The Endocrine Glands Flashcards
Where is the pituitary gland located?
Sell turcica (sphenoid bone) in middle cranial fossa
extends from the hypothalamus infundibulum
Where is the pituitary gland located?
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Pituitary gland structure:
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Pituitary Gland:
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Infundibulum: Tissue:
extension of neural tissue
ends at posterior lobe
Pituitary: Anterior Lobe:
- glandular tissue
- adrenohypophysis = anterior
- secretes multiple hormones:
- Adrenocorticoptrophic (ACTH)
- TSH
- LH
- FSH
- Prolactin (PRL)
- Growth hormone
Pituitary: Posterior Lobe:
- neural extension
- neurohypophysis
- secretes: ADH, oxytocin
Posterior Pituitary - Neural Connection:
- neural cells site within the infundibulum
- hormones transported via axons into
posterior lobe of pituitary - hormones are then directly secreted into
capillary bed in posterior lobe
Posterior Pituitary - Neural Connection:
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Anterior Pituitary - Vascular Connection:
- Hormones secreted into the primary
plexus in the infundibulum - travel into via the hypophyseal vein into
the secondary plexus - leave the pituitary gland via the efferent
hyophyseal veins - into the cavernous sinus
Anterior Pituitary - Vascular Connection:
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Anterior Pituitary-Vascular Connection: low levels of T3 and T4:
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67 year old male with fat deposits around face, thinning of skin, weight gain, red/purple stretch marks on thighs, stomach and progressive ophthalmoplegia
- Cushing’s
- visual problems -> pituitary gland
- enlarged pituitary gland
- pushing on optic chiasm (upwards)
- results in bitemporal hemianopia
- affects ACTH
- hence adrenal gland issue as well
- can also affect internal carotid artery in
cavernous sinue - CN3, 4, V1,V2, 6 in cavernous sinus
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What lies within the cavernous sinus?
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What is the most common treatment for pituitary tumours?
Surgery, via nasal cavity
Disruption to the following hormones results in?
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Adrenal Glands:
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Adrenal Cortex: Secretions:
- aldosterone
- cortisol
- androgens
Adrenal Medulla: Secretions:
- adrenaline
- noradrenaline
Because adrenaline and noradrenaline is released via sympathetic system, the adrenal medulla is
effectively specialised sympathetic ganglion
preganglionic sympathetic fibers synapse in the medulla instead of the sympathetic chain
What are the three layers of the adrenal cortex?
Zona Reticularis
Zone Fasciculata
Zona Glomerulosa
deep to superficial
Which layer of the adrenal cortex secretes androgens?
- testosterone precursor
- zona reticularis