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HISTOLOGY 3 > Endocrine organs > Flashcards

Flashcards in Endocrine organs Deck (28)
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1
Q
  1. Hypothalamus (Gömöri’s chrome-haematoxylin)
A
frontal section
third ventricle
columns of fornix
anterior commissure
internal capsule
optic tract
telencephalon basolateral part
large perikarya of paraventricular nucleus close to ventricular wall
supraoptic nucleus baso-lateral, medial side of optic tract
nucleus basalis of Meynert
2
Q

Magnocellular nuclei

A

supraoptic nucleus and magnocellular division of paraventricular nucleus
produce oxytocin and vasopressin

3
Q

Nucleus basalis of Meynert

A

in baso-medial telencephalon
large cholinergic neurons
sole source of cholinergic innervation of cortex

4
Q
  1. Hypophysis (HE)
A

2 parts: neurohypophysis and adenohypophysis
on slide: neurohypophysis, pars distalis, pars intermedia
CT capsule
Chromophobe cells
Chromophil cells

5
Q

Divisions of adenohypophysis

A
  1. pars distalis
    - largest past
    - higly vascular
    - several secretory epithelial cells in cords + irregular follicles
  2. pars tuberalis
    - surrounds infundibulum
    - contains hypthalamo-hypphyseal portal system
  3. pars intermedia
    - narrow between neurohypophysis and pars distalis
    - rudimentary region
    - basophilic cell cords and follicles,lined by chromophore cells that contain colloid material, alpha-beta endorphin, production of MSH-> melanocyte melanin
6
Q

Chromophobe cells

A

little affinity for dyes
small amount of lightly stained cytoplasm
majority of adenohypophyseal cells

7
Q

Neurohypohysis

A

lighter stained
masses of unmyelinated axons of secretory neurons- perikarya in supraoptic and paraventricular nuclei
25% of volume- highly branched glial cells “pituicytes” (astrocytes)
fenestrated capillaries

8
Q
  1. Hypophysis (Gömöri’s chrome-haematoxylin phloxine)
A

neuro and adenohypophysis
basophils - dark bluish-grey
acidophils - bright pink
dilated axons in neurohypophysis - neurosecretory material accumulated
neurophysin in neurosecretory material - dark bluish-grey- “Herring bodies”

9
Q
  1. Thyroid gland (HE)
A
  • thin CT capsule + collagenous septa
  • divided into lobules
  • follicles with inactive hormone
  • C cell/parafollicular cell
  • fenestrated capillaries, lymph vessels, sympathetic nerve fibers
  • sternothyroid muscle, muscle spindles
  • solid nest cell, small cystic structures, mixed follicles
10
Q

Thyroid follicles

A

large amount of inactive hormone
lined by squamous, cuboidal or low columnar secretory epithelium - secretes T3 and T4 hormones
surrounded by rich capillary network
colloid material (thyroglobulin) in lumen +stores hormones
active gland: small follicles
hypoactive gland: distended follicles + full of colloid

11
Q

Calcitonin cell/ C cell/ parafollicular cell of thyroid gland

A

endocrine secretory cell
in intermolecular space, solid nest cells, CT space
form small clusters
secretes calcitonin

12
Q

Solid nest cells of thyroid gland

A
embryonic remnant of endodermal origin
Main cells: 
-polygonal, elongated, spindle-shaped
-Stem cell nature
C-cell:
-clear cytoplasm + small dense nuclei
13
Q
  1. Thyroid gland (calcitonin immunostaining -H)
A

calcitonin producing cells

in central part of lateral lobes

14
Q
  1. Parathyroid gland (HE)
A
  • CT capsule of thyroid encapsulates
  • thin septa
  • Chief/Principal cell: small, polygonal, prominent nuclei, little cytoplasm
  • Oxyphil cells: larger polygonal, smaller densely stained nuclei. Occur in clumps
  • Adipose tissue in older individuals
  • fenestrated capillaries, lymph vessels
15
Q

32.Adrenal gland (HE)

A
  • dense, collagenous CT capsule
  • adrenal cortex and medulla
  • trabeculae
  • prominent vein in center of medulla
  • zona glomerulosa, fasciculate, reticularis
  • secretory cells of medulla - catecholamines
  • neurons in medulla
  • medullary and suprarenal veins- longitudinal smooth m on wall(regulates blood flow, glucocorticoid hormone)
  • autonomic ganglia
16
Q

Zona glomerulosa of adrenal gland

A

outermost layer in cortex, 15%
irregular, packed, ovoid/rounded clusters of columnar /pyramidal cells
a lot of SER + lipid droplets
steroid synthesis - mineralocorticoids

17
Q

Zona fasciculata of adrenal gland

A
widest zone, 80%
narrow,parallel rows of cells, separated by sinusoid capillaries
cells are large, polyhedral
a lot of set and lipid droplets
secrete glucocorticoids
18
Q

Zona reticular of adrenal gland

A
innermost layer of cortex- thin, 5%
contain less lipid droplets
irregular anastomosing cords of smaller cells
lipofuscin granules
pyknotic nuclei - cell degeneration
secrete weak androgens
19
Q

Secretory cells of adrenal medulla

A
closely packed clumps + reticular fibers
columnar cells around venous sinusoids
a lot of capillaries around
strong basophilic and granular nuclei
chromaffin cells- high affinity for chrome salts, innervated by preganglionic sympathetic fibers, secrete epinephrine + norepinephrine
ganglion cells
20
Q
  1. Endocrine pancreas (HE)
A

islets of Langerhans- lightly stained
irregular cords of secretory cells + collagenous CT around + capillaries
thin capsule around islets
endocrine cells: small, polygonal (insulin, glucagon, somatostatin, gastric inhibitory peptide, CCK, ACTH secreting cells)

21
Q
  1. Pineal gland (HE)
A

enclosed in pia mater
CT septa + blood vessels
irregular lobes/ follicles
Pinealocytes: basophilic cytoplasm, large infolded nuclei, prominent nucleoli, processes to capillaries, releases Ca2+, secretes melatonin
Astroglial cells: long cytoplasmic extensions
Myelinated nerve fibers- ramify into unmyelinated
Corpora arenacea/brain sand: calcium condensed in concentric layers
Pineal recess-> pineal stalk
Posterior commissure

22
Q

Synthesis of Thyroid hormones

A
  1. Synthesis of thyroglobulin + thyroperoxidase in rER -> plasma membrane
  2. Uptake of iodide from blood -> iodide in colloid
  3. iodination of thyroglobulin (MIT + DIT)
  4. formation on T3 and T4
  5. respiration of colloid
  6. release of hormone in blood
23
Q

Role of thyroxine

A

normal growth + development

increased metabolic rate

24
Q

Role of calcitonin

A

decrease blood Ca2+ levels

25
Q

Role of Chief cell in parathyroid gland

A

predominant type

secrete parathormone -> increase blood Ca2+ level

26
Q

Acidophils in Adenohypophysis

A

secretes effector hormones:

  • prolactin- milk formation, mammary gland development
  • growth hormone- insulin-like factor I -> body growth
27
Q

Basophil cells in Adenohypophysis

A

secretes tropic hormones:

  • ACTH- secretion of glucocorticoids in adrenal gland
  • TSH- secretion of thyroglobulin+thyroid hormones
  • FSH- folliculo/ spermiogenesis
  • LH- corpus luteum, testosteron production
28
Q

Hypophyseal portal vein

A

internal carotid a. -> superior hypophyseal a. -> primary capillary plexus -> long portal vein -> secondary capillary plexus -> sinus cavernosus