WALL OF THORAXIntercostal spaces are (^11) on the back and only 9 in
front of chest.
Intercostal muscles are in 3 layers, external,
internal and transversus. These correspond to the
muscle layers of anterior abdominal wall.
Neurovascular bundle lies in the upper part of the
intercostal space in between internal and inner-
most intercostal muscles.
Posterior intercostal artery and its collateral
branch supplies 2/3rd of the intercostal space.
Right posterior intercostal arteries are longer than
the left ones.
Accessory hemiazygos and hemiazygos veins on
left side drain 5-11 left intercostal spaces.
Correspondingveins on right side drain into vena
azySos.
One student is climbing the stairs at a fast pace as he
is late for his examination and the lift got out of order.
His heart is beating fast against his chest wall. He
has dryness of mouth and sweating of the palm.
o What is the reason for rapid heart beat
(tachycardia)?
r \Mhat is the effect of sympathetic on the skin?
Ans: As he is late for the examination, the sym-
pathetic system gets overactive, increasing the heart
rate, and blood pressure.
Sympathetic has three foid effect on the skin, i.e"
vasomotor, pilomotor and sudomotor. The sweat
secretion is markedly increased, including the pale
skin rtith hair standing erect.
Sy athetic activity decreases the secretion of the
glands. Dryness of rrrouth results from decreased
salirrary secretion.
MUITIPIE CHOICE SUESTIONS
of
1n
The order of structures in the upper part
intercostal space from above downwards is
a. Vein, artery and nerve
b. Artery, vein and nerve
c. Vein, nerve and artery
d. VeirU nerve, artery and vein
Parts of transversus thoracis are all except:
a. Subcostalis
b. Intercostalis intimi
c. Sternocostalis
d. Serratus posterior superior
Which of the following arteries are enlarged
coarctation of aorta?
a. Subclavian
b. Internal mammary
c. Posterior intercostals
d. Anterior intercostals- \Atrhich posterior intercostal veins of left side drain
into accessory hemiazygos vein?
a. Lst to Sth b. 2nd to 4th
c. 9th to 11th d. sth to 8th - Which one is not a branch of internal thoracic
artery?
a. Superior epigastric b. Musculophrenic
c. Anterior intercostal d. Posterior intercostal - Thoracolumbar outflow starts from lateral horn of
which segments of spinal cord?
a. T1-L1 segments b. T1-T12 segments
c. T1.-L2 segments d. T1-L5 segments - Following are the effects of sympathetic on skin
except;
a. Sudomotor
b. Vasomotor
c. Pilomotor
d. Decreases pigmentation
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