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26 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What are fraternal twins also known as? Why? |
Dizygotic Because 2 separate eggs have been ovulated and fertilised |
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How long does the egg live for after being ovulated? Where is it moving through at first? |
12-24 hours Uterine tube. |
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1. How long do sperm live for? 2. What do sperm need to be fully functional? 3. What is the reaction called at the tip of the sperm? |
1. A few days. 2. Capacitation AKA exposure to seminal gland excretions & exposure to the female tract 3. Acrosomal reaction |
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1. What is the acrosomal reaction? 2. What happens to the "shell" of the egg when a single sperm enters? 3. Why does the shell change the way it does? |
1. Acrosome contains enzymes that allow the sperm to burrow in to the egg through the cells around it 2. A cortical reaction takes place whereby the zona pellucida hardens. 3. Prevents polyspermy. |
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What are identical twins also known as? What happens in this? |
Monozygotic Single egg released, divides though early in development. |
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1. What are the three stages of birth? |
1. i) Dilation of cervix. ii) Expulsion of baby. iii) Placental stage. |
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1. What is the name of the first stage of birth? 2. How long does it typically last? 3. What are the intervals? 4. What happens to blood flow? 5. What breaks? |
1. Dialation (of cervix) 2. 8 hours. Longer for first birth. Shorter for many. 3. Contractions begin @ 30 mins apart. Get shorter over time. 4. Breaks in contractions allow for blood flow. 5. "Waters". Fetal membrane ruptures. |
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What is "engagement" in the first stage of birth? What happens to the cervix during this stage? |
Dilation stage. It is when the babies head enters the pelvis. It softens, stretches, thins & dilates until it is 10cm wide. |
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1. How long does it take from full dilation until birth? What stage is this now? 2. What is happening to the uterus at this stage? 3. Where does it crown, and what happens? |
1. From 10-30 mins, +. It is the expulsion stage. 2. Contraction of myothelium. Every 2-3 minutes for 1 minute. 3. Vulva. Head extension. |
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1. What is the 3rd stage of birth? What happens here? 2. How long does it take? ** |
1. Placental. Expulsion of placental, umbilical cords & membranes. 2. 5 to 30 mins after the baby itself removed. |
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What are the (5) parts of stage 5. |
1. Uterus continues to contract for a while - oxytocin. 2. Blood vessels constrict (placental & umbilical) 3. Placental separates from uterine wall. 4. Uterine blood vessels tear, bleed. 5. Uterine contractions help constrict blood flow by constricting vessles. |
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What are the 3 stages of intrauterine development? |
pre-embryonic stage = from 0 – 2 weeks embryonic stage from 3 – 8 weeks foetal stage = from 9 weeks – birth |
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What is the name of the egg "shell" ? |
Zona Pellucida |
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What happens after fertilisation of the egg in the ovum duct? |
The egg moves down the uterine tube, dividing and dividing more as it goes. Cells eventually will "specialise" into roles in the blastocyst e.g. fetus & membrane/placenta before implanting in the uterine wall |
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What happens, in stages, when the blastocyst / early embryo implants in the uterus? (4) |
1. Secretes enzyme into function zone of endometrium 2. Errodes path in endometrium, burrows into the uterus. 3. Becomes enclosed in mothers tissue by day 10 when mothers tissue heals over it. 4. Burrowing mobilises nutrients (glycogen). |
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What are the three trimesters characterised by? |
1st: major organ system appear. embryonic + early foetal. 2nd: Development of organs + organ systems. 3rd: rapid growth, most organs fully functional. |
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What happens to the mother's circulatory system when she is pregnant? (4) |
1. Blood flow to placenta limits systemic blood flow 2. Fetal metabolic activity reduces blood PO2 and increases blood PC02 3. Stimulates erythropoietin from kidney 4. maternal blood volume up by 30-50% at full term. |
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What happens to the mother's kidneys during pregnancy? (2) |
1. GFR is up by 50% because of increase in blood volume 2. Wastes from foetal metabolism excreted |
Pregnant women need to pee more: GFR up + fetus pressing on bladder |
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What happens to the mother's respiratory system during pregnancy? (3) |
1. More 02 needs as metabolic rate is up 2. increased tidal volume, deeper breathing 3. Mum more sensitive to c02 because of progesterone, meaning the co2/breathing reminder is set lower making diffusion easier |
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1. What hormones help the mammary glands develop during pregnancy? (3) 2. What is milk called for the first few days? What does it contain? |
- progesterone - prolactin - oestrogen 2. Colostrum. Contains antibodies for passive immunity of baby. |
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What happens to the G.I. tract of a mother? (2) |
1. Nausea + vomiting + heartburn 2. Constipation. Progesterone suppresses smooth muscle, interfering with motility of GI tract. |
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What happens to the metabolic rate of a mother? (4) |
1. Requirement for nutrients climb 10 to 30% 2. BMR may climb by 15% 3. may feel overheated 4. Effort of carrying extra weight |
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What are the key hormones involved in the lead up to birth + birth? (5) |
1. Oestorgen 2. Oxytocin 3. Cortisol 4. Prostaglandin 5. Relaxin |
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1. What does oestrogen do in the preparation/lead up to birth? (2) 2. What does relaxin do? (2) |
1. Increases sensitivity of myometrium & increases sensitivity to oxytocin. (2) 2. Dilates cervix & relaxes pelvic articulation (2) |
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How is birth induced, do they think? (3) |
1. Foetus may trigger birth via releasing cortisol & oxytocin 2. Stretching: cervix + myometrium. Any stretching of smooth muscle makes it increase its contractions. 3. Feedback loop of babies head on cervix |
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Where is oxytocin released from during the positive feedback mechanism of birth? (2) |
1. Posterior pituitary + 2. Uterine wall |
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