Endocrine: Pituitary and the thyroid Flashcards
What are the two ways endocrine disease can present?
Primary - Gland failure
Secondary - Feedback failure
What controls hormone production in the pituitary gland?
Signals from the hypothalamus
What hormones are secreted from the anterior pituitary?
The growth hormone
TSH: Thyroid stimulating hormone
ACTH: Adrenocorticotrophic hormone (stimulates cortisol)
What hormones are secreted from the posterior pituitary?
ADH: antidiuretic hormone
Oxytocin
What are the two types of pituitary tumours?
Functional - hormones produced
Non-Functional - no hormone produced
Describe a functional adenoma.
Tumour arises from a cell secreting a hormone - excess of the hormone is produced and there is a deficiency of others as tumour grows to occupy the space of the pituitary gland (squishes the other cells)
Describe a non-functions adenoma.
Tumour does not produce any hormone and grows to occupy the space of the pituitary gland therefore prevents other pituitary cells from secreting hormones.
How are pituitary tumours removed?
Trans-sphenoidal surgery
What is the consequence of a growing tumour in the pituitary gland?
Pituitary gland is encased in bone, therefore the tumour will grow up and out of the bone and put pressure on the optic chiasma.
= visual field defects and loss of peripheral vision.
Where is the growth hormone produced?
Anterior pituitary
What happens when there is a deficiency of growth hormone as a child?
The individual will be small and proportionate
What happens when there is a deficiency of growth hormone as an adult?
Subtle changes
increased fat and reduced vitality/energy
What happens when there is an excess of growth hormone as a child?
Gigantism with everything proportionate
What happens when there is an excess of growth hormone as an adult?
Acromegaly - membranous bone and soft tissue continue to grow
How do you measure the levels of growth hormone within the body?
Measuring IGF - 1
What are the features of acromegaly?
Enlarged hands and feet.
Broad nose
Large mandible
Type 2 diabetic - GH is antagonistic to insulin
Cardiovascular problems - heart is bigger and less efficient = heart failure.
Loss of peripheral vision - if adenoma is growing up and out of the boney case surrounding pituitary.
What will be observed within the mouth of an individual with acromegaly?
Enlarged tongue
Interdental spacing
Reversed overbite
Complaining of denture ‘shrunk’
What are the primary causes of hyperthyroidism?
Graves disease - autoimmune disease, autoantibodies produced mimic the effect of the TSH hormone.
Adenoma of the thyroid gland
How do you diagnose primary hyperthyroidism?
Low TSH
High thyroxine
What are the secondary causes of hyperthyroidism?
Pituitary adenoma
How do you diagnose secondary hyperthyroidism?
high TSH
High thyroxine
What are the symptoms of hyperthyroidism?
Hot and sweaty Anxious Irritable weight loss heart palpitations
What are the signs of hyperthyroidism?
Tachycardia
A fib
warm and moist skin
lid lag
What is graves disease usually associated with?
A family history of autoimmune disease
i.e. type 1 diabetes, vitiligo
What is a visual indication of hyperthyroidism?
Opthalmopthy - autoantibodies also bind to the fat cells in the orbit and cause irritation and swelling which projects the eyeballs out of the socket
Once the hyperthyroidism has be treated, what will happen to the opthalmopthy?
Will remain - treating the high levels of thyroxine will have no impact on the orbit as it is the autoantibodies that affect it.
What is myxoedema?
Hypothyroidism
What are the primary causes of myxoedema/hypothyroidism?
Thyroiditis - autoimmune disease
Commonly Hashimoto’s thyroiditis - gland becomes inflamed initially and swells (goitre), then it shrinks and stops producing thyroxine.
Drugs i.e. carbimazole (used to treat hyperthyroidism)
Idiopathic - no reason
Hyperthyroid treatment:
i.e. radioiodine - radiation released destroys gland tissue and reduces the amount of thyroxine produced. Once in the body this cannot be stopped therefore will eventually lead to the patient developing hypothyroidism.
How do you diagnose primary hypothyroidism?
High TSH
Low thyroxine
What are the secondary causes of hypothyroidism?
Hypothalamus/pituitary diseases
How do you diagnose secondary hypothyroidism?
Low TSH
Low thyroxine
What are the symptoms of hypothyroidism?
puffy
hair loss
Cold intolerant
What are the signs of hypothyroidism?
Delayed reflexes
bradycardia
slow pulse and low BP
confusion
How do you treat hyperthyroidism?
Surgery - partial thyroidectomy
Drugs i.e. carbimazole
Radioiodine - radiation released destroys gland tissue and reduced/stops production of thyroxine.
Beta blockers address the symptoms only !!
How do you treat myxoedema/hypothyroidism?
Thyroxine tablets
Dosage of thyroxine starts off low and is gradually increased until the body reaches normal TSH levels.
In the dental setting ; what must the dentist be looking out for?
Goitre - swelling in the neck
Hyperthyroid =
Anxiety
Psychiatric problems
What must you avoid in patients with hypothyroidism/myxoedema?
Sedatives as they have a reduced metabolism.
In terms of dental treatment; how must a patient with controlled hyper/hypothyroidism be treated?
As normal !!
