B8 W5 Flashcards
Mouth
Forms by splitting the first pharyngeal arch
Largest gland in the body
Thyroid gland
Mesoderm
Cells of the pharyngeal arch which form cartilage, muscle, nerves and arteries
Nerve supplying first pharyngeal arch
Trigeminal nerve
Nerve suppling 2nd pharyngeal arch
Facial
Muscles of mastication
Muscles of 1st pharyngeal arch
Where does the adrenohypophysis develop?
Oral ectoderm
Adrenohypophysis cells that stain
Chromophils
Adrenhypophysis cells that do not stain
Chromophobes
Corticotrophin region
Basophil cells, contain melanocyte stimulating hormone and adrenocorticotropin hormone
Thyroiditrophs
Basophil region
Neurohypophysis
Non-myelinated neurons with cell bodty in hypothalamus
Superior thyroid artery
Branch of the external carotid
Thyroid primordium
Thickening in the primordial pharynx which forms the thyroid
Thyroglossal tract
Eptihelial lined tract where the primordial thyrid gland migrates to end at thyroid isthmus.
Foramen caecum
Tongue base
Which cells produce calcitonin?
Parafollicular cells, in the thyroid gland
Weight loss, lack of energy, heat intolerance, increased appetite, weight gain
Hyperthyoridism/ Graves’ disease
Blood supply to the parathyroid glands
Superior and inferior thyroid arteries
Which cells produce parathyroid hormone?
Chief cells of the parathyroid gland
Oxyphil cells
Present in parathyroid gland with no known origin
Palatine tonsils origin
2nd pharnygeal pouch
Origin of parafollicuclar cells
4th pharyngeal pouch
What does the hypothalamus secrete?
Thyrotropin releasing hormone
Which enzyme converts trosine in reaction with iodine to monoiodotyrosine?
Peroxidase
What enables iodide trapping?
Sodium-iodide symporter
T3
3,5,3-triiodothyronine
Thyroxine
T4
Dyshormonogenesis
Inherited disorder of thyroid hormone synthesis. Low levels of T4 and T3 but high TSH. Causes goitre.
Congenital hypotyhroidism
Absence of thyroid gland or ectopic thyroid with Guthrie blood spot
Fatigue, cold intolerance, depression, poor concentration
Hypothyroidism symptoms
Dry skin, coarse hair, bradycardia, puffy eyes, anaemia
Hypothyroidism signs
Myexdema
Water retention by carbs due to altered metabolsim and hypothyroidism
What is the target in Hashimoto’s disease?
Thyroid peroxidase for formation of thyroid hormones. Lesser extent, thyroglobulin antibodies.
Low levels of T4 and TSH and high TRH
Secondary hypothyroidism
GOitre, tremor, warm skin, tachycardia, hypertension, myoxdema
Signs of hyperthyroidism
Causes of goitre
Radiotherapy, iodine deficiency, lithium medication, Graves disease/hyperthyroidism
Action of thionamides
Inhibit iodide oxidation of thyroid peroxidase
Proteins other than albumin which bind to thyroid hormone
Thyroxine binding prealbumin and albumin
Thyroid hormones effects- processes
Catabolic effect- Gluconegneesis, glycogenolysis, lipolysis, rpotein synthesis, glucose absorptionn, oxygen consumption
Role of thyroid hormones in CNS
Nerve myelination, brain development, intellectual development and emotional stability
Impact of surgery for primary hyperparathyroidism
Kidney stones, fragility fracture, weakness
Lipid soluble hormones
Adrenal cortical hormones and gonadal hormones (oestrogen, testosterone, progesterone)
Anterior pituitary hormones
Water soluble
Location of hypothalamus]
Below 3rd brain ventricle
What inhibits growth hormone release?
Somatostatin
Somatostatin
Released from hypothalamus. Inhibits growth hormone, insulin, glucagon, gastrin and pancreatic enzymes and gastric secretion
Adrenal insufficiency test
Synacthen test
Test for secondary adrenal insufficnecy
Insulin stress test
Cushing’s disease
Excess of steroid hromones due to pituitary issue which causes increased levels of ACTH
Test for Cushing’s disease
Dexamethasone test
Increase in ACTH and CRH with pigmentation. Decrease in cortisol
Primary adrenal deficiency
Cushing’s syndrome
Adrenal gland produces excess cortisol which will inhibit the hypothalamuus and pituitary from producing excess CRH or ACTH
Steroid excess
Cortisol decrease, ACTH decrease, CRH decrease
Syntehtic substance similar to testosterone.
Anabolic steroids- causes primary hypergonadism
Prolactin control
Positive feedback
Bromocriptine
Dopamine agonist drug to inhibit breastfeeding
Mectalopride
Dopamine antagonist for hyperprolactinemia
Acromegaly
Gigantisim caused by excess growth hormones
Ocreotide
Somatostatin analogue- INhibits GnRH for relaease of GH from adrenohypophysis to treat gigantism
Effects of alcohol on ADH
Inhibited
Treatment of diabetes insipidus
Desmopressin-ADH analogue to treat low ADH