Endocrinology Flashcards
Hormones released from adrenal
Cortisol (zona fasciculata cortex)
Androgens (zona reticularis cortex)
Aldosterone (zona glomerulosa cortex)
Epinephrine (Chromaffin cells Medulla)
Dopamine (Chromaffin cells Medulla)
Norepinephrine (Chromaffin cells Medulla)
Where is cortisol released from?
Zona fasciculata cortex
Where are androgens released from?
Zona reticularis cortex
Where is aldosterone released from?
Zone glomerulosa cortex
Hormones released from thyroid
T3 (Epithelial cells)
T4 (Epithelial cells)
Calcitonin (parafollicular cells)
Hormones from hypothalamus
Growth hormone releasing hormone
Gonadotrophin releasing hormone
Thyrotropin-releasing hormone
Corticotropin-releasing hormone
Oxytocin
Vasopressin
Somatostatin
Vasopressin
Where are oxytocin and ADH (vasopressin) synthesized?
Supraoptic and Periventricular nuclei of the hypothalamus
Hormones from Pituitary (anterior)
Growth Hormone
TSH
Prolactin
ACTH
FSH
LH
Hormones from pituitary (posterior)
Releases ADH & Oxytocin (synthesised by hypothalamus)
Hormones from Placenta
Progesterone
hCG (Syncytiotrophoblast)
hPL (Syncytiotrophoblast)
Hormones from pancreas
Glucagon (alpha cells)
Insulin (beta cells)
Somatostatin (delta cells - note also produced by pylorus)
gamma cells secrete pancreatic polypeptide
Hormones from gastrointestinal tract
Gastrin (Stomach G cells)
Somatostatin (Stomach D cells)
Histamine (StomachECL cells)
Secretin (S cells duodenum)
Cholecystokinin (I cells duodenum)
Hormones from liver
Insulin like growth factors
Thrombopoietin
Angiotensinogen and angiotensin
Hormones from ovary
Oestragens
Progesterone
Androgen (theca cells)
AntiMullerian Hormone (Granulosa cells)
Hormones from pregnant uterus
Prolactin (Decidual cells)
Relaxin (Decidual cells)
Hormones from adipose tissue
Leptin
Small amounts Progesterone
Estrone
Hormones from kidney
Renin (granular cells of the juxtaglomerular apparatus)
Erythropoietin (Extraglomerular mesangial cells)
Thrombopoietin
Autosomal Dominant
Tuberous Sclerosis
Von Willebrand
Adult PKD
Huntingtons
Marfans
Neurofibromatosis
Noonans
Autosomal recessive
Cystic Fibrosis
Haemochromatosis
Infantile PKD
Thalassemia
Wilson’s Disease
X-Linked Dominant
Fragile X
Rett Syndrome
Vitamin D resistant Ricketts
X-Linked Recessive
Duchenne Muscular Dystrophy
Red/Green Colour Blindness
G6PD deficiency
Haemophilia
Most common cause of hypothyroidism worldwide?
Iodine deficiency
In UK: 90% of cases of hypothyroidism are autoimmune or iatrogenic.
Pheochromocytoma accounts for what percentage of cases of hypertension?
0.1%
- neuroendocrine tumour of the medulla of the adrenal glands that secretes high amounts of catecholamines.
Interpretation of hepatitis serology:
HBsAg = Indicates current infection either acute or chronic
Anti HBs = Indicates immunity either due to infection or vaccination
Anti HBc = Indicates either current or past infection
IgM Anti HBc = Indicates recent infection
What is responsible for the formation of Angiotensin 1 from Angiotensinogen?
Renin
What is the normal arterial pH range for fetal cord sample?
7.26-7.30
Threshold pH for adverse neurological outcomes 7.1
How much testosterone is bound to SHBG?
The binding constant of SHBG for testosterone is 3 times that of estrogen. Because of the higher concentrations of SHBG and the lower concentration of testosterone in the female, only 1% of testosterone is free (compared with 2% in the male).
In women: 60% to SHBG and 39% to albumin
In men: 60% is bound to SHBG and 38% to albumin
What is the most common cause of hyperprolactinaemia?
Primary hypothyroidism.
Other common causes include neuroleptic medication and dopamine D2 receptor anti-emetics.
How much testosterone is free?
Male 1.5-3% and female approx 1%.
Causes of Low Sex Hormone Binding Globulin
Androgens (inc anabolic steroids)
PCOS
Hypothyroidism
Obesity
Cushing’s syndrome
Acromegaly
Causes of High Sex Hormone Binding Globulin
Oestrogens e.g. oral contraceptives
Pregnancy
Hyperthyroidism
Liver cirrhosis
Anorexia nervosa
Drugs e.g. clomid, anticonvulsants
Acromegaly features:
Acromegaly Features
Elargement of the hands, feet, nose, lips and ears.
Skin thickening
Generalised soft tissue swelling of internal organs including the heart.
Deepening of voice and slowing of speech
Skull enlargement with frontal bossing
Mandibular protrusion (prognathism)
Macroglossia (enlargement of the tongue)
What are the causes of raised prolactin?
Hypothyroidism
Chronic renal failure
Liver disease
Pregnancy
Stress
Lactation
Chest wall stimulation & surgery
Acromegaly
PCOS
What drugs cause raised prolactin?
Opiates, H2 antagonists e.g. Ranitidine, SSRI’s e.g. Fluoxetine, Verapamil, Atenolol, some antipsychotics e.g risperidone and haloperidol, Amitriptyline, Methyldopa
What is WHO Type 1 ovulation disorder?
WHO type I hypo-gonadotropic, hypo-estrogenic, (15%)
- Causes: Damage to the pituitary gland or hypothalamus from surgery, injury, tumor, infection, or radiation
- High doses or long-term use of opioid or steroid (glucocorticoid) medicines
- Nutritional problems (both rapid weight gain or weight loss)
- hypothalamic pituitary failure
What is WHO Type 2 ovulation disorder?
WHO type II normo-gonadotropic, normo-estrogenic, (80%)
PCOS
What is WHO Type 3 ovulation disorder?
hyper-gonadotropic, hypo-estrogenic (5%)
Ovarian failure
What are the healthy adult hemoglobins?
-Adult haemoglobin (HbA) is made of 2 alpha globulin chains and 2 beta globulin chains and accounts for 97% of total haemoglobin in a normal adult.
- HbA2 is a normal variant of hemoglobin A that consists of two alpha and two delta chains
What is the fetal hemoglobin?
- Fetal haemogobin (HBF) is the main haemoglobin type in the fetus and persists after birth for around 6 months. Fetal hemoglobin is composed of two alpha and two gamma subunits
What chromosome defect causes Alpha Thalassemias?
Chromosome16 defects