AXIAL MUSCLES & SKELETAL MUSCLE HISTOLOGY BIO LAB PRACTICAL 2

Masseter

Masseter insertion

Mandible

Masseter origin

Zygomatic

Masseter action

Elevates mandible

Temporalis

Temporalis insertion

Mandible

Temporalis origin

Temporal

Temporalis action

Elevates mandible

Splenius capitis

Splenius capitis insertion

Temporal, occipital

Splenius capitis origin

Vertebrae

Splenius capitis action

Both together: Extend neck

Sternocleidomastoid

Sternocleidomastoid insertion

Temporal, occipital

Sternocleidomastoid origin

Sternum, clavicle

Sternocleidomastoid action

Both together: Flex neck

Diaphragm

Diaphragm insertion

Central tendon

Diaphragm origin

Sternum, vertebrae

Diaphragm action

Expand thoracic cavity

External intercostals

External intercostals insertion

Inferior rib

External intercostals origin

Superior rib

External intercostals action

Elevate ribs

Internal intercostals

Internal intercostals insertion

Superior rib

Internal intercostals origin 

Inferior rib 

Internal intercostals action

Depress ribs

External oblique

External oblique insertion

Ilium, linea alba, pubis

External oblique origin

Ribs

External oblique action

Both together: Compress abdomen

Internal oblique

Internal oblique insertion

Ribs, linea alba, pubis

Internal oblique origin

Ilium, thoracolumbar fascia

Internal oblique action

Both together: Compress abdomen

Rectus abdominis

Rectus abdominis insertion

Ribs, sternum

Rectus abdominis origin

Pubis

Rectus abdominis action

Compress abdomen

Transversus abdominis

Transversus abdominis insertion

Linea alba, pubis

Transversus abdominis origin

Ilium, ribs, lumbodorsal fascia

Erector spinae group

Iliocostalis, longissimus, spinalis

Iliocostalis

Iliocostalis insertion

ribs, vertebrae

Iliocostalis origin

Ilium, ribs, sacrum, vertebrae

Iliocostalis action

Both together: extend neck

Transversus abdominis action

Compress abdomen

Longissimus

Longissimus insertion

ribs, temporal, vertebrae

Longissimus origin

vertebrae

Longissimus action

Both together: extend neck

Spinalis

Spinalis insertion

vertebrae

Spinalis origin

vertebrae

Spinalis action

extend neck

Endomysium

thin, innermost layer of connective tissue that surrounds individual muscle fibers (cells) within a skeletal muscle

Epimysium

the outer, tough, fibrous layer of dense connective tissue that surrounds an entire skeletal muscle

Fascicle

a bundle of muscle fibers (muscle cells) that are grouped together and enclosed by a connective tissue sheath

Perimysium

a sheath of dense irregular connective tissue that groups muscle fibers into bundles or fascicles

Myofibril

 cylindrical structures within skeletal muscle fibers that play a crucial role in muscle contraction 

Skeletal muscle fiber/cell

a single muscle cell that contracts to produce movement, composed of bundled myofibrils