Abdomen Fascia, Muscles and Nerves

R Lower Quadrant

Cecum, Appendix, most of Ileum, Ascending Colon, R Ovary, R uterine tube, Abdominal part of R Ureter, Abdominal part of R spermatic cord, Uterus, Urinary bladder

Opposes the Diaphragm

Compression of the abdominal wall by the abdominal wall mm increases intra-abdominal pressure and in doing so _______, .

Anterolateral abdominal wall

Consists of skin and subcutaneous tissue (superficial fascia) composed mainly of fat, muscle, and their apneuroses and deep fascia, extra peritoneal fat, and parietal peritoneum

Abdominal walls

Contracts to increase intra-abdominal pressure and distend distally to accommodate expansions caused by ingestion, pregnancy, fat deposition, or pathology

Superior boundary of the abdomen

Diaphragm

Median plane

Divides the body into R an L halves; used to delineate the quadrants of the abdomen

Inspiration, relax

During ________, anterolateral abdominal wall expands as its muscles _______ to make room for the organs such as the liver , that are pushed inferiorly.

3 openings in the diaphragm

Esophageal hiatus, Aortic Hiatus, Vena Caval Foramen

Abdominal cavity

Extends as far superiorly as the 4th intercostal space.

Transversus abdominis mm fibers

Fibers of this flat muscle run more or less transversely, except the inferior ones, which run parallel with the internal oblique

Internal oblique mm fibers

Fibers run perpendicular to the fibers of the external oblique mm; superiorly and medially

Inguinal ligament

Fibrous band formed by the inferior thickening of the external oblique apneurosis m

Function of the Anterolateral Abdominal Wall Muscles

Form a strong expandable support for the anterolateral abdominal wall; Support the abdominal viscera and protect them from most injuries; Compress the abdominal contents to maintain or increase the intra-abdominal pressure; Moves the trunk to maintain posture

Abdominal Cavity

Has no floor of its own because it is continuous with the pelvic cavity

2 vertical muscles of the anterolateral abdominal wall

Include: the Large rectus abdomens and the small pyramidal is mm; Are contained w/ in the rectus sheath

Muscles of the anterolateral abdominal wall

Includes 5 (bilaterally paired) muscles in the anterolateral abdominal wall: 3 flat mm and 2 vertical mm

3 flat mm of the anterolateral abdominal wall

Includes: B external oblique m, B internal oblique mm, B transversus abdomens mm; are continued anteriorly and medially as strong sheet like apneuroses.

Rectus Sheath

Incomplete compartment that contains the rectus abdominis m and pyramidalis m, superior and inferior epigastric aa and vv lymphatics and distal portions of the thoraco-abdominal nerves

Transpyloric plane

Is a useful landmark because it also transects the fundus of the gallbladder, neck of the pancreas, origins of the superior mesenteric a and hepatic portal vv, roots of the transverse mesocolon, duodenojejunal junction, and half of the kidneys

L Upper quadrant

Left lobe of liver, spleen, Stomach, jejunum and proximal ileum, body and tail of pancreas, left kidney, left supra adrenal gland, left colic flexure, left half of transverse colon, descending colon

Spino-umbilical line

Line running from the umbilicus to the ASIS;

Neurovascular plane of the anterolateral abdominal wall

Located in between the internal oblique m and the transversus abdominis mm; contains nerves and arteries supplying the anterolateral abdominal wall

Between the MCL and midline

Location of the rectus sheath

Dermatomes of the anterolateral abdominal wall

Map almost identically to the peripheral nerve distribution map because the anterior rami of spinal nerves T7-T12 do not participate in plexus formation.

Endoabdominal fascia

Membranous and areolar sheets of varying thickness that lines the internal aspects of the abdominal wall

Scarpa fascia

Membranous layer of the double layered subcutaneous tissue inferior to the umbilicus; extends into the perineal region

Transtubercular plane

Most commonly, the inferior transverse plane that separates the regions of the abdomen; passes through the iliac tubercles (posterior to the ASIS) and the body of the L5 vertebra

Subcostal plane

Most commonly, the superior transverse plane that separates the regions of the abdomen; passes through the inferior border of the 10th costal cartilage on each side

External and Internal oblique mm

Muscles of the abdominal wall that form a digastric muscles.

