practice questions Flashcards
1
Q
puberty and hormones
A
- high activity in GABA/NPY nuerons means puberty hasn’t started
- Inhibition of GABA activates release of KNDy and GnRH
- enters the pituitary gland - anterior part detects this and releases LH and FSH (gonadotropins)
- post pituitary gland then releases vasopressin and oxytocin
- gonadotropins travel to gonads where testosterone is released in response to LH in males (FSH triggers sperm production)
- forms a negative feedback system: binds to receptors in hypothalamus, inhibiting the release of GnRH and in the anterior pituitary gland gonadotropins are inhibited.
- In females FSH stimulates the follicle to ripen and LH induces ovulation.
2
Q
sexual arousal
A
- testesterone levels in men and women when sex and oestradiol determines sexual motivation in women.
- pheromones - picked up by the nose
- type of pheromones: androstadienone which is mens sweat and estratetrene in womens urine which causes activation in hypothalamus in women
- info is integrated and excites the parasympathetic nervous system which excites preganglionic neuron which releases acetylcholine which binds onto nicotine on a post ganglionic neuron which again releases acetylcholine into muscles
- causing blood vessels relax allowing more blood to enter causing erection
- sympathetic nervous system joins in the same way (acetylcholine release) when orgasm is approached but also releases noradrenaline.
3
Q
pain and pain suppression
A
- Somatosensory pathways:
- the descending analgesic pathway begins with damaged cells producing cytokines including prostaglandis which respond to inflammation
- incomming nociceptor creates a cell body in the dorsal horn of the spinal cord and create a synapse.
- Glutamate is the main neurotransmitter and substance-P as a co-transmitter (amplifier)
- the axon of that neuron runs through the other side of the spinal cord, through medulla and mid brain and makes a synapse in the thalamus.
- neurons from thalamus make synapses onto neurons in the primary somatosensory cortex which tells us where the pain is
- if message doesn’t reach brain - not pain
