topic 2- sexual function Flashcards
what is appetitive behaviour?
aimed at finiding and obtaining a sexual partner
how are pheremones an external stimuli in appetitive behaviour
pheremones are molecules that trigger other responses. Detected by vomeronasal organ and the human equivalent is the olfactory epithelum.
example of pheremones
womens t-shirts smell sexier during fertile phase. androstadienone triggers alertness, good mood and sexual arousal.
how do female hormones play a role in the internal motivations behind appetitive behaviour?
females: sexual interest fluctuates with the cycle- oestradoil.
what also increases the effect of oestradoil
androgens increases the effect by 3x and this increase in T also rises with anticipation of sex.
role of hormones in sexual interest for males
suppression of testosterone reduces sexual interest and consequently anticipation of sex increases T
on the day before meeting their partner what happens to the t levels
increase by 30% supporting the increase of T in anticipation of sex
outline the 4 stages of arousal
excitement, plateau, orgasm and resolution
excitement and plateau are controlled by what system
the parasympathetic nervous system which controls our bodily functions- it is involuntary.
the PNS divides into what 2 sets of neurons?
preganglionic neurons (sit close to the target organs) and post-ganglionic neurons. Both for acetycholine
what is the function of acetycholine
increases saliva, reduces heart rate. It increases somatic function (relaxation and digestion).
the parasympathetic stimulation does what ?
relaxes the smooth muscles in blood vessels and they then expand which allows more blood to enter the genitals.
what does the increase in blood flow in genitals lead to?
penile/clitoral erection, engorgement of labia and vaginal lubrication.
what does viagra do?
it blocks the breakdown of cGMP- keeping the blood in the penis because it cannot be broken down– maintain the erection longer.
what is the function of cGMP?
messenger molecule triggered by nitric oxide that is responsible for muscle relaxation.
summarise the process of acetycholine
- neuron 1 detects a stimulus and sends it to neuron 2.
- neuron 2 sends signal to neuron 3, excitatory that activates smooth muscle.
- neuron 3 influenced by neuron 6 and 7
- neuron 3 fires- releases acetycholine- action potential for smooth muscle.
what happens if you damage the local reflex arc?
if damaged above this level will not be able to feel anything in the genetalia but able to get an erection.
what leads to erectile dysfunction?
stress leads to increased sympathetic activity = vasoconstriction. Take in less blood and erection goes away.
orgasm is controlled by what system
sympathetic nervous system = controls muscle movements.
orgasm is the triggered combination of?
local stimulation and central input.
orgasm requires the disinhibition…
by the central nervous system.
what is meant by the central inhibition of orgasm?
nucleus paragigantocellularis (nPGi) in medulla inhibits orgasm circuitry in the lumbar spinal cord. During intercourse the hypothalamus inibits the PAG which usually stimulates the nPGi.
what is satiety?
active inihibtion of sexual motivation.
what happens during orgasm?
blood oxytocin levels peak and during orgasm: prolactin is released.
