Hormones Paper 2 Flashcards
Blood is transported to the kidney vía what artery
Renal artery
Blood leaves the kidneys via the
Renal vein
Renal artery vs renal vein
Renal artery brings blood to kidneys
Renal vein takes blood away from kidneys
What 3 things does urine contain
Excess Water
Urea
Excess ions
2 main poisonous waste products
Urea
Carbon dioxide
Where is urea made
Liver
(Ammonia is made from deamination but is toxic so is immediately converted into urea)
What is ammonia immediately converted into that can be safely excreted from the body
Urea
What is deamination
Process in liver where amino group is removed from amino acids to form ammonia
What hormone controls water concentration
ADH (secreted by pituitary gland)
3 ways body can lose water
Lungs (exhaling)
Urine
Sweating
When blood enters the kidneys via the renal artery which 4 key substances are involved in selective reabsorbtion
Glucose (all reabsorbed back into blood)
Urea (none reabsorbed back into blood)
Water (some reabsorbed back into blood)
Mineral ions (some reabsorbed back into blood)
What is selective re absorption in the kidneys
When blood passes through the kidneys all small substances (ions, water, urea, glucose) are absorbed by the tubules
Certain amounts are reabsorbed back in the blood e.g all glucose and no urea, some ions and some water to maintain normal levels of these substances in the blood
Anything not reabsorbed is produced as urine
How does kidney dialysis work
Patient attached to machine where blood passes through semi permeable membrane with dialysis fluid (normal water and mineral ion concentration and no urea) on other side
All urea diffuses out of blood into dialysis fluid
Some mineral ions and water diffuse out of blood
Concentration in patients blood returns to normal
Advantages and disadvantages of kidney dialysis
Good:
Always machine available
Bad:
Expensive
Patient must go to hospital several times a week (inconvenient)
Must have controlled diet (not too much protein)
Advantages and disadvantages of kidney transplant
Good:
Patient can have normal life
Bad:
Shortage of donors
Can be rejected by immune system (must take immunosuppressant drugs)
Facts about testosterone
Main male reproductive hormone
Produced by testes
Stimulates sperm production
What is puberty
Period in which adolescents start to develop secondary sex characteristics (e.g facial hair and breasts) which is triggered by reproductive hormones
Which hormones trigger puberty
Reproductive hormones (mainly oestrogen in girls and testosterone in boys)
Average length of menstrual cycle
28 days
4 key hormones involved in menstrual cycle
LH
FSH
Progesterone
Oestrogen
Facts about stage 1 of menstrual cycle
4 days
Menstruation occurs (bleeding)
Uterus lining breaks down
Facts about stage 2 of menstrual cycle
Uterus lining builds up and thickens
Day 5-13
What is the endocrine system composed of
Glands that secrete hormones (chemical messengers) into the bloodstream
Where does the blood carry hormones to once they’ve been secreted by the gland
A target organ where an effect is produced
Role of pituitary gland
Secretes several hormones into the blood which act on other glands to stimulate the release of other hormones and bring about effects
2 key things thyroxine is important for
Growth and development
Thyroxine controls what
Basal metabolic rate
What happens when thyroxine levels In bloodstream are low
Hypothalamus releases TRH
Causes Pituitary gland to release TSH
Thyroid gland releases more thyroxine
Thyroxine levels turn to normal
3 uses of giberellins
End seed dormancy
Promote flowering
Increase fruit size
Which plant hormone
Ends seed dormancy
Increases fruit size
Promotes flowering
Giberellins
Role of ethene plant hormone
Control ripening of fruit (during storage and transport)
Which plant hormone controls ripening of fruit
Ethene
3 uses of plant hormone auxin (not phototropism and gravitropism)
Weed killer
Rooting powder
Promoting growth in tissue cultures
Which plant hormone is used in rooting powder, weed killer and promoting growth in tissue cultures
Auxins
What is phototropism
Orientation and growth of plant in response to light
