topic 1- sex differences Flashcards
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what is the difference between neurons and neurones
within cell communication via electrically (neurons) and between cells they communicate chemically (neurones)
How action potentials generate?
actively generate across the axon, constantly triggering they do not lose strength.
what is the synapse?
the synaptic cleft is the small gap between neurons that allows them to communicate.
what is post synaptic density?
located here is the receptor molecues specific NTs for specific receptors.
EPSP (excitatory post synaptic potential)
make the neuron more likely to fire an action potential.
IPSP (inhibitory post synaptic potential)
makes the neuron less likely to fire an action potential.
what is a neurotransmitter?
from one neuron to the next, local action, effects either active or inhibit, physiological property.
what is a hormone?
through the blood stream, global action, varying effects based on combinations.
difference between gender and sex
Gender- cultural aspects & sex- biological aspects.
what does sex differentiation start with?
gametes.
what are gametes?
they are haploids not diploids, so you either get a XX or an XY (girl or boy), the presence or absence of Y chromosome.
What on the Y chromosome is responsible for the gametes to develop into male?
the SRY gene- it is responsible for turning the foetal gonad into a testis (testis-determining factor).
early testis produces what 2 types of hormones?
androgens (testosterone) and anti-mullerian hormone (defeminsing- gets rid of and disintegrates the mullerian syetm wich turns into fallopian tubes).
what hormone controls the developmental of external sex organs?
DHT0 hidyrotosterone.
what is the role of hidydrotosterone?
if present develops testes but if not then they become female and develop other organs.
what is persistan mullerian duct syndrome?
male external genitalia and internally male and female genitalia- so it masculinises and feminises the embryo are seporate so you can have both as they are independent systems.
the external genitalia of a person with androgen insensitivity syndrome are?
female- they may make androgens but there are no binding to the receptors.
what is meant by the organisational actions of hormones?
effect remains after the hromone has been removed- it is a permanent change such as sex hormones like testosterone.
define activational actions of hormones?
effect is reversible, depending on presence or absence of hormone, so testosterone has both activation and organisational effects on the body.
what is puberty?
development of sencondary sexual characterstics e.g. breast development or wider pelvis.
what affects the onset of puberty?
GABA neurons during childhood are very actively blocking the KNDy neurons which are essential for puberty and hromones. GnRH is now releasing by the hypothalamus, GnRH immediately into the blood vessels of the pituitary which releases hormones.
what is involved in the hypothalamus-pitruitary-gonad axis (feedback system)?
hypothalamua- GnRH, anterior pituitary gland, gonadotropins and gonads.
how does FSH and LH impact females and males
FSH- Females: cause follicles to ripen, male: sperm production.
LH: females; ovulation and forms corpus luteum, male: testosterone production.
how does the HPG axis function in mammals?
simple negatuve feedback system- it keeps testosterone around a set point and if it goes below than the HPG axis activates. if too much testosterone we inhibit GnRH which prevents secreting Lh and FSH
