B11- Hormonal coordination Flashcards
Endocrine system
Composed of?
What do they do?
Effects compared to nervous system?
Endocrine glands, secrete hormones into bloodstream, carried to target organ to create an effect
Slower but last longer
Hormone
Chemical released into bloodstream to travel around the body
How do hormones only affect certain tissues?
Tissues have specific shaped receptors that are complementary to the hormones
Pituitary gland
Found?
3 things secretes?
Known as?
The brain
TSH which stimulates thyroids, growth hormones, FSH which stimulates ovaries and testes
Master gland, stimulates other glands
Thyroid
Found?
Controls?
Secretes?
Throat
Metabolic rate
Hormones which regulate important aspects of body, such as weight and heart rate
Adrenal
Found?
Secretes? and when?
Does what?
Kidneys
Adrenaline in times of fear, excitement and stress
Prepares body for fight/flight
Pancreas
2 things secretes?
Controls?
Enzymes for digestion, insulin
Blood glucose
Ovaries
Controls?
Secretes?
Menstrual cycle
Oestrogen, controls development of female sexual characteristics
Testes
Controls?
Secretes?
Production of sperm
Testosterone, controls development of male sexual characteristics
Negative feedback loop for thyroxine if the level rises?
Thyroxine rises–> detected by hypothalamus–> tells pituitary gland to stop producing TSH–> thyroxine level falls–> returns to optimum
TSH stands for?
Thyroxine stimulating hormone
Negative feedback loop for thyroxine if the level falls?
Thyroxine falls–> detected by hypothalamus–> tells pituitary gland to produce more TSH–> thyroxine level rises–> returns to optimum
4 ways adrenaline affects the body
Increased heart rate, increased breathing rate, increased mental awareness, glycogen turns to glucose for respiration and energy
3 differences between endocrine and nervous system
Endo- uses chemical signals, messages travel relatively slowly, goes all over the body, longer lasting effect
Nervo- uses electrical impulses, messages travel relatively quickly, goes to part of body needed only, slower lasting effect
Type 1 diabetes
Caused by?
% of diabetes cases w type 1?
Who?
Symptoms?
Immune system destroying cells that produce insulin, body doesn’t produce insulin
10%
Starts in young children/ teenagers
Going to toilet frequently, constant thirst, fatigue, losing weight
Type 2 diabetes
Caused by?
% of diabetes cases w type 2?
Who?
Symptoms?
Body cells not responding to insulin
90%
More common in older people, linked to obesity
Going to toilet frequently, constant thirst, fatigue, losing weight
Type 1 diabetes
Treatment?
Cure?
Insulin injections, carb counting, carefully planned exercise
Pancreas transplants (not enough donors and still requires medicine) More research into using stem cells
Type 2 diabetes
Treatment?
Cure?
Monitor carbs, regular exercise
Drugs or injections that help
Primary sex characteristics
Characteristics that people are born with (ovaries/testes)
Secondary sex characteristics
Characteristics that develop during puberty due to an increase in reproductive hormones
Features of both male and female puberty
Growth spurt, pubic hair growth
Features of only male puberty and hormone?
Features of only female puberty and hormone?
Deeper voice, facial hair, sperm production begins, testosterone
Breasts develop, hips widen, menstrual cycle begins, oestrogen
Menstrual cycle
Day 1-7 is called?
What happens (2) and hormone?
*Day 7-14
What happens and hormone?
Menstruation
Bleeding (a period) and egg matures in ovaries due to FSH
*Lining of uterus thickens due to oestrogen
Menstrual cycle
Day 14 is called?
What happens (2) and hormone?
*Day 14-28
What happens and hormone?
Ovulation
Mature egg is released due to LH
High chance of pregnancy
*Lining continues to thicken due to progesterone
FSH
During what days?
Produced by?
Function?
Day 1-7
Pituitary gland
Causes eggs to mature in ovaries, stimulates oestrogen
Oestrogen
During what days?
Produced by?
Function?
Day 7-14
Ovaries
Causes uterus lining to thicken, stops release of FSH, stimulates LH
LH
During what days?
Produced by?
Function?
Day 14
Pituitary gland
Stimulates release of egg
Progesterone
During what days?
Produced by?
Function?
