Physiology and Health Unit 2 KA 2

Question 1

What is a Hormone?

Answer 1

A Hormone is a chemical that is produced at one site, and has an effect at another site

Question 2

What produces Hormones?

Answer 2

Hormones are produced by endocrine glands and are secreted directly into the blood stream

Question 3

What happens when a Hormone reaches a target tissue?

Answer 3

When a Hormone reaches a target tissue, it brings about a specific effect

Question 4

Hormones produced in the ____ and the ____ ____ control what? (3)

(Fill in the blanks)

Answer 4

Hormones produced in the Hypothalamus and the Pituitary gland control:
the onset of puberty, sperm production, the menstrual cycle

Question 5

At puberty, the Hypothalamus secretes a releaser hormone, what is the target?

Answer 5

At puberty, the Hypothalamus secretes a releaser hormone whose target is the pituitary gland

Question 6

What three hormones does the Pituitary gland release?

Answer 6

1) Follicle-stimulating hormone (FSH) (M+F)
2) Interstitial cell-stimulating hormone (ICSH) (M)
3) Luteinising hormone (LH) (F)

Question 7

What does the hormone FSH promote in males? Where does this occur?

Answer 7

FSH promotes sperm production in the seminiferous tubules (in the testes)

Question 8

What does the hormone ICSH promote in males? Where does this occur?

Answer 8

ICSH stimulates the interstitial cells to produce testosterone (male sex hormone)
This happens in the testes

Question 9

What does Testosterone stimulate?

Answer 9

Testosterone stimulates sperm production in the seminiferous tubules, it activates the prostate gland and seminal vesicles to produce their secretions

Question 10

How is Testosterone production regulated?

Answer 10

Testosterone production is regulated by a negative feedback control

As the concentration increases in the bloodstream, it reaches a level where it inhibits the production of FSH and ICSH by the pituitary gland, leading to a decrease which then triggers the pituitary gland to produce more hormones again

Question 11

How long is the Menstrual cycle? (approx)

Answer 11

The Menstrual cycle is approximately 28 days long

Question 12

How is Menstruation indicated?

Answer 12

Menstruation is indicated by blood flow

Question 13

What are the two stages of the Menstrual cycle?

Answer 13

1) Follicular phase
2) Luteal phase

Question 14

What does the hormone FSH stimulate in females? Where?

Answer 14

FSH stimulates the development and maturation of each follicle
It also stimulates the production of oestrogen by the follicle in the Follicular phase (1st)
This occurs at the ovaries

Question 15

What does the hormone LH trigger in females? Where?

Answer 15

LH triggers ovulation and brings about the development of the corpus luteum from the follicle (after ovulation)
It also stimulates the corpus luteum to secrete progesterone (female sex hormone)

Question 16

What happens when the ovary wall secretes Oestrogen? (4)

Answer 16

As the concentration of Oestrogen builds up it stimulates proliferation (cell division) and repair of the endometrium following menstruation
2) Alters cervical mucus - becomes thin and watery so it is more easily penetrated by sperm
3) Peak levels of oestrogen stimulates a surge in the secretion of LH by the pituitary gland (approx day 14 of cycle)
4) Surge in LH triggers ovulation

Question 17

What does Progesterone do? (2)

Answer 17

1) Promotes the further development of the endometrium, preparing it for implantation
2) Inhibits the secretion of FSH and LH by the pituitary gland

Question 18

How many days are women fertile for?

Answer 18

Women are fertile for 2-3 days

Question 19

When fertilisation occurs, the Embryo secretes a hormone called HCG, what does this do?

Answer 19

HCG has the same effect as LH
It maintains the corpus luteum so it doesn’t degenerate and will continue to secrete progesterone
This prevents menstruation from taking place

Question 20

If fertilisation doesn’t occur, what happens to the Corpus luteum?

Answer 20

If fertilisation doesn’t occur the corpus luteum will degenerate because of the lack of LH
The lack of LH leads to a subsequent drop in progesterone and oestrogen
This leads to menstruation