S9- endocrinology Flashcards
6 main endocrine glands:
- hypothalamus/ pituitary
- Thyroid
- parathyroid
- pancreas
- Adrenal
- ovaries/ testicles
the pititary gland controls…
it can be functionally divided into 2 lobes:
most glands in the body
- anterior pituitary= produces various hormones
- posterior pituitary= stores various hormones (which are preduced in hypothalamus)
5 hormones produced by anterior pituitary
- growth hormone (GH)- for skeletal growth
- Adreno-cortico-trophic hormone (ACTH)- stimulates adrenals to produced steriods
- gonado-trophins (FSH and LH)- stimulates testicles and ovaries to produce sex hormones
- thyroid stimulating hormone/ thyrotrophin (TSH)- stimulate thyroid to produce thyroid hormones
- prolactin (PRL)- stimulates breast milk production
posterior pituitary stores 2 hormones (prodeuced in hypothalamus)
- antidiuretic hormone (ADH)- stimulates water reabsorption by kidneys
- oxytocin- main role is to help uterine contraction during labour
the anterior pituitary gland is under control of…
hypothalamus
4 hormones that are produced by hypothalamus to control anterior pituitary:
- Cortico-trophin releasing hormone (CRH)- stimulates ACTH secretion
- growth hormone releasing hormone (GHRH)- stimulates GH secretion
- thyrotropin releasing hormone (TRH)- stimulates TSH secretion
- Gonadotrophin releasing hormone (GnRH)- stimulates FSH and LH secretion
prolactin releasing hormone does not exist and prolactin is under the…of the hypothalamus
inhibitory effect
pituitary hormones are switched off by…
negative feedback (when the target gland/ organ produces the desired hormone—> stops pituitary gland from producing the stimulating hormone)
4 hormones that swtich off pituitary hormones
- Cortisol= ACTH and CRH
- growth hormone= GH and GHRH
- thyroid hormone= TSH and TRH
- sex hormones= FSH/LH and GnRH
4 glands that are not controlled by the pituitary
- adrenal medulla = produce adrenaline and noraadrenaline
- parathyroid= controls calcium levels
- pancreas= controls sugar levels
- gut hormones
the thyroid gland is composed of 3 parts:
Midline isthmus (below the cricoid cartilage)
right lobe
left lobe
the adrenal cortex is under control of…but the madulla isnt
the pituitary gland
calcium metabolism is mainly controlled by…
4 parathyroid glands sitting behind the thyroid
4 other organs involved in calcium metabolism
- kidneys (calcium excretion and production of active virtamin D)
- Gut (absorption of calcium)
- Bone (storage of calcium)
- thyroid (C cells)
2 parts of the adrenal gland are:
- adrenal cortex 90%
- adrenal medulla 10%
what 3 hormones does the adrenal cortex produce
- Cortico-steroids (cortisol)
- Androgens (male hormones)
- Mineral-o-corticoid (aldosterone)
adrenal medulla produces…
Catechol-amines (adrenaline, noradrenaline (neurotransmitter and hormone-important in fight-or-flight response, dopamine)
catecholamine secretion is not controlled by pituitary, instead it is related to…
Mineralocorticoid secretion is also not controlled by pituitary, instead it is relate to…which controls…
blood pressure
renin-angiotensin system (s a hormone system that regulates blood pressure, fluid and electrolyte balance, and systemic vascular resistance)
blood pressure
ovaries are situated in the…
they contain follicles that contain…
Pelvis on either side of the uterus
an oocyte each (at different stage of maturation)
2 hormones that the ovaries produce that switches off the hypothalamus and/or pituitary gland
inhibin= pituitary only
oestradiol= both glands (stimulates and inhibits)
in adults, testes are found in the…(except in a minority with testicular…)
scrotum
maldescent (ie: undescended testicle)
2 hormones released by testes that switch off the hypothalamus and/or pituitary glands
- inhibin (Sertoli cells)= pituitary only
- testosterone (leydig cells)= both glands
thyroid cells are arranged in…and produce…hormones
thyroid also contains…cells which produce…(..metabolism)
follicles
thyroid hormones (control gene expression and various aspects of organ function)
C cells (parafollicular cell)
calcitonin
calcium metabolism
testes are composed of 3 parts:
- interstitial or leydig cells= produce testosterone
- Seminiferous tubules= has germ cells that produce sperm
- sertoli cells= help in sperm production and produce inhibin