Exam 1: AI Lecture 7 Flashcards
What is mitral regurgitation?
A leaky valve between the left ventricle and left atria
When does retrograde perfusion occur in mitral regurgitation?
When the pressure in the ventricle is higher than the pressure in the atria
During which phase does backward blood flow start due to mitral regurgitation?
Beginning of Phase 2 (isovolumetric contraction)
What happens to backward blood flow during Phase 3?
It continues throughout systole
Why is backward blood flow during Phase 4 less than during Phase 3?
The Delta p is diminishing and the atria is likely full
When is the highest amount of backward blood flow expected during Phase 4?
At the beginning of Phase 4
What is the formula for calculating Ejection Fraction (EF)?
Stroke Volume ÷ End Diastolic Volume
What is the normal Ejection Fraction value?
Approximately 58% (e.g., 70 over 120)
What type of hypertrophy is associated with thin ventricular walls?
Eccentric hypertrophy
EF with Eccentric hypertrophy would be
Lower than 58%
weak, thin, walls cannot get as much blood out
What type of hypertrophy is associated with thick ventricular walls?
Concentric hypertrophy
EF with Concentric hypertrophy would be
Higher than 58%
- Thick strong walls can get more blood out to a point
In concentric hypertrophy, how are sarcomeres added?
In parallel
Stacked on top of each other
In eccentric hypertrophy, how are sarcomeres added?
In series
Next to each other
How does the heart decide to which route to go between the two forms of cardiac hypertrophy?
If change is due to high afterload (SVR)
- concentric (in parallel)
If infarction or congenital issue (genitically inherited)
- Eccentric (in series)
What is a potential giveaway symptom of hyperthyroidism?
Increased heart rate at rest
What is a goiter?
Protrusion of the neck due to an enlarged thyroid gland
What type of hormone is thyroid hormone considered to be? Why is this significant?
Fat-soluble hormone
- it is hard to get a handle on to assess if someone has hyperthyroidism or not
Could go undetected for months or years
What is a significant risk when manipulating the thyroid gland during surgery?
Bleeding due to rich vascularization
Causing thyroid storm
What controls the muscles inside the larynx?
Motor neurons from the vagus nerve
What is the name of the nerve that innervates the muscles of the larynx?
Right and left recurrent laryngeal nerves
What is the alternate name for the right recurrent laryngeal nerve after a certain curve?
Right Inferior laryngeal nerve
Where does the left recurrent laryngeal nerve pass before turning back up towards the voice box?
Under the aortic arch
True or False: The left recurrent laryngeal nerve is more inferior than the right recurrent laryngeal nerve.
True
What is the primary function of the inferior laryngeal nerve?
It plays a crucial role in the ability to speak.
If damaged, it can lead to speaking difficulties.
How does the left recurrent laryngeal nerve differ from the right?
The left recurrent laryngeal nerve passes under the aortic arch before ascending, making it more inferior than the right.
This anatomical difference is significant during surgeries in the neck.
What happens if both laryngeal nerves are lost?
The individual will not be able to speak at all.
What is the main hormone produced by the thyroid gland?
Thyroid hormone, which includes T3 and T4.
What are the two main compounds related to thyroid hormone?
- T3 (triiodothyronine)
- T4 (thyroxine)
What is the percentage of T4 released compared to T3 by the thyroid gland?
93% T4 and 7% T3.
What is another name for T4?
Thyroxine.
What is the chemical structure of T3?
A tyrosine amino acid with three iodides attached.
What is the role of iodine in thyroid hormone production?
Iodine is essential for the synthesis of thyroid hormones, typically requiring 50 mg per year.
What is TSH and its role in thyroid function?
TSH stands for thyroid stimulating hormone, which regulates the release of T3 and T4 from the thyroid gland.
What gland produces TSH?
The anterior pituitary gland.
It could be called an Adenohypophyseal hormone
The nickname for TSH is
Thyrotropic
What hormone does the hypothalamus release to regulate TSH?
TRH (thyrotropin releasing hormone).
What is the primary carrier protein for thyroid hormones in the blood?
Thyroxine binding globulin (TBG).
What are the three main carrier proteins for thyroid hormones?
- Thyroxine binding globulin (TBG)
- Thyroxine binding prealbumin
- Albumin
Where are the three main carrier proteins for thyroid hormones made?
Liver
How do thyroid hormones affect metabolic rate? What does the new metabolic rate affect? (9)
They increase metabolic rate which increases:
- Mitochondria activity
- Na/K pump
- oxygen consumption
- glucose absorption
- gluconeogenesis
- glycogenolysis
- Lipolysis
- Protein synthesis
- BMR (basal metabolic rate)
What happens to cardiovascular system when thyroid hormone levels increase?
