Sexual behaviour

Question 1

a full sexual response cycle

Answer 1

arousal
plateau
orgasm
resolution

Question 2

neural control of sexual behaviour

Answer 2

cerebral cortex- is where the erotic thoughts occur

and the spinal cord coordinates this brain acitivity with sensory information from the genitals and garnets the critical outputs that mediate the sexual response of the genitals

Question 3

the best evidence that engorgement can be generated by a simple reflex

Answer 3

is that most men who suffer from a complete transection of the spinal cord at the thoracic or lumbar level can nonetheless have erections when mechanically stimulated

Question 4

the mechanosensory pathways from the genitals to the somatosensory system

Answer 4

axons from mechanoreceptors in the penis and clitoris collect in the dorsal roots of the sacral spinal cord

they then send branches into the dorsal horns of the cord
and into the dorsal columns through which project towards the brain

Question 5

engorgement and erection controlled primarily by axons of the

Answer 5

parasympathetic branch of ANS

Question 6

within the sacral spinal cord the parasymptathic neurones can be excited by either….

Answer 6

mechanosensory activity from the genitals (which directly cause reflexive erection)

or by axons descending from the brain (which account for responses mediated by more cerebral stimuli)

Question 7

parasympathetic nerve endings release

Answer 7

combo of ACh and vasoactive intestinal polypeptide (VIP) and nitric oxide (NO) directly into erectile tissue

causing a relaxation of smooth muscle in the arteries and the spongy substance of the clitoris and penis

the arteries become filled with blood

Question 8

viagra

Answer 8

enhancing the effect of NO (nitric oxide)

Question 9

secretion of lubricating fluids

Answer 9

from the vaginal walls and from man’s bulbourethral gland

Question 10

what triggers the process of emission

Answer 10

the sympathetic efferent axons

Question 11

process of emission in male

Answer 11

muscular contraction move sperm from storage sites near testes through two tubes (vas deferens) combine the pserm with fluids from various glands and propel the mixture (semen) into urethra

Question 12

polygyny

Answer 12

most common among mammals
1 male, many females
but female only mates with that 1 male

‘many women’

Question 13

harem (type of polygyny)

Answer 13

1 male mates with a set of females

gorillas elaphant seals

Question 14

polyandry

Answer 14

‘many men’

one female, many males

rare
but in phalarope, a shorebird that breed in cold tundra

Question 15

polygamy

Answer 15

more than one spouse

Question 16

vole species and hormones

Answer 16

praire -monogamous
meadow- polygynous

oxytocin and vasopressin

Question 17

bulbocavernosus

Answer 17

collection of spinal motor neurones at base of penis
and surrounds opening of vagine in women

penile erection
urine ejection
constricts vagina tightly
onuf’s nuleas is the motor neurone pool that controls the BC muscles (located in the sacral spinal cord)

Question 18

sexual dimorphism of the BC

Answer 18

bigger in men than women

more neurons in Onuf’s nucleus in males because their BC is larger than females

Question 19

the most distinct sexual dimorphism in mammals is

Answer 19

3rd ventricle within the pre optic area of the anterior hypothalamus

role in reproductive behaviour

lesions in rats leads to disruption of oestrus cycle in females and copulation rate in males

‘sexually dimorphic nucleus’ (of pre optic area of hypothalamus(
5-8x larger in males than females

Question 20

treating females with testosterone ealrly in development

Answer 20

means they fail to elicit the typical female mating posture: lordosis

Question 21

when a cow carries twin calves that include both male and female

Answer 21

the female calf is exposed in utero to some testosterone produced by her male twin
as an adult she’s know as a ‘free martin’
will invariably behave like a bull and be infertile

Question 22

androgen insensitivty (genetic males)

Answer 22

genetic males carrying a defective androgen receptor gene on their X chromosome
they thus have only one copy of it
males with this defective gene cannot respond to androgen
they develop normal testes and produce ample testosterone but they are outwardly female
they have a vagina a clitoris and do not menstruate
and remain infertile

androgen insensitive genentic males look and behave like they are genetically female

Question 23

congenital adrenal hyperplasia CAH (genetic females)

Answer 23

literally means overgrown adrenal glands present at birth

their adrenal glands over produce androgens
although genetically female, being exposed to abnormally high levels of circulating androgens early intheir development

they have normal ovaries and no testes at birth

but they develop external genitalia that are half way between penis and clitoris

treatment: surgically remove the penis structure

often described as aggressive/boyish