Anterior abdominal cutaneous branches of thoraco-abdominal nerves T10

Nerve(s) that supplies the skin around the umbilicus

Anterior abdominal cutaneous branches of thoraco-abdominal nerves T11 + the cutaneous branch of subcostal n, Iliohypogastric and ilio-inguinal nerves

Nerve(s) that supplies the skin inferior to the umbilicus

Anterior abdominal cutaneous branches of thoraco-abdominal nerves T7- T9

Nerve(s) that supplies the skin superior to the umbilicus

Right Upper Quadrant

Organs (parts) in this quadrant include: R Lobe of the liver, Gallbladder, Pylorus of the stomach, Head of pancreas, R suprarenal gland, R kidney, R colic flexure, Ascending colon, Transverse colon

Double layered peritoneum

Passes between walls and viscera providing passageway for the blood vessels, lymphatics and nerves

Transversalis Fascia

Portion of endoabdominal fascia lining the deep surface of the transversalis abdominis m and its apneurosis

External oblique mm fibers

Run inferiorly and medial and end in aponeurosis that contributes to the rectus sheath

Peritoneum

Serous membrane that covers the internal aspects anterolateral abdominal wall and several organs lying on the posterior abdominal wall and reflects onto the abdominal viscera such as the stomach, intestines, liver and spleen.

Left Lower Quadrant

Sigmoid colon, inf. part of descending colon, left ovary, left uterine tube, abdominal part of left spermatic cord, uterus (if enlarged), urinary bladder( if very full)

Nerves and vessels in the anterior abdominal wall

Structures that leave the neuromuscular plane and lie mostly in the subcutaneous tissue

Camper's fascia

Superficial fatty layer of double layered subcutaneous tissue inferior to the umbilicus

Transversus abdominis

Supplied by the inferior epigastric a

External oblique, Internal oblique and Rectus Abdominis mm

Supplied by the superior and inferior epigastric aa

The anterolateral músculo-apneurotic wall

Suspended between and supported by the two bony rings: the inferior margin of the thoracic skeleton superiorly and the pelvic girdle inferiorly.

Parietal peritoneum

The glistening lining of the abdominal cavity, formed by a single layer of epithelial cells and supporting connective tissue; deep to the transversals fascia and separated from it by a variable amount of fat

Transversus abdominis mm

The innermost of the three flat abdominal muscles

Subcostal nerve

The large anterior rams of spinal nerve T12

External oblique mm

The largest and most superficial flat mm of the anterolateral abdominal wall

Aproximately at the MCL medially at the spino-umbilical line

The muscle fibers of the internal, external oblique m becomes aponeurotic at what location?

Inferior boundary of the abdomen

The muscles of the pelvis

Abdomen

The part of the trunk between the thorax and pelvis

Anterolateral boundary of the Abdomen

musculo-apneurotic wall

Lateral cutaneous branches

of thoracic spinal nerves T7-T9 (T10)

Transpyloric plane and the interspinous planes

sometimes used by clinicians to establish the nine regions

Transpyloric plane

sometimes used instead of the subcostal plane, the superior transverse plane that separates the regions of the abdomen; midway between the superior borders of the manubrium of the sternum and pubic symphysis (L1 vertebral level) commonly transects pylorus when the patient is recumbent

Organs that are of the abdominal cavity protected by the thoracic cage

spleen, liver, parts of the kidneys, and the stomach

Iliohypogastric and ilio-inguinal nerves

terminal branches of anterior ramus of spinal nerve L1

Inferior epigastric artery

A Arises from the external iliac a, just superior to the inguinal ligament

Umbilical ring

A defect in the line alba through which the fetal umbilical vessels passed to and from the umbilical cord and placenta

Superior epigastric a

A direct continuation off of internal thoracic a; enters the rectus sheath superiorly through its posterior layer

