Endocrine System Flashcards
How are most hormones regulated? Positive or negative feedback loop?
Negative feedback loop
The interactions within the endocrine system constitute the ____________ a major part of the neuroendocrine system that controls reactions to stress and regulates many body processes.
hypothalamic-pituitary axis
The endocrine system helps regulate: (7)
Chemical composition and volume of interstitial fluid
Metabolism and energy balance
Biological clock or circadian rhythms
Contraction of smooth and cardiac muscle fibers
Glandular secretions
Some immune system activities
Operations of reproductive system
Does the endocrine system control growth and development?
Yes
Identify:
Thyroid Feedback Loop
The thyroid senses low levels of thyroid hormones ___ and ___ which then responds by releasing what hormone?
T3 and T4
thyrotropin-releasing hormone (TRH)
The TRH (thyroid-releasing hormone) stimulates the pituitary to produce what?
thyroid-stimulating hormone (TSH)
What hormone is released from the hypothalamus?
TRH (thyroid releasing hormone)
What hormone is released from the anterior pituitary gland?
TSH
________ stimulates the thyroid gland to secrete the hormone thyroxine (T4) (inactive form) which is converted to triiodothyronine (T3), which is the active hormone that stimulates metabolism.
TSH
________ is also produced by the hypothalamus, and has an opposite effect on the pituitary production of TSH, decreasing or inhibiting its release.
Somatostatin
The concentration of thyroid hormones (T3 and T4) in the blood regulates the pituitary release of TSH. True or false?
true
When T3 and T4 concentrations are low, the production of TSH is ______ and vice-versa.
increased
Note: This is known as a negative feedback loop.
T4 and T3 (controlled by TSH) levels peak in the early morning. True or false?
false
Diurnal peaks in late evening.
What factors influence secreted amounts of T3 and T4? (6)
Gender
Pregnancy
Gonadal- and adrenal cortical-increased steroids (increase)
Exposure to cold (increase)
Nutritional state
Chemicals (dopamine, catecholamines)
What are the functions of T3 and T4? (9)
Regulate protein, fat, and carbohydrate catabolism in cells
Regulates metabolic rate and body heat production
Insulin antagonist
Maintains growth hormone secretion, skeletal maturation
Affects CNS development
Maintains cardiac rate, force, and output
Affects respiratory rate and oxygen utilization
Affects RBC production
Enhances cholesterol excretion in the bile
What type of thyroid condition results in a goiter?
Hyperthyroidism
What type of thyroid condition results in exophthalmos?
Hyperthyroidism
What are the symptoms of hyperthyroidism? (10)
Nervousness or anxiety
Increased sweating
Heat intolerance
Palpitations
Dyspnea
Fatigue and weakness
Weight loss or gain
Increased appetite
Hyperdefication or loose stools
Menstrual irregularity
What are the signs and symptoms of hyperthyroidism? (5)
Thyroid enlargement (goiter)
Tachycardia
Atrial fibrillation
Hyperkinesis (state of overactive restlessness)
Eye signs (exophthalmos)
For hyperthyroidism, we would expect the following increase/decrease in labs:
_________ T3 and T4
________ free thyroxine or T4
___________ TSH
elevated T3 and T4
elevated free thyroxine or T4
decreased TSH
What other labs could you expect for a pt with hyperthyroidism? (5)
Hypercalcemia
Increased alkaline phosphatase
Anemia
Decreased granulocytes
Increased erythrocyte sedimentation rate
What is the treatment for hyperthyroidism? (4)
Thioamides
Iodine
Beta-adrenergic blockade
Thyroid surgery
What are preoperative considerations for pts with hyperthyroidism? (2)
Airway exam is important, especially if a goiter is present.
Ptoptosis will require diligent eye protection.
In an emergency surgery situation, what drugs will we need to have available for a pt with hyperthyroidism? (4)
Propythiouracil (PTU)
Propanolol
Potassium iodide
Corticosteroids
What are the symptoms of hypothyroidism? (10)
Cold intolerance
Dyspnea
Anorexia
Constipation
Decreased libido
Menorrhagia, amenorrhea
Oliguria
Arthalgias, myalgias, muscle stiffness and cramps
Dryness
Fatigue
What are the signs of hypothyroidism? (5)
Weight gain (or loss)
Bradycardia
Diastolic hypertension
Cardiac rub or soft heart tones causes by pericardial effusion
Ileus
For hypothyroidism, we would expect the following increase/decrease in labs:
_____ Free T4
________ TSH in primary hypothyroidism
_______ or normal TSH in pituitary insufficiency
Decreased free T4
Increased TSH
Decreased or normal TSH
What other labs could you expect for a pt with hypothyroidism? (4)
Increased serum cholesterol, liver enzymes, creatine
Hyponatremia
Hypoglycemia
Anemia
What is a major complication of severe hypothyroidism?
