Histology of Endocrine Organs Flashcards
Humoral Stimuli
H release stimulated by ion and nutrients in the blood Ex: low Ca+2 causes PTH release
Neuronal Stimuli
H. Released by nerve signal Ex: sympathetic nerves stimulate E release
Hormonal Stimuli
H. release due to another H. Ex: TSH causes release oh TH
Endocrine glands have what kind of cells, are the vascularized
Epithelioid cells ( no free surface) High vascularized with finest rated endothelium
Direct Targets of Hypothalamic H.
AP (can inhibit it) Kidney and uterus (ADH and Oxytocin from PP) Adrenal Medulla (stimulate sympathetic nerves to it)
Indirect Targets of Hypo
Tropic H.s released by Hypo go to AP This causes the AP to secrete H.s that effect the Thyroid, adrenal, mammary, gonads, Bone
Pituitary is from what origin
Ectodermal, in the Sephnoid bone Rathke’s pouch= AP Diencephalon= Infundibulum +PP
3 parts of the AP
Pars Tuberalis Pars intermedia Pars Distalis
2 parts of PP
Infundibular stalk Pars nervosa
Cell type of the AP
Somatotropic cells= GH Thyropropic cells= TSH Corticotropic cells= ACTH- adrenal cortex production of stress H.s, and MSH -melanocytes production on melanin Gonadotropic cells= FSH and LH Mammotropic cells= prolactin ——> milk production + immune
Acidophils (pars Distalis)
Somatotrophs Mammotrophs Red taking up EOSIN
Basophils (pars Distalis)
Corticotrophs Thyrotrophs Gonadotrophs Dark stained with HEMATOXYLIN
Chromophobes (pars Distalis)
Stained white, don’t like any stain = no function
(Pars nervosa)
Continuous with median eminence of hypo stalk = infundibulum stalk DOES NOT MAKE H.s , just stores and releases 1. Hypothalamic N. (Unmyelinated) (make O and ADH) = Herring bodies where the Ns go to in the PP 2. Pituicytes support cells 3. Fenestrated capillaries (likeAP)
Herring Bodies
Picture
Hypothalamic- Hypophyseal Portal System For AP
A—> caps——> V——> caps——> V How H.s are released into the AP 1. Hypo neurons release H. To the primary capillary plexus 2. Travel to the AP and release H. 3. AP secretes H.s to the Secondary cap plexus
Hypothalamic- Hypophyseal Portal System For PP
NON-PORTAL, only 1 capillary bed involved which is in the PP 1. Hypo neurons make Oxytocin and ADH (supraoptic nucleus and paraventricular nucleus) 2. ADH and O are transported down the axon into the PP 3. ADH and O are stored in the Herring Bodies 4 . Hypo N fire and the ADH and O are released form the bodies
ADH
Kidney for Na+ and H2O retention
Oxytocin
Uterus for contraction + lactation, sexual arousal, social bonding
Pineal gland
Roof of 3rd ventricle Growth/ development + circadian rhythm Make melatonin and serotonin IS RESPONDING TO LIGHT hitting the retina At early childhood: Ca+2 crystals form
Thyroid Gland
Has follicles simple cuboidal Surrounded by colloid = thyroglobulin stored [T3+T4] Controls basal metabolism, O2 usage, body temp
How TH is made
- TRH, TSH, TH—-> makes Thyroglobulin in RER, glycosylated in Golgi, and excreted into lumen (colloid) 2. Thyroglobulin gets iodinated into t3 and t4 3. TSH causes degradation of Thyroglobulin by taking it in the follicle 4. T3 and T4 are released to blood
Parafollicular C Cells
Around the follicles of the thyroid gland Secrete CALCITONIN, when Ca+2 is HIGH = increase kidney secretion of Ca+2, increase osteoblasts, decrease osteoclasts
Grave’s disease
Over active thyroid Abnormal Abs bind to TSH R. Causing permanent TH stimulation Sx: high metabolism, sweating high HR, weight loss, eyeballs protrude (due to high fat deposition behind the eye)
Hypothyroidism
Low T3 and T4 Sx: low metabolic rate, weight gain, tired, cold edema, metal sluggish
Goiters
Enlarged thyroid, due to LOW IODINE Thyroglobulin can’t iodinate to make T3 and T4 So there is HIGH Thyroglobulin made and HIGH TSH
Parathyroid Glands And its 2 cell types
Behind thyroid Release PTH, regulates Ca+2 and P 1. Chief cells: release PTH, when Ca+2 is low 2. Oxyphil cells: can also sense Ca+2 levels
PTH
Bone: bind to osteoblasts ——> release RANKL——> bind osteoclasts to stimulate them Kidney: reabsorb Ca+, and covert inactive VITD-> active VITD GI: active VITD absorbs more Ca+2
Adrenal medulla
above kidney Has cortex (Zona glomerulosa (secretary cells), zone fascicularis, zone reticularis) and medulla (Out to in)
Zona glomerulosa
For MINERALCORTIcoIds= ALDOSTERONE Influence Na and K levels To increase BP
Zona fascicularis
GLUCOCORtICOIDS = CORTISOL[form ACTH stimulation] Influence glucose metabolism + anti inflammatory system Stress and glucose metabolism and
Zona Reticularis
ANDROGENS = estrogen, testosterone, progesterone Secondary Sex characteristics
Medulla of the adrenal gland
Large clusters of CHROMAFFIN CELLS Sympathetic N.s go to stimulate chromaffin cells secretes E and NE Fight or flight
Addison’s Disease
Hyposecretion of GLUCOCORTICOIDS and MINERALCORTICOIDS * AP failure, low cortisol, HIGH ACTH Hypoglycemia, hypotension, dehydrated, loss of appetite Hyperpigmentation
Crushing’s syndrome
Hypersecretion of cortisol (GLUCOCORTICOIDS) due to AP or Ad. Cortex tumor = high ACTH = used to make HIGH cortisol Hyperglycemia, HTN, degraded muscle, depressed immune Weight gain, swollen face, buffalo hump
Pancreas EXOCRINE
H made are transported in a duct to the GI Organized into acini, serous and mucous
Endocrine Pancreas And its 4 cells
Cells organized into clusters = Pancreatic ISLETS ISLETS OF LANGERHANS 1. Alpha cells: GLUCAGON =red 2. Beta cells: INSULIN =green 3. Delta cells: SOMATOSTATIN ——I insulin and glucagon, regulates nutrients 4. F-cells: PANCREATIC POLYPEPTIDE——I somatostatin- regulate appetite
Pancreatic Blood Supply Insuloacinar portal system
Supplies islet of langerhans ——> pancreatic acini (for local islet H. actions on acini) Connects the islets to the acini
Pancreatic Blood Supply Acinar Vascular System
Independent artery supplying the acini Only the acini
Endocrine Gland with endocrine epitheliod cells around some vasculature
Pars Distalis
and the cells types acidic and basilic
GH and prolactin=acid
ACTH, FSH/LH, TSH= basic
Pars nervosa
Pineal Gland
Pineal gland
Thyroid Gland
Parafollicular cells
Parathyroid
Pancreas
exocrine acini and endocrine islets
Pancreas cells
