Hormones Flashcards
(49 cards)
1
Q
What are hormones?
A
Chemical messages produced by endocrine glands and that are released directly into the blood
-they only effect particular cells in certain organs (target organs)
2
Q
What is the pituitary gland and thyroid gland?
A
- the pituitary gland produces growth hormones that regulate body conditions. They act on other glands directing them to release hormones that bring about change
- thyroid gland produces thyroxine which is involved in regulating rate of metabolism, heart rate and temperature (how quickly chemical reactions take place in the body)
3
Q
What are the ovaries and testes?
A
- ovaries produce oestrogen and control female development during puberty
- testes produce testosterone which controls puberty and sperm production in males
4
Q
What is the pancreas and adrenal gland?
A
- adrenal gland produce Adrenalin which is used to prepare the body for ‘fight or flight’ response
- pancreas procures insulin which regulates blood glucose levels
5
Q
What does the release of Adrenalin stimulate?
A
- heart muscle contracts, increasing heart rate and therefore blood pressure as blood is pumped more strongly
- raises blood sugar levels by stimulating liver to change glycogen into glucose to help respiration
- increased blood flow to muscles as blood vessels widen
6
Q
What are negative feedback systems?
A
When the body detects that the level of a substance has Gombe above of below the normal level which triggers a response to regulate this
7
Q
How does thyroxine effect metabolic rate?
A
- causes heart cells to contract more
- causes proteins and carbohydrates to be broken down more quickly
8
Q
What is the negative feedback system of thyroxine?
A
- Low levels of thyroxine stimulates the the production of TRH in the hypothalamus
- stimulates the pituitary gland to release TSH
- this stimulates the thyroid gland to produce and release thyroxine to regulate the levels of it in the body
- when blood thyroxine levels become normal, thyroxine inhabits the production of TSH and release of TRH
9
Q
What are the stages of the menstrual cycle?
A
- day 1 is when menstruation starts so the lining of the uterus breaks down and is released
- from day 4 to 14 the uterus lining is repaired until it becomes a thick, layer of blood vessels the fertilised egg can implant in
- around day 14 an egg is released from the ovary
- until day 28 the lining is maintained but if no fertilised egg lands in the uterus wall, lining starts to break down again
10
Q
What is stage 1 of the menstrual cycle using FSH?
A
- FSH is released by the pituitary gland and travels in the blood to ovaries
- this causes a follicle (an egg and its surrounding cells) to mature in one of the ovaries
- stimulates the production and release of oestrogen
11
Q
What is stage 2 of the use of hormones in the menstrual cycle?
A
- oestrogen is released by the ovaries
- stops FSH being produces so that only a egg matures in a cycle
- stimulates the pituitary gland to release a surge in LH
12
Q
What is stage 3 of the use of hormones in the menstrual cycle?
A
- LH is released from the pituitary gland when oestrogen reaches it
- travels to the ovaries stimulating ovulation (the mature egg to be released)
- stimulates the remains of the follicle to develop into a corpus luteum which secrets progesterone
13
Q
What is stage 4 of the use of hormones in the menstrual cycle?
A
- progesterone is secreted after the egg is released
- this thickens and maintain the lining of the uterus and inhibits the release of FSH and LH
- if the egg is fertilised levels stay high, if not the lower causing the cycle to start again and uterus lining to break down
14
Q
How is the pill and implant as well as too much oestrogen used as a contraceptive?
A
- both release hormones to prevent ovulation and thickens cervical muscles making it difficult for sperm to pass through
- too much oestrogen (taken every day)keeps its level permanently high inhibiting the production of FSH
15
Q
What barrier methods are there to contraception?
A
- these put a barrier between the sperm and the egg so fertilisation can’t take place
- e.g. condoms placed over an erect penis and diaphragms which are flexible dome shaped devices that fit over the opening of the uterus and are inserted before sex
16
Q
Which are more effecting for contraception -hormonal or barrier methods?
