Endocrine block exam

Describe tyrosine derived hormone, give example, where they act on the cell

Describe peptide/protein hormone, give example, where they act on the cell

Describe steriod hormone, give example, where they act on the cell

tumor of pituitary (somatotrophs) causes what and what are 2 disease associated with it?

Excessive GH secretion causing gigantism and acromegaly

Why would you give patients with diabetes insipidus a isotonic dextrose?

In Diabetes insipidus, the problem is loss of free water due to lack of ADH effect

Giving isotonic dextrose: Glucose will be taken up by cell leaving free water behind which will dilute the extracellular compartment decreasing its osmolarity.

Why would taking anterior pituitary and transplanting to the abdomen lead to hypersecretion of prolactin

Once anterior pituitary gland loses connection to the hypothalamus → no portal blood supply → no regulatory signals.

Therefore dopamine signal decreases and can no longer inhibit the release of prolactin

For a child with a mid-parental height range of 75th to 25th percentile, where on the

growth chart would you expect the child to fall if they were exposed to chronic food and

housing insecurity? and why?

Even if the child is genetically programmed to be between the 25th–75th percentile:

• Adverse conditions → they fail to reach their genetic potential

• Growth shifts downward on the curve

➡ So the child will likely fall below their expected range, often:
👉 ≤ 25th percentile

Hormone related to bone repair and mineralization:

1. PTH

2. GH

3. Insulin

4. Sex steriod

5. cortisol

Why would apparent Mineralocorticoid Excess (AME) is caused by a deficiency of 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) cause low plasma aldosterone levels?

1. Cortisol is not inactivated, so cortisol accumulates at the mineralocorticoid receptor and acts like aldosterone

2. Because the body senses excess mineralocorticoid activity, renin and aldosterone are both suppressed, so plasma aldosterone is low

Why does prolonged treatment with Dexamethasone (a synthetic glucocorticoid) may result in Diabetes mellitus?

Because of increased glucose production + insulin resistance, long-term use can cause steroid-induced diabetes mellitus

Why does addison’s disease cause hypotension?

Addison’s disease = primary adrenal insufficiency caused by destruction of the adrenal cortex. This leads to:

• ↓ Cortisol

• ↓ Aldosterone

Loss of aldosterone → Na⁺ loss, volume depletion—> hypotension

What causes Hypertrophy

• Hyperplasia

• Enlarged thyroid (goiter)

• Increased thyroid hormone synthesis

TSH is trophic to the thyroid gland. Chronic stimulation by TSH causes

What are Thyroid stimulating immunoglobulins (TSI)

• These are autoantibodies that bind and stimulate the TSH receptor.

• Classically found in Graves' disease, not in healthy individuals.

A pituitary tumor of the somatotropes in an adult would likely cause:

Effects of excess GH:

• ↑ Growth hormone (GH)

• ↑ Hepatic production of IGF-1

The body responds with negative feedback, increasing hypothalamic somatostatin, which inhibits GH release.

Somatostatin negatively inhibit what 2 things?

TSH (thyrotropes) and GH (somatotropes)

Why would too much GH cause diabetes?

Chronic GH —> inc blood glucose —>inc insulin—> eventually insulin resistance

Non surgical treatment for acromegaly

Somatostatin analog which because decrease GH and possibly shrink tumor before surgery

How do natural glucocorticoids compare to synthetic therapeutic molecules?

Synthetic glucocorticoids:
• are more potent than natural glucocorticoids.
• are less effective at activating the mineralocorticoid receptor.

What is Cushing disease vs syndrome?

Cushing’s Syndrome: excess glucocorticoid activity (primary) due to adrenal tumor
• Cushing’s Disease: pituitary adenoma w/ increased ACTH (secondary)

Effects of glucocorticoids on Immune Function

—> Decreases immunity/ inflammation
→ Decreases the response to injury or infection

used for patients with organ transplant

How does cortisol reduce insulin sensitivity?

By decreasing GLUT4 translocation in muscle and fat cells

How does cortisol elevate blood pressure?

increased responsiveness of adrenergic receptors to catecholamines

True or false: chronic cortisol level (long-term) causes lipogenesis in face, neck and truncal (abdominal, visceral) areas, leading to central obesity

True

how would synthetic glucocorticoids and cushing disease effect adrenal androgen level:

synthetic glucocorticoids: decreases

cushing disease: increases

hirsutism, clitoromegaly, deep voice, and acne caused by

excess sex hormones

Cortisol and aldosterone levels are found to be low. What would their ACTH, Angio II and Renin level be like (high or low)

ACTH: high (less negative feedback)

Angio II: high (compensate low blood volume due to low aldo)

Renin: high

Patients with Addison’s disease, level of sodium reabsorption and response to catecholamines: (inc or dec)

Decreased sodium reabsorption
Decreased response to catecholamines

Patients with Addison’s disease would likely have which of the
following results of blood levels of glucose, K+ and Na+ ?

Blood glucose: low

K+: high

Na+: low

Cause and classification of conn’s disease?

Caused by Aldosterone secreting tumor and it’s classified as primary
hyperaldosteronism

CRH hypersecretion and Tertiary hypercortisolism is characteristic of

severe chronic depression

Why does increase in testosterone cause acne?

Testosterone is converted into DHT which activates sebaceous gland

For restoring endogenous testosterone production following cessation of anabolic steroid use, what can be used?

Treatment with hCG, which is functionally indistinguishable from LH, stimulates
testicular growth, testosterone production and spermatogenesis by binding to the LH receptor in Leydig cells to increase steroidogenesis lost by exogenous T treatment

bind to estrogen receptors at the anterior pituitary and hypothalamus antagonizing the inhibitory effect estrogen has on gonadotropin releas

Selective estrogen receptor modulators

Cessation of menses due to pregnancy, hypothalamic dysfunction ( stress, weight loss), pituitary disorder, menopause causes what kind of amenorrhea

Secondary amenorrhea

You never had period

primary amenorrhea

Woman experiencing menopause will have primary vs secondary hypogonadism:

primary hypogonadism

An athlete with significant weight loss will experience primary vs secondary hypogonadism:

secondary hypogonadism

In brief starvation (3days), main source of energy? (3)

inc protein degradation=amino acid, lactate, ketone body

In prolonged starvation, main source of energy? (2)

Inc ketone body formation

Muscle switches to fatty acid

Ketoacidosis is common in type I or II diabetes patient:

Type 1 because complete destruction of B cells leads to no insulin and when you have no insulin then you produce ketone body thus can lead to ketoacidosis.