Muscle tissues 1. Smooth m. 2. Cardiac m. 3. Skeletal m.

Organisation of skeletal muscles A muscle consists of many m. fibers A muscle consists of many m. fibers It is covered by epimysium It is covered by epimysium The fibers are collected into fascicles The fibers are collected into fascicles Each fascicle is coverd by perimysium Each fascicle is coverd by perimysium

The individual m.fiber is coverd by endomysium The individual m.fiber is coverd by endomysium The CT of the muscle blend together at each end to form the tendon which scrues the m. to bones The CT of the muscle blend together at each end to form the tendon which scrues the m. to bones

Skeletal muscles The muscles contract in response to motor nerve impulses arriving at neuromuscular junction.

The major functions of sk. M. Force production for locomotion & breathing Force production for locomotion & breathing Force production formaintaining posture & stabilizing joints Force production formaintaining posture & stabilizing joints Heat production Heat production Helps venous drainage Helps venous drainage

Contraction 1. Transmission of action potential at neuromuscular junction by neurotransmitter Acetylcholine 2. Spread of action potential along the sarcolemma & penetrates deep into T. tubules 3. Release of calcium from Sarcoplasmic reticulum

4. Calcium binds troponin C causes tropomyosin to move away from its position covering the actin active sites 5. Binding of myosin to actin filamints forming Cross- bridges

4. ATP provides energy for sliding of the 2 filaments 5. Shortening of sarcomere occurs

The muscle then relaxes when calcium is pumped back into SR. This breaks the cross- bridges. Then they slide back & lengthening occurs

Principle skeletal muscles Muscles of the face & neck Muscles of the face & neck Muscles of the trunk Muscles of the trunk Mucsles of the shoulder & upper limb Mucsles of the shoulder & upper limb Mucsles of the hip & lower limb Mucsles of the hip & lower limb

Muscles of the face Occipitofrontalis : it raises the eyebrows. Occipitofrontalis : it raises the eyebrows. Levator palpebrae superioris : raise the eyelid. Levator palpebrae superioris : raise the eyelid. Orbicularis oculi: closes the eyes Orbicularis oculi: closes the eyes

Orbicularis oris: colses the lips Orbicularis oris: colses the lips Muscles of Mastication: Muscles of Mastication: 1. Masseter 2. Temporalis 3. Pterygoid

Muscles of the Neck Sternocleidomastoid: when thew muscle contracts on one side it drws the head towrds the shoulder.when both contracts they flex the neck Sternocleidomastoid: when thew muscle contracts on one side it drws the head towrds the shoulder.when both contracts they flex the neck Trapezius: pulls the head bach wards & controls movement of scapula Trapezius: pulls the head bach wards & controls movement of scapula

Muscles of the back 1. Trapezius 2. Latissimus dorsi 3. Teres major 4. Poas 5. Quadratus lumborum 6. Sacrospinalis

Muscles of abdominal wall 1. Rectus abdominis 2. External oblique 3. Internal oblique 4. Trasversus abdominis 5. Quadratus lumborum

Functions 1. Compress the abdominal organs 2. Flex the vertebral column in lumbar region

Muscles of pelvic floor 1. Levator ani 2. Coccygeus They support the pelvic organs & maintain continence

Mucsles of the shoulder & upper limb Deltoid: ant. flexion Deltoid: ant. flexion middle abduction middle abduction post. extension post. extension Pectoralis : flex & adduct Pectoralis : flex & adduct Coracobrachialis: flex Coracobrachialis: flex

Biceps: short head Biceps: short head Long head Long head Distal tendon Distal tendon Action: on shoulder? on elbow ? on elbow ? Brachialis: main flexor of elbow Brachialis: main flexor of elbow

Triceps: 3 heads? Triceps: 3 heads? Action: Shoulder? elbow? elbow? Brachioradialis: flex elbow Brachioradialis: flex elbow Pronator quadratus: pronation of hand Pronator quadratus: pronation of hand Pronator teres: pronation of hand Pronator teres: pronation of hand Supinator : supination Supinator : supination

Flexor carpi radialis Flexor carpi radialis Flexor carpi ulnaris Flexor carpi ulnaris Extensor carpi radialis Extensor carpi radialis Extensor carpi ulnaris Extensor carpi ulnaris Palmaris longus Palmaris longus Extensor digitorum Extensor digitorum

Muscles that control finger movement Large m. in the forearm that extend to the hand Large m. in the forearm that extend to the hand Smaller m. which originate from carpal & metacarpal bones ( Thenar & hypothenar m.) Smaller m. which originate from carpal & metacarpal bones ( Thenar & hypothenar m.)

Muscles of the hip & lower limb Psoas: flex the hip Psoas: flex the hip Iliacus: flex the hip Iliacus: flex the hip Quadriceps femoris Quadriceps femoris Obturators: lateral rotation of hip Obturators: lateral rotation of hip Gluteals: extension. abd. & med. rotation of hip Gluteals: extension. abd. & med. rotation of hip

Sartorius: 2 actions? Sartorius: 2 actions? Adductor group Adductor group Hamstrings Hamstrings Gastrocnemius: 2 actions? Gastrocnemius: 2 actions? Anterior tibialis: dorsi flexion of foot Anterior tibialis: dorsi flexion of foot Soleus: plantar flexion of ankle Soleus: plantar flexion of ankle