Endocrinology Lecture 1

Question 1

What is an endocrine gland?

Answer 1

Ductless glands that secrete long distance messenger hormones into blood

They may synthesis hormones or receive them from elsewhere and store them

Question 2

What main mechanism maintains homeostasis?

Answer 2

Negative feedback is key to homeostasis

Question 3

Difference between negative and positive feedback?

Answer 3

Positive feedback is not homeostatic and tries to apology a signal using a signal eg childbirth

Question 4

Hormone classifications?

Answer 4

Steroid hormones
Peptide hormones
Amino acid derivatives
Asap Eicosanoids (modified from lipids and NO)

Question 5

Steroid hormone facts

Answer 5

Produced by the adrenal cortex and gonads/placenta

Lipophilic so can’t be stored in vesicles and usually transported via carrier proteins

Receptors are typically inside target cell

Question 6

Polypeptide hormone facts

Answer 6

Hydrophilic,lipophobic so usually has to bind to receptors on cell surface (usually trigger second messengers)

Can be synthesised earlier and stored in vesicles for later

Question 7

Amino acid derivatives facts

Answer 7

Hydrophilic but some lipophobic

Tyrosine derivatives:
epinephrine,norepinephrine,dopamine

Thyroid hormones:T3,T4

Tryptophan derivatives:
Melatonin serotonin

Question 8

How can hormone release be triggered?

Answer 8

Humoral (changing levels of ions/nutrients in blood)

Hormonal

Neural

Question 9

Humoral release…

Answer 9

Changing legal of substance in blood
Release of PTH
For calcium homeostasis

Question 10

Order of hormonal release?

Answer 10

From hypothalamus the pituitary gland will secrete messenger hormones that go to either thyroid adrenal cortex or gonads to release their hormone

Question 11

Neurohormones facts

Answer 11

Neurohormones released into blood from neural tissue