Endocrine System + hormones Flashcards
What are the two responces for when your body is too hot?
- sweat is produced by sweat glands and evaporates from skin
- blood vessels supplying skin dilate so more blood flows close to surface of the skin - vasodilation
What are the four responces for when body is too cold?
- hair stand up to trap insulating layer of air
- no sweat is produced
- blood vessels supplying skin capillaries constrict to close off the skins blood supply - Vasoconstriction
- you shiver so muscles contracting need respiration producing energy to warm the body
What are hormones?
chemicals released directly into the blood
Where are hormones produced?
endocrine glands
WHat are the six types of glands?
- pituitary
- ovaries
- testes
- thyroid
- adrenal gland
- pancreas
What does the thyroid produce and whats it involved in?
- thyroxin - regulating rate of metabolism, heart rate, temperature
What does the adrenal gland produce and whats it involved in?
- adrenal, fight or flight
WHat is the pancreas involved in and what does it produce?
- insulin, regulates blood glucose levels
What is the testes involved in and what does it produce?
- testosterone, controls puberty and sperm production
What are the ovaries involved in and what do they produce?
- oestrogen, menstrual cycle
What is the pituitary gland involved in and what do they produce?
- produces many hormones
Explain what happens when blood glucose levels are too high?
- blood with too much glucose
- insulin secreted by pancreas
- too much insulin and glucose
- glucose moves from blood into liver and muscle cells
- insulin makes liver turn glucose into glycogen
Explain what happens when blood glucose levels are too low?
- glucagon secreted by pancreas
- too little glucose and glucagon
- glucagon absorbed into liver turning into glucose
- glucose released in blood by liver
- blood glucose increases
What is type 1 diabetes?
pancreas produces no or little insulin
What do people with type 1 diabetes need?
insulin therapy
What is insulin therapy?
- injections of insuling throughout the day, making sure that glucose is removed from blood quickly
What is type 2 diabetes?
person becomes resistant to their own insulin, causes a persons blood sugar levels to rise to a dangerous level
How can type 2 diabetes be treated?
eating a carbohydrate - controlled diet and getting regular excersise
What do the kidneys make?
urine
What is filtration?
substances are filtered out the blood as it passes through the kidneys
What are the three substances removed from the body in urine?
urea, ions, water
Explain urea being removed in the urine?
- proteins cant be stored in the body so excess amino acids converted to fats and carbohydrates - deamination
- ammonia produced as waste product to this but it is toxic so converted to urea where filtered into urine
Explain why ions are in urine?
- ions absorbed from food
- if ion content is wrong can upset balance between ion and water so excess is disposed in urine
- some ions are lost in sweat
Explain water loss in urine?
- loose water from sweat and lungs when breathing out
What is the concentration of urine controlled by?
anti-diuretic hormone
What is ADH released from?
pituitary gland
What is the whole water content of the blood controlled by?
negative feedback
What can be used to prevent the release of an egg
oestrogen
How does oestrogen prevent the release of an egg?
keeps oestrogen levels permanently high inhibiting production of FSH
What other chemical reduces fertility?
progesterone
How does progesterone reduce fertility?
- stimulates production of thick mucas which prevents sperm getting to egg
WHat is the pill?
an oral contraceptive containing oestrogen and progesterone
What are the advantages and disadvantages of the pill?
99% effective, can have side effects - headaches nausea and doesnt prevent STDs
What are the three barrier methods of controlling fertility?
condoms, diaphragm, spermicide
WHat are the three drastic ways of preventing fertility?
- sterilisation
- natural methods
- abstinence
What are four hormonal methods of preventing fertility?
- contraceptive patch
- contraceptive implant
- contraceptive injection
- intrauterine device
Why can some people not get pregnant?
- FSH is too low to cause eggs to mature so no eggs released
What can be given to women who cant get pregnant?
- FSH and LH can be given in drug to stimulate ovulation
WHat are the pros of FSH and LH drug?
- can get pregnant
WHat are the cons of FSH and LH drug?
- doesnt always work
- too many eggs can be stimulated, resulting in unexpected pregnancies
WHat does adrenaline do?
prepares you for fight or flight
What does thyroxin regulate?
metabolism
Where is thyroxin released from?
thyroid gland
What is the basal metabolic rate?
speed at which chemical reactions in the body occur in the body at rest
What is thyroxin released in responce to?
thyroxine stimulating hormone
WHat is TSH released from>
pituitary gland
Explain process of IVF?
- collect eggs from woman’s ovaries and injected in lab with mans sperm
- fertilised eggs are then grown into embryos in a laboratory incubator
- once tiny ball of cells, one or two transferred to woman’s uterus to improve pregnancy chance
- FSH and LH are given before egg collection to stimulate several eggs to mature
What are the pros of IVF?
fertility treatment can give infertile couple a child
what are the cons of IVF?
- multiple births can occur, risky for mother and baby
- low success rate
- emotionally and physically stressful for women
Why are some people against IVF?
- often results in unused embryos what are destroyed, unethical as it was a potential human life
- genetic testing before in-plantation as can lead to selection of preferred characteristics
What does the kidney do?
remove waste substances from the blood
What happens if your kidney doesnt work properly?
waste substances build up in the blood and you lose your ability to control the levels of ions and water in your blood
How can people with kidney failure be kept alive?
by having dialysis treatment or kidney transplant
What do dialysis machines do?
filter the blood
WHy does dialysis have to be done regularly?
to keep concentrations of dissolved substances in the blood at normal levels and to remove waste substances
Explain dialysis machine?
- persons blood flows between partially permeable membranes surrounded by dialysis fluid. Its permeable to things like ions and waste substances but not big molecules like protein
- dialysis fluid has the same concentration of dissolved ions and glucose as healthy blood
- this means that useful dissolved ions and glucose wont be lost from the blood during dialysis
- only waste substances (such as urea) and excess ions and water diffuse across membrane
How many times a week do people have dialysis?
3-4 hours
Disadvantages of dialysis?
may cause blood clots or infections.
can be expensive for NHS
What is the only cure for kidney failure?
kidney transplants
What is the risk with kidney transplants?
may be rejected by patients immune system
What do hormones do?
promote sexual characteristics at puberty
WHat happens at puberty?
body starts releasing sex hormones that trigger off secondary sexual characteristics and cause eggs to mature in women
What is the reproductive hormone in men?
testosterone
What does testosterone do?
stimulate sperm production
What is the main reproductive hormone in women?
oestrogen
What is stage 1 of menstral cycle?
menstration starts, uterus lining breaks down for four days
What is stage two of the menstration cycle?
uterus lining builds up again from day 4- 14 into a thick spongy layer full of blood vessels ready to receive a fertilised egg
What is stage three of the menstration cycle?
an egg develops and is then released from the ovary at day 14 - ovulation
What is stage four of the menstration cycle?
wall is maintained from day 14 -28
. if no egg on day 28 spongy layer starts to break down
What are the four hormones that control the menstrual cycle?
Oestrogen, FSH, progesterone, LH
Explain FSH?
- produced in pituitary gland
- causes an egg to mature in one of ovaries in structure called follicle
- stimulates ovaries to produce oestrogen
Explain oestrogen?
- produced in ovaries
- causes lining of uterus to grow
- stimulates release of LH and inhibits FSH
Explain LH?
- produced by pituitary gland
- stimulates egg release at day 14
Explain progesterone?
- produced in ovaries by the remains of the follicle after ovulation
- maintains lining in second part of cycle
- inhibits release of LH and FSH
