Endocrine (Exam II) Flashcards
What provides sensory innervation above the vocal cords?
Internal laryngeal branch of the superior laryngeal branch of the vagus nerve.
What provides sensory innervation below the vocal cords?
Recurrent Laryngeal Nerve
All intrinsic muscles of the larynx except the _______ muscle are supplied by the ______ ______ nerve.
Cricothyroid : Recurrent laryngeal nerve
What muscle gets its motor innervation from the external laryngeal branch of the superior laryngeal nerve?
Cricothyroid Muscle
What stores thyroglobulin?
Colloid filled follicles
What produces calcitonin?
Parafollicular cells
Do parasympathetic or sympathetic nerve fibers run with the blood vessels of the thyroid?
Sympathetic
What is the innervation of the thyroid gland?
What are the three sources of arterial blood to the thryoid gland?
- Superior thyroid artery (branch of external carotid).
- Inferior thyroid artery (branch of subclavian artery)
- Throid ima artery (Only in 3-10% of people)
What would be the expected diagnosis from the following labs?
- ↑ T₃
- ↑ T₄
- ↔ or ↓ TSH
Hyperthyroidism
What would be the expected diagnosis from the following labs?
- ↑ T₃
- ↔ T₄
- ↔ TSH
Pregnancy
What would be the expected diagnosis from the following labs?
- ↓ T₃
- ↓ or ↔ T4
- ↑ TSH
Primary Hypothyroidism
What would be the expected diagnosis from the following labs?
- ↓ T₃
- ↓ T₄
- ↓ TSH
Secondary Hypothyroidism
What is a normal TSH level?
0.4 - 5.0 milliunits/L
What occurs with unilateral recurrent laryngeal nerve injury?
- Hoarseness
- Globus sensation
Rarely an airway issue.
What is a normal T₄ level?
60 - 120 nmole / L
What is a normal T₃ level?
0.92 - 3 nmole / L
What are indications for thyroidectomy?
- Large goiter
- Compression
- Children/young
- Cancer
- Allergy to anti-thyroid drugs
- Pregnant patients
- Moderate - severe opthalmopathy
- Cosmetic desire of patient
Patient must be rendered _____ prior to thyroidectomy.
euthyroid
Goal of 85 - 90 bpm.
What VAA is the choice anesthetic for thyroidectomy?
Isoflurane
What is our “triad of concerns” with hyperthyroidism patients?
- Airway obstruction
- Tetany
- Recurrent Laryngeal Nerve injury
What is the treatment for hypoparathyroidism?
- High dose Ca⁺⁺
- Calcitriol
- Vitamin D
Low ____ post-operatively can predict hypocalcemia.
PTH
Why should most hypothyroid patients be deferred for elective surgeries?
↑ risk of CV complications vcv
What cells do pheochromocytoma’s originate from?
Chromaffin cells of the adrenal medula
What is the biochemical pathway for epinephrine development?
Phenylalanine → tyrosine
→ dopa → dopamine → NE → Epi
Catecholamines will increase/decrease the following:
________ glycogenolysis
________ gluconeogenesis
________ glucagon secretion
________ glucose uptake
↑ glycogenolysis
↑ gluconeogenesis
↑ glucagon secretion
↓ glucose uptake
How do pheochromocytomas present?
Signs: HTN, ↑HR
Symptoms: Headaches, sweating, N/V, anxiety
What are our goals for perioperative managment of pheochromocytoma?
- Treat HTN (α blockers)
- Volume Expansion (fluids)
- Control arrhythmias (β blockers)
When should phenoxybenzamine be initiated prior to pheochromocytoma resection?
1 - 3 weeks preoperatively.
What drug is use for α blockade alongside phenoxybenzamine?
Doxazosin
What should be started first for pheochromocytoma patient? Why?
α blocker before a β blocker
If a βblocker is started first then the unopposed α of the catecholamine can worsen vasoconstriction and precipitate HTN crisis & pulm edema.
α antagonists should be titrated to mild ____ ______.
Orthostatic hypotension
Which VAA’s would be a good choice for pheochromocytoma?
Isoflurane or enflurane
Least cardiac depressant.
If a pregnant patient is diagnosed with pheochromocytoma, then when should it be resected?
2ⁿᵈ trimester (surgery)
1st trimester (medical therapy)
If a pheochromocytoma is developed or diagnosed late in a pregnancy, what should be done?
Elective c-section as vaginal delivery may precipitate HTN crisis.
The parathyroid gland is composed primarily of ___ cells.
Chief
What cells secrete PTH?
Chief cells
Which parathyroid cells begin to appear at puberty and have an unknown function?
Oxyphyl cells
PTH is secreted in response to ____ Ca⁺⁺.
low
Lithium will ____ PTH secretion and _____ cell sensitivity to Ca⁺⁺.
↑ PTH : ↓ cell sensitivity
1,25 (OH)₂D will _____ PTH secretion.
↓
What common psychiatric drug will increase PTH secretion and decrease cell sensitivity to Ca⁺⁺?
Lithium
What effects does PTH have on Ca⁺⁺?
- ↑ activity of osteoclasts = release of Ca⁺⁺ from bones
- ↑ Ca⁺⁺ reabsorption in the kidneys
- ↑ GI absorption of Ca⁺⁺
What are the renal effects of PTH?
- ↑ urinary phosphate excretion
- ↑ renal production of Vitamin D (increases GI absorption of Ca⁺⁺).
How should the signs/symptoms of Hyperparathyroidism be remembered?
Stones, bones, groans, and moans
What drugs are used for hypercalcemia? Are these a fix for hyperparathyroidism?
- Biphosphonates (↓ Ca⁺⁺ but ↑ PTH)
- Cinacalcet (↓ Ca⁺⁺ , does not ↑ Ca⁺⁺ secretion)
No, these are only stop-gap measures until surgery can be performed.
What is parathyroid crisis? How is this managed?
- ↑ Ca⁺⁺ = 15 or greater
- Fluids to dilute Ca⁺⁺ and then lasix to “flush” out the Ca⁺⁺.
> ____% decline in PTH of the after the gland has been removed indicates a successful surgery.
> 50%
