (L: Hip)

Gracilis (L: Inner Thigh)

Soleus (L: Lower Leg)

Latissimus Dorsi (L: Back)

Zygomaticus (L: Upper Cheek)

Temporalis (L: Temples on Head)

Calceneal Tendon (L: Back of Foot)

Pectoralis Major (L: Chest)

Extensor Digitorum (L: Lower Arm)

Tríceps Brachili (L: Triceps)

Gluteus Medius (L: Upper Butt)

Splenius Capitis (L: Inner Neck)

Sternocleidomastoid (L: Outer Neck)

ANTERIOR BODY

POSTERIOR BODY

Connective Tissue Coverings

LAYERS: Fasicles, aponeuroses, epimysium, perimysium, muscle cell/ fiber, endomysium.

Skeletal Muscle Fibers

Sacrolemma, sacroplasm (Contains- Glycogen, myogloulin, parallel myofibrils (made up of myofilaments), Z line, I bands, A bands, H zoneM line.

Sacroplasmic Reticulum is associated with transverse. T- tubules penetrate into muscle fiber.

Neuromuscular Junction

Synapse, neurotransmitters, motor end plate, synaptic vesicles, synaptic cleft.