B11 - Hormonal Coordination

what is the endocrine system

a number of glands which directly secrete hormones into the bloodstream

what is a difference between the endocrine system and the nervous system

in the endocrine system the effects are slower but more long lasting

what is the role of the pancreas

controls the concentration of glucose in the blood

what is the role of the ovaries and testes

releases hormones involved in puberty and reproduction

what is the role of the thyroid gland

produces growth hormones and regulates the body’s basal metabolic rate

what is the role of the adrenal galnd

releases adrenaline

what is the role of the pituitary gland

secretes several hormones in response to body conditions which stimulates other glands to produce hormones

how are blood glucose levels monitored

the pancreas monitors the levels and produces either insulin or glucagon in response

what two hormones does the pancreas produce

insulin and glucagon

what is the role of insulin

allows glucose to move from the blood into the cells to then be stored as glycogen in the liver or muscles

what is the role of glucagon

allows glycogen to be converted back into glucose and then be released back into the blood

how does glucagon interact with insulin

in a negative feedback cycle to control blood glucose levels

what happens in type 1 and 2 diabetes

1- the pancreas doesn’t secrete enough insulin to control glucose levels

2- the body stops responding to its own insulin

how can type 1 diabetes be treated

regular insulin injections

how can type 2 diabetes be treated

more exercise and a better diet to try and reverse it, however if this doesn’t work drugs may be needed

what is negative feedback

the action taken by the body to return to the optimum level and to maintain a steady state

how does thyroxine use negative feedback

if the levels of thyroxine in the blood begin to fall, TSH is released from the brain increases

what does adrenaline do

increases the heart rate, boosts delivery of oxygen and glucose to the brain and muscles

what is oestrogen

produced by the ovary and repairs the lining of the uterus

what is testosterone

produced by the testes and stimulates sperm production

what are the hormones involved in the menstrual cycle

FSH, LH, oestrogen and progesterone

where is FSH produced and what does it do

produced in pituitary gland and stimulates eggs to mature, an causes the ovary to release oestrogen

where is oestrogen produced and what does it do

secreted by ovaries, stimulates growth of lining of uterus, stimulates release of LH and inhibits FSH

what does LH do

stimulates ovulation

where is progesterone produced and what does it do

produced by the empty follicle after ovulation, maintains lining of uterus, inhibits FSH and LH

how can fertility be controlled

hormonal and non hormonal contraception

what are examples of contraceptive methods

oral contraceptives, hormonal injections, barrier methods, surgical sterilisation

how can FSH and LH be used

used as a fertility drug to stimulate ovulation in women with low FSH levels

what is IVF and how does it work

a method of fertilisation that uses FSH and LH to stimulate the maturation of eggs that are collected, fertilised and then replaced in the uterus after they begin to develop

what are the downsides of IVF

often unsuccessful, can lead to risky births, emotionally stressful

what is phototropism

the response of a plant to light

what is gravitropism

what is the response of a plant to gravity

what is auxin

plant hormone that is released to cause plant responses to light and gravity

how are plant hormones used

in agriculture and horticulture

how are auxins used

weed killers, rooting powders, tissue culture

how is ethene used

to control fruit ripening

how is gibberellins used

increase fruit size, promote flowering, increase the yield of sugar cane and end seed dormancy