Lecture: Endocrine

Question 1

What does the endocrine system include

Answer 1

Endocrine glands and their hormones

Question 2

Function of endocrine system

Answer 2

Secrete hormones into the bloodstream

Question 3

What is a hormone

Answer 3

Chemical messenger which targets a specific group of cells, in order to cause that group of cells to do some activity or stop doing an activity

Question 4

What are exocrine glands

Answer 4

Glands that release their secretions into ducts or tubes

E.g liver releases bile into the gall bladder
Pancreas releases pancreatic juice into small intestine

Question 5

Hormones that are proteins

Answer 5

Growth hormone

Glycoprotein hormone s(e.g. luteinising hormone)

Question 6

Hormone that is a polypeptide

Answer 6

Insulin

Question 7

Peptide hormone example

Answer 7

Thyrotropin-releasing hormone

Question 8

Hormones that are amino acid derivatives

Answer 8

Dopamine, catecholamine, thyroid hormone

Question 9

Examples of steroid hormones

Answer 9

Mineralocorticoids
Glucocorticoids
Sex steroids

Question 10

Example of sterol hormones

Answer 10

Vitamin D

Question 11

What are binding proteins

Answer 11

Proteins that bind to hormones and carry them around the circulation

Question 12

Binding proteins for T4, T3

Answer 12

Thyroxine binding globulin (TBG)
Thyroxine binding prealbumin (TBPA)
Albumin

Question 13

Binding proteins for testosterone

Answer 13

Sex hormone binding globulin

Albumin

Question 14

Binding protein for cortisol

Answer 14

cortisol binding globulin

Question 15

Binding protein for GH

Answer 15

GH-binding protein

Question 16

Binding protein for IGF-1

Answer 16

IGF-binding protein-3 plus the acid labile subunit (ALS)

Question 17

Function of hormones

Answer 17

Differentiation of reproductive and CNS in foetus
Stimulation of growth and development
Coordination of the male and female reproductive system
Maintenance of internal environment
Adaptation to emergency demands of the body

Question 18

How are hormones regulated

Answer 18

By negative/positive feedback mechanisms

Question 19

Example of negative feedback mechanism

Answer 19

Secretion of insulin which tells cells to take in glucose

Glucose levels drop, secretion of insulin stops

Question 20

Example of positive feedback mechanisms

Answer 20

Release of oxytocin to release milk from baby suckling

Question 21

Name human endocrine glands

Answer 21

Pituitary 
Thyroid
Parathyroid
Adrenal 
Pancreas
Testes & ovaries

Question 22

Function of parathyroid

Answer 22

Control metabolism of calcium

Question 23

What does under secretion of parathyroid hormone result in

Answer 23

Never disorders
Brittle bones
Clotting problems

Question 24

What hormones are released from adrenal glands

Answer 24

Cortisone and adrenaline

Question 25

Function of cortisone

Answer 25

Regulate carbohydrate, protein and fat metabolism

Question 26

Function of adrenaline

Answer 26

Raise blood sugar levels and increases heartbeat and breathing rates

Question 27

What does under secretion of adrenaline result in

Answer 27

Inability to deal with stress

Question 28

What is the pituitary

Answer 28

Gland is a round organ located behind the bridge of the nose at the base of the body

Question 29

How many hormones does the pituitary secrete

Answer 29

9

Question 30

What regulates pituitary function

Answer 30

Hypothalamus | Hypothalamic-pituitary-axis

Question 31

What can hyperprolactinaemia cause

Answer 31

Infertility

Question 32

What are causes of hyperprolactinaemia

Answer 32

Stress Drugs Hypothyroidism

Question 33

How to differentiate between prolactinoma and idiopathic hypersection

Answer 33

Detailed radiology + dynamic tests of prolactin secretion [Serum prolactin rises after administration of TRH observed in idiopathic hyperprolactinaemia but not tumour)

Question 34

Name two hormones secreted by posterior pituitary

Answer 34

antidiuretic hormone oxytocin (synthesised in the hypothalamus)

Question 35

How are anterior pituitary function tests preformed

Answer 35

TRH, GnRH and insulin are administered and measured at 0, 30 and 60 m

Question 36

Causes of hypopituitarism

Answer 36

``` Tumour Infarction Traume Congenital malformation Infection Hypothalamic disorder ```

Question 37

What is a cause of goiter

Answer 37

Iodine deficiency in diet

Question 38

Normal T4 plasma concentration

Answer 38

100 nmol/L

Question 39

How is T3 produced

Answer 39

Liver and kidneys (peripheral tissues) deiodinate T4 to produce 2/3rds of T3 (Conc of 2 nmol/L)

Question 40

What does the biosynthesising of thyroid hormones involve

Answer 40

Trapping of circulating iodide by thyroid gland incorporation of iodine into tyrosine Coupling of iodinated tyrosyl residues from the thyronines within the protein backbone of the Tg protein in the follicular lumen. Endocytosis followed by proteolytic cleavage of Tg releases the iodothyronines into circulation

Question 41

T4 can be metabolised to

Answer 41

reverse T3 which is biologically inactive

Question 42

What proteins transfer T4 & T3

Answer 42

TBG (70%) Alb (25%) Transthyretin (5%)

Question 43

When do highest level of TSH occur

Answer 43

between 0200 and 0400 (lowest at 1700 to 1800

Question 44

Causes of hypothyroidism

Answer 44

Primary hypothyroidism | Idiopathic hypothyroidism, hashimotos thyroiditis, surgical removal of thyroid

Question 45

Symptoms of hypothyroidism

Answer 45

Weakness, skin changes (dry), lethargy, slow speach, eyelid edema, cold, decreased sweating, thick tongue, forgetfulness

Question 46

What confirms diagnosis of graves disease

Answer 46

Raised T4, suppressed TSH + TSH receptor antibody level

Question 47

Hyperthyroidism causes

Answer 47

Graves disease Toxic multi nodular goitre Thyroiditis Excessive T4 & T3 ingestion

Question 48

Hyperthyroidism clinical features

Answer 48

``` weight loss sweating heat intolerance fatigue angina/heart failure diarrhoea ```