3 Endocrine Glands Flashcards
3 classes of hormones
Steroid
Amino acid eg catecholamines
Proteins
How endocrine glands formed?
Down growth Loss of duct cells Cords of cells - form endocrine Aggregates Surround by capillaries
Steroid producing cells classification?
Tubular mito
Lipid droplets
Developed SER
Characteristics of endocrine system?
Slow, long-lasting, bloodstream diffusion - bind to complementiry receptors.
3 types of endocrine cells?
Endocrine - effects target organ via blood
Paracrine - effects cells in close vicinity
Autocrine - effect endocrine cells themselves
Endocrine gland classification?
Gland:
Unicellular
Multicellular
Interstitial
Unicellular endocrine glands… 2 examples of…
C cells of thyroid
DNES Diffuse Neuro-endocrine system
DNES - explain?
Unicellular.
Mucosa of Digestive, respiratory system.
Enteroendocrine cells
Argentaffin, argyophillic - affinity for chromium and silver salts
APUD - Amine precursor undergo decarboxylation - hormone synthesised - increase motility.
FUNCTION OF GI DES
Stomach - gastrin and serotonin - stim gastric secretion - increase SI motility
SI - CCK ( cholecystokinin ) - pancreas enzyme secretion
- secretin - stim secretion : pancrease enzymes, bicarbonate
- motilin - increase gastric and SI motility.
4 types of multicellular endocrine glands - and examples
Cords - pituitary, parathyroid, adrenal, pineal
Islets - pancreas
Interstitial - testis and ovary
Follicles - thyroid (only structure)
Why is kidney not an organ of the endocrine system?
Not specialised for endocrine hormone secretion.
Other major functions eg reabsorption of water, ions. Blood filter
What 2 hormones does kidney secrete?
Erythropoietin
Calcitriol
Pituitary, anterior, adenohypophysis : name components
Pars : tuberalis, intermedia, distalis
Neurohypophysis structure?
Pars nervosa and infundibular stalk
How ant pituitary stimulated?
Stimulated via inhibition/secretion factors via primary and secondary capillaries.
Pars distalis - regulate cells in ant. Hypophysis
Does post pituitary prodcue hormones?
No, only hormones release.
Hypothalamus produce hormones via axon - pars nervosa
Name hormones produced by pituitary gland - adenohypophysis.
ACTCH, PRL, FSH, LH, GH, TSH, MSH
adrenal galnds, mammary glands, male and female gonads, liver, thyroid, melanocytes.
FSH, LH - maturation in spermatogenesis, development of follicle in ovary, ovulation
5 types of cells in Ant Pituitary?
Somatotropes - GH, GHRH (growth hormone releasing hormone), somatostatin (inhibit gh release)
Lactotropes prl, dopamine inhibit, vasoactive inhibitory peptide and thyrotropin releasing hormone inhibit
Corticotropes acth
Gonadotropes fsh lh
Thyrotropes tsh
Hormones produce by post lobe
ADH - reabsorption of water in the kidneys
Oxytocin - SM uternine and mammary gland contraction (female)
- (male) SM in ductus deterens and prostate glands.
What is acromegaly?
Post puberty, excess gh produced
Adenonypohysis arrangement of epithelia?
In cords
Adenohypophysis hormone type?
Protein, glycoprotein
3 categories of types of cells in adenohypophysis?
Chromophils ( acidophillic - GH, PRL MSH, basophillic - FSH, LH, TSH, ACTH)
Chromophobe - no stain, unknown maybe (inactive, degranulated, undifferentiated.)
Folliculo-stellate - starlike - transmit signal from pars tuberalis to distalis
Neurohypophysis info?
Release factors stimulate adenohypophysis ADH, oxytocin Unmyelinated nerve fibre CT stroma Specialised glial cells
What inhibits ADH.
Alcohol
What do you find in nerve fibres and glial cells of the pituitary?
Herrin bodies.
What are herrin bodies and where are they found?
Storage of hormones in granules.
Terminal axon branch
Pineal gland, brain sand, what is?
Ca2+ concentration increases with age.
Visible on x ray.
Allows you to visualise other structures in brain
3 types of cells in pineal gland?
Glial, pinealocytes, interstitial cells(astrocytes)
Hormones in pineal gland?
Serotonin day
Melatonin night
Function of pineal gland
Antioxidant Linked to depression Anti cancer Adjust to changes in day and night Circadian activities Timing of puberty - eg inhibition of gonads
Suprachiasmatic nuclei in hypothalamus
Real body clock
Genes expressed
Leads to expression of other genes
Release of specific hormones
What type of endocrine gland thyroid
.
Follicle
What in colloid?
Hormones
Thyroglobins
What type of cells thyroid follicles?