Day 14-28
Ovaries
Maintains uterus lining, stops release of LH and FSH
Contraception
Preventing the egg and sperm cell meeting or a fertilised egg implanting in the uterus
Hormonal contraception methods
Combines pill, mini pill, implants, patch, injections
Oral pill (combined)
What?
Ad?
Dis?
Contains oestrogen and progesterone, prevents egg release
Very effective, easy to use
Must remember to take daily, has side effects
Oral pill (mini)
What?
Ad?
Dis?
Contains progesterone, no egg release
Very effective, fewer side effects than combined pill
Must remember to take frequently, side effects
Implant
What?
Ad?
Dis?
Implant under skin that slowly releases progesterone
Lasts few years, very effective
Side effects
Patch
What?
Ad?
Dis?
Stuck to skin, releases progesterone and oestrogen into blood
Replace once a week
Side effects, skin irritation
Injections
What?
Ad?
Dis?
Progesterone injected into the arm
Effective
Only last few months, side effects
Spermicides
What?
Ad?
Dis?
Gel put in vagina before sex, kills sperm
Readily available
Unreliable
Barriers (condoms, diaphragms)
What?
Ad?
Dis?
Prevents sperm meeting egg, placed over penis or cervix
No side effects, some protection from STDs
Can be damaged or let sperm through
Intrauterine device (coil)
What?
Ad?
Dis?
Structure inserted into uterus, release progesterone or prevent embryo implanting
Lasts few years, very effective
Infection, period problems
Abstinence
What?
Ad?
Dis?
Avoiding intercourse, especially around ovulation
No side effects
Very unreliable
Surgeries
What?
Ad?
Dis?
Vasectomy, cut and tie sperm ducts; cut and tie oviducts
Effective, permanent
Women need general anaesthetic
Reasons for infertility
Male?
Female?
General?
Lack of sperm in semen
Sperm not functioning correctly
*Lack of hormones resulting in no ovulation
*Damaged oviducts
-Age, eating disorders
Fertility drugs
What form?
What does it contain?
What does that do?
Hormonal injections
FSH and LH
Triggers eggs in the ovaries to mature, then triggers ovulation
IVF
Stands for?
4 steps?
In vitro fertilisation
1. Give mother FSH, stimulate egg to mature, then LH to stimulate ovulation
2. Collect eggs from ovaries
3. Fertilise them with sperm in lab or inject sperm cell directly, leave to form embryos
4. Once developed, one or two are implanted into uterus
How has modern technology helped IVF?
Microscopy allowed high magnification to work on single cells
3 advantages and disadvantages of IVF
Ads- Allows infertile people to have their own baby; eggs can be frozen and stored for later in life; genetic screening can take place before implanting
Dis- Expensive; not always successful; increased chance of a multiple pregnancy, increases risk
Def?
Tropisms
Phototropism
Gravitropism/ geotropism
-Growth of plant roots and shoots in response to light and gravity
-Growth of a plant in response to light
-Growth of a plant in response to gravity
What controls plant growth?
Produced where?
Effect on growth in the shoots and roots?
Uneven distribution of auxin
Tip of the roots & shoots
Shoots= promotes growth
Roots= inhibits growth
Def and example for
Positive phototropism?
Negative phototropism?
Towards light e.g shoots
Away from light e.g roots
Def and example for
Positive gravitropism?
Negative gravitropism?
In the direction of gravity e.g roots
Against gravity e.g shoots
In the roots, which side will grow faster?
In the shoots, which side will grow faster?
Side with less auxin
Side with more auxin
Investigating the growth of plants practical
Place 8 seeds in water-soaked cotton wool in a petri dish, repeat 2 more times.
Place one petri dish in full sunlight, one in partial sunlight and one in complete darkness.
Allow the seeds to germinate and make sure each dish has the same number of seeds.
Measure the height of the seeds every day for a week.
What 2 sectors can plant hormones be used for?
Horticulture and agriculture
Uses of auxins?
-Rooting powder to encourage growth of clones
-Weed killers, causes cells to grow too quickly and die
-In tissue cultures to help growth
Uses of gibberellins?
-Brewing industry to end seed dormancy, and speed up germination of barley
-Promote flowering throughout year
-Increase the size of fruit
Uses of ethene?
-Control the ripening of fruit during transport and storage
