THORAX AND
ABDOMEN
For descriptive purpose, the human body is divided
into head, neck, trunk and limbs. The trunk is divided by the diaphragm into an
upper part called the thorax, and the lower part is called the abdomen.
THE SKELETON OF THE THORAX (thoracic
cage).- It is an osseocartilaginous,
elastic cage.
- Formation:- Anteriorly- by the sternum.
Posteriorly- by the 12
thoracic vertebrae and intervertebral discs.
one each side- by 12
ribs with their cartilage.
2.
THE SUPERIOR
APERTURE(INLET)OF THE THORAX:The narrow upper end of the thorax, which is
continuous with the neck ,is called the inlet of the thorax.
3. DIAPHRAGM OF THE INLET OF THE
LIVER: The diaphragm is in two
halves, right and left. Each half is also known as Sibson’s fascia or supra
pleural membrane. The membrane is triangular in shape. Its apex is attached to
the tip of the transverse process of C7 vertebra and base to the inner border
of 1st rib.
BOUNDARIES:- Anteriorly- upper border of manubrium sterni .
Posteriorly – superior
surface of body of 1st thoracic vertebra. On
each side- 1st rib with its costal cartilage.
4. INFERIOR APERTURE (OUTLET) OF
THORAX: It is the broad end of the thorax which surrounds the upper part of
the abdominal cavity, but is separated from it by the diaphragm.
BOUNDARIES: Anteriorly-
Infra sternal angle .
Posteriorly- inferior surface of the body of the 12th
thoracic vertebra.
On each side- coastal margin
formed (7, 8,9,10) and 11th to 12th ribs.
DIAPHRAGM OF THE OUTLET OF
THORAX:-The outlet is closed by a large musculotendinous partition, called the
diaphragm-which separates the thorax from the abdomen . Structure passing
through the inlet:
§ Trachea, oesophagus,
apices of the lungs.
§ Brachiocephalic
artery, left common carotid artery and subclavian artery, right and left brachiocephalic
veins.
§ Right phrenic
nerve, right and left vagus nerve.
Structure passing through the outlet: Large openings: in the diaphragm.
§ Aortic openings: It
transmits 1. The aorta, 2. The thoracic duct,(level-12th thoracic
vertebra).
§ The oesophageal
openings: It transmits 1.oesophagus 2. The vagus nerve (level-10th
thoracic vertebra).
§ The vena caval
opening: It transmits 1. Inferior vena cava, 2. Branches of right phrenic nerve
(level- 8th thoracic vertebra).
INTRODUCTION OF ABDOMEN:-
It is the lower part of the trunk and lies below the diaphragm. It is
divided by the plane of the pelvic inlet into a larger upper parts, the abdomen
proper and the smaller lower part the true (lesser)pelvis.
ABDOMINAL WALL:- Extends
1. In the anterior
median plane the abdominal wall extends from xiphoid process to the pubic
symphysis.
2. Superolateral
margins of anterior abdominal wall are formed by right and left coastal
margins.
3. The iliac crest
forms the lower limit of the abdominal wall at the side.
4. Inguinal ligament
extends from the anterior superior iliac spine to pubic tubercle. It is placed at
the junction of the anterior abdominal wall with the front of the thigh.
5. Transpyloric plane
is an imaginary transverse plane, it passes through the tips of the 9th
coastal cartilage, and posteriorly through the lower part of the body of the 1st
lumber vertebra.
NINE REGIONS OF
ABDOMEN:-
For the purpose of describing the location of viscera, the abdomen is
divided into nine regions by imaginary planes, two horizontal and two vertical.
1. Transpyloric
plane:- passes midway between the suprasternal notch and the pubic symphysis.
Anteriorly it passes through the tips of 9th coastal cartilages and
Posteriorly through the body of vertebra L1.(lower)
2. Trans tubercular
plane:- passes through the tubercles of the iliac crest and body of vertebra L5
(upper) .
3. Right and left
lateral planes:- passes through the mid inguinal point and crosses the tip of
the 9th coastal cartilage.
NINE REGION:- epigastric , umbilical, hypogastric,
right and left hypochondriac, right and left lumbar (lateral) and right and
left iliac(Inguinal).
(Median regions are….. Rt.
& Lt. regions are……..)
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