9.0 ENDOCRINE ORGANS: INTRODUCTION
The endocrine system comprises the following elements:
9.2 - images: Hypophysis, pituitary gland.
The pituitary gland consists of (1) the epithelial-derived adenohypophysis ( anterior pituitary) with the pars distalis, the pars intermedia and the pars tuberalis; and (2) neurohypophysis, with the pars nervosa (neural lobe) and the infundibulum (pituitary stalk and median eminence).
- Lactotroph (prolactin, PRL), (25%), scattered throughout.
- Corticotrophys (ACTH, beta-lipotropin, alpha-MSH and beta-endorphins), (15-20%),
in the median portion of the gland
- Thyrothrophs (TSH), also in the median portion of the gland.
- Gonadotrophs (FSH, LH), (10%)
See: 9.2 POJA-L2762+2764+2781+2783+4384+La0216
9.3 - images: Thyroid gland.
The thyroid gland secretes thyroxine (basal metabolic rate) and calcitonine (calcium homeostasis). The thyroid epithelial cells form a wide acinus and the lumen is filled with thyroid colloid. A fine capillary network surrounds the acinus. Thyroxine is released from the thyroglobulin colloid and transported to the surrounding capillaries.
Calcitonin-producing cells (C cells) are dispersed between the epithelial cells of the wall of the acinus.
See: 9.3 POJA-L2794+2801+2803+2806 and 9.3 POJA-L2792+2728+3489+3492+La0245
9.4 - images: Parathyroid glands, located in the neck region near the thyroid gland.
The parathormone is invoved in calcium homeostasis. The organ contains chief cells (parathormone), the larger and pale oxyphilic cells (mitochondria rich) and adipocytes. The oxyphilic cells are possibly involved in the synthesis of Parathyroid hormone-related protein (PTHrP) and calcitriol.
See: 9.4 POJA-L2816+2818+2821+3485+2823+2825
9.5 - images: Adrenal gland. Located in the upper poles of the kidneys.
The adrenal cortex contains a zona glomerulosa (aldosteron, deoxycorticosterone), a zona fasciculata (cortisol, corticosterone) and a zona reticularis (androgenic steroids, glucocorticoids).
The adrenal medulla produces adrenaline, noradrenaline and enkephalins.
See: 9.5 POJA-L2871+2888+2890+La0236
9.6 - images: Pineal gland. Located below the corpus callosum of the brain. Consists of pinealocytes (melatonin) and glial cells. Melatonin is released into capillaries and carried to peripheral organs to transmit information about the light/dark cycle and to the SCN to contribute to the entrainment of the 24-hour central clock to the light dark cycle. In humans, light inhibits melatonin secretion during the day.
See: 9.6 POJA-L3480+La0240+2906+2907
9.7 - images: Peripheral chemoreceptors.
See: 9.7 POJA-L2909+3370+2910+2912+3369
9.8 - images:
See: gastro-entero-pancreatic (GEP) system (4.1.1 and 4.4)
9.9 - images: Pathology.
Adenoma of the adrenal gland: See: 9.9 POJA-L3856..... et al.
Medullary thyroid carcinoma: See: 9.9 POJA-L3862 et al.
Papilliferous adenocarcinoma of the thyroid gland: See: 9.9 POJA-L3859 et al.
Chromophobe adenoma of the hypophysis: See: 9.9 POJA-L3853 et al.
9.2 - images: Hypophysis, pituitary gland.
The pituitary gland consists of (1) the epithelial-derived adenohypophysis ( anterior pituitary) with the pars distalis, the pars intermedia and the pars tuberalis; and (2) neurohypophysis, with the pars nervosa (neural lobe) and the infundibulum (pituitary stalk and median eminence).
- The adenohypophysis is involved in the production of
- Lactotroph (prolactin, PRL), (25%), scattered throughout.
- Corticotrophys (ACTH, beta-lipotropin, alpha-MSH and beta-endorphins), (15-20%),
in the median portion of the gland
- Thyrothrophs (TSH), also in the median portion of the gland.
