Trunk, Breathing, Core & Pelvic Floor

Prime mover for extension and lateral bending of back

Erector spinae of back

Iliocostalis of erector spinae - lateral

Longissimus of erector spinae - middle

Spinalis of Erector spinae (medial)

Synergists of the back for rotation and extension

Quadratus lumborum (bottom) and semi spinalis (top)

Erector spinae

External intercostals - inspiration (inhaling) by elevating ribs

Internal intercostals - expiration - forcibly breathing out (blowing)

Diaphragm - most important for inspiration

Sits under lungs

between thoracic and abdominal cavity

What is happening when diaphragm contracts vs relax

Contracts - breathing in → diaphragm goes inferior down so chest can expand

Relax - breathing out - diaphragm goes superior up so chest contracts

What is the diaphragm innervated by

phrenic nerves

Which vertebrae keeps the diaphragm alive and is where the phrenic nerves from from

Cervical vertebrae - C3, C4, C5

What are the four paired muscles of the abdominal wall

Rectus abdominis, external obliques, internal obliques, transversus abdominis

Rectus abdominis of abdominal wall

6 packs

External obliques of abdominal wall - most superficial

Internal obliques of abdominal wall

Transversus abdominis of abdominal wall (deepest)

Valsalva Maneuver

Increase in intra abdominal pressure during coughing, vomiting, sneezing, defecation and childbirth → contracts all four of the abdominal wall muscles

What are the two paired muscles of the pelvic floor (pelvic diaphragm)

Levator Ani and coccygeus

Levator Ani of pelvic floor

Coccygeus of pelvic floor

what does Urogenital diaphragm contain → does what

external urethral sphincter - voluntary control of urination