Lecture 4: Endocrine

Question 1

What is the endocrine system?

Answer 1

A system of hormone-secreting glands that regulate and coordinate many body functions

Question 2

List the endocrine organs (7)

Answer 2

• Hypothalamus (brain)
• Pituitary gland (brain)
• Pineal gland (brain)
• Thymus → Thyroid + Parathyroid glands (larynx)
• Adrenal gland (kidneys)
• Pancreas (abdomen)
• Gonads (ovaries + testes)

Question 3

Where is the binding site for steroid hormones?

Answer 3

Nucleus

Alters mRNA after binding

Question 4

Where is the binding site for peptide hormones?

Answer 4

cell surface

GPCR → activates 2nd messengers

Question 4

What are the functions of the hypothalamus (3)?

Answer 4

• Regulation of the pituitary gland:
• Axons travel down the pituitary stalk and synapse in the posterior pituitary
• Connections to the portal system (network of capillaries) allow the hypothalamus to stimulate the anterior pituitary to release hormones

Question 5

Does the posterior pituitary gland produce its own hormones?

Answer 5

No

Question 6

Pars Nervosa is the same as the ______ pituitary

Answer 6

posterior

Question 7

What is the function of Herring bodies? Where are they located?

Answer 7

• store hormones from the hypothalamus
• located in the posterior pituitary

Question 8

Does the anterior pituitary gland produce its own hormones?

Answer 8

Yes

Question 9

What two hormones does the posterior pituitary secrete?

Answer 9

• Vassopressin (ADH)
• Oxytocin

Hypothalamus makes vassopressin + oxytocin → secreted by posterior pituitary

Question 10

Pars Anterior is the same as the ______ pituitary

Answer 10

anterior

Question 11

What two cells secrete hormones in the anterior pituitary?

Answer 11

• Acidophils
• Basophils

Only have acidophils in anterior pituitary

Question 12

What two hormones do acidophils secrete?

Answer 12

• Growth Hormone (GH)
• Prolactin (PRL)

Question 13

What hormones do basophils secrete (4)?

Answer 13

• Thyrotropin (TSH)
• Follitropin (FSH) or Leuteotropin (LH)
• Corticotropin (ACTH)
• Melanocyte stimulating hormone (MSH)

Question 14

What are 1, 2, 3, and 4?

Answer 14

Question 15

The cells circled in red secrete GH + PRL. What are these cells called?

Answer 15

Acidophils (pink stain)

Question 16

The cells circled in dark blue secrete TSH, FSH, LH, ACTH, and MSH. What are these cells called?

Answer 16

Basophils (dark stain)

Question 17

What type of cells are A, B, and C?

Answer 17

Question 18

What two cells are shown in this image?

Answer 18

Axons and pituicytes

Question 19

Identify C (red) and D (dark blue)

Answer 19

Question 20

Identify A and B

Answer 20

Question 21

What is the function of the pineal gland (pineal body)?

Answer 21

secretes melatonin = role in sleep

released by pinealocytes

Question 22

How does daytime affect the pineal gland?

Answer 22

Daytime inhibits the pineal gland → no melatonin

Question 23

How does nighttime affect the pineal gland?

Answer 23

Nighttime activates the pineal gland → secretes melatonin

Question 24

Where is brain sand located?

Answer 24

Pineal gland

Question 25

Identify the structures circled in red

Answer 25

Question 26

What type of cells (2) do the follicles in the thyroid contain?

Answer 26

* Follicular cells * Parafollicular cells

Question 27

What do the follicular cells secrete?

Answer 27

Follicular cells = principal cells → secrete thyroid hormones (T3 + T4)

Question 28

What do the parafollicular cells secrete?

Answer 28

Parafollicular cells = C cells → secrete calcitonin ## Footnote * Anatagonist towards parathyroid (PTH) * Role in regulating Ca2+ secretion

Question 29

Where are thyroid hormones precursors made?

Answer 29

Colloid = inner lumen ## Footnote Only makes precursors

Question 30

How is hormone secretion regulated by iodide in the thyroid (4)?

