MEDI7111 Lecture Notes - Lecture 1: Acinus, Aldosterone, Zona Glomerulosa
Endocrine 1
Histology
Pituitary Gland
The pituitary gland is a derivative of glandular and neuroendocrine tissue situated in the sella
turcica; the anterior pituitary is formed from an extension of the nasopharynx mucosa (Rathke’s
pouch) and the posterior pituitary is an extension of neural tissue from the hypothalamus.
The anterior pituitary has three distinct compartments; pars distalis (distal lobe), the pars intermedia
(intermediate lobe) and the pars tuberalis (extends either side of the infundibulum). The
intermediate lobe is non-functional in humans and often contains a cyst/cleft which is the remnant
of Rathke’s pouch. The posterior pituitary is divided into the median eminence (projection of the
hypothalamus towards the pituitary gland), infundibular stalk (neural connection in the
infundibulum) and the pars nervosa (posterior pituitary proper).
Diagram of Pituitary Microanatomy Histology of Pituitary Micro Anatomy
Red Star
Infundibulum
Purple Star
Pars Tuberalis
Blue Star
Pars Nervosa
Green Star
Pars Intermedia
Yellow Star
Pars Distalis
When identifying specific cell types within the pituitary, cells are described as either chromophils
(takes up lots of pigment) or chromophobes (takes up little pigment) and as either acidophils (pink)
or basophils (purple/blue). Cells which are actively producing hormones have cytoplasmic granules
which stain strongly on H&E, therefore active cells are chromophils (~70% of chromophils are
acidophils). Cells which are producing little/no hormone have less cytoplasmic machinery and thus
stain poorly, therefore these are chromophobes.
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
The anterior pituitary has three distinct compartments; pars distalis (distal lobe), the pars intermedia (intermediate lobe) and the pars tuberalis (extends either side of the infundibulum). The intermediate lobe is non-functional in humans and often contains a cyst/cleft which is the remnant of rathke"s pouch. The posterior pituitary is divided into the median eminence (projection of the hypothalamus towards the pituitary gland), infundibular stalk (neural connection in the infundibulum) and the pars nervosa (posterior pituitary proper). When identifying specific cell types within the pituitary, cells are described as either chromophils (takes up lots of pigment) or chromophobes (takes up little pigment) and as either acidophils (pink) or basophils (purple/blue). Cells which are actively producing hormones have cytoplasmic granules which stain strongly on h&e, therefore active cells are chromophils (~70% of chromophils are acidophils). Cells which are producing little/no hormone have less cytoplasmic machinery and thus stain poorly, therefore these are chromophobes.
