b11 - hormonal coordination

Question 1

define hormone

Answer 1

large chemical released by endocrine gland. they have target tissue and produce an effect when they reach them

Question 2

define a target organ/tissue

Answer 2

destination of a hormone and the place where the effect caused by the hormone happens

Question 3

define insulin

Answer 3

the hormone released by the pancreas to lower blood glucose concentration, by making cells take in glucose from the blood

Question 4

define glycogen

Answer 4

a large chemical, made from glucose, that acts as a store of glucose in liver and muscle cells.

Question 5

define pituitary gland

Answer 5

• the ‘master gland’ of the endocrine system because, through hormone release, it can make other glands release hormones
• located in the brain

Question 6

how does the nervous system and endocrine system compare?

Answer 6

• effects caused by the endocrine
  system are slower but act for longer

Question 7

what happens when blood glucose is too high?

Answer 7

• pancreas releases insulin which causes glucose to move out of the blood and into cells
• e.g: muscle and liver cells take in glucose and convert it to glycogen for storage

Question 8

what happens when blood glucose is too low?

Answer 8

• pancreas releases glucagon which causes muscle and liver cells to convert glycogen back in to glucose and release this into the blood

Question 9

define negative feedback

Answer 9

responds when conditions change from the ideal or set point and returns conditions to this set point

Question 10

give two examples of hormones controlled by negative feedback

Answer 10

1) thyroxine
2) adrenaline

Question 11

define thyroxine

Answer 11

• produced by thyroid gland
• stimulates basal metabolic rate (baseline for speed of chemical reactions in the body)

Question 12

define adrenaline

Answer 12

• released by adrenal glands in response to being scared or stressed
• increases heart rate so more oxygen and glucose can be delivered to brain and muscles

Question 13

define reproductive hormones

Answer 13

hormones that control reproduction e.g: testosterone (males) and oestrogen and progesterone (females)

Question 14

define FSH

Answer 14

• follicle stimulating hormone
• released by the pituitary gland and causes maturation of an egg in the ovary

Question 15

define LH

Answer 15

• luteinising hormone
• released by the pituitary gland and causes release of a mature egg (ovulation)

Question 16

define uterus lining

Answer 16

• inside wall of the uterus
• this is where an embryo
  implants when it is only a few cells in size

Question 17

define maturation

Answer 17

• becoming mature
• all a woman’s eggs are in her ovary when she is born, but they must mature before they are released

Question 18

what happens during puberty?-

Answer 18

reproductive hormones cause the development of secondary sexual characterstics

Question 19

define the menstruation cycle

Answer 19

• a 28 day process to prepare the body for pregnancy

Question 20

what happens in the menstruation cycle?

Answer 20

• shedding uterus lining from previous period
• allowing an egg to mature in the ovary (stimulated by FSH)
• thickening and maintaining uterus lining in preparation for pregnancy (controlled by oestrogen and progesterone)
• releasing an egg 2 weeks after the period started (stimulated by LH)

Question 21

what are the 2 main catergory’s of contraception?

Answer 21

1) Hormonal e.g: the pill, skin patches to slow progesterone release
2) Non-hormonal e.g: barrier methods, intrauterine devices

Question 22

what does ‘the pill’ do?

Answer 22

inhibits FSH production so no eggs mature

Question 23

how do hormones interact with the menstruation cycle?

Answer 23

• FSH stimulates release of oestrogen
• high levels of oestrogen stimulate release of LH
• high levels oestrogen inhibit production of FSH
• progesterone inhibits production of both LH and FSH

Question 24

define infertility

Answer 24

unablility to concieve

Question 25

define IVF

Answer 25

- in vitro fertilisation - fertilisation happens in a lab

Question 26

define DNA

Answer 26

- chemical that makes up the genetic material in all cells - DNA is a polymer and arranged as a double helix

Question 27

define chromosome

Answer 27

- structure in cells containing one molecule of DNA - body cells contain 2 copies of each chromosome - one from each parent

Question 28

define genome

Answer 28

the entire genetic material of an organism

Question 29

define a gene

Answer 29

- a section of DNA - each gene is code for a sequence of amino acids - each gene codes for a specific protein

Question 30

how can hormone related contraceptives treat fertility?

Answer 30

fertility drugs contain FSH and LH

Question 31

how does IVF work?

Answer 31

1) FSH is injected (to help eggs mature) and LH is also given (prepare eggs for ovulation) 2) eggs are collected from ovaries once they are matured and ready for ovulation 3) in a lab, eggs are fertilised by father/sperm donor whilst in a Petri dish 4) these then grow into embryos of a few cells on petri dish 5) embryos inserted into mothers uterus (used to insert more embryos but as effectiveness increased, people began having twins or triplets which are more risky)

Question 32

name 4 disadvantages of IVF

Answer 32

- stressful, physically uncomfortable, emotional - only works less than half the time - success rate drops with age - multiple births are more likely

Question 33

why is it important to sequence the human genome?

Answer 33

1) helping the search for genes linked with certain diseases 2) understanding inherited disorders 3) using tiny differences in genetic information between people to track how humans have migrated all over the planet