B11 Hormonal Coordination Flashcards
What is hyperglycema?
When the glucose level in the blood is too high.
What is hypoglycema?
When glucose level in the blood is too low.
What happens when glucose level in the blood is too high?
When blood glucose is too high, cells start to lose water by osmosis and undergo crenation.
What happens when the level of glucose in the blood is too low?
When the glucose level in blood is too low, cells can’t respire efficiently to release energy.
How does the body control hyperglycema (too high glucose level in the blood)?
1) High glucose level in blood is detected by the pancreas
2) Pancreas releases insulin hormone into blood
3) Blood transports insulin to its target organs
4) Liver converte glucose into glycogen and it’s stored in the liver
5) Muscles start to respire faster to use up more glucose
Glucose level in blood decreases
How does the body control hypoglycema (low levels of glucose in the blood)?
1) Low level of glucose in the blood is detected by pancreas
2) Pancreas releases glucagon in the blood
3) Blood transports glucagon to targeted organs
4) Liver converts glycogen into glucose and it’s released
5) Muscules start to respire at a slower rate so less glucose is used
Glucose level in the blood increases
What is type 1 diabetes?
This is a genetically inherited and is classified as an ‘auto-immune’ disease, so anti-bodies are produced to damage the pancreatic cells meaning that there is not enough insulin being produced
What is an auto-immune disease?
When white blood cells can’t distinguish on cells and they produce antibodies to damage those cells.
How is type 1 diabetes treated?
It is treated by injecting insulin hormone into the body.
What is type 2 diabetes?
When target cells ,such as muscles and liver cells, don’t respond to insulin.
How is type 2 diabetes controlled?
- Less intake of carbohydrates
- Exercise
- Medicine
What is the role of the hormone produced by the pituitary gland?
- Controls growth in children
- Stimulate thyroid gland to make more thyroxine
- Stimulates the ovaries to produce/release eggs and oestrogen
- Stimulates testes to make sperm and testostrone
What is the role of the hormone produced by the thyroid gland?
Controls metabolic rate of the body.
What is the role of the hormone produced by the pancreas?
Controls level of glucose in the blood.
What is the role of the hormone produced by the adrenal gland?
Prepares the body for stressful situations - eg. the flight or fight response
What is the role of the hormone produced by the ovaries?
Controls the development of the female secondary characteristics and is involved in the menstrual cycle.
What is the role of the hormone produced by the testes?
Controls the development of the male secondary characterists and is involved in the production of sperm.
Where is adrenaline secreted from?
From the adrenal glands, above the kidneys
What happens to the body when adrenaline is released into the body.
- Increases heart rate
- Increases breathing rate
- Blood circulation is deviated from less important organs
- Pupils dialate
- Breaking down of glycogen
Why does the heart rate increase when adrenaline is released?
To pump out more blood to muscles so they can receive more glucose and oxygen for increased respiration.
Why does the breathing rate increase when adrenaline is released into the body?
To provide more oxygen by inhalation and to get rid of more CO2 by exhalation.
Why is the blood circulation deviated from less important organs when adrenaline is released?
Blood circulation is deviated from less important organs ,such as; the digestive system, reproductive organs, so there is more blood for the important organs such as brain and muscles.
Why do pupils dialate when adrenaline is released?
To let more light it.
Why is glycogen broken down when adrenaline is released?
Broken down into glucose and is released into the blood for more energy.
How is thyroxine secreted?
By the thyroid gland using iodine and thyrosine amino acids.
What does the thyroxine hormone control?
Basal Metabolic Rate (rate of all chemical reactions in living organisms)
What are the two type of metabolic reactions?
Anabolic (synthesis)
Catabolic (breaking down)
What metabolic reaction is always occuring in the body?
Respiration.
How does the body control a low rate of respiration?
1) Hypothalamus detects low-level of energy in cells and it sends signals to pituitary gland
2) Pituitary gland secretes more TSH into the blood
3) Blood carries more TSH in thyroid gland
4) Thyroid gland secretes more thyroxine into blood
5) Thyroxine increases rate of respiration in cells
How does the body control a high rate of respiration?
1) Hypothalamus detects high-level of energy in cells and sends signals to the pituitary gland
2) Pituitary gland secretes TSH inhibitor
3) Blood carries less/none TSH in thyroid gland
4) Thyroid gland secretes less/none thyroxine into the blood
5) Rate of respiration decreases
What is a hormone?
A chemical produced and released by endocrine glands which are released into the bloodstream
What is the role of FSH?
- Causes the egg to mature
- Stimulates oestrogen to be released
What is the role of LH?
- Triggers ovulation
What is the role of Oestrogen?
- Causes the lining of the uterus to develop
- Stimulates release of LH
What is the role of Progestrone?
- Maintain the lining of the uterus
- Inhibits FSH and LH
What is the hormone cycle during menustration?
