ANATOMY PRACTICAL 2

Diaphragm Origin

First 3 lumbar vertebrae, Lower 6 costal cartilages, Xiphoid process of sternum

Diaphragm Insertion

Central tendon of the diaphragm (Clover leaf shaped aponeurosis)

Diaphragm Action

Flattening of central tendon (Increases vertical diameter of thoracic cavity in inspiration)

Diaphragm Innervation

Phrenic n C3-5

Rectus Abdominis Origin

Pubic symphysis & Pubic crest

Rectus Abdominis Insertion

Costal cartilages of ribs 5,6, 7, Xiphoid process

Rectus Abdominis Action

Flexion of trunk, Compression and support of abdominal viscera

Rectus Abdominis Innervation

Thoracoabdominal ns (T7-11)

External Oblique Origin

Lower 8 ribs (5-12)

External Oblique Insertion

Linea alba, Pubis, Anterior iliac crest

External Oblique Action

Bilateral: Flexion of trunk, Compression and support of abdominal viscera Unilateral: Lateral flexion of trunk, Rotation of trunk to opposite side

External Oblique Innervation

Thoracoabdominal ns (T7-11), Subcostal n (T12)

Internal Oblique Origin

Inguinal ligament, Anterior iliac crest, Thoracolumbar aponeurosis

Internal Oblique Insertion

Costal cartilages of lower 4 ribs (9-12), Abdominal aponeurosis, Linea alba

Internal Oblique Action

Bilateral: Flexion of trunk, Compression and support of abdominal viscera Unilateral: Lateral flexion of trunk, Rotation of trunk to same side

Internal Oblique Innervation

Thoracoabdominal ns (T7-12, L1)

Transverse Abdominis Origin

Inguinal ligament, Iliac crest, Thoracolumbar aponeurosis, Internal surfaces of costal cartilages of ribs 7-12

Transverse Abdominis Insertion

Abdominal aponeurosis, Linea alba, Pubis

Transverse Abdominis Action

Compression and support of abdominal viscera

Transverse Abdominis Innervation

Thoracoabdominal ns (T7-12, L1)

Transversus Thoracis Origin

sternum posterior surface

Transversus Thoracis Insertion

costal cartilages 2-6

Transversus Thoracis Action

depression of the ribs in expiration

Transversus Thoracis Innervation

intercostal ns--thoracic spinal ns, ventral rami

Quadratus Lumborum Origin

Internal lip of iliac crest of ilium

Quadratus Lumborum Insertion

Inferior margin of 12th rib, Transverse processes of L1-4

Quadratus Lumborum Action

Bilateral: Stabilization of 12th rib in inspiration Unilateral: Lateral flexion of trunk to same side, Elevation of pelvis to same side if thorax & vertebral column are fixed

Quadratus Lumborum Innervation

T12, L1-4 Spinal nn - ventral rami

Bulbospongiosus Origin

Perineal body

Bulbospongiosus Insertion

Penis

Bulbospongiosus Action

Compression of urethra, Assist erection of clitoris/penis

Bulbospongiosus Innervation

Pudendal n (S2-4)

Ischiocavernosus Origin

Ischial ramus

Ischiocavernosus Insertion

Penis

Ischiocavernosus Action

Assists erection of clitoris/penis

Ischiocavernosus Innervation

Pudendal n (S2-4)

Superficial Transverse Perineal Origin

Ischial ramus

Superficial Transverse Perineal Insertion

Perineal body

Superficial Transverse Perineal Action

Stabilization of perineal body, Assists support of pelvic viscera

Superficial Transverse Perineal Innervation

Pudendal n (S2-4)

Levator Ani Origin

Pubis

Levator Ani Insertion

Coccyx

Levator Ani Action

Support of pelvic viscera, Assists urine and fecal continence

Levator Ani Innervation

N to levator ani (S4), Coccygeal plexus

Coccygeus Origin

Ischial spine

Coccygeus Insertion

Lower sacrum, Coccyx

Coccygeus Action

Support of pelvic viscera, Assists urine and fecal continence, Flexion of coccyx

Coccygeus Innervation

S4-S5 branches

Piriformis Origin

Anterior sacrum, Sacral Ligament

Piriformis Insertion

Greater trochanter of femur

Piriformis Action

Lateral rotation of femur

Piriformis Innervation

N to piriformis S1, S2

Obturator Internus Origin

Obturator foramen

Obturator Internus Insertion

Greater trochanter of femur

Obturator Internus Action

Lateral rotation of femur

Obturator Internus Innervation

N to obturator internus L5, S1

Psoas Major Origin

Transverse processes of lumbar vertebrae L1-L5, Bodies and intervertebral discs of T12-L5 vertebrae

Psoas Major Insertion

Lesser trochanter of femur

Psoas Major Action

Flex femur, Flex trunk (lumbar spine), Assist lateral flexion of trunk (lumbar spine)

Psoas Major Innervation

L2-3 Spinal ns

Iliacus Origin

Iliac fossa of ilium

Iliacus Insertion

Lesser trochanter of femur

Iliacus Action

Flexion of femur

Iliacus Innervation

Femoral n (L2-3)

Gluteus Maximus Origin

Posterior sacrum, Ilium via sacrotuberous ligament, Posterior superior gluteal line of ilium

Gluteus Maximus Insertion

Gluteal tuberosity of femur, Iliotibial tract (attaching to the lateral condyle of tibia)

Gluteus Maximus Action

Extension of femur, Lateral rotation of extended hip

Gluteus Maximus Innervation

Inferior gluteal n L5, S1, S2