1. We were assigned to present on the problem statement. In
the problem statement we were supposed to identify the reason behind Tim’s
reading change after the accident. Before the accident, Tim was a very healthy
person who has a heart rate of 65bpm and blood pressure of 115/80 mmHg. After
the accident, Tim’s heart rate increased to 150bpm while his blood pressure
decreased to 75/60 mmHg. The reason behind this is due to hypovolemic shock.
During the accident, Tim suffered from severe bleeding injuries. This may have
caused him to lose more than 20% of his blood. There would be insufficient
amount of blood in circulation for heart to be an effective pump. Therefore,
the blood pressure would drop and to compensate for the drop in blood pressure
the heart would speed up by pumping blood at a higher rate to ensure that there
is sufficient amount of blood around the body.
2. The aorta is the main artery that carries oxygenated
blood to all the different parts of the body. An example of underdeveloped
aorta would be the interrupted aorta arch. This a rare heart defect that occurs
when the baby is still in the mother’s womb. A new-born that is diagnosed with
interrupted aortic arch would face a complete blockage between the ascending
and descending aorta. Therefore, blood is unable to reach a new-born’s lower
The aortic valve closes off the left ventricle that holds
the oxygen-rich blood before it is being pumped out to the body. It also opens
to allow blood to leave the heart from the left ventricle to the aorta and on
to the body. These actions occur very quickly to prevent regurgitation of
blood. An example of an underdeveloped aortic valve is aortic stenosis. Aortic
stenosis occurs when the aortic valve is too small, narrow or stiff. This would
mean that the valve would not open all the way, causing the heart to exert more
force to push the blood across the valve. Over a period of time, this
additional stress would weaken the heart.
The left ventricle discharges blood into the pulmonary
circuit. The left ventricle requires more force to propel blood through the
systemic circuit than around the pulmonary circuit. This is due to the thick
muscular wall of the left ventricle. One example of an underdeveloped left
ventricle would be the hypoplastic left heart syndrome. New-borns that are
diagnosed are not able to pump oxygenated blood to the body therefore the right
side of the heart must pump blood to the lungs and also the rest of the body.
For the first few days after they are born, the right side of the heart is able
to pump blood to both the lungs and rest of the body through a blood vessel
that links the pulmonary artery directly to the aorta. However, after a few
days, the vessels would close, and blood would not be able to be pumped out to
the body by the right heart. Therefore, making it a life-threatening defect.
The mitral valve closes off the left atrium, collecting the
oxygenated blood coming in from the lungs. The valve would open to allow blood
to pass from the left atrium to the left ventricle.