The following increase to meet new metabolic demand:
- Cardiac output
- HR
- Tissue blood flow
- Heart strength (contractility?)
- Respiration
Hyperthyriodism causes glucoses levels to
Drop
consumed as metabolism increases
hunger will increase as well
True or False: Increased thyroid hormone levels typically lead to elevated blood pressure.
False.
What impact does thyroid hormone have on growth and development?
It is crucial for proper maturation and development of the nervous system.
Can manifest as personality, memory, or cognition issues
What can happen if there is a deficiency of thyroid hormone during growth?
It can lead to cognitive issues and developmental deficiencies with the CNS.
What is required for proper maturation of the nervous system?
A healthy amount of thyroid hormone
Absence of thyroid hormone can lead to major deficiencies in cognition and personality.
What happens to blood cholesterol levels in hyperthyroidism?
Blood cholesterol levels typically drop
Cholesterol is consumed at a cellular level for various functions, leading to reduced levels in the blood.
How long does it take for thyroid hormone effects to manifest?
6 to 8 hours for significant amounts; up to 10 days for small amounts
Thyroid hormone effects are generally longer-term and not immediate.
What is a pituitary tumor’s effect on thyroid hormone production?
Increases TSH, leading to hyperthyroidism
The hypothalamus will stop producing TRH but cannot control the tumor, resulting in high TSH and thyroid hormone levels.
What occurs with a thyroid gland tumor?
Produces excess thyroid hormone independent of TSH or TRH
This results in reduced TRH and TSH due to feedback mechanisms.
What happens with a hypothalamic tumor? What does it secrete?
Elevated TRH, TSH, and thyroid hormone levels
TRH
The normal feedback mechanism is disrupted in this scenario.
Which form of thyroid hormone is primarily delivered to cells?
T4 (93% of circulating thyroid hormone)
T4 is converted to T3 within cells via the enzyme Iodinase.
What is the active form of thyroid hormone that binds to receptors?
T3
T4 has much less activity compared to T3.
What is Grave’s disease?
An autoimmune disorder where the body creates antibodies that activate the TSH receptor causing increased thyroid hormone production
Symptoms include exophthalmos and goiter.
Where is the tumor in Grave’s disease?
On the thyroid gland
What is Hashimoto’s thyroiditis?
An autoimmune condition where antibodies destroy the thyroid gland
It leads to hypothyroidism over time.
What is the consequence of iodine deficiency?
Inability to produce sufficient thyroid hormone, leading to high TRH and TSH levels
This can result in an enlarged thyroid gland (goiter).
True or False: We will not have any of the building blocks needed to produce thyroid hormone without adequate amounts of iodine.
False
We still have Tyrosine
We cannot make all five compounds or building blocks after tyrosine without Iodine to bind to tyrosine
What is the role of radioactive iodine in treating thyroid cancer?
Targets thyroid tumors, as the thyroid gland primarily uses iodine
I-131 is commonly used for this purpose.
What happens with excessive iodine intake?
Decreased ability to produce thyroid hormone
High doses can interfere with the cellular mechanisms for thyroid hormone production.
Fill in the blank: A tumor in the hypothalamus secreting TRH will likely cause _______.
Elevated levels of TRH, TSH, and thyroid hormone.
True or False: Exophthalmos is present in iodine deficiency with goiter.
False
Exophthalmos is a result of excessive thyroid hormone, not iodine deficiency.
What nutritional requirements increase with elevated thyroid hormone levels?
Increased need for proteins and carbohydrates
This is due to the increased metabolic rate.
What is the predominant effect of T3 in the body?
Regulation of metabolic processes
T3 binds to thyroid hormone receptors to exert its effects.
What is Exophthalmos?
A condition characterized by protrusion of the eyeball.
- presents a higher risk for corneal abrasion
Commonly associated with hyperthyroidism.
What effect does excessive iodine have on the thyroid gland?
It can temporarily shut down the thyroid gland.
This may occur or be useful during a thyroid storm.
Excessive iodine could be useful in ____ or if the ___
Thyroid storm; thyroid gland got cut
Cutting the thyroid gland = massive release of TSH
What happens to blood vessels when metabolic demand increases due to high circulating thyroid hormone?
Blood vessels relax to allow for higher cardiac output due to reduced systemic vascular resistance (SVR).
This process helps deliver nutrients to more active tissues.
