L2 – The Anterior pituitary gland and its hypothalamic control
Keywords:
Parvocellular, adenohypophysis, sella turnica, rathke’s pouch, median eminence (connects
hypothalamus and pit, reg hormone release) microadenoma (<1cm),macroadenoma (>1cm),
meninges (connective tissue cover of brain and spinal cord),metabolic (food→energy), anabolism
(synth of complex molecules for storage of energy)
Lecture:
Hypothalamus controls body temp, circadian rhythm and appetite
o Depression via adrenocortical hypothalamus-anterior pit axis
Hypothalamic-pituitary system = final area in which all senses are
o Main interface between brain and periphery
o Organizes hormonal responses (internal/external)
o Pituitary gland = separate organ to brain (attached to hypothalamus via stalk)
Based in bone in cranium
Sella turcica/pituitary fossa = where pituitary gland sits in bone
Nonfunctioning adenomas
Histology:
Pituitary (0.5g)
Anterior = more vascularized
o Doubles in pregnancy and puberty
Anterior = larger, pink lobe and posterior = smaller, yellow lobe
o Tumors
Grown from Rathke’s pouch (up growth from roof of mouth) into sella
turnica/pituitary fossa
Remnants of Rathke’s pouch = fluid filled cysts = ↑ pressure in
pituitary fossa
↑ # of tumors bc ↑ hormone conc?
Upward tumor growth out of pit fossa = bitemporal hemianopia bc
compressed optic chiasm (bitemporal visual field loss bc crossing retinas)
Upper field lost first bc pressure comes from below
Treat w/↓ pressure on chiasm (radiotherapy)
Lateral extension into sinus can cause ophthalmoplegia (eye paralysis bc ↓
extraocular muscle movement)
Best imaged w/MRI
Headaches (bc obstruction to CSF drain and stretching of meninges)
Non benign = metastasis, meningioma and lymphoma
o No nerve fibers
o 5 types of secretory cell
Chromophobes (afraid of stain – no uptake - pale)
Undifferentiated cells
Chromophiles (red/purple staining)
Acidophils – take up acidic
o Somatotrophs (release GH)
Keywords:
Parvocellular, adenohypophysis, sella turnica, rathke’s pouch, median eminence (connects
hypothalamus and pit, reg hormone release) microadenoma (<1cm),macroadenoma (>1cm),
meninges (connective tissue cover of brain and spinal cord),metabolic (food→energy), anabolism
(synth of complex molecules for storage of energy)
Lecture:
Hypothalamus controls body temp, circadian rhythm and appetite
o Depression via adrenocortical hypothalamus-anterior pit axis
Hypothalamic-pituitary system = final area in which all senses are
o Main interface between brain and periphery
o Organizes hormonal responses (internal/external)
o Pituitary gland = separate organ to brain (attached to hypothalamus via stalk)
Based in bone in cranium
Sella turcica/pituitary fossa = where pituitary gland sits in bone
Nonfunctioning adenomas
Histology:
Pituitary (0.5g)
Anterior = more vascularized
o Doubles in pregnancy and puberty
Anterior = larger, pink lobe and posterior = smaller, yellow lobe
o Tumors
Grown from Rathke’s pouch (up growth from roof of mouth) into sella
turnica/pituitary fossa
Remnants of Rathke’s pouch = fluid filled cysts = ↑ pressure in
pituitary fossa
↑ # of tumors bc ↑ hormone conc?
Upward tumor growth out of pit fossa = bitemporal hemianopia bc
compressed optic chiasm (bitemporal visual field loss bc crossing retinas)
Upper field lost first bc pressure comes from below
Treat w/↓ pressure on chiasm (radiotherapy)
Lateral extension into sinus can cause ophthalmoplegia (eye paralysis bc ↓
extraocular muscle movement)
Best imaged w/MRI
Headaches (bc obstruction to CSF drain and stretching of meninges)
Non benign = metastasis, meningioma and lymphoma
o No nerve fibers
o 5 types of secretory cell
Chromophobes (afraid of stain – no uptake - pale)
Undifferentiated cells
Chromophiles (red/purple staining)
Acidophils – take up acidic
o Somatotrophs (release GH)
