ERS Flashcards
Development of the internal gonads begins from migration of what cell to where
PGC (primordial germ cell) arise from epiblast and migrate to genital ridges
How does PGC migrate
Throug amoeboid movement (chemotaxis)
Expression of results in the
Development of male internal reproductive organ
Degeneration of mullarian tube and growth of WolffIan tube
99% of acromegaly is caused by
Pituitary adenoma - esp overgrowth of somatotroph cells
When does acromegaly start to develop
In adults 30-50 hrs after epiphyseal plate closure
If in younger children - gigantism
Cushing disease result from
Pituitary adenoma which increases ACTH levels thereby influencing downstream secretions
Sertoli cells produce
ABP androgen binding hormone
Most common cause if hyperthyroidism
Graves diseases
Stimulating Autoimmune Ab binds to TSH receptor and activate TH production
Dipsogenic Diabetes instipidus cause
Increase in ADH level due to defect or damage in hypothalamus
Hashimoto disease is
An autoimmune disease caused by autoreactive Ab against thyroid globulin (destroy thyroid gland
Hyperpigmentation is a characteristic of which of the following disease
1) Cushing
2) Addison
Addison
Addison’s disease is characterised by low levels of
Low levels of cortisol,aldosterone and androgens
- LT endocrine disorder in which the adrenal glands don’t produce enough Steroid hormone
Peptide hormone receptors has intrinsic and recruited functions, state examples
RTKs
- intrinsic - EGFR, insulin - pi3k, MAPK
- recruited - GH, PRL - JAKstat
How does jak stat pathway work
Binding of the hormone to the receptor (already dimerised) - JAK Pi cytoplasmic tail of the receptor - STAT recruitment - JAK Pi STAT which allow it to translocation into the nucleus to drive transcription
Difference between EGFR and Insulin receptors
EGFR dimerises after ligand binding whilst Insulin receptor is already dimerised before binding
Intracellular receptors characteristics
Receptor can be in cytoplasm or nucleus
- some of them are present on cell surface for more rapid release (progesterone)
- and some of which can be orphan receptors
Intracellular receptors have slower response why
Stimulate de novo synthesis as the product cannot be stored
Normal sperm index (semen analysis
>1.5 mL in volume > 15 x 10^6 / mL in concentration > 39 x 10^9 total count >32% motility > 4% normal looking morphology
Define teratozoospermia
Odd looking sperm
< 4% normal looking sperm
Asthenozoopermia indicates what
Less than 32% sperm are moving progressively (motility <32%
Oligozoospermia definition
In semen analysis there is less than 15 mil sperm/ mL (look at concentration
Androgen insensitivity syndrome In male results from
Insensitivity of testes to androgens that it secretes - can result in degeneration of wolffian duct
Mutation in 5a reductase results in the failure to convert what to what and the consequence of this?
Failure to convert testosterone to DHT (dihtdrotestosterone) affecting external reproductive organ development in males - ambiguous genitalia, virilisation at Ivette
Testosterone is essential in doing what In makes during puberty
Secondary sexual characteristics
KAllmann syndrome causes
Reproductive and smelling problems
What’s the pathophysiology of KAllmann syndrome
Failure of GnRH neurones to migrate to the hypothalamus from the olfactory bulb - body deem itself as unsuitable for pregnancies
Early onset of puberty (precocious puberty) age in male and female
Male - 9yrs
Female - 8 yrs
Short stature due to puberty induced premature closure of epiphyseal plate is caused by
Early puberty
Delayed puberty age for male and female
14 female
16 male
Markers for bone turnover
Osteonectin/calcin/pontin
Function of osteoblasts, osteocytes and osteoclasts
Osteoblasts secrete ECM and calcify the ECM
Osteocytes has long foot processes that can communicate with osteocytes and respond to stress
Osteoclasts reabsorb bone and have immune function
Calcification of bone is the the collagen type I interaction with
Hydroxyapatite
Most dynamic bit of the bone is the
Spongy bone
Steps of bone remodelling
- Communication with osteocytes
- Osteoblasts receives signal and reabsorb bone which release collagen, phosphate and calcium
- Osteoblasts comes in and lay down matrix (refill collagen phosphate and calcium)
- Calcification/mineralisation of matrix forming osteoid
Hyperparathyroidism results in
Increase PTH hence increase bone absorption to increase serum Ca
Can cause osteoporosis
Rickett’s disease presentation of bendy bones is due to
Inability to calcify collagen with hydroxyapatite hence cannot form supportive bone
Patient also have difficulty in Ca absorption from GIT
NIS is present on what side of membrane
Basolateral
To take up iodide
Spermiation is the process of
Last step of spermatogenesis whereby the spermatids is released via rupture of the cytoplasmic bridges into the lumen becoming spermatozoa
PTH is a small peptide consist of how many aa and from which aa is the biologically active bit
84 a pair prehormone and 1-34 aa has activity
Goal of PTH
Secreted due to decrease calcium in serum hence goal is to bring Ca up
