Lecture Ten Flashcards
What happens post fertilisation?
-7 days post fertilization: “Burrowing of the blastocyst into the uterine wall”
Describe a zygote, blastocyst, embryo, foetus and what is the length of pregnancy?
- Zygote – once male and female nucleus combine
- Blastocyst – first 2 weeks
- Embryo = 2 – 8 weeks
- Foetus = week 9 to birth
- Length of Pregnancy = 40 weeks
What is human chorionic gonadotropin in pregnancy?
-Human chorionic gonadotropin (HCG)
o Secreted by blastocyst and placenta
o Found in urine gives indication of pregnancy
o Stimulates growth of the corpus luteum x2 in size
= increased amounts of oestrogen and progesterone
What is human relaxin in pregnancy?
-Relaxin
o Secreted by the corpus luteum and placenta
-Relaxes the ligaments of the body
What is human placenta in pregnancy?
-Placenta
o Also secretes
-Estrogen: increase water retention and protein synthesis
-Progesterone: smooth muscle relaxation, raises body temp
What happens after 3 months to the corpus luteum?
-After 3 months the corpus luteum is no longer needed the placenta is both
o A point of exchange between the foetus and mother
o An endocrine gland that secretes hormones to maintain pregnancy
= increased levels of oestrogen and progesterone during pregnancy
Why do physiological changes during pregnancy occur?
- Why these changes occur
1. To provide a suitable environment for the growth, nutrition and development of the foetus.
2. To protect and prepare the mother for the process of pregnancy and support for the newborn.
Describe the maternal changes in cardiac position and size
-Cardiac position and size o Diaphragm pushed upwards o Apex of the heart pushed upwards and laterally o Heart enlarges by 70-80 mL -Wall thickness -Increased venous filling
Describe the maternal changes in plasma volume
-Plasma Volume
o Increases by 50% to ~3800 mL
o To accommodate the increased blood flow to the uterus and other organs
Describe the maternal changes in heart rate
-Heart Rate
o Increases by 15 bpm
Describe the maternal changes in stroke volume
-Stroke Volume
o Increases by 10%
Describe the maternal changes in cardiac output
-Cardiac Output
o Increase by 1.5 L (30-50%)
o Falls when lying supine as the uterus compresses the inferior vena cava therefore decreasing venous return
Describe the maternal changes in blood pressure
-Blood Pressure
o Mean arterial pressure decreases by 10 mmHg by 8 weeks’ gestation
o 24 weeks it will be at its lowest
o Supine hypotension syndrome
-Mother lying in supine position particularly on the left side
Describe the maternal changes in peripheral resistance
-Peripheral Resistance
o Mean arterial pressure / CO
o ~ 50% reduction
o Increase progesterone causes vasodilation = decreased resistance
What are the changes in maternal respiratory, what does it increase & decrease in?
-No change o Respiratory rate o Vital capacity -Increases in: o Tidal volume (40%) o Inspiratory capacity o Minute volume o Oxygen consumption o Ventilation – ‘over-breathing’ -Decreases in: o Expiratory reserve volume o Residual volume o Airway resistance -These increases and corresponding decreases all assist with more efficient gas mixing
What changes happen during maternity in the renal system?
-As a result of increased vascular volume:
o Kidneys enlarge (volume enlarges)
o Increases in:
-Renal blood flow (30-50%)
-Glomerular filtration rate (50%)
-Evidence of glucosuria during pregnancy
o Not an indication of diabetes
o Possibly due to less efficient tubular reabsorption
Describe the maternal changes in thermoregulation
-During pregnancy the metabolic rate increases o = increase in heat production -How does the body dissipate additional heat load? o Increase in ventilation o Increase skin blood flow -Considerations o Keep hydrated o Avoid high environmental
Describe the maternal changes in the endocrine system
-Anterior Pituitary:
o Increased plasma concentrations of Prolactin
o Placenta produces CRH and ACTH
o GH, LH, FSH are supressed
-Posterior Pituitary:
o Increased number of oxytocin receptors
-Thyroid function increases
What physical changes increase and what can centre of gravity altercations cause?
-Increased: o Weight gain to the anterior o Ligament Laxity - Relaxin o Joint mobility (hypermobility) -Centre of gravity alterations o Some contention: -Shift backwards to prevent falling -More pressure in the heels -Shift forwards with enlarged tummy and breasts o Upwards -Can cause: o Lordosis of the lumbar o Lordosis of the cervical o Protraction of the shoulders o Hyperextension of the knees o Back pain
What does the pelvic floor support?
-Layer of muscles which support the pelvic organs: o Uterus o Bladder o Bowel -These muscles can weaken
What is menopause, when does it occur, why does it happen and what are the symptoms?
-Cessation of the menstrual cycle
-When:
o 40-50 yrs of age
-Why:
o Remaining number of follicles is small
o Follicles left are less sensitive to FSH and LH
o Reduced amount of estrogen and progesterone
-Symptoms:
o Uncomfortable sweating (hot flushes)
o Anxiety
o Fatigue
o Emotional disturbances
What is the post-menopausal osteoporosis?
-Post-menopausal Osteoporosis
o 1 in 3 women
o Reduction in bone mineral density due to hormonal factors
-Reduced estrogen = increased bone loss
o Consequences increased risk of fractures