A
- hormonal are generally more effective and it means the couple don’t have to stop to apply contraception each time before intercourse
- yet hormonal methods can have unpleasant side effects such as headaches, acne and mood swings. They also don’t protect against STI’s whereas condoms do
17
Q
What is IVF?
A
- fertility drugs containing FSH and LH are given too the women to stimulate the maturation of eggs which are then collected by a needle carried by ultrasound
- the eggs are fertilised by sperm in the lab
- this then develops into embryos of which one or two are inserted into the mother’s uterus
18
Q
Why might IVF be used and what is ART?
A
- a women may have blocked oviducts
- a man ma produces too few sperm
- ART is assisted reproductive technology a form of artificial fertilisation which IVF is one
19
Q
What is clomifene therapy used for?
A
- women who don’t violate regularly enough or at all can take a drug called clomifene
- this works by causing more FSH and LH to be released stimulating egg maturation and ovulation
- the couple can then have intercourse during this period to improved chances of becoming pregnant of this can happen before IVF
20
Q
What is homeostasis?
A
- maintains a constant internal environment
- this is important because cells need the right conditions in order to function properly and enzyme’s need specific conditions
- to maintain this your body must respond to external and internal changes whilst balancing inputs and outputs
21
Q
What happens to blood glucose and what should regular levels of it be?
A
- concentration should be around 100mg/dl yet this will fluctuated depending on what you doing
- digestive systems break down carbohydrates into glucose molecules which diffuse into the bloodstream
22
Q
What does it mean to be hypoglycaemic and and hyperglycaemic?
A
- Hypo is when there is too little glucose in the bloodstream
- Hyper is when there is too much
23
Q
What do insulation and glucagon hormones do when released by the pancreas?
A
- insulin is made by the pancreas and regulates blood glucose levels allowing the body to use glucose to male glycogen if too high
- glucagon is released in response to too low blood glucose levels and stimulates the breakdown of glycogen into glucose
24
Q
What factors influence blood glucose levels?
A
- metabolic rate removes glucose from the blood naturally
- eating foods heavy in glucose like carbohydrates
- vigorous exercise removes much more glucose from the blood
25
What is glycogen?
Stored carbohydrates which are readily available and stored in the liver and muscles
-if these are full it is stored then excess glucose is stored as lipids in tissues
26
What is type 1 diabetes?
Condition where the pancreas produces little or no insulin as the cells in the pancreas that originally would are destroyed so the persons body glucose can rise to a level that can kill you
-increase likelihood if relatives have the condition
27
How it type 1 diabetes controlled?
- insulin therapy which Involves injecting insulin into the blood which is often done at meal times so the glucose is removed quicker once the food is digested
- limit intake of food risk in simple carbohydrates like sugars
- doing regular exercise to remove excess blood glucose
28
What is type 2 diabetes?
- condition where the pancreas doesn’t produce enough insulin or when they become resistant to insulin so glucose levels rise
- correlation between obesity and diabetes especially abdominal as a lot of fat is stored (BMI over 30) and (waist to hip ratio of above 1 for men and 0.85 for women)
29
How is type 2 diabetes stored?
- eating a healthy diet
- regular exercise
- losing weight
- some still have medication or insulin injections
30
What is thermoregulation?
Regulating body temperature which is done by the hypothalamus
-enzymes in the human body work best at 37° below this they will slow down and above this they may become denatured
31
What does the hypothalamus in the brain contain?
Reception that are sensitive to body temperature
- receive impulses from skin receptors providing info about external temperatures
- these receptors are located in the epidermis (outer skin layer) and in the dermis (deeper layer of skin)
32
What happens when your too hot -vasodilation?
- erector muscles relax so hairs lie flat and trap less warm air
- lots of sweat is produced in sweat glands in the dermis which evaporate through pores in the epidermis transferring energy to the environment cooling you down
- blood vessels close to the surface of the skin dilate allowing more blood to flow near the surface so it can transfer more energy to the surroundings to cool you down
33
What happens when your too cold - Vasoconstriction?
