Miscellaneous Flashcards
Round ligament of the uterus
Remnants of the gubernaculum. Embryonic structure - guides the descent of ovaries from abdo to pelvis
URACHUS
remnant of channel between bladder and umbilicus (attached to the apex of the bladder)
Urachus is the one that if it’s still patent at birth you get urine leaking through the umbilicus
Forms from allatoniss which connects the ys to hind gut until week 8
Cancer derived from which layers
Carcinomas are derived from endoderm or ectoderm
Sarcomas are derived from mesoderm
Leukaemias are a class of sarcomas that grow as individual cells in the blood
Prostaglandins, what are they made of and how do they work (which receptor)
All prostaglandins are synthesised from arachidonic acid, a polyunsaturated fatty acid.
Prostaglandins exert their effects on target cells via G protein coupled receptors on the cell surface.
Uterine contractant molecules
Oxytocin – peptide molecule from then uterus
Prostaglandins – specifically F2a
Both of these activate phospholipase C à Increasing intracellular Ca2+ and activation of myosin light chain kinase and calmodulin dependent protein kinase à increase force of myometrial contraction.
The stimulation of myometrial contractions is augmented by the fact oxytocin can stimulate uterine prostaglandin synthesis.
Uterine relaxant molecules
The major myometrial relaxant is progesterone, which impairs the synthesis and action of both oxytocin and prostaglandin. Progesterone decreases operation of gap junctions.
The actions of progesterone are supplemented by the relaxant actions of:
Nitric oxide
Relaxin
Prostacyclin
At term, there is a decline in placental progesterone output.
Calcium - how does it be in the body
Ca2+ - 99% stored in skeleton as hydroxyapatite. 1% is present intracellularly – calcium is not free in the cytoplasm but sequestered in intracellular organelles.
Normal serum concentration = 2.2 – 2.6 mmol/l
Most Ca ingested is absorbed by small intestine.
Calcium regulation
3 HORMONES
PTH and vit D which increase serum Ca concentrations
Calcitonin which reduces Ca .
LOW LEVELS
The concentration of Ca is detected by the Ca sensing receptor on the parathyroid glands.
In response to low Ca, parathyroid hormone (PTH) is released.
It acts on the bone to stimulate bone resorption.
In the kidney PTH promotes resorption of Ca and excretion of phosphate (PO43-). It also increases the activity of the enzyme 25-hydroxyvitamin D3 1a hydroxylase, which catalyses the conversion of calcidiol to its active metabolite calcitriol.
Calcitriol increases bone turnover, increases absorption of Ca from intestine and enhances Ca + phosphate reabsorption in the kidney, resulting in an increase in serum Ca concentration.
Ca and calcitriol provide negative feedback to the parathyroid gland to inhibit further secretion of PTH.
HIGH LEVELS
Calcitonin produced in the thyroid gland acts to decrease the serum Ca concentration and is secreted in response to hypercalcaemia. It inhibits renal Ca and phosphate reabsorption and osteoclastic bone resorption.
PTH what does it do
PTH acts on the bone and kidney. In the bone is causes bone resorption and Ca and phosphate release .
In the distal convoluted tubule it increases Ca reabsorption.
PRimary hyper PTH
Caused by a defect of the parathyroid glands – normally benign tumour.
Increased PTH and calcitriol
Decreased phosphate
Hypercalcaemia
The increase in calcitriol and decrease in phosphate indicate that the kidneys are functioning. Individual cells respond normally to feedback signals but the increase in cell numbers means that PTH is released in excess.
Secondary hyper PTH
Defective feedback – usually defect is in the kidneys caused by CKD.
In renal disease, kidney can’t respond to PTH so renal absorption of Ca is not stimulated and vit D activation in s not promoted. As a result Ca absorption from intestine cannot be increased on demand. One consequence is that bone is the only place PTH can act to increase serum Ca levels. The resulting loss of Ca from bone causes high bone turnover, osteomalacia and CKD.
As a result of failure to increase serum Ca and lack of vit D signalling the normal negative feedback on the parathyroid glands is absent and they continue to secrete PTH. Results in hyperplasia and parathyroids lose their sensitivity to Ca and vit D.
Ultimately will progress to tertiary hyperparathyroidism.
Viruses class DNA/RNA ss/ds
RNA
SS:
Hep A/C/D/E
Rubella
HIV
DS:
Rotavirus
DNA
SS:
Parovirus 19
DS:
Hep B
CMV
VZV
HSV1/2
EB
HPV
70 HPV
70% of hpv cleared in 1 year (90 by2)
70% of cervical ca caused by hpv
