Endocrine system

Question 1

What are the main anatomical components of the endocrine system?

Answer 1

Hypothalamus, pituitary gland, thyroid gland, parathyroid glands, adrenal glands, pancreas

Question 2

What is the general function of the endocrine system?

Answer 2

Uses hormones to regulate:

• metabolism
• growth and development
• homeostasis
• stress response
• reproduction

Question 3

How does the autonomic nervous system (ANS) produce effects?

Answer 3

Neurotransmitters → fast, localized responses

Question 4

What is the pathway of the autonomic nervous system?

Answer 4

Hypothalamus → brainstem & spinal cord → autonomic nerve fibres → target → homeostasis

Question 5

How does the endocrine system produce effects?

Answer 5

Hormones → slower, widespread responses

Question 6

What is the general endocrine pathway?

Answer 6

Hypothalamus → pituitary → hormones → target → homeostasis

Question 7

What hormones are released from the posterior pituitary (neurohypophysis)?

Answer 7

ADH (antidiuretic hormone) and oxytocin

Question 8

What types of hormones does the hypothalamus release to control the anterior pituitary? (general)

Answer 8

Releasing and inhibiting hormones

Question 9

What are the 6 hormones released by the anterior pituitary (adenohypophysis)?

Answer 9

• Thyroid-stimulating hormone (TRH)
• Adrenocorticotropic hormone (ACTH)
• Follicle stimulating hormone (FSH)
• Luteinizing hormone (LH)
• Growth hormone (GH)
• Prolactin (PRL)

Question 10

What is the TRH → TSH pathway?

Answer 10

Hypothalamus (TRH) → portal system → anterior pituitary → TSH → bloodstream → thyroid gland

Question 11

What is the CRH → ACTH pathway?

Answer 11

Hypothalamus (CRH) → portal system → anterior pituitary → ACTH → bloodstream → adrenal cortex

Question 12

What stimulates thyroid hormone release?

Answer 12

Low T3/T4 levels or low body temperature

Question 13

Where is thyroid hormone produced and what is its effect?

Answer 13

Follicular cells → increases metabolism and body temperature

Question 14

What stimulates calcitonin release?

Answer 14

High blood Ca²⁺

Question 15

What synthesizes calcitonin?

Answer 15

parafollicular cells of thyroid gland

Question 16

What does calcitonin do? (its target cells, + effect)

Answer 16

Inhibits osteoclasts → lowers blood Ca²⁺

Question 17

What stimulates parathyroid hormone (PTH)?

Answer 17

Low blood Ca²⁺

Question 18

what synthesizes PTH?

Answer 18

chief cells of parathyroid gland

Question 19

What are the effects of PTH? (+ its target region/cells)

Answer 19

Increases osteoclast activity, increases kidney Ca²⁺ reabsorption, activates vitamin D → raises blood Ca²⁺

Question 20

What stimulates mineralocorticoid (aldosterone) release?

Answer 20

Low blood pressure

Question 21

Where are mineralocorticoids produced and what do they do? (synthesized where? and effect)

Answer 21

Zona glomerulosa → increase Na⁺ reabsorption (target region is nephron) → increase blood volume

Question 22

What stimulates glucocorticoid (cortisol) release?

Answer 22

Stress → CRH → ACTH → cortisol (multi-step pathway)

Question 23

Where are glucocorticoids produced and what do they do? + what is its target cells

Answer 23

Zona fasciculata → increase blood glucose, anti-inflammatory

target cells: most cells

Question 24

What produces androgen precursors and what stimulates them?

Answer 24

Zona reticularis → stimulated likely by ACTH (but lots is unknown)

Question 25

What stimulates insulin release and what is its effect?

Answer 25

stimulate by high blood glucose → effect: lowers blood glucose

Question 26

Where is insulin produced?

Answer 26

Beta cells of pancreatic islets

Question 27

What stimulates glucagon release and what is its effect?

Answer 27

stimulate by low blood glucose → effect: raises blood glucose

Question 28

where is the target cells of insulin

Answer 28

most cells!

Question 29

Where is glucagon produced and what are its targets?

Answer 29

Alpha cells → targets liver and adipose tissue