The Abdomen I Flashcards
Abdomen = part of the trunk between the thorax + pelvis.
What are its superior, inferior, anterolateral borders?
superior = diaphragm
inferior = muscles of the pelvis
anterolaterally = musculoaponeurotic walls
What are 2 principle functions of the abdomen?
**protect **+ enclose abdominal contents
**flexibility **= for respiration, posture, locomotion
Name the 2 transverse planes + 2 sagittal planes of the abdomen
Transverse:
- subcostal plane (most superior)
- transtubercular plane (most inferior)
Sagittal:
- midclavicular lines (x2)
Name the 9 regions of the abdomin, as numbered in this figure.
- Right hypochondriac
- Right lumbar
- Right inguinal
- Epigaastric
- Umbilical
- Hypogastric
- Left hypochondriac
- Left lumbar
- Left inguinal
What are the superior and inferior landmarks for the 2 sagittal planes ?
Superior = midclavicular planes; pass approximately 9 cm from the midline
inferior = midinguinal points; midway between the anterior superior iliac spine and the superior edge of the pubic symphysis on each side
What are the landmarks for the 2 transverse abdominal planes?
subcostal plane = passes through inferior border of the 10th costal cartilage on each side
transtubercular plane = passes through the iliac tubercles (approx. 5 cm posterior to anterior superior iliac spine) + body of L5
Where is the transpyloric plane located?
approximate midpoint between:
superior border of manubrium + superior border of pubic symphysis
(L1 vertebral level)
- comonly transects the pylorus (distal part of stomach)
What other important structures are transected by the transpyloric plane?
- fundus of gallbladdar
- neck of pancreas
- origins of superior mesenteric artery & portal vein
- root of transverse mesocolon
- duodenojejunal junction
- hila of kidneys
Where does the interspinous plane pass through
anterior superior iliac spine on each side
(easily palpated)
Which part of the abdominal wall is NOT musculoaponeurotic?
posterior abdominal wall
(includes lumbar vertebral column)
The anterolateral abdominal wall extends
from__________ to ___________?
thoracic cage to the pelvis
What are the superior and inferior boundaries of the anterolateral abdominal wall?
superior = 7th - 10th rib cartilages + xiphoid process
inferior = inguinal ligament + superior margins of the anterolateral aspects of the pelvic girdle (iliac crests, pubic crests, + pubic symphysis).
Identify the numbered muscles of the anterior abdominal wall:
- external oblique
- internal oblique
- transverse abdominis
Identify the fascia in the anterior abdominal wall:
- Camper fascia (superficial, fatty, subcutaneous)
- Scarpa fasca (deep, membranous, subcutaneous)
- a) Superficial Investing (deep) fascia
- b) Intermediate Investing (deep) fascia
- c) Deep Investing (deep) fascia
- Endoabdominal (transversalis) fascia
Identify these anterior abdominal wall structures:
- skin (cut edge)
- extraperitoneal fat
- parietal peritoneum
In what area is the skin firmly attached to the subcutaneous tissue (in the anterior abdominal wall) ?
at the unbilicus
Why is it structurally significant that the muscle fibers of the abdominal walls go in 3 different directions?
b/c the abdomin is a positive pressure area
- higher chance of herniation so intersecting fibers = added strength
The subcutaneous tissue over most of the abdominal walls is a major storage site for what?
What happens if there is too much of this substance stored here?
FAT
too much fat** = obesity;** can cause sagging folds “panniculi” (apron)
There are some areas of the body that maintain fat storage even during starvation. These areas include…?
- face
- bottocks
*fun facts from Dr. Ray :)*
- Inferior to the umbilicus, the deepest part of the subcutaneous tissue is reinforced by which types of fibers?
- What are the two layers of subcutaneous tissue here?
- many elastic and collagen fibers
-
Camper fascia = superficial fatty layer
- Scarpa fascia = deep membranous layer
-
Camper fascia = superficial fatty layer
The membranous layer (Scarpa fascia) continues inferiorly into the ___________.
perineal region as the superficial perineal fascia (Colles fascia)
*NOT into the thighs (fascia lata)*
What is the clinical significance of the membranous Scarpa fascia being sufficiently complete ?
Significant because:
fluids** escaping from a ruptured vessel or urethra (blood and/or urine) may **accumulate deep to it
The superficial, intermediate, and deep layers of investing fascia cover____________ ?
the external aspects of the three muscle layers of the anterolateral abdominal wall + their aponeuroses (flat expanded tendons)
The endoabdominal fascia (membranous sheet of varying thickness) lines the __________?
the internal aspect of the abdominal wall
The portion of fascia lining the deep surface of the transverse abdominal muscle and its aponeurosis is called…?
“transversalis fascia”
(relatively firm)
The portion of fascia lining the abdominal cavity is called…?
“parietal peritoneum”
(internal to transversalis fascia; separated by extraperitoneal fat)
What is the clinical significance of fascia and fascial spaces of abdominal wall?
1. potential space b/t membranous layer of subcutaneous tissue + deep fascia (covering rectus abdominis + external oblique m.)
** fluid may accumulate**
- cannot spread inferiorly into the thigh because the membranous layer fuses with the deep fascia of the thigh (fascia lata)
2. helps **protect against contamination **therefore, during surgeries, entry into the periotoneal cavity is aoided as much as possible.
Why is the potential (or fat-filled) space b/t the endoabdominal fascia of special importance in surgery?
it can be opened during surgery
- access structures on/in anterior aspect of posterior abdominal wall without entering the peritoneal sac
- minimize risk of contamination
- Space of Bogros = b/t transversalis fascia + parietal peritoneum; anterolateral part of potential space used for placing prostheses (ex. when repairing inguinal hernias);
How many bilaterally paired muscles are there in the anterolateral abdominal wall?
5 muscles
- 3 flat (external oblique, internal oblique, and transverse abdominal)
- 2 verticle (rectus abdominis, pyrimidalis)
The fibers of which 3 abdominal muscles are blended together for increased strength?
external oblique
internal oblique
transverse abdominal