- Gonadotrophs (FSH, LH), (10%)
- The neurohypophysis (posterior pituitary) is composed of neuronal processes and glia cells. The axons originate from cells in the hypothalamus and contain granules with oxytocin and vasopressin associated with the protein neurophysin. Herring bodies are swellings with neurosecretory granules.
- The stellate-shaped glial cells are called pituicytes.
See: 9.2 POJA-L2762+2764+2781+2783+4384+La0216
9.3 - images: Thyroid gland.
The thyroid gland secretes thyroxine (basal metabolic rate) and calcitonine (calcium homeostasis). The thyroid epithelial cells form a wide acinus and the lumen is filled with thyroid colloid. A fine capillary network surrounds the acinus. Thyroxine is released from the thyroglobulin colloid and transported to the surrounding capillaries.
Calcitonin-producing cells (C cells) are dispersed between the epithelial cells of the wall of the acinus.
See: 9.3 POJA-L2794+2801+2803+2806 and 9.3 POJA-L2792+2728+3489+3492+La0245
9.4 - images: Parathyroid glands, located in the neck region near the thyroid gland.
The parathormone is invoved in calcium homeostasis. The organ contains chief cells (parathormone), the larger and pale oxyphilic cells (mitochondria rich) and adipocytes. The oxyphilic cells are possibly involved in the synthesis of Parathyroid hormone-related protein (PTHrP) and calcitriol.
See: 9.4 POJA-L2816+2818+2821+3485+2823+2825
9.5 - images: Adrenal gland. Located in the upper poles of the kidneys.
The adrenal cortex contains a zona glomerulosa (aldosteron, deoxycorticosterone), a zona fasciculata (cortisol, corticosterone) and a zona reticularis (androgenic steroids, glucocorticoids).
The adrenal medulla produces adrenaline, noradrenaline and enkephalins.
See: 9.5 POJA-L2871+2888+2890+La0236
9.6 - images: Pineal gland. Located below the corpus callosum of the brain. Consists of pinealocytes (melatonin) and glial cells. Melatonin is released into capillaries and carried to peripheral organs to transmit information about the light/dark cycle and to the SCN to contribute to the entrainment of the 24-hour central clock to the light dark cycle. In humans, light inhibits melatonin secretion during the day.
See: 9.6 POJA-L3480+La0240+2906+2907
9.7 - images: Peripheral chemoreceptors.
See: 9.7 POJA-L2909+3370+2910+2912+3369
9.8 - images:
See: gastro-entero-pancreatic (GEP) system (4.1.1 and 4.4)
9.9 - images: Pathology.
Adenoma of the adrenal gland: See: 9.9 POJA-L3856..... et al.
Medullary thyroid carcinoma: See: 9.9 POJA-L3862 et al.
Papilliferous adenocarcinoma of the thyroid gland: See: 9.9 POJA-L3859 et al.
Chromophobe adenoma of the hypophysis: See: 9.9 POJA-L3853 et al.
COPYRIGHTS
All rights reserves worldwide for the POJA collection are hold by L.G. Poels and P.H.K. Jap and Radboud University Medical Center (Radboud UMC Nijmegen). No one may modify, copy, distribute, transmit, display, or publish any materials contained in the POJA collection without prior written permission of the authors Poels and Jap or the UMC St Radboud. Any commercial use of the POJA collection is forbidden. POJA images are partly deposited in the Health Education Assets Library (HEAL database) as well as in the MedEdPortal/AAMC database).
All rights reserves worldwide for the POJA collection are hold by L.G. Poels and P.H.K. Jap and Radboud University Medical Center (Radboud UMC Nijmegen). No one may modify, copy, distribute, transmit, display, or publish any materials contained in the POJA collection without prior written permission of the authors Poels and Jap or the UMC St Radboud. Any commercial use of the POJA collection is forbidden. POJA images are partly deposited in the Health Education Assets Library (HEAL database) as well as in the MedEdPortal/AAMC database).