How does hyperthyroidism affect blood cholesterol levels?
Blood cholesterol and triglycerides are likely to be low.
Hyperthyroidism increases metabolism and cholesterol use.
What is a major concern with untreated hypothyroidism in older adults?
Atherosclerosis due to elevated cholesterol levels.
Higher cholesterol can lead to thickening of blood vessel walls.
What is the patient compliance rate for synthetic thyroid hormone (Synthroid)?
Extremely low.
Patients often dislike the side effects associated with Synthroid.
What is shock in a medical context?
A problem getting the required nutrients to tissues that need them.
What defines cardiogenic shock?
Problems with the heart’s ability to pump adequate cardiac output.
Examples include heart attacks and issues with venous return.
What causes neurogenic shock?
Loss of sympathetic tone, often induced by anesthetics or high spinal procedures.
What triggers anaphylactic shock?
Histamine response from mast cells due to an immune reaction.
Common triggers include allergies to latex or peanuts.
Massive histamine release is more concerning when it effects the arteries or the veins? Why?
The veins
There will be a large decrease in venous return = drop in filling pressure, drop in CO
What type of bacteria is usually associated with septic shock?
Gram-positive bacteria.
What is hypovolemic shock?
The most common form of shock related to low blood volume.
Often due to blood loss or dehydration.
How does the sympathetic nervous system (SNS) affect cardiovascular maintenance?
It helps maintain blood pressure and cardiac output during blood loss.
What happens to cardiac output and blood pressure when 20% of blood volume is lost?
Blood pressure may appear normal, but cardiac output decreases.
This can lead to serious complications if not monitored.
What are the consequences of losing more than 20% of blood volume?
Increased risk of severe complications and potential mortality.
What is progressive shock?
A state where the body can no longer compensate for blood loss, leading to organ failure.
What is the significance of measuring cardiac output?
It provides a more accurate assessment of cardiovascular function than blood pressure alone.
Fill in the blank: Anaphylactic shock is driven by ________ released from mast cells.
histamine
What is the threshold percentage of blood volume loss where survival becomes very difficult?
40%
Beyond this level, if not addressed quickly, survival chances are significantly reduced.
At what percentage of blood volume loss is a person likely to feel perfectly fine?
Up to 20%
This is contingent on the individual being relatively healthy prior to hemorrhage.
What are three areas in the body mentioned in lecture that can respond to blood loss?
- The spleen - stores extra hemoglobin and red blood cells.
- Pulmonary circulation - can shift 200-300 cc’s of blood to the systemic circulation
- GI system - can shift extra blood to places that need it more
The spleen can release these stored components into circulation when needed.
In the context of heart failure, what is the initial body response to a failing heart?
Increase in filling pressures.
This is due to blood vessels tightening to assist the failing heart.
What is the normal cardiac output required for a young, healthy individual?
Approximately 5 L/min
This is crucial for maintaining life functions.
True or False: Cardiac glycosides can provide a complete cure for heart failure.
False
These medications can help improve cardiac output but are not a miracle cure.
What is the consequence of the kidneys retaining fluid when blood pressure is low?
It can lead to overfilling the heart and worsening the condition.
This occurs when the heart cannot utilize the excess volume effectively.
What is the purpose of diuretics in heart failure management?
To prevent the kidneys from retaining excess fluid.
This helps to avoid overloading the heart and improves cardiac function.
Fill in the blank: The kidneys monitor _______ to assess the health of the circulatory system.
blood pressure
This monitoring influences their decisions on fluid retention.
What is the limitation of using blood pressure as an indicator of cardiac output?
It does not provide a complete picture of cardiac function.
Blood pressure monitoring alone may miss critical aspects of cardiac health.
What does the Edwards FlowTrac equipment measure?
Pulse pressure variation.
It’s an algorithm that assesses heart function via arterial line tracing.
What happens when the heart is excessively stretched due to high filling pressures?
It can become less effective at pumping.
Overstretching can impair cardiac function, leading to further complications.
What is a critical requirement for a patient to stay alive in the context of cardiac output?
Normal cardiac output levels.
If the output is insufficient, survival is unlikely.
In heart failure, what happens if the cardiac output does not improve despite fluid retention?
The patient’s condition may worsen.
Continuous retention without improvement can lead to severe complications.
What type of medications can be used to help improve cardiac output in failing hearts?
Cardiac glycosides and phosphodiesterase inhibitors.
These medications can provide short-term assistance to the heart.
Where does the phrenic nerve originate?
C3, C4, and C5
Controls diaphragm