- erector muscles contract so hairs stand in end which trap a layer of warm air near to the surface of your skin to keep your warm
- very little sweat is produced
- blood vessels near the skin surface constrict so less blood flows near the surfaces so less energy is transferred to the surroundings
34
What impact does shivering have on your body temperature?
Shivering is the action where your muscles contract and then relax quickly
-this makes the cells respire quickly and heat is given off as a product of respiration so more energy is transferred to your body to heat up
35
What is osmoregulation and why is it important?
- important that the water content of the blood is controlled to keeps cells functioning normally and allows the transport of molecules
- if blood water concentration is too high water will move into bodily cells through osmosis and vice versa (if water moves out it causes cells to shrink)so is needed to maintain their shape
- the kidneys help control how much water is reabsorbed and how much is in urine
36
What are the main roles of the kidney?
- removal of urea from the blood which is produced in the liver from the breakdown of excess amino acids
- adjustment of ion, sugar and water levels in the blood
- they do this by filtering things out the body under high pressure and then reabsorbing the useful things
37
What two parts is the kidney divided into?
Cortex (outer area) which is full of nephron filters for the blood
Medulla (inner area) which has tubes to carry filtered waste to centre of the kidney
38
How can a kidney transplant be used to treat kidney failure?
- kidney transplants usually from healthy people who have dies suddenly yet these can be rejected so to decrease this risk
- use a donor with similar tissue type to the patient
- the patient is treated with drugs to suppress the immune system so that the transplanted kidney isn’t trapped
39
How can kidney dialysis be used to treat kidney failure?
- patients can no longer filter their blood properly but a dialysis machine can do it for them as substances are exchanged between the dialysis fluid and the blood as it is permeable
- has to be done regularly to keep substances like water at the right concentrations and to remove waste (urea)
40
How does the structure of a nephron allow it to filter blood and form urine?
- the liquid part of the blood is forced out of the glomerulus and into the bowman’s capsule at high pressures but bigger molecules like blood cells can’t pass through the membrane so aren’t
- as they flow useful substances are reabsorbed (sufficient water and ions, glucose is selectively reabsorbed against Cgradient)
- whatever isn’t reabsorbed continues out the nephron via the collecting duct passing into the ureter and down to the bladder as urine
41
What is ADH and what does it do?
A hormone that controls the amount of water reabsorbed in the kidney nephrons by a negative feedback loop
- the brain monitors the water content of blood and instructs the pituitary gland to release ADH into blood according to how much is needed
- it makes the nephron collecting ducts more permeable so more water is reabsorbed back into the blood stopping dehydration
42
What is the structure of the urinary system?
- ureter where waste and fluid exit as urine
- renal artery to bring blood and waste into the kidney
- renal vein takes clean blood out of the kidney
- glomeruli are tiny filters throughout the kidney
43
How is the glomerus, Bowman’s capsule and 1st convulated tubule adapted?
- small holes to allow small molecules to pass into nephron
- bowman’s capsule has a large surface area between nephron and capillary so more filtration can take place
- 1st convulated tube contains protein pumps for active transport in selective transport and cell membranes lined with microvilli to increase surface area:volume ratio
44
Where is water reabsorbed in the kidney?
The loop of henle via osmosis
45
What effect do hormones have on muscle and bone?
Increases growth and division of tissue and therefore they grow faster and the body increases in size
46
What is one disadvantage of treating infertility by using hormones?
May stimulate the release of more than one egg leading to multiple births and increased complications
47
What happens in the nephron to ensure glucose isn’t in the urine?
It passes through the bow and capsule where sufficient water is selectively reabsorbed and taken back into the bloodstream by the convulated tube
48
How is water reabsorbed at the kidney?
Through osmosis from an area of high concentration in the collecting duct to a low concentration in the bloodstream through a partially permeable membrane.
49
How do substances more from the glomerulus to the bowman’s capsule?
Through filtration
-this is because there is a partially permeable membrane which allows smaller substances to pass through at high pressures
