ANAT 322 Lecture Notes - Lecture 2: Corpus Luteum, Posterior Pituitary, Anterior Pituitary

51 views4 pages
ANAT 322 Lecture 2 (Jan 13)
Dr. Stroh
Part I: Anatomical Organization of the Neuroendocrine Hypothalamus
The Pituitary Gland (Hypophysis)
Endocrine gland weighing about 0.5 g, composed of an anterior, intermediate, and posterior lobe
oVery different histological staining
Connected with the brain (hypothalamus) via the median eminence and the infundibulum
Located in a concave pouch of the sphenoid bone named “sella turcica”
Cells in the anterior portion tend to become cancerous (benign), which is still life threatening if not
treated
Derived from two distinct embryological sources:
oAdenohypophysis (anterior lobe, intermediate lobe, pars tuberalis) arising from Rathke’s pouch
(stomatic ectoderm) in the roof of the developing pharynx
oNeurohypophysis (posterior pituitary, infundibular stem and median eminence) originates from
the base of the diencephalon
Cell types of the anterior lobe
Classical endocrine tissue – NO neurons
oOnly regulated by neurons
Posterior part is true brain tissue
3 different staining behaviours:
obasophilic  blue
oacidophilic  red
ochromophobic  no colour
eg. Corticotropes (ACTH)
Different staining populations correspond to functionally different cells
Somatotropes (dorsal, acidophilic)
oMake up the vast majority of the anterior pituitary hormone-secreting cells
oProduces GH
Lactotropes
oProduce prolactin, which acts on the mammary glands in females
Corticotropes (dorsal, chromophobic)
oProduces ACTH which acts on the adrenal cortex
Gonadotropes (ventral, basophilic)
oProduces FSH and LH, acts on the gonads
Thyrotropes (central, basophilic)
oProduces TSH which acts on the thyroid
Hormones of the anterior lobe
Growth Hormone (GH)  somatotopin, somatotropic hormone
oStimulates growth of bone and muscle as well as protein synthesis and carbohydrate
metabolism mediated by IGF-1
oGH stimulates the liver to make IGF-1, which then regulates many aspects of GH function
Adrenocorticotropic Hormone (ACTH)  stimulates glucocorticoid (cortisol) secretion from the adrenal
cortex
find more resources at oneclass.com
find more resources at oneclass.com
Unlock document

This preview shows page 1 of the document.
Unlock all 4 pages and 3 million more documents.

Already have an account? Log in

Get access

Grade+
$10 USD/m
Billed $120 USD annually
Homework Help
Class Notes
Textbook Notes
40 Verified Answers
Study Guides
1 Booster Class
Class+
$8 USD/m
Billed $96 USD annually
Homework Help
Class Notes
Textbook Notes
30 Verified Answers
Study Guides
1 Booster Class