Chapter 1
The Human Body: An Orientation
19
1
Te
umbilical region
is the centermost region deep to and
surrounding the umbilicus (navel).
Te
epigastric region
is located superior to the umbilical
region (
epi
5
upon, above;
gastri
5
belly).
Te
hypogastric (pubic) region
is located inferior to the
umbilical region (
hypo
5
below).
Te
right
and
lef iliac
, or
inguinal
,
regions
(ing
9
gwĭ-nal)
are located lateral to the hypogastric region (
iliac
5
superior
part of the hip bone).
Te
right
and
lef
lumbar
regions
lie lateral to the umbilical
region (
lumbus
5
loin).
Te
right
and
lef hypochondriac regions
lie lateral to the
epigastric region and deep to the ribs (
chondro
5
cartilage).
Other Body Cavities
In addition to the large closed body cavities, there are several
smaller body cavities. Most of these are in the head and most
open to the body exterior. Figure 1.7 provides the terms that
will help you locate all but the last two cavities mentioned here.
Oral and digestive cavities.
Te oral cavity, commonly called
the mouth, contains the teeth and tongue. Tis cavity is part
of and continuous with the cavity of the digestive organs,
which opens to the body exterior at the anus.
Nasal cavity.
Located within and posterior to the nose, the
nasal cavity is part of the respiratory system passageways.
Orbital cavities.
Te orbital cavities (orbits) in the skull house
the eyes and present them in an anterior position.
Homeostatic Imbalance
1.2
When serous membranes are inflamed, their normally smooth
surfaces become roughened. Tis roughness causes the organs
to stick together and drag across one another, leading to ex-
cruciating pain, as anyone who has experienced
pleurisy
(in-
flammation of the pleurae) or
peritonitis
(inflammation of the
peritoneums) knows.
Abdominopelvic Regions and Quadrants
Because the ab-
dominopelvic cavity is large and contains several organs, it helps
to divide it into smaller areas for study. Medical personnel usu-
ally use a simple scheme to locate the abdominopelvic cavity or-
gans
(Figure 1.11)
. In this scheme, a transverse and a median
plane pass through the umbilicus at right angles. Te four re-
sulting quadrants are named according to their positions from
the subject’s point of view: the
right upper quadrant (RUQ)
,
lef upper quadrant (LUQ)
,
right lower quadrant (RLQ)
, and
lef lower quadrant (LLQ)
.
Another division method, used primarily by anatomists, uses
two transverse and two parasagittal planes. Tese planes, posi-
tioned like a tic-tac-toe grid on the abdomen, divide the cavity
into nine regions
(Figure 1.12)
:
Outer balloon wall
(comparable to parietal serosa)
Air (comparable to serous cavity)
Inner balloon wall
(comparable to visceral serosa)
Heart
Parietal
pericardium
Pericardial
space with
serous fluid
Visceral
pericardium
(a) A fist thrust into a flaccid balloon demonstrates
the relationship between the parietal and visceral
serous membrane layers.
(b) The serosae associated with the heart.
Figure 1.10
Serous membrane relationships.
Right upper
quadrant
(RUQ)
Right lower
quadrant
(RLQ)
Left upper
quadrant
(LUQ)
Left lower
quadrant
(LLQ)
Figure 1.11
The four abdominopelvic quadrants.
In this
scheme, the abdominopelvic cavity is divided into four quadrants by
two planes.
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