Lecture 7 Flashcards
exam 1 content
Where would the fastest/most backwards blood flow happen during the cardiac cycle with mitral regurgitation?
at the beginning of phase III (where the pressure in the ventricle is pretty high and the atria are most empty)
what is the formula for ejection fraction?
(EDV-ESV) / EDV or SV/EDV
what is the giveaway that people may have hyperthyroidism?
high HR at rest with no known cardiac issues
the thyroid is highly vascularized, why is this important?
- any procedures in this area pose a high bleeding risk (ex. emergent airway)
- able to get thyroid hormones into systemic circulation quickly
What other structures do you have to be mindful of performing any a procedures in the anterior neck or near the aorta
the laryngeal nerves run parallel to the thyroid gland and carotid arteries and loop around the aortic arch. These nerves give us the ability to speak
how much of our thyroid hormone is T3? T4?
T3: 7%
T4: 93%
What’s another name for T4 and what is it made up of?
thyroxine. A tyrosine with 4 iodides attached to it
What’s another name for T3 and what is it made up of?
triiodothyronine. A tyrosine with 3 iodides attached to it
how much iodine do humans need to produce enough thyroid hormones?
about 50 mg per year
what would you see if someone was iodine deficient?
goiter
What is TSH and where is it produced?
Thyroid stimulating hormone that comes from the anterior pituitary gland (adenohypophysis) TSH tells the thyroid to release T3/T4
What is TRH and where is it produced?
Thyrotropin releasing hormone produced in the hypothalamus. TRH tells the adenohypophysis to release TSH.
How do the thyroid hormones make their way through the bloodstream?
they are lipid soluble so they rely on carrier proteins to travel through the bloodstream
What are the three main carrier proteins the thyroid hormones use to circulate the blood?
- Thyroxine binding globulin
- Thyroxine binding pre-albumin
- Albumin
where are these carrier proteins made
by the liver
What is significant if hyperthyroidism goes uncheck?
increased thyroid hormone increases all cellular metabolic processes which increases HR and CO.
What is one good thing hyperthyroidism does?
decreases cholesterol
How long does it take thyroid hormone to reach peak effects?
10 days (long time before you start realizing it’s effects)
What would a pituitary tumor cause?
more TSH causing the thyroid gland to release more thyroid hormone. TRH would decrease in d/t hypothalamic response to increased T3/T4.
What would happen if there was a tumor in the thyroid gland producing copious amounts of thyroid hormone?
The hypothalamus would respond by releasing less TRH and this would reduce TSH levels released by the pituitary as well
What would you expect to see with a hypothalamic tumor?
Increased TRH would cause the pituitary to release more TSH, which would cause the thyroid to release more T3/T4. This system goes unchecked (as far as we are concerned in this class)
Which is the active version of thyroid hormone? and where is the majority of it produced?
T3. Only 7% is made by the thyroid and the tissues/cells create even more T3 by pulling an iodide off of T4.
What is Grave’s disease?
An autoimmune disorder where the body creates antibodies that bind and activate TSH receptors on the thyroid gland
What are a few symptoms of Grave’s disease?
- goiter
- exophthalmos
- increased thyroid hormones
What is Hashimoto’s thyroiditis?
an autoimmune disorder that creates antibodies that attack the thyroid gland and results in primary hypothyroidism (increased TSH and decreased T4)
How can you treat thyroid cancer?
give radioactive iodine (I-131). The thyroid is the only structure in the body that uses iodine
What is a problem you can run into r/t the thyroid if you give a patient a lots of amiodarone?
Amiodarone is packaged in iodine containing solution. Lots of iodine can decrease T3/T4 production
What circulatory problem do you have to worry about with r/t hypothyroidism?
increased cholesterol leading to atherosclerosis
What is the most common form of shock?
hypovolemic shock
What would you expect to see in BP and CO if we experienced 10% blood loss?
both arterial pressure and CO stay relatively normal
What would you expect to see in BP and CO if we experienced 20% blood loss?
arterial pressure is about the same, but CO is reduced
What percent blood loss is unrecoverable by the body without intervention?
greater than 40% blood loss
What can the body do to help increase CO with a failing heart?
the kidneys can hold onto more water leading to increased filling pressures
Why do we give patients with heart failure diuretics?
there is a point where the kidneys hold on to too much water that it actually reduces CO
What is secondary hypothyroidism?
Decreased TSH and decreased T3/T4
