Anatomy - Body Wall II Flashcards
Arrangement of abdominal wall muscles
EAO - caudal ventrally
IAO - cranial ventrally
TA - Dorso ventrally - contain intercostal nerves (lumbar regions of ventral spinal nerves)
Abdominal muscles
Attachment
Action
Innervation
Attachment: linea alba & prepubic tendon
Action: compress viscera, bilateral- flex trunk ventrally, unilateral- rotate trunk laterally
Innervation: lateral branches of intercostal nerves
Last intercostal nn & 1-3L nn
Internal fascia is comprised of
Endothoracic fascia - lining thoracic cavity
Endo-abdominal fascia - lining ab cavity & extends into pelvic cavity
- transversalis fascia - over TA
- diaphragmatic fascia - over diaphragm
- psoas fascia - over psoas muscles
EAO
Attachment
Costal: 4-13 ribs, interdigitates w serratus vent thora
Lumbar: thoracolumbar fascia extending from the transvers processes of lumbar vertebrae
More extensively formed in cats than dogs
Heaves
COPD
Airway obstruction causes excessive work of EAO can lead to hypertrophy of EAO
Heaves line is prominent musculotendiunous junction between EAO and its apenurosis
Subiliac lymph node
Absent in D&C
Easily palpable on ox
Drains superficial body wall of caudal thorax & ab
IAO
Runs cranioventrally
Caudal border forms cranial boundary of deep inguinal ring
Less develops in horses than cows
TA
Dorsi ventrally
Lumbar transverse process
Medial aspect of ribs & costal cartilages
Inserts on linea alba
RA
Longitudinal craniocaudal
3-6 transverse tendinous intersections/inscriptions (not distinct in cats)
OG: ventral aspect of sternum, xiphoid process & costal arch
IN: pecten pubis via prepubic tendon
Action: draws pelvis cranially
Paired & fused along linea alba
Prepubic tendon rupture
Important in herbs
Palpable
Late pregnancy could lead to rupture
Could be torn in dogs hit by cars
Cats have no distinct PPT
External laminate of rectus sheath
Formed by aponeurosis (flat tendon) of EAO & portion of Apon of IAO
apon of TA joins lamina near pubis
Internal lamina of rectus sheath
Portion of Apon of IAO and TA + transversalis fascia
Internal disappears in caudal 3rd of abdomen where Apon of IAO joins ext lamina, leaving caudal RA covered by transversalis fascia & peritoneum
Ventral branches of spinal nerves supply
Flank muscles but skin is supplies by both dorsal and ventral branches
Disadvantages of dorsal approach to paravertebral block
Block all branches of spinal nerves including to Epaxial muscles = back muscle paralysis on one side, convex trunk to one side = viscera bulge out incision
Verifying T block or L block
1/3 upper flake unaffected = missed dorsal branches
Ventral 2/3 flank unaffected=missed ventral branches
Successful block will cause vasodilation and are blocked will become warm and red
Layers cut in a flank laparotomy
Skin
Cutaneous trunci
Tunica flava
EAO, IAO, TA
Transversalis fascia & parietal peritoneum
Blood supply to ab wall
Craniodorsal - cranial abdominal artery
Cranioventral - cranial epigastric artery
Caudalventral - caudal epigastric artery
Caudodorsal - deep circumflex iliac artery
Hypaxial muscles include
Longus colli
Longus capitits
Psoas minor
Psoas major
Quadratus lumborum
Iliacus
Ilioposas
Function of hypaxial vs epaxial
Hypaxial muscles - all are flexors to vertebral column
Epaxial - all are extensors of vertebral column
Longus colli
Attachment : cervical & thoracic vert from t6-c1
Innervation ventral branches of cervical spinal nerve
Longus capitis
Attachment: from cervical transverse process to skull basilar tubercles
Ventral to cervical vert transv processes
Lateral to cervical part of longus colli
Action
Innervation
Lumbar hypaxial muscles
Psoas minor/major
Ilioposas
Quadratus lumborum
Attachment: thoracolumbar vert to pelvis & femur
Action: flex hip & lumbar vert column
Innervation: ventral branches of T, L, S spinal nerves
General function of epaxial muscles
Extensors, bilateral contraction
Bend trunk laterally - unilateral contraction
Innervation by dorsal branches of C, T, L, S spinal nerves
Ideal for IM injection but abscess draining is difficult
Iliocostalis system
From ilium to ribs
Thoracis & lumborum parts
Defined by flat shiny tendons
Longissimus system
Intermediate group - longest & strongest. Runs between ilium & wing of atlas
Parts are defined by location
Cervicis, thoracis, lumborum,
Transversospinalis system
Most medial - attaches to bodies of DSP of vert
Multifidus
(- rotators
- interspinales mm
- spinalis cervicis & thoracis )
Semispinalis capitis - deep to Splenius
Splenius
Deep to cleidocephlicus, trap, Rhomboideus
Attaches- DSP of T1, Apon tendon on nuchal crest
Action : extends and raises head and neck
Unilateral contraction moves laterally
Innervation: cervical nerve
Sternocephalicus
Attachment: between manubrium of sternum & skull
Action: flex neck, draw head & neck side to side
Innervation: ventral branch of accessory nerve & ventral branch of cervical spinal nerve
Will attach in different places on different species
Cribbing
Vice of horses, due to ventral branch of accessory nerve which supplies Sternocephalicus
Can cut nerve to stop action
Injection side on lateral neck area is formed by ____ in horses
Nuchal ligament
Cervical spine
Cranial margin of subclavius
Muscles in area of IM injection site in horses
Scapula, funiculus Nuchal, atlas, traps, serratus ventralis cervicis, Splenius cervicis, subclavius
Clinical sig of cervical deep fascia in horses
Envelopes ventral neck muscles, limits spread of abscesses
Is continuous caudally w endothoracici fascia - infections of neck may spread to thorax
Clin sig of lower neck not being optimal for jugular vein puncture
Ext jug is too close to carotid sheath
Cutaneous colli is thick and covers ext jug
What muscle covers the trachea
Sternohyoideus
Which side offers protection to esophagus
Left
Nerves of the neck
Accessory
Ventral branches of cervical spinal (C1-8)
Vagosympathetic trunk
Roots of phrenic (C5,6,7)
