Endocrinolgy (SEM1) Flashcards
Where is the hypothalamus situated?
below the thalamus, above brain stem
What is the role of the hypothalamus?
releasing hormones and regulating body temperature
how is the hypothalamus connected to the pituitary gland?
via the infundibulum
how many lobes does the pituitary lobe have?
what are these?
Two: the anterior and posterior lobes
how is the posterior pituitary lobe connected to the hypothalamus?
via magnocellular neurons -
these have long axons which extend down the posterior lobe from the hypothalamus
how is the anterior pituitary lobe connected to the hypothalamus?
via parvicellular neurons -
secrete regulatory hormones into the bloodstream which travel through the portal system in the anterior pituitary lobe triggering secretion of more hormones
Another name for the pituitary gland is ?
The hypophysis
Another name for the anterior pituitary lobe is ?
the endohypophysis
another name for the posterior pituitary gland is the..?
the neurohypophysis
The infundibulum is also know as…?
The pituitary stalk
What are the hormones of the anterior pituitary lobe? what are the effects of these hormones?
Growth hormone -promotes growth of tissues
Prolactin - promotes milk production from mammary glands
LH -stimulates androgen production by gonads
FSH - stimulates gamete production by gonads
TSH - stimulates thyroid release from the thyroid
Adrenocorticotropic hormone - stimulates hormone release from adrenal cortex
Hormones of the posterior pituitary lobe?
ADH - binds to receptors on kidney causing water retention via increased water reabsorption
oxytocin - stimulates uterine contractions during childbirth. Also essential formula ejection reflex
Where is the pineal gland located? How big is it?
It is located in the epithalamus 2 hemispheres, in the centre of the brain
it is 6mm long
What hormone is secreted by the pineal gland? what cell secretes it? What is the effect of this hormone?
melatonin - controls circadian rhythm of the body. secreted by pinealocytes
what inhibits the production of melatonin? What is it used to treat?
light to the retina
SAD and insomnia
What is a hormone?
a chemical messenger released by a gland that invokes an effect on a target cell
Endocrine signalling has an effect on
distant target e.g. pituitary gland to adrenal gland
Paracrine signalling has an effect on
neighbouring target e.g. eyelets of Langerhans
Autocrine signalling has an effect on
same cell e.g. beta cells in liver
Name 3 steroid derived hormones
cortisol, aldosterone and testosterone
Name 4 protein derived hormones
GSH, Lh, hCRG, Prolactin
Name 3 peptide derived hormones
ADH, oxytocin and melatonin
name 4 amino acid derived hormones
noradrenaline, adrenaline, dopamine,T4 (all from tyrosine)
describe how oxytocin and ADH can cause cross -reactions
large quantities of oxytocin can have an anti-diuretic effect whilst high levels of ADH can cause uterine contractions in females
\where is insulin produced? Describe the structure
Insulin is produced in the pancreas. It has a hetero dimer protein structure (2 alpha chains linked by disulphide bonds)
What hormone is derived from tryptophan?
melatonin
name the primary endocrine organs
pineal gland, pituitary gland, pancreas, ovaries, testes, thyroid gland, parathyroid gland, hypothalamus and adrenal glands. The hypothalamus and pituitary gland are neuroendocrine organs.
name the secondary endocrine organs
skin, heart,GI tract, kidneys
t3 hormone stands for? What does it do?
tri-iodothyronine,, regulates metabolism.
t4 hormone is? what does it do?
thyroxine? regulates metabolism
the thymus is the site of
T cell maturation and thymosin production
what is the function of thymosin?
stimulates T cell activity and antibody production in the bone marrow
most common thymus disease is myasthenia gravis. What is this?
the over-production of antibodies directed towards the nAChR at the neuromuscular junction, causing the muscles to become weak and easily tired.
describe pancreatic endocrine function?
production of insulin, glucagon,somatostatin,ghrelin,pancreatic polypeptide
where are the adrenal glands located?
At the top of the kidneys
2 regions of the adrenal glands?
central cortex and outer medulla
what are the ovaries? What hormones do they produces
the female reproductive organs
they secrete steroid hormones: oestrogen and progesterone and protein hormones inhibit and relaxin
what are tropic hormones?
Tropic hormones are those that have other endocrine glands as their targets
what does exocrine mean?
Pertaining to the secretion of a substance out through a duct.
what does endocrine mean?
Pertaining to the secretion of a substance from a gland to the bloodstream
which hormones regulate ovaries? where are these hormones produced?
FSH and LH (gonadatropins) the anterior pituitary gland
what are the testes? What hormones do they produces
male reproductive organs
steroid hormones (androgens) primarily testosterone
describe the endocrine function of the placenta?
production of:
Steroid hormones
Oestrogens
Progesterone
Protein hormones
Chorionic Gonadotropin (CG)
Corticotropin Releasing Hormone (CRH )
Placental Lactogenic (PL)
these hormone
describe the endocrine function of the placenta?
production of:
Steroid hormones
Oestrogens
Progesterone
Protein hormones
Chorionic Gonadotropin (CG)
Corticotropin Releasing Hormone (CRH )
Placental Lactogenic (PL)
these hormones are important for healthy pregnancy
name hormones produced in the:
heart
kidneys
Skin
Heart: Atrial natriuretic peptide (ANP) stimulates kidney to secrete more salt - lowers BP
Kidney: Juxtaglomerular cells secrete Renin
Renin indirectly signals adrenal cortex to secrete aldosterone
Erythropoietin: signals bone marrow to increase RBC production
Skin:Modified cholesterol with UV exposure becomes Vitamin D precursor Vitamin D necessary for calcium metabolism
