Endocrine - Anatomy

Question 1

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?

Answer 1

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

Question 2

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

Answer 2

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

Question 3

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

Answer 3

Renin-angiotensin; aldosterone

Question 4

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

Answer 4

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

Question 5

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

Answer 5

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

Question 6

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

Answer 6

Sympathetic; chromaffin

Question 7

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

Answer 7

Pheochromocytoma; neuroblastoma

Question 8

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

Answer 8

Pheochromocytomas cause episodic hypertension whereas neuroblastomas do not

Question 9

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

Answer 9

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”)

Question 10

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

Answer 10

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

Question 11

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

Answer 11

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

Question 12

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

Answer 12

Right gonadal vein

Question 13

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

Answer 13

Neuroectoderm; oral ectoderm

Question 14

What does the posterior pituitary gland secrete?

Answer 14

Vasopressin (antidiuretic hormone) and oxytocin

Question 15

Where are the secretory products of the posterior pituitary formed?

Answer 15

In the hypothalamus

Question 16

What are the secretory products of the anterior pituitary?

Answer 16

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

Question 17

Which pituitary hormones have a common alpha subunit?

Answer 17

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

Question 18

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

Answer 18

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

Question 19

What is the significance of the subunit of pituitary hormones?

Answer 19

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

Question 20

Which hormones are secreted from acidophilic cells?

Answer 20

Growth hormone, prolactin

Question 21

Which hormones are secreted from basophilic cells?

Answer 21

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

Question 22

What cell types are found in the islets of Langerhans?

Answer 22

α, β, and δ endocrine cells

Question 23

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

Answer 23

Peripherally; glucagon

Question 24

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

Answer 24

Centrally; insulin (remember: INSide INSulin)

Question 25

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

Answer 25

Throughout; somatostatin

Question 26

Where are islets of Langerhans most numerous?

Answer 26

In the tail of the pancreas

Question 27

From what embryonic structures do the islets of Langerhans arise?

Answer 27

Pancreatic buds

Question 28

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

Answer 28

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

Question 29

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

Answer 29

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

Question 30

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

Answer 30

Closing; opening

Question 31

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

Answer 31

Insulin inhibits glucagon release

Question 32

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

Answer 32

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

Question 33

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

Answer 33

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

Question 34

Which cells require insulin for glucose uptake?

Answer 34

Skeletal muscle and adipose have glucose transporter type 4 (insulin-responsive) glucose transporters (remember: **In**sulin moves glucose **In**to cells)

Question 35

Which cells do not need insulin for glucose uptake?

Answer 35

**BRICK L**: **B**rain, **R**BCs, **I**ntestine, **C**ornea, **K**idney, and **L**iver

Question 36

Which cells have glucose transporters type 1?

Answer 36

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

Question 37

Which cells have bidirectional glucose transporters?

Answer 37

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

Question 38

What causes the exocytosis of insulin from -cells?

Answer 38

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

Question 39

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

Answer 39

They have insulin-responsive glucose transporters type 4

Question 40

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

Answer 40

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

Question 41

What does the brain use for metabolism under starvation states?

Answer 41

Ketones made by the liver

Question 42

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

Answer 42

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