Abdomen

A flexible and dynamic "container" which houses the organs of the alimentary system and part of the urogenital system

Rectus Abdominis mm

A long, broad, strap-like, paired muscle, is the principal vertical muscle of the anterior abdominal wall

Linea alba

A midline raphe formed by the interweaving of the R, L, superior and inferior rectus sheath fibers; extends from the xiphoid process to the pubic symphysis

Pyramidalis

A small insignificant triangular muscle that is absent in about 20% of people. Lies anteriorly to the inferior part of the rectus abdominis m

Digastric muscle

A two bellied musclesharing a common central tendon

3 flat mm of the anterolateral abdominal wall

Act together bilaterally to form a muscular girdle that exerts firm pressure on the abdominal viscera

Scarpa fascia, investing (deep) fascia

After liposuction, fluid (i.e. urine from a ruptured urethra) may accumulate in a potential space between the ________ and the ______ covering the rectus abdominis and the external oblique muscles.

Umbilicus

All layers of the anterolateral abdominal wall fuse at this site

Superior Pelvic Aperture

Also known as the pelvic inlet; arbitrarily but not physically separates the abdominal pelvic cavities

Thoraco-abdominal nerves

Anterior rami of spinal nerves T7-T12; innervation of the muscles of the anterolateral abdominal wall

Rectus sheath above arcuate line

Anterior wall composed of aponeurosis of External oblique and the anterior laminae of aponeurosis of internal oblique Posterior wall composed of posterior laminae of internal oblique, and aponeurosis of transversus abdominis

Rectus sheath below arcuate line

Anterior wall composed of aponeurosis of all three flat mm posterior wall composed of

Defecation, micturition, vomiting, and pacturition, and heavy lifting

Besides elevating a the relaxed diaphragm, increased intra abdominal pressure is also used for _______.

Superior and inferior epigastric aa

Blood supply to the anterolateral abdominal wall

Anterolateral abdominal wall

Bound superiorly by the 7th-10th ribs and the xiphoid process and inferiorly by the inguinal ligament and the anterolateral aspects of the pelvic girdle

Abdominal cavity

Cavity that extends between the thoracic diaphragm and pelvic diaphragm

Internal oblique m

Thin, intermediate of the 3 flat abdominal muscles

Nerves that supply the Anterolateral abdominal wall

Thoraco-abdominal nerves, Lateral cutaneous branches, subcostal nerve, iliohypogastric and ilioinguinal nerves

Rectus sheath

Tough, apneurotic, tendinous structure formed by the apneuroses of the 3 flat abdominal mm (B external oblique m, B internal oblique mm, B transversus abdomens mm)

Transumbilical plane

Transverse plane that divides the abdomen into quadrants; passes through the umbilicus at level L3/L4 IV disc

Interspinous plane

Transverse plane that is sometimes used instead of the transtubercular plane, passes through the easily palpated ASIS on each side

Transpyloric plane

Transverse plane that passes through the pylorus on the right and the tips of the 9th costal cartilages on either side

Midclavicular plane

Two sagital planes that delineate e the regions of the abdomen; pass from the midpoint of the clavicles to the midinguinal points of the lines joining the ASISand the pubic tubercles on each side

Inguinal Ligament

Useful landmark, also serves as a retinaculum for the muscular and nervous structures passing deep to it to enter the thigh

Investing fascia of abdominal wall mm

Very thin fascia layer that invest the mm of the abdominal wall and can not easily be separated from them

Membranous layer (scarpa fasca)

When closing an incision inferior to the umbilicus, a surgeon must remember to include the __________, the deep layer of superficial facia that provides strength to the abdominal wall.

Scarpa's fascia

_____ fuses with the deep fascia of the leg along a line apron. 2.5 cm inferior and parallel to the inguinal ligament.

Intra-abdominal pressure

______ increased when abdominal viscera are compressed, elevating the diaphragm to expel air during respiration and more forcibly during coughing, sneezing, nose blowing, burping, yelling or screaming.