Pituitary gland and its disorders

Question 1

What hormones does the anterior pituitary produce?

Answer 1

→ ACTH 
→ TSH
→ GH 
→ LH/FSH
→ Prolactin

Question 2

What hormones does the posterior pituitary produce?

Answer 2

→ oxytocin

→ ADH

Question 3

What does oxytocin do?

Answer 3

→ uterine contractions

→ breast milk expression

Question 4

What are the three layers of the endocrine system?

Answer 4

→ end organ is the primary layer
→ the secondary layer is the pituitary
→ third layer is the hypothalamus

Question 5

What are the 2 functions of the hypothalamus?

Answer 5

→ it takes sensory input - electrical signal

→ and produces hormones to adapt to the physical state - chemical signal

Question 6

In what blood vessel do the hormones get released into?

Answer 6

→ hypophyseal portal blood vessel

Question 7

What is the negative feedback system in endocrinology?

Answer 7

→ The production of the end hormone stops the pituitary and hypothalamus producing more

Question 8

What happens when you get pituitary tumors?

Answer 8

→ Hormone hypersecretion
→ Space occupying lesion- visual loss
→ Hormone deficiency states

Question 9

What is excess growth hormone?

Answer 9

→ acromegaly

Question 10

What is too much ACTH?

Answer 10

→ Cushings disease

Question 11

What is excess TSH?

Answer 11

→ secondary thyrotoxicosis

Question 12

What is excess LH and FSH?

Answer 12

→ Non functioning pituitary tumor

Question 13

What is excess prolactin?

Answer 13

→ prolactinoma

Question 14

Describe the growth hormone circulation

Answer 14

→ GF acts on the liver to produce IGF
→ IGF acts on bones to stimulate chondrocytes to grow which form new bone
→ it reduces body fat

Question 15

What are symptoms of acromegaly?

Answer 15

→ hands grow
→ Macroglossia
→ Carpal tunnel
→ Change of appearance

Question 16

Why do people with acromegaly get polyps or cancer?

Answer 16

→ skin and bowel tissue turns over a lot

Question 17

What are the actions of cortisol?

Answer 17

→ increases plasma glucose levels 
→ increases lipolysis 
→ Proteins are catabolized 
→ Na+ and H2O retention to maintain BP 
→ increase glycogenolysis

Question 18

What are visible changes in cushings?

Answer 18

→ change body shape
→ central obesity 
→ moon face
→ thin skin 
→ excess hair growth
→ irregular periods 
→ High BP

Question 19

How is prolactin controlled?

Answer 19

→ The stimulus to production of milk is an external signal
→ Intrinsic high production of prolactin from the pituitary
→ Tonic inhibitory dopamine signal from the hypothalamus to the pituitary

Question 20

How does lactation occur?

Answer 20

→ mechanical stimulation of the nipple sends a neuronal signal to the brain
→ goes to the hypothalamus
→ switches off dopamine production

Question 21

What happens if you have excess prolactin?

Answer 21

→ Infertility

→ No periods - amenorrhoea

Question 22

What drugs would interfere with prolactin formation?

Answer 22

→ drugs that interfere with dopamine such as antiemetics and antipsychotics

Question 23

What is the treatment for excess prolactin?

Answer 23

→ Dopamine agonists
→ bromocriptine
→ Cabergoline

Question 24

Why do non functioning pituitary tumors cause problems?

Answer 24

→ Pressure on the surrounding structures
→ no syndromes
→ headache - visual field defects

Question 25

Why do we have front facing eyes?

Answer 25

→ Humans are predators | → Gives depth vision

Question 26

What is homologous vision?

Answer 26

→ Nasal fibres from the same side cross and line up with temporal fibres on the other side → Go into one piece back to the brain for interpretation

Question 27

Where is the optic chiasm?

Answer 27

→ Above the pituitary

Question 28

What is bitemporal hemianopia?

Answer 28

→ Partial blindness | → Vision is missing in the outer half of both right and left visual field

Question 29

In what order are the hormones lost in when the tumor grows?

Answer 29

1) sex hormones 2) growth hormones 3) metabolic 4) Survival

Question 30

What rises when a tumor is made?

Answer 30

→ prolactin | → obstructs the pituitary and stops dopamine coming in the brain

Question 31

What are the treatments for pituitary adenomas?

Answer 31

→ Transsphenoidal surgery → Radiotherapy → Drugs - block hormone production, stops hormone release

Question 32

What are the causes of pituitary failure?

Answer 32

``` → Tumor → Trauma → Infection → Inflammation - sarcoidosis → Iatrogenic ```

Question 33

What happens if you don't produce enough thyroid hormone?

Answer 33

``` → Bradycardia → Weight gain → Cold intolerance → Hypothermia → Constipation ```

Question 34

What happens when you don't produce enough sex steroids?

Answer 34

→ Oligomenorrhoea → Reduced libido → Hot flushes → Less body hair

Question 35

What happens if you have reduced cortisol?

Answer 35

``` → Tiredness → Weakness → Anorexia → Postural hypotension → Myalgia ```

Question 36

What happens if you have reduced GH?

Answer 36

→ Tiredness | → Central weight gain

Question 37

What is the treatment for underproduction of thyroid hormone?

Answer 37

→ Thyroxine

Question 38

What is the treatment for underproduction of sex steroids?

Answer 38

→ Testosterone | → Estrogen

Question 39

What is the treatment for reduced hydrocortisol?

Answer 39

→ Hydrocortisone

Question 40

What is the treatment for reduced GH?

Answer 40

→ Growth hormone

Question 41

What is the action of ADH?

Answer 41

→ Collecting ducts → Increases permeability for H2O → Reabsorption of free water → Vasoconstriction

Question 42

How is ADH stimulated?

Answer 42

→ Increased osmolality → Decreased blood pressure → Decrease in O2 → Increase in CO2

Question 43

What is the cause of syndrome of inappropriate ADH production?

Answer 43

→ Brain injury → Lung cancer → Metabolic - hypothyroidism, Addisons

Question 44

How do you diagnose SIADH?

Answer 44

→ Dilute plasma | → Concentrated urine

Question 45

What happens during diabetes insipidus?

Answer 45

→ Cranial → Lack of production of ADH → Nephrogenic - receptor doesnt respond to it

Question 46

What is a symptom of SIADH?

Answer 46

→ Urinating a lot

Question 47

What is the water deprivation test?

Answer 47

→ Checking if someone is dehydrated when depriving them of water