[Exam 1] Lecture 7: Thyroid Flashcards
What is mitral regurgitation?
A leaky valve between the left ventricle and left atrium
It causes retrograde perfusion when ventricular pressure exceeds atrial pressure.
During which phase does backward blood flow begin due to mitral regurgitation?
Phase 2, at the beginning of isovolumetric contraction
The valve is leaking, making it no longer isovolumetric.
What factors influence backward blood flow in mitral regurgitation?
Delta P and the relative fullness of the atria
Delta P refers to the pressure difference between the ventricle and atria.
During which phase is backward blood flow expected to be highest?
Phase 3
Backward blood flow continues throughout systole.
What happens to backward blood flow during Phase 4 of mitral regurgitation?
There is still some backward blood flow, but it diminishes as ventricular pressure decreases
The highest backward blood flow occurs at the beginning of Phase 4.
True or False: Backward blood flow is constant throughout the cardiac cycle in mitral regurgitation.
False
Backward blood flow varies with different phases of the cardiac cycle.
What is the formula for calculating ejection fraction (EF)?
Stroke Volume divided by End Diastolic Volume
Normal EF is approximately 58%.
What does a high ejection fraction in mitral regurgitation indicate?
It may be falsely high due to backward flow
Echo measurements can be misleading in regurgitation cases.
What type of hypertrophy is characterized by thin ventricular walls?
Eccentric hypertrophy
Eccentric hypertrophy involves adding sarcomeres in series.
What type of hypertrophy is characterized by thick ventricular walls?
Concentric hypertrophy
Concentric hypertrophy involves adding sarcomeres in parallel.
Which endocrine system significantly impacts the cardiovascular system?
The thyroid system
Thyroid hormones influence metabolism and cardiovascular health.
What is a common sign of hyperthyroidism?
Increase in resting heart rate
This can occur in patients without any heart problems.
What is a goiter?
Protrusion of the neck due to an enlarged thyroid gland
It can be caused by various factors.
What is the role of the parathyroid gland?
Controller of calcium levels in the blood
It works alongside the thyroid gland.
What is the risk associated with manipulating the thyroid gland during surgery?
Bleeding due to its rich vascular supply
The thyroid has extensive blood vessels that pose a bleeding hazard.
What nerve controls the muscles inside the larynx?
Right recurrent laryngeal nerve
It branches off the vagus nerve.
What happens to the name of the recurrent laryngeal nerve after it curves around a blood vessel?
It may be referred to as the inferior laryngeal nerve
This occurs after the initial curve beneath the artery.
What is another name for the inferior laryngeal nerve?
Recurrent laryngeal nerve
The recurrent laryngeal nerve is named for its anatomical path, which involves a curve around major blood vessels.
Where does the left recurrent laryngeal nerve pass before turning back towards the voice box?
Under the aortic arch
What happens if one of the laryngeal nerves is cut during surgery?
The patient may have a hard time speaking
What is the predominant thyroid hormone released by the thyroid gland?
T4 (Thyroxine)
What percentage of thyroid hormone released by the thyroid gland is T4?
93%
What is the chemical name for T3?
Triiodothyronine
What is the other name for T4?
Thyroxine