homeostasis: Hormonal coordination in humans Flashcards
what does the endocrine system consist of?
the endocrine system consist of:
* glands which secretes chemicals called hormones directly into the blood stream
what is a hormone?
a hormone is a chemical messenger secreted by the gland and it travles in the blood to a target organ where it causes a response
compare the endocrine system to the Ceneteral nervouse system?
- the endocrine system uses chemical called hormones hwich are carried into the blood stream and the centeral nervouse system uses electricsl signals which travel through nuerons
- CNS produces fast effect, endocrine is very slow but is more long lasting.
what is the pitutary gland?
the master gland which secretes several hormones into the blood in resposnse to the bodys conditions
where is the pitutary gland based?
in the brain
why is the pituatary gland called the master gland?
this is because the hormones which it secretes act on other glands to stimualte other hormones to be releases to bring effect.
what is the role of the pitautary gland? what does it stimulate and control
- controls human growth
- stimulates the thyroid gland
- stimualtes the ovulation
what is the role of the pancrease?
seceretes hormone insulin and glucagon and controls blood glucose level
what is the role of the throid gland?
it secretes the hormone thyroxine, controls the metabolism, heart rate and body temp
what si the role of the adrenal gland?
secretes adrenaline, controls the bodys flight or fight response
what is the role of the ovaries?
secretes oestregon, which coordinates the mentral cylcle and devolpment of the female secondary sexual characteristics
what is the role of the testes?
secretes testosterone, which coordinates the prodcution of the sperm and the devoplemt of the male secondary charateristics
on this diagram label everything
which organ monitors the blood glucose concentration?
the pancrease
how does insulin control the blood gluscose level in the body?
high blood glucose level
- the pancrease produces hormone called insulin
- insulin causes the glucose to move from the blood into the cells
- insulin triggers the liver and muscle cells to store excess glucose
excess glucose is converted to glycogen and stored for storage
how does the body handle low blood glucose level?
- glucagon is secreted by the pancrease
- glucagon triggers and makes the liver cells turn glycogen into glucose
- glucose released into the blood by liver
- blood glucose level increased
glucagon and glycogen are different wordss
what is type 1 diabetes?
type one diabtets is a disorder when the pancrease fails to produce sufficieint insulin?
why is type 1 diabetes bad?
this is bevcause insuffinent insulin leveles leads to uncontrollable high blood glucose levels
how do your treate type 1 diabetes?
with insulin injections
describe type 2 diabetes?
type 2 diabtetes is when the body cells no longer reposnd to the insulin produced by the pancrease.
what is a risk factor for type 2 diabetes?
obesity
how can type 2 diabtetes be dealt with?
a carbohydrated controlled diet with and exercise routine
comepare type 1 and type 2 diabetes?
what are 3 ways our body can lose water?
- lose water through lungs when we exhale
- water, ions and urea are lost from the skin through sweat
- excess water, ions and urea are removed through the kidney in the urine
why can our body not control how much water is lost by ions, urea, skin or lungs?
this is because sweating is part of our bodys temeprature control system.
how can osmosis affect our cells in a negative way?
if our cells lose or gain too much water they will not fucntion efficiently?
how does the kidney remove urea?
- the blood enters the kidney through an artery
- kidney removes urea and excess ions and water
- this leaves the urine to be stored into the bladder
- the blood leaves through the veins
what is the funtion of the kidney
removes excess water,ions and urea and adjusting the levels of water and ions in the blood
how are excess amino acids excreted from the body?
- in the liver the amino acids are deaminated (removal of amino group from an amino acid) to form ammonia
- ammonia is toxic so it is converted to urea for safe excretion by the kidney
what does deamination mean?
whne the liver breaks down the excess amino acids and produces the chemical ammonia
how do the kidneys maintain the balance of water and other substances in the body?
- filter the blood in order to remove water products
- selectivly reabsorb the useful molelecules e.g glucose,water and ions
what is the full name of the hormone ADH?
anti diuretic hormone
whwre the the hormone ADH secreted?
the hormone adh is secreted from the pitutary gland
describe the effect ADH has on the permeability of the kidney tubles?
this will help increase water levels indisde the blood.
- causes the kidney tubles to be more permeable to water
- more water can pass out the kidney tubles
- more water is reabsorbed from the tubles back into the blood
- is controlled by the negative feedback cycle
what happens if the level of water in the blood falls?
the pitutary gland relases the hormone ADH
how does kidney dialysis work? (to Removes waste and excess fluid or some times smthing else)
kidney dialysis works by a speacialist machine to carry out the funtion of the kidneys.
* dialysis fluid contains the same concentration of water and ions and no urea.
* urea diffuses from the blood into dialiysis fluid
* dialysis fluid is constantly refreshred, ensures there is always a large concentartion gradient
what happnes if the blood has too much of a high concentration of water is ‘ dilute’?
more urine is produces and pitatuary gland stops releasing ADH and concentration of water in blood returns back to normal.
what are the 2 main ways of treating kidney failure?
- kidney dialysis
- transplant
why is kidney faliure dangerous?
this kidney will be unable to filter the blood properly so will lead to:
* a build up of toxic molelcules in the body
* uncontrollable ion and water balances, cells being damadged due to osmosis
what are inconviniences of kidney dialysis?
