seminar notes (osmosis/ fertalisation/ medicine/ effects on fetus)
osmosis- the movement of water particles through a semi-permiable membrane down a concentration gradient to an area of low concentration
diffusion- the movement of air from an area of high concentration down a concentration gradient to an area of low concentration.
concentration gradient- two areas of different numbers of particles. usually high or low
equilibrium- when both concentrations are the same.
plasma osmolarity- measurements of different solutes in plasma. help tell if amount of solutes are in the normal range
fertalisation proccess- the spermatocyte meets the oocyte in the fallopian tube after ejaculation. the spermatocyte then causes meosis 2 and a second polar body is formed, this is the cell with the least cytoplasm. the spermatocyte and oocyte then share genetic info.
where and how can fertilisation fail- the uterus and vaginal canal are acidic and can kill the alkali sperm before they reach the fallopian tube.
implantation of a fertalised oocyte- the spermatocyte has a sack of digestive enzymes that desintegrate the zona pellucida before sharing genetic information and starting mitosis.
what happens from fertalisation to implantation- first the cells in the zona pellucida undergo mitosis where they divide and multiply this is called the clevage stage, this also happens in the zona pellucida and the cells dont grow. next the cells start to look different and the outer layer of cells are called trophoblasts and the inner layer are called embryoblasts. the embryoblasts will become the fetus and the trophoblasts will become the placenta. after this the embryoblasts clump together leaving a gap in the zona pellucida, this is called a bastula, the zona pellucida also desintergrates. this proccess is called blastation. the cell is then called a blastula and implants into the uterine wall.
why implantation may fail- hormone imbalance/ immune system disorder/ infections/ uterine abnormalities/ lifestyle factors (smoking/ excessive alchohol consumption/ stress).
functions of placenta- the placents acts as a barrier between the mother ans fetus. it means that the mothers immune system wont try and attack the fetus as well as being a way for gass and waste to be exchanged. it helps give the fetus nutrience from the mother and protects the fetus from some medications the mother may be taking. finally it releases progesterone/ estrogen/ HCG/ HPL (human placental lactogen) and acts as a protective barrier physically to keep the fetus safe in the amniotic fluid.
germinal/ embryonic/ fetal stages-
Germinal stages- oogenesis: firstly the oogonium undergoes mitosis and the daughter oogonium is formed. this then grows in puberty. then the oogonium splits and undergoes meosis 1, this is the cell splitting and the cell with the least cytoplasm dies and is called the first polar body and the new cell is called the oocyte. in fertalisation the sperm stimulates meosis 2 and the oocyte splits again forming the second polar body.
spermatogenasis: firstly the spermatogonium undergoes mitosis and splits and doubles them and they are called spermatocytes. then meosis splits these cells in half and they are called primary spermatocytes. then meosis 2 happens and the primary spermatocyte splits and is renames the secondary spermatocyte. these then undergo defferintiation and are made into sperm cells.
embryonic stages- clevage: the cells undergo mitosis while not growing in size and staying in the zona pellucida.
Blastation: the cells start to change and the outer cells are trophoblasts and the inner cells are embryoblasts. the embryoblasts clump together and a gap is formed called the blastula.
gasturlation: the blastula divides and forms 3 germ layers. these are endoderm- digestive system, liver, pancreas, inner layer of lungs. mesoderm- nervous system, skeletal system, muscular system, epithelial cells of lungs. ecdoderm- hair, nails, skin, circlatory system.
neurlation- a notochord is formed and it folds and divides and becomes the spinal cord.
fetal stages- 4 weeks- cardiovascular system starts/ lumb buds start/ in a c-shape/ heart start pumping
6 weeks- start twitching/ elbow and hands/ head larger than body
8 weeks- fingers separate but webbes/ make purpose movements/ human characteristics
12 weeks- full developed/ misscarage less likely/ placenta take over hormones.
5 factors effecting growth and development of fetus- mother smoking/ mother drinking alchohol/ hormone levels/ nutrience/ maternal infections.
levothroxine-
used for- treating underactive thyroid
dossage- betwen 50/100 mg tp start and then 100/200 mg if needed. take once a day. lower dossages are available
side effects- nausea/ headaches/ diarrhoea/ shaking, usually hands/ sweating/ muscle cramps.
synthetic growth hormones-
used for- treat growth hormone deficiency, reach milestone height for age
dossage- males: 0.4-10 ng/ml, females: 1/14 ng/ml, children: 10/50 ng/ml
side effects- swelling in arms and legs/ joint or muscle pain/ enlarged breast tissue in men/ increased risk of certain cancers/ carpal tunnel syndrome.
actrapid (homan insulin)-
used for- treat diabetes
dossage- 0.3- 1 international units (IU) per kg of body weight.
side effects- loss of appetite/ low blood sugar/ pale skin/ dizziness/ shaking
combined oral contraceptive pill (COCP)-
used for- contraception/ contains progesterone and oestrogen and prevents ovaries releasing egg each month
dossage- either: everyday and 7 dummy pills are taken to give woman period/ 21-day pill where taken every 21 days and not for 7.
side effects- blood clots/ increased risk of cancer/ dizziness/ nausea/ headaches/ weight gain
HTR (oestrogen and progesterone)-
used for- help treat menopause symptoms like: hot flushes/ night sweats/ sleep problems/ mood swings/ anxiety or low mood/ vaginal dryness.
dossage- 200mg every night for 2 weeks out of 4 but can change depeding on brands
side effects- headache/ hair loss/ breast tenderness/ mood changes/ mild rash/ leg cramps.
alchohol effect on fetus- it can increase risk of misscarage/ cause fetal alcohol spectrum disorder- learning behaviours/ joint, bone, muscle, some organ issues/ ADHD/ speech issues.
smoking effect on fetus- increase risk of miscarrage and premature labour/ lower birth weight/ lung problems/ increase risk of birth defect like cleft lip or cleft palate/ can cause issues with brain development and a decrease in cognative function