What is gravitropism
Growth of plants in response to gravity
Positive vs negative tropism
Positive- grow towards stimulus
Negatives grow away from stimulus
Name for response to light in plant stem
Positive phototropism
(Plant stem grows towards light)
Name for response to light in plant root
Negative phototropism
(Roots grow away from light)
How do auxins travel to other parts in plant from tips of stems and roots
Diffusion
Where are auxins made in a plant
Tips of growing stems and roots
Name for when plant stem grows against force of gravity
Negative gravitropism
Name for when plant roots grow in direction of force of gravity
Positive gravitropism
In the plant stem does more auxin cause more or less growth
More
In a plant root does more auxin cause more or less growth
Less
3 disadvantages of IVF
Emotionally and physically stressful
Low success rate
Often leads to multiple births which can be a risk for the mother and babies
Also some people think it’s unethical (not all embryos transferred into uterus so some are destroyed)
Expensive
2 hormones used in drug for to treat infertility
FSH
LH
How does IVF work
Mother given FSH and LH to stimulate maturation of eggs
Eggs collected from mother and fertilised by sperm from father (in a laboratory)
Fertilised eggs develop into embryos
1- 2 embryos inserted into mother’s uterus when the embryos are still tiny balls of cells
Oral contraceptive meaning
Form of contraception that contains hormones to inhibit FSH production so no eggs mature
Oral contraceptives contain hormones that inhibit the production of what
FSH
So that no eggs mature
Role of FSH (not interaction with other hormones)
Causes eggs to mature
Key example of oral contraception (contains hormones to inhibit production of FSH so no eggs mature)
Contraceptive pill
Advantages and disadvantages of contraceptive pill
Highly affective (good)
Must take it every day (bad)
2 categories for hormonal contraception
Oral contraceptives (contain hormones to inhibit production of FSH so no eggs mature e.g contraceptive pill)
Slow release of progesterone in injection/ implant/ skin patch (inhibits maturing and release of eggs)
3 examples of hormonal contraceptives that slowly releases progesterone to inhibit maturing and release of eggs
Implant
Injection
Skin patch
Advantage of implant/ skin patch/ injection (contains slow release of progesterone to inhibit eggs from maturing and being released) over the contraceptive pill
More convenient than taking daily pill
One key disadvantage of all hormonal forms of contraception (including skin patch/ injection/ implant + pill (oral contraceptive)
Don’t protect against STIs e.g HIV
Contraception meaning
Act of preventing pregnancy
(But not all forms of contraception protect against STIs)
Examples of non hormonal forms of contraception
Barrier methods (condom/ diaphragm)
Intrauterine devices (IUD)
Spermicides
Sterilisation (surgical forms)
Abstinence (no sexual intercourse)
How does an IUD work as contraception
Prevents embryo from implanting in uterus
Can release hormones like oral contraceptives
How do diaphragm and condom work as forms of contraception
Prevent sperm reaching the egg
How sterilisation (surgical forms of contraception) work
Prevents egg from reaching uterus (in women)
Prevents sperm leaving penis (in men)
How spermicides work as form of contraception
Kill/ disable sperm
Which types of contraception can cause side effects
Any hormonal types e.g oral contraceptives (contraceptive pill) and skin patch/ injection/ implant
What releases FSH and LH
Pituitary gland
Role of LH (not interaction with other hormones)
Stimulates release of mature eggs from ovaries (ovulation)
What is ovulation
Release of mature eggs from ovaries
Role of oestrogen (not interaction with other hormones)
Cause lining off uterus wall to thicken
Role of progesterone (not interaction with other hormones)
Maintains thick uterus lining
How different hormones interact with each other in menstrual cycle
FSH stimulates oestrogen
Oestrogen stimulates LH
Oestrogen inhibits FSH
Progesterone inhibits FSH and LH
(All inhibits/ stimulates mean stimulate/ inhibit the release of)