Thyreocyte
Columnar or cuboidal
What does the white space in the colloid of thyroid gland represent?
Decrease in colloid,
Hormone absorbed by follicle cells
What are thyroglobins?
Inactive storage of hormone t3 and t4
What is thyroglobin made of?
Tyrosine residues connected by iodine
C cells in thyroid.
Unicellular cells.
Release calcitonin
Function of T hormones?
Increase o2, met, atp consumption, body temp.
Increase body growth and correct dev of nervous sytem
Calcitonin function
Maintain calcium level in blood
Too high calcium therefore…
Inhibit osteoclast…hypocalcemia.
Parathyroid antagonist
Active/inactive thyreoctye shaoe and function
Active - columnar - thyroglobin synthesis and breakdown
Iodide in capillary to peroxidase to iodine. Bind to tyrosine residues. Released into colloid.
Inactive - cuboidal - stored colloid
Where calcitonin produce?
Parafollicular cells of thyroid.
Diseases of thyroid?
Cretinism, hyperthyroidism
Parathyroid info?
In cords and lumps
Post thyroid
Thin connective capsule
Parathyroid hormone 2 main functions.
2 main functions of parathyroid hormone?
Ca2+ kidney reabsorption
Ca2+ osteoclast breakdown of bone, inhibit osteoblasts/bone formation - increase ca2+ blood levels.
2 types of cells in parathyroid and their function
Chief cells - synthesise parathyroid hormone
Oxyphils - unknown, of large size than chief cells.
- large no of mitochondria - basophilic ( hemotoxilin)
Adrenal gland structure
2 located supra kidneys
Outer - Capsule.
Inner - medulla
Innermost - cortex
Adrenal Medulla hormones?
Epinephrine, norepinephrine. Fight or flight Sympathetic Increase hr, bp, met. Stimulate by nervous system
3 layers of adrenal cortex?
Glomerulosa - 15% - coiled
Fasiculata - 80% - parallel cords
Reticularis - 7% - irregular - white spaces capillaries
Glomerulosa hormones?
Mineral corticoids - aldosterone - Na+ reabsorption therefore control h20 reabsorption in kidneys
What is addisons disease?
Decrease in glucocorticoids ( fasiculata ) therefore increse stim of MSH - increase in melanocytes
What is crushings disease
Increase in glucocorticoids - redistribution of body fat
Fasiculata andreal hormones
Anti inflammatory and immune suppression
Breakdown of fatty acids, proteins and gluconeogenesis. Release fatty acids and glucose into blood stream
Zona Reticularis adrenal cortex hormones
Sex hormones
Androgen and oestrogen
Parasypathetic effect on pancrease?
Increase both insulin and glucose
Sympathetic effect on pancreas?
Increase glucagon secretion
Inhibit insulin
Normal blood glucose level for a fasting human?
Between 80mg and 110mg per 100ml (4.4 to 6.1mmol per L)
Pancreas - cause and treament of INSULINOMA
Benign tumour 90%
B cells of pancreas
Treatment = surgical removal of tumour
Pancreatic cancer, cause and info?
Malignant neoplasm.
Adenocarcinoma head of pancreas
Prognosis 6m - 1y
Male 4x > female
Symptoms for diagnosis : wwjb weight weakness jaundice back-pain
Exploratory biopsy required for diagnosis
Insulin dependant diabetes mellitus?
Type 1 - onset pre-20 - juvenile-onset diabetes mellitus Autoimmune response to b cells B cells destroyed No more insulin production Treatment of diet and insulin therapy
Non insulin dependant diabetes?
Type 2 - overweight 40+
Insulin resistant, unable to bind to receptors
Change in receptor 3d shape/tertiary structure - no receptor insulin complex formed…
Controlled by diet
Symptoms of diabetes?
Copious urine Blurry vision osmotic loss of water from cells Frequently urination Polyphagia ( hunger ) Polydipsia ( excessive thirst )
Type 3 diabetes?
ADDLs Amyloid B derived diffusible ligands -> bind to receptors on axons for memory function
Insulin receptors not replenished from cytosol to axon
Insulin unable to bind. Loss of memory.
Alzheimer’s -> assoc. dementia
Islets of langerhans - anatomy
Richly vascularised
Spread among pancreatic acini - random
Small clusters surrounded by fine net of reticular fibres
Islets of langerhans - 3 main types of cell, 3 less common types. Each 1 hormone produces.
Cells
A - glucagon
B - insulin
D - somatostatin - VIP(?) inhibit gastrin, glucagon, insulin, pancreatic enzymes.
Gastrin producing - gastrin - HCL secretion stomach
PP - pancreas polypeptide - inhibit exocrine pancreas secretion + bile from gallbladder.
Epsilon - Ghelin - feeling of hunger
