2.2

Question 1

what are and what produces hormones

Answer 1

they are chemical messengers and are produced by endocrine glands

Question 2

what do hormones do in general

Answer 2

they are secreted into the bloodstream and travel to their target tissue where they bring about a specific response

Question 3

what do hormones control in reference to reproduction

Answer 3

• the onset of puberty
• sperm production
• the menstrual cycle

Question 4

what is puberty

Answer 4

the sequence of physical changes in which a child’s body develops into an adults, capable of reproduction

Question 5

what happens at puberty

Answer 5

the hypothalamus secretes a releaser hormone that targets the pituitary gland

Question 6

what does the releaser hormone secreted by the hypothalamus (during puberty) stimulate the pituitary gland to release

Answer 6

1. follicle stimulators hormone (FSH)
2. luteinising hormone (LH) in women
   & interstitial cell-stimulating hormone (ICSH)

Question 7

what does fsh promote

Answer 7

sperm production in the seminiferous tubules

Question 8

what does icsh stimulate

Answer 8

the interstitial cells to produce testosterone

Question 9

what does testosterone stimulate and activate

Answer 9

the seminiferous tubules to produce sperm and activates the prostrate gland and the seminal vesicles to produce secretions

Question 10

when do males stop releasing fsh and icsh

Answer 10

they don’t, they release these hormones from puberty

Question 11

what type of fertility do men have and what does it mean

Answer 11

continuous, means they are always fertile

Question 12

what type of fertility do women have & what does it
mean

Answer 12

cyclical, means they are only fertile a few days a month

Question 13

what happens during negative feedback control of testosterone

Answer 13

high concentrations of testosterone inhibit the pituitary gland from secreting FSH and ICSH so interstitial cells produce less testosterone

Question 14

how long does the menstrual cycle take

Answer 14

around 28 days

Question 15

what are the two halves of the menstrual cycle

Answer 15

1st half - follicular phase
2nd half - luteal phase

Question 16

what happens in the follicular phase

Answer 16

• fsh stimulates development of follicle and production of oestrogen by the follicle
• oestrogen stimulates proliferation of the endometrium to prepare it for implantation. it also affects the consistency of cervical mucus, making it more easily penetrated by sperm
• around day 14, peak levels of oestrogen stimulate a surge in secretion of LH by pituitary gland
• surge of LH triggers ovulation which is the release of an egg from follicle in ovary
• the ovum moves slowly along oviduct and in next 3-4 days fertilisation may occur

Question 17

what happens in the luteal phase

Answer 17

• LH also stimulates the follicle to develop into the corpus outrun which secrets progesterone
• progesterone promotes further development and vascularisation of the endometrium, preparing it for implantation of a blastocyst if fertilisation occurs
• progesterone causes thickening of cervical mucus, preventing sperm from meeting and protecting the blastocyst from infection

Question 18

negative feedback (women)

Answer 18

• high levels of progesterone inhibit the secretion of FSH and LH by the pituitary gland
• lack of FSH prevents further follicles from developing
• lack of LH leads to degeneration of the corpusluteum which has a subsequent drop in progesterone levels
• by day 22, these hormones levels are so low that the endometrium breaks down and triggers start of menstruation

Question 19

what happens to prepare the body for pregnancy

Answer 19

• the corpus luteum doesn’t degenerate and continues to produce progesterone, which maintains the endometrium and prevents miscarriage
• the placenta then takes over the production of progesterone a few weeks into pregnancy