Endocrine - Anatomy Flashcards Preview

USMLE (S1) Endocrinology > Endocrine - Anatomy > Flashcards

Flashcards in Endocrine - Anatomy Deck (42)
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1
Q

A 19-year-old with type 1 diabetes comes in for a routine check-up. Where in the islets of Langerhans is the root of her condition?

A

(A) the β cells, which should be centrally located; patients with type 1 diabetes do not produce enough insulin

2
Q

You realize that you have not eaten in six hours. In the image, what cell in the islets of Langerhans is working overtime?

A

(B) the α cell, which should be peripherally located; it produces glucagon because of your fasting state

3
Q

The zona glomerulosa of the adrenal gland is regulated by _____ and secretes _____.

A

Renin-angiotensin; aldosterone

4
Q

The zona fasciculata of the adrenal gland is regulated by _____ and secretes _____.

A

Adrenocorticotropic hormone and hypothalamic corticotropin-releasing hormone; cortisol and sex hormones

5
Q

The zona reticularis of the adrenal gland is regulated by _____ and secretes _____.

A

Adrenocorticotropic hormone and hypothalamic corticotropin-releasing hormone; sex hormones (eg, androgens)

6
Q

The adrenal medulla is primarily regulated by (parasympathetic/sympathetic) fibers and is composed of (chromaffin/chromophobe) cells.

A

Sympathetic; chromaffin

7
Q

The most common tumor of the adrenal medulla in adults is _____, whereas in children it is _____.

A

Pheochromocytoma; neuroblastoma

8
Q

What are the effects of pheochromocytomas and neuroblastomas on blood pressure?

A

Pheochromocytomas cause episodic hypertension whereas neuroblastomas do not

9
Q

What mnemonic helps you remember the three layers of the adrenal cortex and their corresponding products?

A

Zona Glomerulosa (salt), Zona Fasciculata (glucocorticoids), Zona Reticularis (sex hormones): GFR corresponds to salt, sugar, and sex ("the deeper you go, the sweeter it gets")

10
Q

Trace the blood flow from the left adrenal gland to the inferior vena cava.

A

Left adrenal gland to the left adrenal vein to the left renal vein to the inferior vena cava

11
Q

Trace blood flow from the right adrenal gland to the inferior vena cava.

A

Right adrenal gland to the right adrenal vein to the inferior vena cava

12
Q

Which gonadal vein drains directly into the inferior vena cava: the right or the left?

A

Right gonadal vein

13
Q

Embryologically, the posterior pituitary is derived from the _____, whereas the anterior pituitary is derived from the _____.

A

Neuroectoderm; oral ectoderm

14
Q

What does the posterior pituitary gland secrete?

A

Vasopressin (antidiuretic hormone) and oxytocin

15
Q

Where are the secretory products of the posterior pituitary formed?

A

In the hypothalamus

16
Q

What are the secretory products of the anterior pituitary?

A

Follicle-stimulating hormone (FSH), luteinizing hormone (LH), adrenocorticotropic hormone (ACTH), thyroid-stimulating hormone (TSH), Prolactin, growth hormone (GH), and melanotropin (remember: FLAT PiG)

17
Q

Which pituitary hormones have a common alpha subunit?

A

Thyroid-stimulating hormone, luteinizing hormone, follicle-stimulating hormone, and human chorionic gonadotropin

18
Q

What is the clinical significance of the shared subunit of thyroid-stimulating hormone, luteinizing hormone, follicle-stimulating hormone, human chorionic gonadotropin?

A

At high enough concentrations, a given hormone can partially activate the receptor of another hormone with the same a subunit

19
Q

What is the significance of the subunit of pituitary hormones?

A

It determines the hormone specificity of thyroid-stimulating hormone, luteinizing hormone, follicle-stimulating hormone, and human chorionic gonadotropin

20
Q

Which hormones are secreted from acidophilic cells?

A

Growth hormone, prolactin

21
Q

Which hormones are secreted from basophilic cells?

A

Basophils secrete follicle-stimulating hormone (FSH), luteinizing hormone (LH), adrenocorticotropic hormone (ACTH), and thyroid-stimulating hormone (TSH) (remember: B-FLAT)

22
Q

What cell types are found in the islets of Langerhans?

A

, , and δ endocrine cells

23
Q

In the islets of Langerhans, α- endocrine cells are located _____ and secrete _____.

A

Peripherally; glucagon

24
Q

In the islets of Langerhans, β- endocrine cells are located _____ and secrete _____.

A

Centrally; insulin (remember: INSide INSulin)

25
Q

In the islets of Langerhans, δ endocrine cells are located _____ and secrete _____.

A

Throughout; somatostatin

26
Q

Where are islets of Langerhans most numerous?

A

In the tail of the pancreas

27
Q

From what embryonic structures do the islets of Langerhans arise?

A

Pancreatic buds

28
Q

-Cells in the pancreas make insulin in response to what cellular process?

A

Increased glucose metabolism increases adenosine triphosphate, which closes potassium channels and depolarizes the cell

29
Q

What effect would a -cell potassium channel blocker have on the release of insulin?

A

Increased insulin release, because potassium channel closure depolarizes the β-cell

30
Q

Insulin release from -cells is increased by (opening/closing) potassium channels and (opening/closing) calcium channels.

A

Closing; opening

31
Q

What is the effect of insulin on -cells of the pancreas?

A

Insulin inhibits glucagon release

32
Q

What is the effect of insulin on electrolyte (Na+, K+) handling?

A

Insulin increases Na+ retention by the kidneys and shifts K+ into cells

33
Q

What effects does insulin have on glucose, protein, and lipid production and storage?

A

Insulin increases glucose transport into cells, increases glycogen and triglyceride synthesis and storage, and increases protein synthesis in muscles

34
Q

Which cells require insulin for glucose uptake?

A

Skeletal muscle and adipose have glucose transporter type 4 (insulin-responsive) glucose transporters (remember: Insulin moves glucose Into cells)

35
Q

Which cells do not need insulin for glucose uptake?

A

BRICK L: Brain, RBCs, Intestine, Cornea, Kidney, and Liver

36
Q

Which cells have glucose transporters type 1?

A

Red blood cells and brain cells have glucose transporters type 1, which do not require insulin for glucose uptake

37
Q

Which cells have bidirectional glucose transporters?

A

Those with glucose transporters type 2 channels: islet cells, liver, kidney

38
Q

What causes the exocytosis of insulin from -cells?

A

The influx of calcium, following depolarization of the cell by potassium channel closure

39
Q

What makes adipose and skeletal muscle dependent on insulin for glucose uptake?

A

They have insulin-responsive glucose transporters type 4

40
Q

Why are red blood cells and the brain not dependent on insulin for glucose uptake?

A

They have insulin-independent glucose transporters (glucose transporter type 1)

41
Q

What does the brain use for metabolism under starvation states?

A

Ketones made by the liver

42
Q

What do red blood cells use for metabolism under starvation states?

A

Glucose; red blood cells only have the glycolysis pathway to make adenosine triphosphate; thus, they cannot use ketones like the brain in starvation states