Hypothalamus, Pituitary Gland and Diseases

Question 1

What are the different causes of pituitary diseases?

Answer 1

functional adenoma - produces hormones e.g. Cushing’s disease (ACTH), acromegaly (growth hormone)
non-functional adenoma - space occupying

Question 2

What is Acromegaly?

Answer 2

excess growth hormone production in adults due to functional adenoma (benign tumour)

Question 3

What are the signs and symptoms for Acromegaly?

Answer 3

coarse features, enlarged supra-orbital ridges, broad nose, thickened lips and soft tissues (tongue), enlarged hands (carpal tunnel syndrome), type 2 diabetes, CV disease, intraoral changes (mandible growth), visual field defects (lose peripheral vision), hyperprolactinaemia, hypopituitarism

Question 4

What is the dental relevance for patients with Acromegaly?

Answer 4

intraoral changes therefore we can diagnose it - enlarged tongue, interdental spacing, shrunk dentures, reverse overbite (mandible growth)

Question 5

What is increased oral pigmentation (hyperpigmentation) associated with?

Answer 5

High ACTH levels (Addison’s disease, cushings disease etc)

Question 6

What is the relationship between the hypothalamus and posterior pituitary?

Answer 6

hormones produced in hypothalamus pass to posterior pituitary along nerve axons
released into circulation from posterior pituitary (antidiuretic hormone, oxytocin)

Question 7

What is the relationship between the hypothalamus and anterior pituitary?

Answer 7

hypothalamus produces releasing hormones
these pass to anterior pituitary via blood vessels
trigger secretion of hormones from anterior pituitary

Question 8

What are the releasing hormones produced by the hypothalamus?

Answer 8

corticotropin releasing hormone (CRH)
gonadotropin releasing hormone (GRH)
thyrotropin releasing hormone (TRH)
growth hormone releasing hormone (GRH)
somatostatin (SS) (GH inhibiting hormone)
prolactin releasing hormone (PLRH)
dopamine (DA) (PLIH)

Question 9

What are the hormones released by the anterior pituitary?

Answer 9

adrenocorticotropic hormone (ACTH)
follicle stimulating hormone (FSH)
luteinising hormone (LH)
thyroid stimulating hormone (TSH)
growth hormone (GH)
prolactin (PL)

Question 10

How does the hypothalamic pituitary axis control the stress reaction?

Answer 10

direct influences and negative feedback of cortisol

stimulus -> hypothalamus secretes corticotropin releasing hormone (CRH) -> anterior pituitary releases adrenocorticotropic hormone (ACTH) -> stimulates cortex of adrenal gland to produce cortisol