B11 - Hormonal Coordination

What is the endocrine system?

The endocrine system is composed of glands that secrete chemicals called hormones directly into the blood stream. The blood carries the hormone to the target organ where it produces an effect.

Compared to the nervous system, what is the effects of the hormones?

Slower but longer lasting

What are the 6 key endocrine glands?

pituitary, thyroid, pancreas, adrenal gland, ovaries, testes

What is the role of the pituitary gland?

The pituitary gland is the master gland which secretes several hormones into the blood in response to body conditions. Some of these hormones act on other glands and stimulate them to release hormones to bring about specific effects.

What does the pancreas control?

Your blood glucose concentration

What does the hormone insulin do?

The pancreas produces insulin which allows glucose to move from the blood into the cells and to be stored as glycogen in the liver and muscles

What does the pancreas also produce and what does it do?

The pancreas also produces glucagon which allows glycogen to be converted back into glucose and released into the blood

How does glucagon react with insulin and why?

Glucagon interacts with insulin on a negative feedback cycle to control glucose levels.

What is the difference between type 1 and 2 diabetes?

In type 1 diabetes, the blood glucose may rise to fatally high levels because the pancreas does not secret enough insulin.

In type 2 diabetes, the body stops reacting to its own insulin.

How is Type 1 diabetes controlled?

Type 1 diabetes is controlled by injecting insulin to replace the hormone that is not made in the body

How is Type 2 diabetes controlled?

Through a carbohydrate-controlled diet and taking more exercise. If its unsuccessful, drugs may be needed

What does the hormone thyroxin do?

Thyroxine from the thyroid gland stimulates the basal metabolic rate. It is made from iodine and plays a big part in growth and development.

What does the hormone adrenaline do?

Adrenaline is produced in the adrenal glands in times of stress and fear. It increases the heart rate and boosts the delivery of oxygen and glucose to the brain and muscles, preparing the body for fight or flight.

What is the difference between the way thyroxine and adrenaline is controlled?

Thyroxine is controlled by a negative feedback cycle whereas adrenaline is not

What happens in puberty?

Secondary sexual characteristics develop

What is the hormone oestrogen?

The main female reproductive hormone which is produced in the ovary. At puberty, eggs begin to mature in the ovary and one is released every 28 days at ovulation.

What is the hormone testosterone?

Testosterone is the main male reproductive hormone produced by the testes and stimulates sperm production

What 4 hormones that are involved in a womans menstrual cycle?

follicle stimulating hormone (FSH), luteinising hormone (LH), oestrogen, progesterone

What does the 4 hormones control in a womans menstrual cycle?

The interaction of these four hormones control the maturing and release of an egg from an ovary and the build up of the lining of the uterus in the menstrual cycle.

What does FSH do?

FSH from the pituatary stimulates eggs to mature in the follicles of the ovary and the ovary to produce oestrogen

What does LH do?

Stimulates ovulation

What does oestrogen do?

Oestrogen secreted by the ovaries stimulates the growth of the lining of the uterus and the release of LH and inhibits FSH.

What does progesterone do?

Progesterone is produced by the empty follicle after ovulation. It maintains the lining of the uterus for around 10 days and inhibits FSH and LH

How can fertillity be controlled?

A number of hormonal and non-hormonal methods of contraception

Name some contraceptive methods

Oral contraceptives, hormonal injections, implants and patches, barrier methods such as condoms and diaphragms,intrauterine devices, spermicidal agents, abstinence and surgical sterillisation.

what can FSH and LH be used as?

A fertillity drug to stimulate ovulation in women with low FSH levels

What happens in Vitro Fertilisation (IVF)

IVF uses LH and FSH to stimulate maturation of eggs. they are collected and fertillised

What are disadvantages of IVF?

IVF is emotionally and physically stressful, often unsuccessful and can lead to risky multiple births

What two factors are plants sensitive to ?

Light and Gravity

What does the hormone auxin control?

The responses to Light and Gravity

What the responses of the roots and shoots to stimuli of light and gravity the result of?

unequal distribution of auxin

How does shoots grow in response to light and gravity?

Shoots grow towards light and against the force of gravity.

How does roots grow in response to light and gravity?

Roots grow in the direction of the force of gravity

What does the terms phototropism and gravitropism mean?

phototropism - the plants response to light

gravitropism - the plants response to gravity

What sectors are plant hormones used in?

agriculture and horticulture

What is auxin used as?

weed killers

rooting powders

in tissue culture

What is ethene used to control

Fruit ripening

What can the hormone gibberellins do?

Increase fruit size

end seed dormancy

promote flowering in the malting process

increase the yield of sugar cane.