Biology unit 2 Flashcards
to pass
where are gametes produced in men
testes
where are gametes produced in women
ovaries
where is sperm produced
seminiferous tubules
where is testosterone produced interstitial cells
interstitial cells
why does the prostate gland and seminal vesicle secrete fluid
to maintain mobility and viability of sperm
what does the pituitary gland produce
hormones FSH and LH
what produces a releaser which stimulates the pituitary gland
hypothalamus
what promotes sperm production
FSH
what hormone promotes testosterone
ICSH
what does testostosterone stimulate
sperm production
activates prostate gland and seminal vesicle
how long is the menstrual cycle
28 days
in what phase does the corpus luteum develop
luteal phase
what does progesterone promote
further development and vascularisation of the endometrium preparing for implantation if fertilization occurs.
what prevents further follicles of the ovarian hormone and pituitary gland from developing
negative feedback
what does the lack of LH lead to
degeneration of the corpus luteum
what does a drop in progesterone levels lead to
menstruation
how long are women fertile for
a few days during menstrual cycle
how long are men fertile for
continuously
by how much does a woman’s temperature rise after ovulation
0.5oC
what happens to the cervical mucus during ovulation
thins and becomes watery
by what is the treatment for infertility stimulated by
drugs that prevent the negative feedback of oestrogen and FSH secretion
what do other ovulatory drugs mimic
the action of FSH and LH
what do FSH and LH do to ovulation
cause super ovulation and can result in multiple births
why would super ovulatin be useful
to collect ova for in vitro fertilisation IVF
what is artificial insemination
when several samples of semen are collected
when is artificial insemination useful
when a male has a low sperm count
what is done when a partner is sterine
a donor may be used to provide sperm
what does ICSI stand for
Intra cytoplasmic sperm injection
what is Intra cytoplasmic sperm injection
when a man has a low sperm count
the head of the sperm is drawn into a needle and injected directly into the egg to achieve fertilisation
what does IVF stand for
In Vitro fertilisation
what is In vitro fertilisation
eggs are removed from the ovaries after hormone stimulation and the eggs are mixed with sperm in a culture dish
about 8 eggs are transferred into the uterus for implantation
name a chemical method of contraception
oral contraceptive pill
how does the oral contraceptive pill work
it’s a combination of synthetic oestrogen and progesterone that mimics negative feedback preventing the release of FSH and LH
where is FSH and LH produced
pituitary gland
what does the mini pill do
thickens the cervical mucus
what does the morning after pill do
prevent ovulation or implantation
what does antenatal screening do
identifies the risk of a disorder so that further tests and prenatal diagnosis can be offered
how many ultrasound scans is a pregnant women given
2
a dating scan (determines pregnancy stage)
a due date
when does a dating scan take place
8 to 14 weeks
what does an anomaly scan do
detect serious physical abnormalities in the fetus
when can an anomaly scan be taken
18 to 20 weeks
what other minor tests are taken during pregnancy
blood and urine
what does CVS stand for
Chorionic villus sampling
why is CVS useful
can be carried out earlier in the pregnancy than amniocentesis
what is the problem with CVS
has a higher risk of miscarriage
what is a karyotype
an individual’s chromosomes arranged in homologous pairs
what are the 4 patterns of inheritance
autosomal recessive
autosomal dominant
incomplete dominant
sex linked recessive
what is postnatal screening used for
testing for PKU
what is wrong with the genes during PKU
the enzyme which converts phenylalanine to tyrosine.
in what order does blood circulate the body
arteries to capillaries to veins
what happens to the blood pressure as if moves away from the heart
decreases
why do veins have valves
to prevent backflow of blood
what is the formula for heart rate
CO=HRxSV
what does the aorta and pulmonary vein do
pump the same volume of blood through the left and right ventricle
what are the cardiac cycle functions
diastole systole and ventricular systole
what happens during diastole
blood returning to the atrial flows into the ventricle
what happens during ventricular systole
closes the AV valves and pumps the blood out through the semilunar valves
what produces the sound of the heart
the opening and closing of the AV and SL valves
where is the pacemaker located
in the wall of the right atrium
what does the pacemaker do
set the rate at which the heart contracts
what happens to the blood pressure during ventricular systole
increases
what happens to the blood pressure during diastole
decreases
what is a typical blood pressure
120/80 mmHg
how can PKU be treated
diet with tyrosine
what is atherosclerosis
the accumulation of fatty materials (cholesterol) forming an atheroma or plaque beneath the endothelium
what happens to the artery as the arthroma grows
thickens and loses its elasticity
what is thrombosis
the formation of a clot
