Overview of Endocrinology

Question 1

What is the function of hormones?

Answer 1

enable cells to communicate; they are
very sophisticated body communicators

Question 2

What are the major endocrine organs?

Answer 2

 Hypothalamus
 Pituitary gland
 Peripheral endocrines tissues:
-Thyroid
- adrenal cortex
- gonads
-Pancreas
- Parathyroid glands

Question 3

Name the major endocrine organs and their secretions:

Answer 3

HYPOTHALAMUS - Releasing & inhibiting hormones

PITUITARY GLAND -
a) Anterior lobe - trophic hormones
b) Posterior lobe – vaspressin + oxytocin

THYROID GLAND - Thyroxine, tri-iodothyronine

ADRENAL GLAND -
a) Cortex: Cortisol, aldosterone
b) Medulla: Adrenaline/noradrenaline

GONADS - Oestrogens, androgens, progesterones

PANCREAS - Insulin, glucagon

PARATHYROID GLAND - Parathyroid hormone

Question 4

4 different Signalling mechanisms in the endocrine system:

Answer 4

Endocrine
Paracrine
Autocrine
Intracrine

Question 5

What are trophic hormones?

Answer 5

Hormones that act on another gland than the one they are released from

Question 6

What does the CVS secrete?

Answer 6

Atrial natriutic peptides (ANP),
endothelins

Question 7

Pineal gland secretions?

Answer 7

Melatonin

Question 8

Thymus gland secretions?

Answer 8

Thymic hormones

Question 9

Adipose tissue secretions?

Answer 9

Leptin (controls appetite)

Question 10

What does endocrine mean?

Answer 10

Hormones released by endocrine cell into general secretion (acting in distant target sites)

Question 11

Paracrine?

Answer 11

Hormones released by an endocrine cell which acts locallly on adjacent cells

Question 12

Autocrine?

Answer 12

Hormones released by a cell which acts back on the same cell

Question 13

Intracrine?

Answer 13

Conversion of inactive hormone into active hormone that acts within that same cell (goes into nucleus to be activated)

Question 14

3 General functions of hormones?

Answer 14

-Reproduction, growth and development
-Maintenance of internal environment
-Energy production, utilization and storage

Question 15

Reproduction, growth and development

Answer 15

Sex Steroids, thyroid hormones, prolactin, growth hormone

Question 16

Maintenance of internal environment

Answer 16

Aldosterone, parathyroid hormone, vitamin D

Question 17

Energy production, utilization and storage

Answer 17

Insulin, glucagon, thyroid hormones, cortisol, growth hormone

Question 18

4 Chemical classifcations of hormones?

Answer 18

• Protein/peptide
  -Steroid(cholesterol)
  -Amino acid derivatives
  -Fatty acid derivatives

Question 19

Half life/ transport of Proteins/peptide hormones

Answer 19

Minutes

Mainly unbound (travels freely)

Question 20

Half life/ transport of Tyrosine derivates)

Answer 20

Seconds

Question 21

Magnocellular neurones

Answer 21

Project to posterior pituitary and release to
capillaries supplied by inferior hypophysial
artery

Question 22

Parvocellular neurones

Answer 22

Neurosecretory cells release hormones to
capillaries of median eminence
conveyed by
portal veins to anterior pituitary where they
regulate endocrine secretion

Question 23

Flat peg (hormones of the anterior pituitary gland)

Answer 23

-FSH
-LH
-ACTH
-TSH

-Prolactin
-Endorphin
-Growth hormone

Question 24

The hypothalamus released which two types of hormones?

Answer 24

Releasing/inhibiting hormones

Question 25

Acromegaly

Answer 25

Excess growth hormone Most commonly due to pituitary adenoma: increase in GH-secreting somatotrophs * Less commonly secondary: tumour elsewhere secretes GHRH

Question 26

Hypothyroidism

Answer 26

* Decrease in thyroid hormone production and/or * Impaired action of thyroid hormones on target tissues

Question 27

Lack of cortisol causes?

Answer 27

Addison's disease

Question 28

Excess cortisol causes?

Answer 28

Cushing's disease

Question 29

What does cortisol affect?

Answer 29

Gluconeogenesis Protein mobilisation Fat mobilisation Anti-inflammatory effects

Question 30

How is cortisol secreted?

Answer 30

hypothalamus releases cortisol releasing hormone to anterior pituitary releases adrenocorticotropic hormone (acth) causes adrenal cortex to release cortisol

Question 31

what does cortisol control?

Answer 31

It aids in the body's stress response by increasing blood sugar and providing energy. Cortisol regulates metabolism of carbohydrates, fats, and proteins. -Gluconeogenesis -Fat mobilisation -Protein mobilisation -reduces inflammation. Cortisol helps maintain blood pressure and electrolyte balance. It influences growth, development, and the body's circadian rhythm

Question 32

Which glands are controlled by the hypothalmic pituitary axis?

Answer 32

The hypothalmus secretes releasing/inhibiting neurohormones to the anterior pituitary gland which releases trophic hormones Thyroid Adrenal cortex Gonads

Question 33

Anterior hypothalamus

Answer 33

releases releasing and inhibiting hormones regulates hormone production by anterior pituitary gland