- The pitutary gland secretes FSH which causes an egg to mature
- FSH causes the ovary to secrete oestrogen
- Oestrogen causes pitutary gland to secrete LH which causes the egg to be released from the ovary
- Progestrone is released and inhibits both LH and FSH
How do oral contraceptives work?
They contain hormones to inhibit FSH production so that no eggs mature
How do conctraceptive injections,implants or skin patches work?
They provide a slow release progesterone to inhibit the maturation and release of eggs for a number of months or years.
How do contraceptive barrier methods work?
They prevent the sperm reaching the egg
How do intrauterine devices work?
It is inserted into the uterus to release copper atoms gradually and to kill sperm cells.
-this can be effective up to 10yrs
How do spermicidal agents work?
They kill or disable sperm
What is the role of the pituitary gland?
- acts as the master gland
- controls child growth
What is the role of the thyroid gland?
Controls metabolism
What is the role of the pancrease?
Controls blood glucose level
What is the role of the adrenal gland?
Controls fight or flight response
What is the role of testostrone?
Promotes male secondary characterisitucs and stimulates sperm production.
What is a tropism?
The directional growth response in which the direction of the response is determined by the direction of the external stimulus.
What is a positive tropism?
A growth response towards the stimulus
- e.g. Light
What is a negative tropism?
A growth away from the stimulus
- e.g. Gravity
Give two examples of an anabolic reaction.
- Protien synthesis
- Photosynthesis
Give two examples of a catabolic reaction.
- Respiration
- Digestion
What is a vasectomy?
The surgical process which is used to block or cut the sperm ducts.
What is tubal ligation?
The surgical process which is used to block or cut the fallopian tube
What are three factors which cause infertility?
- Low hormone concentration
- Low sperm count
- Wrong shape of sperm (unhealthy)
What is the process of IVF (Invitro Fertilisation)?
1) Female is treated with FSH and LH to stimulate maturation and ovulation
2) Egg cells are extracted and transferred to petridishes
3) Each egg cell is fertilised by sperm cells to form zygotes and embryos
4) Embyos are examined for their growth and inhertiance of genetic diseases
5) One or two healthy embryos are transplanted back to mother’s uterus
During IVF, what kind of nutrients will the petridishes contain?
Vitamins, amino acids, glucose, etc.
What are the advantages of IVF?
- can be used anytime
- can be used as a fertility treatment
- safe
What are the disadvantages of IVF?
- expensive
- low sucess rate
- high stress
- surgery required
What occurs in the shoots and roots during phototropism?
- Shoots have positive tropism (towards light)
- Roots have negative tropism (away light)
What is phototropism?
A plant’s growth response towards light
What is geotropism?
A plant’s growth response towards gravity
What is the benefit of positive phototropism?
To maximise amount of light received for photosynthesis
What is the benefit for negative phototropism?
Less chance of drying out
What happens during positive phototropism in the shoots?
1) Auxin hormone is produced in the shoot tips
2) Auxin diffuses down to zone of elongation
3) Auxin moves away from light
4) The higher the concentration of auxin the faster the cell elongation
5) Therefore shoot bends towards light
What occurs in the shoots and roots during geotropism?
- Shoots have negative tropism (away gravity)
- Roots have positive tropism (towards gravity)
Why is positive geotropism important for plants?
To get more water and nutrients from the soil
What happens during positive geotropism in roots?
1) Auxin hormone is produced by the root tip
2) Auxin diffuses into zone of elongation
3) Auxin moves towards gravity
4) The higher the concentration of auxin the slower the cell elongation
5) Therefore root bends towards gravity
What are commercial uses of auxin?
- selective weed killer
- root powder
- added to growth medium in tissue culture
How is the hormone auxin used in selective weed killer?
- Plants with broad leaves absorb herbicide with a high concentration of auxin
- High auxin level increases it’s metabloic rate
- Plant can’t tolerate high metabolic rate and dies
What are herbicides?
Chemicals used to kill unwanted plants which compete with crops
How is auxin used in root powder?
Plants cuttings are used to make identical plants in asexual reproduction. These plant cuttings are placed in rooting powder to stimulate root formation
What is gibberellin?
Hormone required for stem elongation in plants
What are uses of the hormone gibberellin?
- making seedless fruit
- making fruit bigger
- to break dormancy in seeds
- increases flowering in plants
What is ethene?
A gaseous hormone which stimulates the rippening of fruits.
What is a commercial use of ethene hormone?
Fruits are harvested unripe and then fed ethene near selling time to ripen.
If three plants were put under No sunlight, Partial sunlight and Full sunlight, which would grow the tallest in a given time?
The plant with no sunlight will grow the tallest as seedlings grow rapidly in the dark trying to reach the light.
However it’s leaves will appear small and yellow due to lack of photosynthesis
What are the independant variable in the Effect of Light in Plants practical?
Light intensity
What are the dependant variable in the Effect of Light in Plants practical?
Height of seedlings
What are the control variable in the Effect of Light in Plants practical?
- Type of seeds
- Amount of water
- Amount of seeeds
- Average temperature of surroundings
What is negative feedback?
