Case 8 Flashcards
What is the function of Cooper’s Ligaments?
Fibrous connective tissue which supports the breast.
What type of epithelium are acini cells?
Columnar
What is the function of acini cells?
Produce milk
What is the function of myoepithelial cells?
Contract to eject milk
What effect does puberty have on the breast?
Elongation and bifurcation (branching) of lactiferous ducts, formation of spherical masses at the end of each duct, development of immature alveoli, increased fat deposition.
Human Placental Lactogen
Reduces maternal insulin sensitivity.
Reduces maternal glucose utilisation.
Increased lipolysis with release of free fatty acids.
Increases availability of glucose for the foetus.
Why do women suddenly produce milk following miscarriage/abortion?
Large amounts of progesterone and oestrogen inhibit prolactin during pregnancy.
These hormone levels fall suddenly following miscarriage/abortion.
Where is milk stored during pregnancy?
Cannot be stored, it is absorbed into the blood.
How is milk production prevented in women following miscarriage/abortion?
Dopamine agonist
Which immunoglobulin is found in breast milk?
IgA
What is the effect of dopamine on prolactin?
Inhibitory
What is the effect of oxytocin on the lactating breast?
Contraction of myoepithelial cells
What stimuli cause release of oxytocin?
Suckling
Mother hearing the sound of crying
How does oxytocin cause contraction of myoepithelial cells?
Binding to its receptors causes an increase in intracellular calcium.
How long must suckling cease for, for milk production to stop?
2-3 weeks
Colostrum is high in…
Protein, minerals, vitamins A, D, E and K, immunoglobulins.
Meconium
Earliest stool
What important immunological effect does lactose have on the gut of the neonate?
Promotes growth of the intestinal flora.
What is the function of Alpha Lactalbumin?
Regulatory subunit of lactose synthase. Transfer of galactose moieties to glucose.
Promotes growth of bifidobacterium (intestinal bacteria)
Immunoglobulins found in breast milk:
IgA, IgG, IgM
What is the role of lactoferrin found in breast milk?
Iron Chelation
Blocks adsorption/penetration of viruses (rotavirus)
Blocks adhesion of bacteria (e.g. Vibriocholerae, E. Coli)
Promotes intestinal growth and repair
Immune modulation(reduces production of IL-1,2,6 and TNF-alpha
What is the function of lysozyme found in breast milk?
Inhibits endotoxin
Macrophage activation
Bacterial cell wall lysis
Increases IgA production
What is the function of casein found in breast milk?
Inhibits adhesion of bacteria
Promotes growth of bifidobacterium (intestinal bacteria)
What is the function of oligosaccharides in breast milk?
Prevent adhesion of common respiratory pathogens to respiratory epithelium (e.g. haemophilus influenzae, streptococcus pneumoniae)
What sort of fibres are involved in pain during Stage 1 of labour?
C fibres (slow, unmyelinated)
What vertebral levels are involved in pain during stage 1 of labour?
T10-L1
Which nerve plexi are involved in pain during stage 1 of labour?
Hypogastric
Paracervical
Lumbar sympathetic chain
What type of pain is felt during stage 1 of labour?
Cramping, poorly localised, Visceral pain
What type of pain is felt during stage 2 of labour?
Well localised, sharp, somatic pain
Which nerve plexi are involved in pain during stage 2 of labour?
Lumbosacral plexus and pudendal nerves
What vertebral levels are involved in pain during stage 2 of labour?
T10-L4
What sort of fibres are involved in pain during stage 2 of labour?
A delta fibres (fast, myelinated)
What are the effects of entonox?
Analgesia, euphoria, anxiolytic, sedatory
MOA of Pethidine
Mu-opioid receptor agonist
Why are NSAIDs contraindicated in pregnancy/labour?
Cause neonatal haemorrhage due to thrombocytopenia
Interfere with prostaglandin synthesis (important for uterine contraction)
MOA of Entonox
Stimulates endogenous endomorphin and endomorphin secretion
Composition of Entonox
50% N2O and 50% O2
ADRs of Entonox
Nausea and vomiting
B12 inactivation with prolonged use
may be neurologically toxic
Contraindications of Entonox
Pneumothorax or other air cavity injury
What is the name of the active metabolite in pethidine?
Norpethidine
ADRs of Pethidine
Biliary Spasm Bradycardia Confusion Constipation Dependence
MOA of Pethidine
Mu-opioid receptor agonist
+ Postsynaptic Potassium efflux, hyperpolarisation prevents pain transmission
Route of administration of Pethidine as a labour analgesic
I/M injection
Contraindications for Pethidine
Acute respiratory depression
Head injury
MOA of Bupivacaine
Sodium channel blocker in nociceptive axons - prevents transmission of action potential to CNS
Route of administration of Bupivacaine
IV injection
ADRs of Bupivacaine
Convulsions, cardiac arrhythmias, dizziness
Contraindications of Bupivacaine
Cardiac arrhythmia
What are the benefits of fentanyl over pethidine?
Same effect (mu-opioid R agonist) but with less potential for drug interaction
MOA of fentanyl
Mu-opioid receptor agonist - suppresses presynaptic GABA release
ADRs of fentanyl
Biliary Spasm Bradycardia Confusion Constipation Dependence
Contraindications of Fentanyl
Acute respiratory depression
Head injury
What is the negative impact of opiates on labour?
Prolongs labour time
Which structures are penetrated when providing an epidural?
Skin, Subcutaneous tissue, supraspinous ligament, interspinous ligament, ligamentum flavum –> epidural space
When is an epidural given?
When cervical dilatation has reached 4-5cm
Which drugs can be given epidurally?
Bupivacaine and some opiates
What are the benefits of epidural administration of analgesia?
Prolonged effect and can be topped up
Minimal foetal transfer of drugs
Continued mobility - still able to push
What is the disadvantage of epidural compared to spinal analgesia?
Slower - effects reached 15-20 minutes after administration (cf. 5-10 minutes)