Lecture 28: Abdomen I Functional Anatomy of the Wall Flashcards
functions of abdominal wall during contraction (4)
-compression of abdominal viscera
-expiration, urination, defecation, parturition
3 ventral abdominal wall regions (surface anatomy)
-cranial abdominal region
-middle abdominal region
-caudal abdominal region
ventral abdominal wall cranial abdominal region: 3 subregions
-xiphoid
-left and right hypochondriac region
ventral abdominal wall middle abdominal region: 4 subregions
-umbilicus
-left and right lateral regions
-umbilical region
ventral abdominal wall caudal abdominal region: 3 subregions
-left and right inguinal regions
-pubic region
which regions are inguinal ligament and superficial inguinal ring found in
left and right inguinal regions
lateral abdominal wall surface anatomy: 3 areas
-dorsal
-ventral
-xiphoid process
lateral abdominal wall surface anatomy: dorsal region
lumbar
lateral abdominal wall: 3 subregions of ventral region
-cranial
-middle
-caudal
lateral abdominal wall surface anatomy beginning at xiphoid process
Xiphoid process –> last rib –> umbilicus –> lumbar spinous process –> lumbar transverse process (large) –> iliac crest (tuber coxae) –> pubis (medial to hindlimb) –> Greater trochanter (femur) –> tuber ischiarum
what is a trait/feature that defines all mammals
mammary glands
mammary glands: anatomy definition
modified, enlarged sweat glands
mammary glands: 2 products of interest
-colostrum
-milk
colostrum: definition and function (when is it produced)
-modified milk produced immediately after parturition
-passive transfer of immunity to newborn
-alkaline secretion with higher protein, vitamin A and antibodies
mammary gland composition
-compound tubuloalveolar gland
-consists of secretory units grouped into lobules by intervening connective tissue septa
bovine udder: what kind of teats
supernumerary
supernumerary teats: definition
-more developed glands
problem with supernumerary teats
may interfere with milking –> often removed from udders of cows and goats
udders specialization: venous drainage
drains to internal thoracic and external + internal pudendal veins
udders specialization: lymphatic drainage
from mammary lymph node
innervation of abdominal wall: flank and udder (5)
Last intercostal
Costoabdominal
Iliohypogastric
Ilioinguinal
Genitofemoral
3 holes in abdominal diaphragm
-caval foramen
-esophageal hiatus
-aortic hiatus
what passes through caval foramen
caudal vena cava
what passes through esophageal hiatus
-esophagus
-vagal trunks
what passes through aortic hiatus
-aorta
-azygous vein
-thoracic duct
right and left crura: definition and function
-tendinous insertions that connect diaphragm to body wall
caval-caval anastamosis: definition
venous blood can be returned to heart from either cranial or caudal vena cava
2 caval-caval anastamoses in abdominal wall
-superficial
-deep
superficial caval-caval anastamosis: definition, vessels, supply to
-within superficial fascia of ventral abdominal wall
-between cranial and caudal superficial epigastric vessels
-supply blood to superficial layers including mammary glands
muscle layers of abdominal wall (4)
-external abdominal oblique
-internal abdominal oblique
-transversus abdominis
-rectus abdominis
rectus abdominis, external and internal oblique: 2 unique actions
-flex vertebral column when fellow muscles contract
-unilateral bending of vertebral column
what is a specialization of external abdominal oblique
inguinal ligament
inguinal ligament
gap where caudal edge of external abdominal oblique doesn’t have bony insertion
superficial inguinal ring is found in what muscle layer
external abdominal oblique
superficial inguinal ring: definition and function
-opening between abdominal and pelvic tendons of external abdominal oblique
-allows passage of vessels and spermatic cord in males
what passes through the inguinal canal in males and females (3)
-external pudendal artery
-efferent vessels from inguinal lymph nodes
-genitofemoral nereve
what passes through inguinal canal in males only
-spermatic cord
components of spermatic cord (5)
-testicular artery and vein
-deferent artery and vein
-ductus deferens
-cremaster muscle
-spermatic fascia
cremaster muscle: definition and action
-muscle slip detached from internal oblique that passes onto spermatic cord
-pulls in testes for temperature regulation
what is the deepest muscle of the lateral abdominal wall
transversus abdominis
specialization of internal oblique
cremaster muscle
what nerves innervate the abdominal wall
ventral rami/lumbar nerves
what axons are found in lumbar nerves (3)
-motor
-sensory
-postganglionic sympathetic
what abdominal muscle is homologous to rectus thoracis
rectus abdominis
rectus abdominis: origin and insertion
O: sternum and costal cartilages
I: prepubic tendon to pubic brim
what is the common insertion for the abdominal muscles and the linea alba
prepubic tendon
transversalis fascia
lining of fascia deep to transversus abdominis that contacts peritoneum of abdominal cavity
transversalis fascia aka
subserous fascia because adjacent to peritoneum (serous membrane)
innervation of abdominal muscles (4)
last 8-9 intercostal nerves
costoabdominal nerve
iliohypogastric nerve
ilioinguinal nerve
layers of abdominal wall muscles: superficial to deep
-skin
-superficial fascia
-external abdominal oblique
-internal abdominal oblique
-transversus abdominis
-transversalis fascia
-peritoneum
What forms the linea alba
Rectus sheath
Parent artery for cranial epigastric artery
Internal thoracic artery
Rectus sheath definition
Aponeuroses of abdominal wall muscles coming together at midline
Why is body wall weaker caudal to umbilicus
Aponeuroses of internal oblique and transversus abdominis change relative position to Rectus abdominis
Rectus sheath: cranial to umbilicus
-superficial: external oblique, internal oblique splits around Rectus abdominis
-deep: transversus abdominis, epigastric arteries and veins
Rectus sheath: caudal to umbilicus
-superficial: external oblique, entire internal oblique
-deep: transversus abdominis, epigastric arteries and veins
Rectus sheath: near pubis
-superficial: external oblique, internal oblique, transversus abdominis
-lateral: epigastric arteries and veins
Importance of linea alba
Site of superficial fascia and rectus aponeurosis where surgical approaches will not damage muscle tissue
What is a natural passageway from abdominal cavity out to abdominal wall
Inguinal canal
What structure is the abdominal entrance
Deep Inguinal ring
What structure is the exit from the Inguinal canal
Superficial Inguinal ring
Hernia definition
Displacement and protrusion of part of an organ through walls of body cavity
2 types of abdominal hernias
-umbilical
-Inguinal
Umbilical hernia
Abdominal contents protrude into overlying subcutaneous fascia
Inguinal hernia
Abdominal contents pass through Inguinal canal and may project into scrotum in males
Deep muscles of dorsal abdominal wall (3)
-psoas major
-psoas minor
-quadratus lumborum
Psoas major, psoas minor, quadratus lumborum innervation
Lumbar ventral rami
Psoas major action
-flex hip joint
-draw pelvic limb forward
Psoas minor action
Flex lumbar vertebral column
Quadratus lumborum action
-stabilize lumbar vertebral column
-assist in lateral bending
Passage of lumbar ventral rami in abdominal wall
-Through transversus abdominis close to transverse processes
-run deep to internal oblique toward ventral wall
Blood supply of abdominal wall deep to rectus abdominis within rectus sheath
Cranial and caudal epigastric arteries
(Deep) Cranial and caudal epigastric arteries definition
Anastamoses between continuation of internal thoracic and external iliac arteries
(Deep) Cranial and caudal epigastric veins definition
Anastamoses between caudal and cranial vena cava drainage