26 Endocrine Flashcards
these isolated cells in an epithelium that secrete a hormone that diffuses only a short distance in the CT to NEARBY target cells
Paracrine cells
these cells are specialized neurons that secrete hormones into the blood supply
NEUROENDOCRINE cells
Where does the ANTERIOR lobe develop from
ECTODERM in the roof of the oral cavity
this pouch in the ANTERIOR lobe detaches and grows upward towards the developing brain
RATHKES POUCH
The anterior lobe secretes what hormones
FSH (Gonadotroph)
LH (Gonadotroph)
ACTH (Corticotroph)
TSH (Thyrotroph)
( basophilic)
Prolactin (Mammotroph)
GH (somatroph)
(acidophilic)
The posterior lobe secretes what hormones
Oxytocin and ADH
this pea sized organ is attached by a stalk to the underside of the hypothalamus and surrounded by bone
PITUITARY GLAND
What lobe of the pituatary gland releases CHROMOPHILS which are colorful grandular epithelial cells
ANTERIOR LOBE = ADENOHYPOPHYSIS
releases ACIDOPHILIC and BASOPHILIC
This lobe of the pituitary gland develops from the downgrowth of the neural tube ectoderm
POSTERIOR LOBE (NEUROHYOPHOSIS)
Neurons in the hypothalamus release hormones into what?
a VENOUS PORTAL SYSTEM (Capillaries –> veins –> capillaries
The POSTERIOR pituitary is composed of UNMYELINATED axons and their terminals with associated glial cells called?
PITUICYTES
Where are hormones synthesized in the HYPOTHALAMUS
CELL BODIES of neurons
this hormone promotes the REABSORPTION of water in the kidney
ADH (vasopressin)
reduced ADH due to leision in CNS –> diabetes insipidues (large amounts of dilute urine and increased thirst)
The PINEAL gland is derived from what?
NEURAL TUBE
this component of the pineal gland has calcified concretions that look like BASOPHILIC ROCKS
BRAIN SAND
this component of the pineal gland are modified neurons with euchromatic nucleus and pale staining cytoplasm with many extensions
secretes MELATONIN into fenestrated capillaries
PINEALOCYTES
This gland consists of 4 small oval organs embedded in the thyroid gland
intially develops in the endoderm, lining the 3rd and 4th pharyngeal pouches but then migrates into the developing thyroid gland
PARATHYROID glands
What cells are found in the parathyroid gland
CHIEF/PRINCIPAL cells and OXYPHILL cells
these cells found in the parathyroid gland secrete PTH into fenestrated capillaries
Chief cells
PTH increases calcium levels in the blood by increasing bone breakdown and calcium resorption from the kidney
these acidophilic cells are found in the parathyroid gland and appear at puberty, unknown function
OXYPHIL cells
This pathology of the parathyroid gland is due to low blood calcium and can result in tetany and death
HYPOPARATHYROIDISM
this pathology of the parathyroid gland is due to LOW blood calcium
associated with osteoporosis due to increased activity of osteoclasts
HYPERTHYROIDISM
What are the two secretory cells found in the Thyroid Gland
Follicle and Parafollicular (C-Cells)
these cells found in the thyroid gland are simple epithelial cells arranged as hollow spheres filled with colloid = acidophilic gelatinous material
FOLLICLE CELLS
these cells found in the thyroid gland are found as a smnall population of cells in the CT between follicles or hiding under the basal lamina of follicles
SECRETES CALCITONIN
Parafollicular Cells or C Cells
these cells of the thyroid gland release thyroid homrones T3/T4 into fenestrated capillaries
FOLLICLES CELLS
Where do follicular and parafollicular cells develop from?
Follicle – endoderm lining the pharynx
Parafollicule – neureal crest in the pharyngeal pounch 4
Why is the thyroid gland unique
it produces an INACTIVE form of its homrone, thyroglobulin in the colloid – only organ to store its product extracellularly
Thyroid Hormone Synthesis ( 4 steps)
- Follicle cells secrete thyroglobulin into the colloid
- Thyroglobulin is iodinated in the colloid
- Thyroglobulin is reabsorbed back into the cell, fused with lysosomes to form thyroid hormones
- Follicle cells release the thyroid hormones (t4/T3) into the CT where it enters the fenestrated capillaries
this pathology of the thyroid gland – enlarged thyroid gland could be associated to hyper or hypothyroidism
GOITER
excess thyroid release –> increased metabolism and eye disease
HYPERTHYROIDISM – toxic goiter/graves disease
low thyroid hormone levels cause an overall reduction of metabolism
Causes:
- insufficent dietary iodine
- hashimoto’s disease = autoimmune disease with replacement of thyroid gland by lymphoid tissue
HYPOTHYROIDISM
this gland is found as triangular shaped structures embedded in the fat at the top of each kidney
ADRENAL (SUPRENAL) Gland
The Adrenal Gland is divided into two parts
Cortex and Medulla
this portion of the adrenal gland contains acidophilic cells that secrete STEROIDS (Aldoesterone, cortisol and androgrens)\
derivied from MESODERM
ADRENAL CORTEX
This portion of the adrenal gland is the inner portion that contains chromaffin cells that secrete catecholamines (epinephrine and norepinephrine)
ADRENAL MEDULLA
where are chromaffin cells derived from and what do they do and what are they innervated by
ANALOGOUS TO POSTganglionic sympathetic cells
NEURAL CREST ECTODERM, SECRETE CATECHOLAMINES (norepinephrine and epinephrine)
innervated by PREganglionic sympathetic nerve fibers
this ZONE of adrenal cortex is the outer zone that secretes mineralcorticoids (mainly aldosesterone) –> BP control
ZONE GLOMERULOSA
this zone of the adrenal cortex is the middle zone that contains sinusoidal capillaries that drain into medulla
secretes GLUCORTICOIDS like cortisol
ZONE FASCICULATA
this zone of the adrenal cortex is the deepest narrow layer that secretes adrenal ANDROGENS (GONADOCORTICOIDS) –> sex characterstics
ZONA RETICULARIS
this disease has HYPERsercretion of CORTISOL due to an adenoma of the anterior pituitary that secretes ACTH
CUSHING’s Disease
this disease is HYPOsecretion of glucocorticoids +/- mineralocorticoids usually due to autoimmune destruction of cortex
ADDISON’s disease
The Adrenal MEDULLA is made up of CORDS of ______
chromaffin (endocrine) cells
this is a neoplasm of the medulla
malignant infant or childhood tumors derived from primitive neural crest cells
NEUROBLASTOMAS
this neoplasm of the medulla are benign adult tumors derived from chromaffin cells
PHEOCHROMOCYTOMAS
