Endocrine Flashcards
Where is the anterior pituitary derived from?
roof of mouth
What does the Ant Pit secrete?
GH, ACTH, LH, FSH, TSH, Prolactin
How is the release of hormones from the ant pit controlled?
Hormonally controlled by hormones from the hypothalamus
What are some cell types for the ant pit?
Corticotrophs (dark) somatotrophs (light)
Where is the post pituitary derived from?
hypothalamus
What does Post pit secrete?
ADH and oxytocin
How is the release of hormones from the post pit controlled?
Neurosecretory, held in Herring bodies
What arteries supply the pituitary?
Superior and Inferior hypophyseal arteries connected by the trabecular artery
What does the medulla of the adrenal glands secrete?
NA and Adrenaline
What are the parts of the adrenal cortex called?
Zona Glomerulosa
Zona fasciculata
Zona reticularis
What does Zona G produce?
Mineralocorticoids (Aldosterone)
What does Zona F produce?
Glucocorticoids (cortisol)
What does zona R produce?
Sex steroids (Androgens)
What is the arterial supply to the adrenal gland?
renal and inferior phrenic arteries
What is the venous drainage of the adrenals?
L- left renal vein
R - IVC
What is a Pheochromocytoma?
Andrenal medullary tumour (XS catecholamines)
What is Conn’s syndrome?
Adrenal cortex tumour (XS androgens)
What nerves supply the adrenal gland?
T10 - L1
What cells are in the adrenal medulla?
Chromaffin cells
What do Chromaffin cells do?
Adrenaline, NA
What is the arterial supply to the thyroid?
Superior and Inferior thyroid arteries
What is the venous drainage of the thyroid?
Superior, middle and inferior thyroid veins
What is the lymph drainage of the thyroid?
Pretracheal and paratracheal to deep cervical nodes.
Prelaryngeal to superior cervical nodes
what is a goitre?
Enlarged Thyroid
What might be a clinical problem of a goitre?
Oesophageal or tracheal obstruction
Compression of recurrent laryngeal nerve
What types of cells are in the Thyroid and what do they do?
Follicular cells (secrete T3/T4) Parafollicular cells (Secretes Calcitonin - opposes PTH)
What is the arterial supply of the Parathyroid gland?
Inferior thyroid arteries
What cells are in the Parathyroid gland and what do they do?
Chief cells (PTH)
Oxyphil cells
Adipocytes
What is the arterial supply of the pancreas?
Splenic and pancreaticoduodenal arteries
What is the venous drainage of the Pancreas?
Splenic and pancreaticoduodenal veins to the hepatic portal vein
What is the lymph drainage of the Pancreas?
Coeliac and superior mesenteric nodes
What does the pineal gland do?
Regulates circadian rhythm and secretes melatonin when dark.
What hormones control the ovaries and testes?
FSH and LH
How do Thyroid hormones travel through the blood?
Bound to proteins. Dissosciates at receptors. Buffering system
How does Thyroxine travel through the blood?
Bound to Thyroxine binding protein (TBG)
What inhibits oxytocin?
Stress and alcohol
How does ADH work?
Produced aquaporins in the collecting ducts = more water reabsorbed.
What is Diabetes Insipidus?
Lack of ADH
What may cause Diabetes Insipidus?
Whiplash injury/tumour
What are the symptoms of diabetes insipidus?
Thirst, frequent urination, dilute urine
What is SIADH?
Syndrome of inappropriate ADH secretion. Usually caused by tumour
What is the result of decreased GH in adults and kids?
Adults - disordered metabolism
Kids - failure to grow
What is the result of increased GH in adults and kids?
Adults - acromegaly
Kids - gigantism
What is inc GH usually caused by?
Pituitary tumour
What is a risk of a pituitary tumour (other than hormonal)?
Compression of optic chiasm = bitemporal hemianopia
What is a prolactinoma?
A pituitary tumour causing xs secretion of prolactin.
What are the symptoms of prolactinoma?
Lactation, periods stop
Low libido, erectile dysfunction
What does ACTH stimulate?
Adrenal cortex to produce Cortisol
What is DHEA?
A sex hormone produced from the adrenal cortex - mostly used in foetal life. Dec with age.
What does Adrenaline form from?
Tyrosine > Dopamine > NA > Adrenaline
What is Cushings syndrome and name some symptoms?
XS cortisol causing fat deposition, muscle wasting, high BP, high glucose etc.
What is cushings disease?
Cushing syndrome caused by a pituitary tumour secreting too much ACTH (secondary Cushing syndrome)
What is the difference between primary and secondary Cushing syndrome?
primary - Inc Cortisol due to adrenal tumour
Secondary - Inc cortisol due to inc ACTH due to pituitary tumour (Cushing disease)
What is Addisons disease? Name symptoms.
Glucocorticoid and mineralocorticoid deficiency.
Weak, weight loss, low glucose, high potassium, hypotension
What are the primary and secondary causes of Addisons disease?
Primary - Adrenal damage
Secondary - Pituitary dysfunction (low ACTH)
How do you treat Addisons disease?
Corticosteroid replacement
What is hyperaldosteronism caused by?
Primary - adrenal tumour (Conn’s syndrome)
Secondary - low blood volume
What are the consequences of hyperaldosteronism?
High BP, hypokalaemia
What is congenital adrenal hyperplasia?
deficiency in adrenal enzymes = dec. mineralocorticoids and glucocorticoids
Less glucocorticoids = less cortisol = more ACTH = xs androgens = ambiguous genitalia at birth
What causes ambiguous genitalia at birth
Problem with adrenal gland causes less glucocorticoids = less cortisol = more ACTH = xs androgens = ambiguous genitalia at birth
What is the precursor to steroid hormones?
Cholesterol
Where is progesterone secreted from?
Placenta or corpus luteum.
What does progesterone do?
Prepares endometrium, thickens cevical mucus, inhibits uterine contractions, suppresses lactation
Where is testosterone produced?
Adrenals and Leydig cells
What does FLUTAMIDE do?
Blocks Androgen receptors
What would you use to treat Benign prostatic hyperplasia, prostate cancer, hirtuism, acne etc?
FLUTAMIDE
Name a pro-Androgen
STANOZOLOL
What does STANOZOLOL do?
Inc muscle mass, increaes recovery from injury. Pro-androgen.
Name and Aromatase inhibitor
ANASTROZOLE
What is ANASTROZOLE used for?
Blocks aromatase. Used in Breast cancer.
Name and anti-oestrogen?
TAMOXIFEN
What is TAMOXIFEN?
Anti-oestrogen
How are T3/T4 formed?
Iodide from blood is taken up into follicular cells where they are oxidised and bound to tyrosines.
Tyrosines pair up to make T3 or T4 depending on the number of iodine molecules involved.
What is Graves disease?
Autoimmune condition causing an enlarged thyroid gland as there is an antibody matching the TSH receptor.
What are toxic nodules?
Toxic nodules on the thyroid gland which overproduce T4
What is thyroid eye disease?
TRAb antibody stimulates TSH receptors in orbit = fibrobalsts make collagen and tissues swell
What do osteoclasts do?
Reabsorb bone
What do osteoblasts do?
Build up bone
What is calcium in blood bound to?
Albumin
What does PTH do?
Stimulates osteoclasts to break down bone Allows PCT to reabsorb more calcium Makes calcitriol (promotes calcium reabsorption from gut)
What is calcitriol?
Active vit D
What does Calcitonin do?
Antagonises PTH. Decreases plasma Calcium