Anatomy Part #1

elongated multi nucleate cell; has a banded (striated) appearance

Individual muscle fiber is surrounded by a fine sheath of connective tissue consisting of areolar and reticular fibers.

bundle of muscle cells, segregated from the rest of the muscle by a connective tissue sheath (perimysium)

Surrounding each fascicle is a layer of fibrous connective tissue

An “overcoat“ of dense irregular connective tissue surrounds the whole muscle.

outside

muscle

around

Temporalis

Orbicularis Oculi

Zygomaticus

Orbicularis Oris

Epicranius, frontal belly

Masseter

Sternocleidomastoid

Pectoralis Major

Deltoid

Biceps Brachii

Rectus abdominis

Internal oblique

Adductor Longus

Gracilis

Sartorius

Tiblias Anterior

Gastrocnemius

external oblique

Tensor Fasciae latae

Rectus Femoris

Vastus Lateralis

Vastus medialis

AP travels the link down the neuron to the axon terminal.

Voltage-gated calcium channels open and calcium ions diffuse into the terminal.

Calcium entry causes synaptic vesicles to release acetylcholine via exocytosis

AcH diffuses across the synaptic cleft and vines to the AcH receptors which contain Ligand-gated cation channels

These ligand-gated cation channels open

Sodium ions enter the muscle fiber potassium ions exit the muscle fiber. The greater end of flux causes the membrane potential to become less negative.

Once the membrane potential reaches its threshold value an Action potential (AP )propagates against the sarcolemma

area where the axon terminal of a motor neuron meets a motor end plate of a muscle fiber

Triceps Brachii

Brachialis

Brachioradialis

Extensor carpi radialis longus

Flexor carpi ulnaris

Extensor carpi ulnaris

Extensor digitorum

Iliotibial tract

Gastrocnemius

Soleus

Fibularis Longus

Calcaneal (Achilles Tendon)

Epicranius, occipital belly

Sternocleidomastoid

Trapezius

Deltoid

Infraspinatus

Teres Major

Rhomboid Major

Latissimus Dorsi

Gluteus Medius

Gluteus Maximus

Adductor magnus

Biceps Femoris

Semitendinosus

Semimembraneous