- patient have to go to hospital several times a week
- have to have a controlled diet
what are troubles with kidney transplants?
- kidney might be rejected by immune system
compare disadvantages and advanatages of mechanial (kidney dialysis) and transplant?
what is the funtion of the reproductive hormones during puberty?
- During puberty reproductive hormones cause secondary sex characteristics to develop
- men= testes start to procues the hormone testosterogn which prodcues sperm
- women= ovaries produyces the hormones oesterogn and eggs start to mature
what is the main male reproductive system?
Testosterone is the main male reproductive hormone produced by the testes and it stimulates sperm production
what is the main female reproductive system?
Oestrogen is the main female reproductive hormone produced in the ovary
what is ovulation?
At puberty eggs begin to mature and one is released
approximately every 28 days.
several hormones are in the mesntral cycle name them?
- FSH
- LH
- oestrergon and progesterone
what is the funtion of the FSH (Follicle stimulating hormone) in the mentstral cycle?
Follicle stimulating hormone (FSH) causes maturation of an egg in the ovary.
what is the funtion of the Luteinising hormones in the mentral cycle?
- Luteinising hormone (LH) stimulates the release of the egg.
what is the role of the oestergone and progtesterone in the mesntral cycle?
- Oestrogen and progesterone are involved in maintaining the uterus lining
what is the menstral cycle?
monthly cycle of phycological chnages that occur in the female which include the shedding of the uterus linning and ovulation.
what happens in the menstral cycle?
- ovary releases an egg
- in prepartion the uterus lining becomes thick and spongy
- the egg makes it way to the uterus
- if sperm fertalises egg pregnancy occurs, if not egg and uterus lining are released = period
how do the 4 homones interact in the menstrual cycle?
- in the first stage the FSH is released by pituatry gland and travels to the blood and causes egg to mature
- FSH triggers the ovaries to produce oesterogen
- oestrogen causes lining of of uterus to be thick and stops pituatry gland from releasing FSH.
- role of protestegerone comes along
what does protesterogn do in the mestrual cycle?
- stops the pitauatry gland from releasing FSH and LH to prevent anymore eggs from maturing and being released
- keeps lining og the uterus thick incase fertalised eggs implant.
what are the roles of Adrenaline?
It increases the heart rate and boosts the delivery of oxygen and glucose to the brain and muscles, preparing the body for ‘flight or fight’.
where is adrelanine secreted?
the adrenal gland
what is the role of thyroxine and where is it secreted from?
secreted from the thyroid gland stimulates the basal metabolic rate. It plays an important role in growth and development.
how can fertalisation be controlled?
by a variety of hormonal and non-hormonal
methods of contraception.
what is a very common method of contraception?
- oral contraceptives that contain hormones to inhibit FSH production so that no eggs mature
what are disadvantage and advanatages of the oral contraceptives?
- advantage= highly effective if take correctly
- disadvanatge= must be taken everyday, increases risk of breast cancer and blood clots
how are injection, implant or skin patch contraceptives?
ensure a slow release progesterone to inhibit the maturation and release of eggs for a number of months or years
what are the advanatage and disadvanates of injections, implant or skin patch?
adanatages= more convenient than taking the pill everyday
disadvanatge = side effects
what is a fertility drug?
giving FSH and LH in a ‘fertility drug’ to a woman. She
may then become pregnant in the normal way as she may not been able to become pregant before.
what is a big disadvanate of hormonal contraceoptives?
none of them protect against sexually transmitted infection (sti) or (HIV)
what is the barrier method of contracpetions?
such as condoms and diaphragms which prevent the sperm reaching an egg
adavanatge of barrier contraception method?
advantage= do not have side effects, reduce risk of sti
disadvanatage= break and slip off
what is spermicid gel?
- spermicidal agents which kill or disable sperm
what is the coil or IUD?
which prevent the implantation of an embryo or release a hormone
what are surgical methods of contraceptions?
for men= sperm ducts are tied
women=ovbidcust are tied
what is abstinence?
practice of not having sex, abstaining from intercourse when an egg may be in the oviduct
what is the effect of adrenaline?
- increase heart and breathing rate- delivers oxygen and glucose to the body
- increases mental awarness
- dilation of pupils
- stored glycogen converted to glucose
describe the steps of an IVF treatment?
- IVF involves giving a mother FSH and LH to stimulate the maturation of several eggs.
- The eggs are collected from the mother and fertilised by sperm from the father in the laboratory.
- The fertilised eggs develop into embryos.
- At the stage when they are tiny balls of cells, one or two embryos are inserted into the mother’s uterus (womb).
what are the three disadvanatges of IVF?(fertility treatment)
- it is very emotionally and physically stressful
- the success rates are not high
- it can lead to multiple births which are a risk to both the babies and the mother
what is an ethical issue with IVF?
not all the embroys will be used so will be killed is unethical so might seem as killing a potential life
how is the release of thyroxine controlled by a negtative feedback?
what is a negative feedback?
negative feedback is a type of control where the body responds to an increase or decrease in a factor by returning the body back to the factors optimum level