PTH binds to PTHR which is a Gs coupled receptor present in the kidney and osteoclast, what does it do
Upregulates 1a Hydroxylase in kidney to convert 25hydrovitD to 1,25 deoxyhydrovitD that can act on VDR (nuclear receptor) to increase Ca absorption in gut by upregulating calbindin
Also act on osteoclast to increase bone degradation
Increase renal excretion of PO4 and increase absorption of Ca in the DCT
FGF23 function is to
Decrease serum phosphate and as a result increase Ca in serum
Suppress vitD transcription
Calcitonin action
Inhibit osteoclast activity and promote Ca uptake into bones
MCT8 is important in thyroid hormone uptake esp in what type of tissue
In neurones
TH receptor type
Type 2 intracellular receptor
Aka nuclear receptor that is already dimerised with RXR and bound to the DNA response element
Absence or mutated MCT8 causes
Allan-Herndon-Dudley disease
X linked
Severe intellect defect
Normal physiological PTH and Ca levels
PTH - 1.6-6.9pmol/L
Ca - 2.1 - 2.6 mM
The histones in sperm DNA is replaced by what to inactivate transcription
Protamine
Uterine tubal obstruction can be caused by
STIS - chlamydia - scarring
Secondary to pelvic infections
Other female tract disorders that causes infertility
Tubal obstruction due to infections (most common STIS) Endometriosis Anatomical abnomalities (septate/bicornuate uterus) Uterine leiomyomas (benign in SMCS)
Retrograde dysfunction can be confirmed by
Measuring semen in urine
What causes retrograde ejeculatiom
Dysfunctional urethral sphincter
Glucagon structure and function
29 aa peptide that is secreted in pro hormone form
Work on GPCR (Gs) that phosphorylstes FBPase2
Activate glycogen phosphorylase to convert glycogen to glycogen1 phosphate
FBPase2 (active) inhibits glycolysis and stimulate gluconeogenesis
T
Clomiphene is given for five days during the initial course of fertility treatment. How does it work
Clomiphene is an aromatise inhibitor that prevent oestrogen synthesis, allowing FSH to stimulate follicle development and also increase no of follicular development
Intrauterine insemination IUI is a method to bypass what in infertility
Bypass sexual intercourse and cervical mucous to directly inject washed sperm into the uterine space via a speculum
IVF Must undergo ovarian stimulation whereby the pituitary gland must be suppressed, how is it achieved
By giving GnRH antagonists or agonists to promote internalisation of receptors
What’s the dif between IUI and IVF
IUI doesn’t necessarily need ovarian stimulation and requires ovulation
IVF requires reset of the HPG axis and requires stimulation of much more follicles by giving recombinant FSH and hCG (mimic LH) prevent ovulation (as it has to be extracted to inseminate in a culture dish) and implanted back afterwards
ICSI = intracytoplasmic semen injection process
Same as IVF up to the insemination step. AFter extraction of eggs, sperm head is singlehandedly injected into the oocyte, bypassing the need of penetration
Where is the 99% of Ca stored
Skeleton
Function of skeleton
Mechanical support (protect organs)
Immune cell and blood cell production (from BM)
Store Ca2+
What stimulate release of Ca into bloodstream
PTH, Steroid hormone (glucocorticoid
Regulation of Ca and PO4 is r_________
Reciprocal
Why is serum Ca important
- physiological functions
Muscle contraction
Nerve conduction
Adhesion of cells
Levels of PTH in the cell
1.6-6.9 pimple/L
Where is the parathyroid gland
Posterior or the thyroid gland, embedded into it
FGF24 function
Increase excretion (decrease reabsorption of PO4) and inhibit Vit D synthesis thereby increase Ca
PTH receptor
GPCR coupled to Gs in kidney and osteoblasts
PGE2 and PGF2a function.
PGE2 - change collagen structure if cervix to a more loose structure (dermatan sulphate to keratin sulphate and increase glycosaminoglycan)
PGF2a - increase spikes and cervical correction
Why does progesterone inhibit PLA2 activity during term
Prevent PG synthesis which can promote contraction and cervical remodelling
Ferguson reflex
Postive feedback reflex that is stimulation by the increase uterine contraction and cervical distension which results in release of oxytocin thereby increasing rate and force of contraction
Prolactin milk production
Positive feedback
Suction in nipples signals release of prolactin which will act on alveolar cells to secrete milk
Oxytocin let down reflex
Positive reflex whereby the suction of nipples results in release of oxytocin from post pit which act on myoepithelial cells to contract and release milk
Colostrum colour and content
Yellowish
Rich in proteins and antibodies for protection
Mature milk content and colour
White
Rich in fat and nutrients (lactate) less proteins
Prolactin inhibits gonadotropin secretion thereby delaying
Ovulation
S/E of breast feeding
Osteoporosis
Ca required in milk
Most dynamic bone is the
Spongy bone
What hormone suppresses insulin action in mother during pregnancy
hPL
HPL is also know as the metabolic screwdriver, why is that
Suppresses insulin action
Increase plasma nutrients (metabolic screwdriver) hence increase fat and aa mobilisation
Facilitate acinar gland development