Myxedema coma
What are the complications of myxedema coma? (5)
hypothermia
hypoventilation
hyponatremia
hypoxia
hypertension
What factors may induce myxedema coma? (4)
infection, cardiac or respiratory
CNS illness
cold exposure
drug use
Elderly men are more at risk for myxedema coma. True or false?
false
elderly women
How is hypothyroidism treated? (2)
Thyroid hormone replacement–synthetic levothyroxine
Treatment monitored closely with lab values and titrated.
What hormone raises serum Ca++ levels while promoting bone reabsorption?
Parathyroid hormone
The following would increase/decrease for pts with hyperparathyroidism:
_______ parathyroid hormone
_______ calcium levels
increased PTH
increased calcium
What are the consequences of hypercalcemia? (7)
renal stones
polyuria
hypertension
constipation
fatigue
mental changes
bone pain
What is the most common cause of hyperparathyroidism?
parathyroid adenoma
Is parathyroid cancer common?
No
What are the signs of hypocalcemia? (8)
tetany
carpopedal spasms
tingling of lips and hands
muscle and abdominal cramps
psychological changes
positive Chvostek’s and Trousseau’s signs
defective nails and teeth
cataracts
What condition may common be seen after thyroidectomy, but may only be transient?
hypoparathyroidism
What is the treatment for hypoparathyroidism? (4)
IV calcium gluconate
oral calcium
Vit D
Magnesium
What are the tests for hypocalcemia? (2)
Chvostek’s sign
Trousseau’s sign
What labs are ordered for parathyroid issues? (6)
Serum calcium
Ionized calcium
Albumin
Serum magnesium
Alkaline phosphatase
Serum phosphate
What is the most common endocrine disease?
Diabetes Mellitus
What are long-term complications of diabetes mellitus?(4)
Injury to:
Eyes
Kidneys
Nerves
Blood vessels
What are the major risks for those with diabetes? (5)
Heart disease
Stroke
Kidney disease
Blindness
Nontraumatic amputations
What type of diabetes?
NO insulin production – thought to be an autoimmune destruction of islet cells in pancreas
Type 1
Note: They become dependent on exogenous insulin.
What type of diabetes?
Relative deficiency in insulin – insulin resistance
Associated findings include – obesity, abnormal insulin levels, strong genetic component
Type 2
What type of diabetes?
Complicates about 4% of pregnancies
Glucose intolerance that is identified during pregnancy
Gestational DM
What are the treatments for DM? (4)
Diet
Oral hypoglycemic drugs
Exercise
Exogenous insulin
What are anesthetic considerations for DM pts? (4)
Autonomic lability (Temp, BP, HR dysfunction)
Silent ischemia or CAD
Inhibited motility of GI
Glucose control–may affect healing
Perform a pregnancy test for any female of childbearing age which is ____-____ YO.
15-50
What are 2 major types of pregnancy test?
Urine
Blood
How accurate are home urine pregnancy tests?
97%
What blood pregnancy test measures the exact amount of hCG in the blood?
quantitative blood test
What blood test gives a simple yes or no answer to whether one is pregnant or not?
qualitative blood test
When are hCG levels at their peak from time of inception?
1-2.5 months
Surgery is only conducted during pregnancy when it is absolutely necessary for the wellbeing of the mother, fetus, or both. True or false?
true
All general anesthetic drugs cross the placenta. True or false?
true
Regional anesthesia is usually preferred in pregnancy when it is practical for the medical and surgical condition. True or false?
true
What are the most common surgeries for pregnant patients not related to the pregnancy? (3)
acute appendicitis
maternal trauma
surgery for maternal malignancy
Surgery should be done at an institution with neonatal and pediatric services. True or false?
true
An obstetric care provider with cesarean delivery privileges should be readily available. True or false.
true
A qualified individual should be readily available to interpret the fetal heart rate patterns. True or false?
What are the cardiovascular changes that occur during pregnancy? (5)
increased CO
increased blood volume
increased HR
decreased peripheral resistance
decreased blood pressure
What are the pulmonary changes that occur during pregnancy? (4)
increased RR
increased tidal volume
decreased FRC
respiratory alkalosis
What are risks presented by a pregnant patient intra-op? (4)
difficult intubation due to swelling
hypoxia
hyptension due to aortocaval compression
aspiration
If the fetus is considered pre-viable, it is sufficient to ascertain the fetal heart rate by Doppler before and after the procedure. True or false?
true
Intraoperative electronic fetal monitoring may be appropriate when all of the following apply: (5)
The fetus is viable.
It is physically possible to perform intraoperative electronic fetal monitoring.
A health care provider with obstetric surgery privileges is available and willing to intervene during the surgical procedure for fetal indications.
When possible, the woman has given informed consent to emergency cesarean delivery.
The nature of the planned surgery will allow the safe interruption or alteration of the procedure to provide access to perform emergency delivery.