Answer 30

1. Iodide gets transported into the colloid (inner lumen) of the follicle 2. In the colloid, iodide generates thyroid hormone precursors 3. Precursors get transported out of the colloid and into the follicular cells 4. In the follicular cells, thyroid hormone (T3/T4) is produced and secreted

Question 31

What causes a goiter? What is the result?

Answer 31

* Lack of iodide → decreased thyroid hormone (T3/T4) * Result = enlarged thyroid gland

Question 32

Identify A, B, C and D

Answer 32

Question 33

What zone is A? What zone is the black arrow pointing to?

Answer 33

Question 34

Identify A and B

Answer 34

Question 35

What structures are the yellow arrows pointing to? What structures are the black arrows pointing to?

Answer 35

Question 36

Identify A, B, and C

Answer 36

Question 37

Identify A, B, C, D, and E

Answer 37

Question 38

Identify A, B, and C

Answer 38

Question 39

Identify C, D, and E

Answer 39

Question 40

Identify A, B, C, D

Answer 40

Question 41

Identify C and D

Answer 41

Question 42

Identify A, B, and C

Answer 42

Question 43

Identify A and B

Answer 43

Question 44

What does calcitonin stimulate in the bone?

Answer 44

calcium salt deposit ## Footnote Calcitonin = ↑ bone Ca2+ ↓blood Ca2+

Question 45

Osteoclasts degrade _____ matrix and release _____ into the blood

Answer 45

* bone * Ca2+

Question 46

What does the parathyroid gland release?

Answer 46

parathyroid hormone (PTH) ## Footnote * Takes Ca2+ out of the bone to release into the blood * PTH = ↑ blood Ca2+ ↓ bone Ca2+

Question 47

Where is the parathyroid gland located?

Answer 47

Behind the thyroid gland ## Footnote The thyroid acts as an antagonist by secreting calcitonin from C cells to work against PTH

Question 48

What are the two types of parathyroid cells?

Answer 48

* **Chief cells** * **Oxyphil cells**

Question 49

**What is the function of chief cells?**

Answer 49

**secrete parathyroid hormone (PTH)** ## Footnote Not the same as chief cells in the stomach

Question 50

**What are oxyphil cells?**

Answer 50

**inactive chief cells**

Question 51

**What is the function of the parathyroid gland? How does it do this (2)?**

Answer 51

* **Regulates blood Ca2+ levels:** **1. A decrease in blood Ca2+ stimulates the release of PTH from chief cells** **2. PTH causes an increase in blood Ca2+ by breaking down bone**

Question 52

**What are the 3 zones of the adrenal gland from outermost to innermost? What does each zone secrete?**

Answer 52

1. Zona **G**lomerulosa = secretes aldosterone (salt) 2. Zona **F**asciculata = secretes cortisol (sugar = sweet) 3. Zona **R**eticularis = secretes androgens (sex)

Question 53

What does the medulla secrete?

Answer 53

secretes epinephrine + noepinephrine ## Footnote "MEN"

Question 54

The adrenal gland divides into the _____ and _____.

Answer 54

* cortex * medulla

Question 55

Identify the cell type: a. Acidophils b. Chief cells c. Oxyphil cells d. Parafollicular cells

Answer 55

c. Oxyphil cells

Question 56

Which region of the adrenal gland is responsible for producing norepinephrine? a. Zona reticularis b. Zona glomerulus c. Zona fasciculata d. Medulla

Answer 56

d. Medulla

Question 57

Identify this region: a. Reticularis b. Fasciculata c. Glomerulosa d. Medulla

Answer 57

b. Fasciculata

Question 58

Calcitonin is important in the regulation of blood calcium levels. Which endocrine organ and cell type are responsible for the secretion of calcitonin? a. Parathyroid gland; oxyphil cells b. Thyroid gland; parafollicular cells c. Pancreas; islet of Langerhans d. Posterior pituitary gland; herring bodies

Answer 58

b. Thyroid gland; parafollicular cells

Question 59

5. Vasopressin (ADH) and oxytocin are hormones produced by which organ? a. Hypothalamus b. Pineal gland c. Anterior pituitary gland d. Adrenal gland

Answer 59

a. Hypothalamus