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Anterior lobe of pituitary gland

The anterior lobe of the pituitary gland, also known as the adenohypophysis, is a major endocrine organ located at the base of the brain within the sella turcica. This glandular lobe plays a vital role in regulating growth, metabolism, and reproductive functions through hormone secretion. It is structurally and functionally distinct from the posterior lobe and is responsible for producing several key hormones that influence various target organs throughout the body.

Synonyms

  • Adenohypophysis

  • Pars distalis (main part)

  • Anterior pituitary

Arterial Supply

  • Primarily supplied by the superior hypophyseal arteries, which are branches of the internal carotid arteries.

  • These arteries form a capillary network in the median eminence and upper part of the stalk, giving rise to the hypophyseal portal system.

  • The portal vessels carry hypothalamic releasing and inhibiting hormones directly to the anterior pituitary.

Venous Drainage

  • Venous blood from the anterior lobe is drained via hypophyseal veins.

  • These veins drain into the cavernous sinus, which eventually empties into the systemic venous circulation.

Function

  • Secretes and releases several essential hormones:

    • Growth hormone (GH)

    • Prolactin (PRL)

    • Adrenocorticotropic hormone (ACTH)

    • Thyroid-stimulating hormone (TSH)

    • Luteinizing hormone (LH)

    • Follicle-stimulating hormone (FSH)

  • Functions include:

    • Regulating growth and development

    • Controlling metabolism

    • Stimulating adrenal and thyroid glands

    • Regulating reproductive processes

MRI Appearance

  • T1-weighted images: Anterior lobe is isointense to hyperintense compared to normal brain tissue.

  • T2-weighted images: Appears isointense to hyperintense.

  • FLAIR images: Also isointense to hyperintense.

  • Generally, the anterior pituitary shows homogenous signal intensity unless affected by pathology.

CT Appearance

  • The anterior lobe appears as a soft tissue density within the sella turcica.

  • It is difficult to distinguish from the posterior lobe on non-contrast CT.

  • Contrast-enhanced CT may show uniform enhancement of the anterior lobe.

MRI images

anterior lobe pituitary gland mri 3t axial image

MRI images

anterior lobe pituitary gland mri 3t sagittal image