Primitive Streak

First arises from a local thickening of the epiblast at the posterior edge of the area pellucida (Koller’s sickle)

By stage 2, the primitive streak cells form a third layer that lies between the hypoblast and epiblast cells.

 By stage 3, the primitive streak has become a definitive region of the epiblast, with cells migrating through it to become the mesoderm and endoderm.

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#Unit 7. System Physiology – Animal

After puberty, growth hormone excess causes acromegaly

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#Unit 7. System Physiology – Animal

Posterior pituitary secretes neuropeptides, ADH and oxytocin

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#Unit 7. System Physiology – Animal

ADH and oxytocin synthesized in cell bodies of hypothalamic neurons and secreted from nerve terminals in the posterior pituitary.

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#Unit 7. System Physiology – Animal

ADH and oxytocin are homologous nonapeptides

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#Unit 7. System Physiology – Animal

ADH is the major hormone concerned with regulation of body fluid osmolarity.

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#Id: 1254

#Unit 7. System Physiology – Animal

The major action of ADH on principal cells in the late distal tubule and collecting duct