Pit and thyroid Flashcards
location of the pit
lies in the sella turcica
what are lat, ant, and post. to pit
lat - cavernous sinouses
ant. - sphenoidal air sinus
post - dorsum sellae
where does pit go if enlarged?
up
what are 2 main portions of adenohypophysis
- pars tuberalis
2. pars distalis
3 main portions of neurophypophysis
- infundibulum
- pars nervosa
- pars intermedia
what 2 areas does the pit dev from?
- posterior from neuroectoderm of neural tube
2. anterior from floor of stomatodeam called rathkes pouch
3 main cell types in neurohypo.
- capils
- axons
- herring bodies
2 hormones released by neurohypo
- oxytocin
2. ADH
2 main types of cells in adenohypo
- chromophobes
2. chromophils
2 main types of chromophils
- acidophils
2. basophils
2 main types of acidophils and their secretions
- somatotropic - somatoropin (growht hormone)
2. prolactin
3 main types of basophils and their secretions
- gonadotropic - FSH (follicle dev) and LH (follicle stim and leydig cells)
- thyrotropic - TSH - stims thyroid
- corticotropic - ACTH - stims adrenals
path of blood through pit
internal carotid>sup. hypohyseal art.>primary cap. plexus>portal veins>sec. cap. plexus
2 main parts of thyroid
- 2 lobes
2. ithsmus
2 main cell types in thyroid
- spherical follicles
2. connective tissue with caps
what happens in active gland
- taller epithelium
2. smaller follicles
what do follicles contain
gel like substance called colloid
what happens in presence of TSH
thyroglobulin phagocytosed and fuse with lysosomes, which then excrete T3 and T4 out
what are parafollicular cells
pale staining cells in follicular lining that produce calcitonin
