slide 10 : reproduction hormonal and neural bases

2 purposes of the gonads

production of gametes and steroid hormones

male gametes

sperm

female gametes

eggs

gonads are required for the development of the

body and the brain, production of gametes, and encouraging behaviors that bring gametes together

male gonads is the ______ and the primary steroid produced is ______

testes and testosterone (androgen)

female gonads is the ______ and the primary steroid produced is ______

ovaries and estrogens

what controls reproduction success

hormones

hormones that lead to the development of gametes are the same ones that

allow for the behavior to occur

gonad steroids activate

reproductive behavior

circulating gonadal steroid hormones act upon the neural circuitry already in place in the brain and are

required for males and females of many species to engage in sexual activity

gonadectomy

eliminates sexual interest and behavior

female rats ovulate every ___________ days with the _______ cycle

4-5 days and the estrous cycle

the estrous cycle is controlled by the hormones in the

hypothalamic pituitary gonadal axis

gonadotropin releasing hormone stimulates the

anterior pituitary to release follicle stimulating hormone and the luteinizing hormone

FSH acts on the ovary to cause development of the

follicle (egg)

estradiol acts to increase

further LH secretion and leads to a surge of LH that causes ovulation

increase in progesterone inhibits the hypothalamus from

releasing more GnRH

progesterone drops when the egg

isn’t fertilized and the cycle starts over again

rise in estradoil and progesterone during the ovulatory cycle is important for

increasing female receptivity and motivation for sex during behavioral estrus

female in estrus exhibit lordosis when

male mounts her allowing for copulation to occur

female not in estrus will _______ a male that tries to make an advance

fight

the hormones that lead to ovulation in females are the same ones that increase her

receptivity and motivation

oral contraceptives contain synthetic

progesterone that inhibit the release of GnRH so no egg is released

in males, the hypothalamic cells relseases GnRH in a

steady fashion

GnRH in men results in the testes producing

testosterone in the leydig cells and sperm in the sertoli cells

a castrated male lose interest in mating because

testosterone is no longer produced

for nonseasonal breeder, a higher level of testosterone does not

increase sexual behavior

estrogen stimulates the production of

progesterone receptors

the ventromedial hypothalamus (VMH) is crucial to the

lordosis response through steroid actions

as the male mounts, the sensory information that comes in via spinal cord combines with the information from the

brain and the female exhibits lorodosis

The VMH sends axons to the periaqueductal gray in the midbrain that projects to the

medullary reticular formation in the hindbrain (this projects to the spinal cord through the reticulospinal tract)

male copulatory behavior is coordinated by the

medial preoptic area

pheromones

chemical signals that communicate information between animals of the SAME species to help coordinate their reproductive behavior

vomeronasal organ by olfactory epithelium detects pheromones, which

activate male arousal

____________ appears to increase sexual motivation in women too

testosterone