- Name the cell types of the pars distalis of the adenohypophysis and state their respective functions
- Somatotrophs – GH production
- Corticotropes – ACTH production
- Lactotrophs – PRL production
- Thyrotropes – TSH production
- Gonadotrophs – FSH and LH production
- What is the function of folliculostellate cells in the pituitary gland
- Regulate the release of hormones from the adenohypophysis by transmitting signals from the pars tuberalis to the pars distalis
- Classify endocrine cells of the adenohypophysis into acidophils, basophils and chromophobes
- Acidophils (40%): Somatotrophs, Lactotrophs
- Basophils (10%): Gonadotrophs, Corticotropes, Thyrotropes
- Chromophobes (50%): Melanotropes
- What are herring bodies?
- Dilated axon terminals at the neurohypophysis formed by the accumulation of neurosecretory vesicles
- Name the hormones secreted by the neurohypophysis and state their respective sources
- Arginine-vasopressin (Antidiuretic Hormone) – supraoptic and paraventricular nucleus
- Oxytocin – supraoptic and paraventricular nucleus
- Name the endocrine cells of the thyroid gland and their respective hormones
- Follicular cells (Principal cells) – T3 and T4 (Thyroxine)
- Parafollicular cells (C cells) – Calcitonin
- Briefly describe the steps involved in thyroid hormone synthesis
- Synthesis of thyroglobulin and secretion into the follicular lumen
- Resorption, diffusion and oxidation of iodide to iodine
- Iodination of thyroglobulin to form MIT and DIT residues
- Formation of T3 and T4 via oxidative coupling
- Resorption of colloid
- Lysosomal pathway
- Transepithelial pathway
- Release of T3 and T4
- What are the cell types of the parathyroid gland
- Principal (Chief) cells – PTH production and secretion
- Oxyphil cells
- Describe the pattern of blood supply to the adrenal gland
- Arterial supply: Superior, middle and inferior suprarenal arteries
- Blood supply to capsule
- Suprarenal arteries → capsular capillaries
- Venous supply to medulla
- Suprarenal arteries → fenestrated cortical sinusoidal capillaries → fenestrated medullary capillary
- Arterial supply to medulla
- Suprarenal arteries → medullary arterioles → medullary capillary sinusoids
- Blood supply to capsule
- Venous drainage
- Cortical and medullary sinusoids → adrenomedullary collecting veins → central adrenomedullary vein → suprarenal vein
- Right suprarenal vein → IVC
- Left suprarenal vein → Left renal vein → IVC
- Arterial supply: Superior, middle and inferior suprarenal arteries
- Describe the zonation and functions of the adrenal cortex
- Zona Glomerulosa – aldosterone secretion
- Zona Fasciculata – cortisol secretion
- Zona Reticularis – Androgen (DHEA) secretion
- What are the cells of the adrenal medulla? State their respective functions
- Chromaffin cells (medullary cells) – synthesize and secrete catecholamines
- Ganglion cells (sympathetic) – Modulate secretory activity of the adrenal cortex, innervate blood vessels, and extend to splanchnic nerves innervating abdominal organs
