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[[Image:PituitaryGlandSchematic..jpg|right|thumb|400px|'''Schematic Diagram of the Pituitary Gland''']]

 

[[Image:PituitaryGlandSchematic..jpg|right|thumb|300px|'''Schematic Diagram of the Pituitary Gland''']]

==Anatomy==

==Anatomy==

==Anterior Pituitary Gland==

==Anterior Pituitary Gland==

 

The anterior pituitary contains the '''pars distalis''', and the '''pars tuberalis'''. This part of the pituitary gland is controlled by ''releasing factors'' from the [[Hypothalamus - Anatomy & Physiology|hypothalamus]]. These factors reach the anterior pituitary via the '''hypophyseal portal system''', venous channels allowing direct passage between the hypothalamus and the pituitary gland. The anterior pituitary gland secretes two types of hormone:

The anterior pituitary contains the '''pars distalis''', and the '''pars tuberalis'''. This part of the pituitary gland is controlled by ''releasing factors'' from the [[Hypothalamus - Anatomy & Physiology|hypothalamus]]. These factors reach the anterior pituitary via the '''hypophyseal portal system''', venous channels allowing direct passage between the hypothalamus and the pituitary gland. The anterior pituitary gland secretes two types of hormone:

===Pars Distalis===

===Pars Distalis===

 

The '''pars distalis''' contains five cell types which produce six hormones. '''Somatotropes''' and '''lactotropes''' are ''acidophillic''. '''Corticotropes, thyrotropes''' and '''gonadotropes''' are ''basophillic''.

The '''pars distalis''' contains five cell types which produce seven hormones. '''Somatotropes''' and '''lactotropes''' are ''acidophillic''. '''Corticotropes, thyrotropes''' and '''gonadotropes''' are ''basophillic''.

During Stage 2 of parturition, the foetus engages the cervix. This initiates a neuroendocrine reflex, '''the Fergusson reflex'''. This is an example of a [[Positive Feedback - Anatomy & Physiology|positive feedback mechanism]], which occurs when stretch receptors in the [[Cervix - Anatomy & Physiology|cervix]] are stimulated. Sensory nerve endings in the cervix are stimulated causing afferent nerve impulses to be sent to the hypothalamus. Neuroendocrine cells of the paraventricular and supraoptic nuclei depolarise and oxytocin is secreted from the pars nervosa. Oxytocin enters the blood circulation and acts on the oxytocin receptors in the myometrium. Uterine contractions therefore, increase in strength and frequency.

During Stage 2 of parturition, the foetus engages the cervix. This initiates a neuroendocrine reflex, '''the Fergusson reflex'''. This is an example of a [[Positive Feedback - Anatomy & Physiology|positive feedback mechanism]], which occurs when stretch receptors in the [[Cervix - Anatomy & Physiology|cervix]] are stimulated. Sensory nerve endings in the cervix are stimulated causing afferent nerve impulses to be sent to the hypothalamus. Neuroendocrine cells of the paraventricular and supraoptic nuclei depolarise and oxytocin is secreted from the pars nervosa. Oxytocin enters the blood circulation and acts on the oxytocin receptors in the myometrium. Uterine contractions therefore, increase in strength and frequency.

==Links==

 

|flashcards = [[Pituitary_Gland_Flash_Cards_- Anatomy & Physiology|Pituitary gland]]

Click here for the [[Pituitary_Gland_Flash_Cards_- Anatomy & Physiology|pituitary gland flashcards]].

|full text = [http://www.cabi.org/cabdirect/FullTextPDF/2008/20083156739.pdf ''' Role of catecholamines in regulation of hypothalamo pituitary ovarian axis: a review.''' Phogat, J. B.; Umed Singh; Inderjeet Singh; College of Veterinary Sciences, Haryana Agricultural University, Hisar, India, Haryana Veterinarian, 2007, 46, pp 1-7, many ref.]

 

==Literature Search==

|OVAM = [http://www.onlineveterinaryanatomy.net/content/equine-pituitary-gland-histology Equine Pituitary Gland Histology]

 

 

[http://www.cabi.org/cabdirect/FullTextPDF/2008/20083156739.pdf ''' Role of catecholamines in regulation of hypothalamo pituitary ovarian axis: a review.''' Phogat, J. B.; Umed Singh; Inderjeet Singh; College of Veterinary Sciences, Haryana Agricultural University, Hisar, India, Haryana Veterinarian, 2007, 46, pp 1-7, many ref. - '''Full Text Article''']

[[Category:Endocrine System - Anatomy & Physiology]]

[[Category:Endocrine System - Anatomy & Physiology]]

[[Category:A&P Done]]

[[Category:A&P Done]]