Cardiac Lecture 7 Flashcards
Concentric hypertrophy adds sarcomeres in _______
parallel - thicker wall
Eccentric hypertrophy adds sarcomeres in ______
series - stretched out wall
Why is it difficult to get an accurate lab value for thyroid hormone?
Fat-soluble hormone
What is the main symptom of hyperthyroidism?
Unexplained tachycardia at rest
The parathyroid gland controls _____ levels in the blood
calcium - PTH
The thyroid gland controls _____
metabolism
Protrusion of the thyroid gland is also called
Protrusion of goiter
The thyroid is highly ______
vascular - bleeding risk
Which recurrent laryngeal nerve loops under aortic arch?
left recurrent laryngeal nerve
The L recurrent laryngeal nerve passes under the _______
aortic arch
Which recurrent laryngeal nerve loops around the brachiocephalic artery?
right recurrent laryngeal nerve
Thyroid hormone makeup
Tyrosine (AA) + 3 or 4 iodides
What kind of thyroid hormone does the thyroid gland release the most?
T4 - thyroxine (93%)
What is the other name for T3?
triiodothyronine
What is the difference in the structure of T3 and T4 from tyrosines with 1-2 iodides attached?
T3 and T4 have 2 benzene rings
- T1/2 only have 1 (combine to form T3)
How much iodine is needed in the diet? What is the main source?
50 mg/year, table salt
TSH comes from the ______
anterior pituitary gland (adenohypophysis)
TRH comes from the ______
hypothalamus
T4 (thyroxin) is produce by an enzyme combining ____
combining 2 diiodityrosine (T2)s together
How does thyroid hormone move in the CV system?
3 carrier proteins - TBG (thyroxine-binding globulin), thyroxine-binding pre-albumin, and albumin
T3 is produced by an enzyme combining _____
combining 1 T1 and 1 T2 together
monoiodotyrosine +diiodotyrosine = triiodothyronine (T3)
Where are the carrier proteins for thyroid hormone made?
the liver
How does thyroid hormone turn on genes?
By passing through the nuclear pore, receptors are in the nucleus
What are the results of thyroid hormone mediated protein synthesis?
Growth, increased metabolism, CNS development, inc CV system (CO, HR, RR)
Does the BP increase in response to thyroid hormone? Why or why not?
No - inc CO if function of reduced SVR
Protein carriers of thyroxine
primary = TBG - thyroxine binding globulin
2ndary: Thyroxine binding prealbumin and Albumin
How long does it take for thyroid hormone to make changes after release?
6-8 hours, peak around 10 days
A pituitary tumor would result in what?
Inc TSH, inc thyroid hormone, sensed by hypothalamus which dec production of TRH
A thyroid tumor would result in what?
Inc thyroid hormone, sensed by hypothalamus which dec production of TRH, resulting in dec production of TSH in the anterior pituitary
A tumor in the hypothalamus would result in what?
Inc TRH, inc TSH, inc thyroid hormone
What is the name of the enzyme that converts T4 into T3 in the cytoplasm?
Iodinase
Which form of thyroid hormone is most active within the nucleus?
T3
_______ disease is an autoimmune disorder in which antibodies activate TSH receptors, resulting in hyperthyroidism
Grave’s
What is the side effect of Grave’s disease that impacts the eyes?
exophthalmos - corneal protrusion
________ is the disorder in which antibodies attack the thyroid gland
Hoshimotos thyroiditis
What would be the result of iodine deficiency?
Inc TRH, TSH, but no thyroid hormone - goiter
How can thyroid cancer be treated?
Radioactive iodine - I-131
What would the result of a massive inc of dietary iodine be?
Dec thyroid hormone - cooks the system, can be used to help treat hyperthyroidism
What medication is packaged in iodine?
Amiodarone
What is the medication given to treat hypothyroidism?
Synthroid - low compliance d/t side effects
What is the most common type of shock?
Hypovolemic
________ shock is induced with volatile anesthetics
neurogenic - takes CV control offline
Describe how anaphylactic shock occurs
histamine release from mast cells causes venous dilation and decreased CO
Describe how septic shock occurs
usually caused by a gram (+) infection which dilates blood vessels and dec CO
Reduced SNS activity has what effect on outcomes of hemorrhage?
Decreased ability to survive
After 20% blood loss, the arterial pressure is ______ and CO is _____
normal, low
Why is arterial BP normal even when CO is reduced after 20% blood loss?
SNS - vasoconstriction, SVR inc (dec CO)
A patient won’t hypovolemic shock once the MAP decreases to less than ____% of normal
45%
The body can compensate for a ___% decrease in MAP
50%
________ is when the body can compensate for shock, while _____ is when the body is unable to compensate for shock
Non-progressive shock, progressive
You can lose ____% of blood volume without impacting MAP or CO
10%
____% of blood loss is not survivable
40%
What are the blood storage pools in the body?
spleen, pulmonary circulation, GI system
What are the body’s compensations for heart failure?
Inc Psf (SNS activation)
Fluid retention (kidneys)
______L/min is the critical CO needed for survival
5
How do digitalis and milrinone help the body compensate for heart failure?
Gives the heart more time to repair itself by increasing CO to the critical level
How can fluid retention result in worsening heart failure?
Heart unable to reach adequate CO so kidneys continue to retain fluid bc they can’t reach their BP goal
