ER Flashcards
Origin of posterior pituitary
Neuroectoderm
Origin of anterior pituitary
Oropharynx
Name the 3 parts of the anterior pituitary
- Pars tuberalis (surrounds infundibulum)
- Pars distalis (cellular portion)
- Pars intermedia (remnant of Rathke’s pouch)
Name the acidophils in the pars distalis
- Somtatotrope: produce GH, inhibited by somatostatin
- Mammotrope: produce prolactin, inhibited by dopamine produced by the hypothalamus
Name the basophils of the pars distalis
B FLAT
- Gonadotropes: produce FSH and LH
- Corticotropes: produce ACTH
- Thyrotropes: produce TSH
Describe the pars intermedia
- associated with cells producing MSH (melanocytes stimulating hormone)
- remnants of Rathke’s pouch
- lined by basophilic cuboidal cells
Describe hormones in the posterior pituitary
- hormones are produced in nuclei located in the hypothalamus and are transported along the hypothalamo-hypophyseal tract and are stored in axonal dilations called HERRING BODIES
Name the nuclei of the hypothalamus
- paraventricular nucleus produces oxytocin
- supraoptic nucleus produces ADH
Describe pituicyte
- located in the pars nervosa of the hypophysis
- they are glial cells containing GFAP
- they surround the axons of the herring bodies and act as supporting cells
Describe the origin of cortex and medulla and what they are stimulated by
- Cortex = mesoderm, stimulated by ACTH produced by the basophils in the AP (except z. glomerulosa)
- Medulla = neural crest, stimulated by sympathetic nerves
Describe the 3 layers of the adrenal cortex
- Zona glomerulosa: produces aldosterone and is stimulated by AGII
- Zona fasiculata: produces cortisol and is stimulated by ACTH
- Zona reticularis: produces androgens, stimulated by ACTH
Describe spongiocytes
- located in z. fasiculata
- this is why fasiculata looks pale; lipids washed away
- well developed smooth ER because of steroid production
- mitochondria with tubular cristae
- cells exhibit cluster of lipid droplets
Describe chromaffin cells
- modified post ganglionic sympathetic neurons - secrete their products (adrenaline and noradrenaline; catecholamines) into fenestrated capillaries - chromogranins are proteins that bind to the catecholamines so they don’t get released - affinity for chromium salts
Describe the cell types of the pancreas
- alpha cells: secrete glucagon (peripheral location) - beta cells: secrete insulin (centrally located) - delta cells: secrete gastrin and somatostatin - F-cells: secrete pancreatic polypeptides
Describe thyroid follicles
- Epithelium = simple cuboidal 2. Colloid - thyroglobulin (inactive hormone) 3. Iodine storage in thyroid hormones (T3 and T4) regulates metabolic activity
Describe parafollicular cells
- alongside thyroid epithelium or as cluster of cells - secretes calcitonin: lowers blood calcium by suppressing osteoclast activity
Describe cells of the parathyroid gland
- Chief cells: produce PTH -increases blood calcium levels -decreases blood phosphate levels 2. Oxyphill cells: large acidophilic cells
Describe the pineal gland
- Consists of melatonin secreting pinealocytes 2. Pineal gland is surrounded by the pia matter 3. Contains astrocytes
Describe Conn’s disease
- adrenal carcinoma - high serum aldosterone; leads to hypertension and low renin levels
Cushing’s syndrome vs Addison’s disease
-Cushing = hypersecretion of ACTH -Addisons = hyposecretion
Describe a pheochromocytoma
-tumor = chromaffinoma - patients have hypertension -increased production of epinephrine and norepinephrine
Describe hyperthyroidism
-follicles turn from simple cuboidal into high cuboidal
name the cells at the arrows
