B11 - Hormonal Coordination Flashcards
(119 cards)
1
Q
What is the endocrine system made up of?
A
Glands that secrete chemicals called hormones directly into the bloodstream
2
Q
Where does the bloodstream carry hormones in general?
A
The bloodstream carrys these hormones to target organs - to produce an effect
3
Q
What are hormones?
A
- Hormones are chemical messengers that control the growth, differentiation, and metabolism of specific target cells.
- The hormones travel around the body, via. The bloodstream - carried the hormones set to effect the target organs.
4
Q
How do hormones trigger a response?
A
Target organs have receptors on the cell membrane –> which pick up the hormone molecules
5
Q
What are the main glands involved in the endocrine system? (6 marks)
A
- Pituitary gland
- Thyroid gland
- Pancreas
- Ovaries
- Testes
- Adrenal glands
6
Q
What are the key differences between the NERVOUS system and the ENDOCRINE system?
A
- NERVOUS system:
- Involves electrical impulses –> rapidly transported by neurons
- Short lived - temporary response can be voluntary and involuntary - ENDOCRINE system:
- Chemical coordination –> slowly transported by the bloodstream
- Short or long lived - can be permanent and involuntary response.
7
Q
What are examples of Hormones that have a rapid response?
A
- Insulin
- Adrenaline
8
Q
What are examples of slow-acting hormones with long-term effects?
A
- Growth hormones
- Sex hormones
9
Q
What is the Pituitary Gland and where is it found?
A
The pituitary gland is also known as the master gland - it is found in the brain and coordinates other glands.
10
Q
What does the pituitary gland do?
A
- Secretes a variety of hormones into the blood - such as: FSH (Follicle Stimulating Hormone) and LH (Lieutenising Hormone) - in response to change or either have an effect on the body
OR
- Act on other glands to stimulate them to produce different hormones
11
Q
What is FSH and what does it do?
A
FSH = Follicle Stimulating Hormone
- Causes the maturation of an egg in an ovary within a structure called follicles to stimulate the ovaries to make the female sex hormone - oestrogen
12
Q
Where is FSH produced?
A
FSH is produced in the pituitary glands in the brain
13
Q
What is TSH and what does it do?
A
TSH = Thyroid Stimulating Hormone
- TSH stimulates the thyroid gland to make THYROXINE, this helps control the rate of metabolism, heart rate and temperature.
14
Q
Where is TSH produced?
A
In the pituitary gland
15
Q
What is the main role of the pituitary gland?
A
- To control the growth in children
- Stimulates the thyroid gland to make thyroxine to control the rate of metabolism
- In women, it stimulates ovaries to produce and release eggs - makes LH (Lieutinising Hormone) and makes the female sex hormone - oestrogen - levels rise.
16
Q
What is the main role of the thyroid gland?
A
- Secretes thyroxine
- Controls the basal metabolic rate if the body –> this is important for growth and development.
17
Q
What is basal metabolic rate?
A
The basal metabolic rate is how quickly substances are broken down and built up - for example: how much oxygen your tissues use and how the brain of a growing child develops.
18
Q
What is the main role of the pancreas gland?
A
- Secretes insulin
- Controls the levels of glucose in the blood
19
Q
What is the main role of the adrenal glands?
A
- Secretes the hormone: adrenaline
- Prepares the body for stressful situations - initiates humans - ‘fight or flight response’
20
Q
What is the main role of the glamds in the ovaries?
A
- Secretes oestrogen (female sex hormone) and progesterone
- Control the development of the female secondary sexual characteristics –> imvolved in menstrual cycle.
21
Q
What is the main role of the glands in the testes?
A
- Secretes testosterone (male sex hormone)
- Controls the development of male secondary characteristics and is involved in the production of the sperm
22
Q
Why is it so important to control the blood glucose concentration?
A
Because glucose is needed by cells in order for respiration to occur
23
Q
What is glucose?
A
Glucose! The sugar used in respiration
24
Q
What is glycogen?
A
Glycogen: a storage carbohydrate found in the liver and muscles
25
What is glucagon?
Glucagon: a hormone that stimulates the liver to break down glycogen to glucose
26
Which organ/ gland detects and controls the change in blood glucose concentration?
The pancreas - as it monitors and controls blood glucose concentration
27
What increases the glucose levels in the blood?
Eating foods that contain high amounts of sugar or high concentrations of carbohydrates
28
Describe what happens when blood glucose levels are too high? (5 marks)
1. Pancreas gland detects that blood glucose levels are too high
2. Pancreas releases the hormone Insulin into the bloodstream
3. Insulin travels in the bloodstream to the liver (and body cells)
4. Body cells take in more glucose for respiration and the liver takes up excess glucose and stores it as glycogen
5. Blood glucose levels are lowered and returned to normal homeostatic levels
29
Describe what happens when blood glucose levels are too low? (5 marks)
1. Pancreas gland detects that blood glucose levels are too low
2. The pancreas detects the drop in glucose levels and releases glucogon into the bloodstream
3. The glucogon in the bloodstream makes its way down to the liver (and body cells)
4. It binds with the glucose in the liver and creates glycogen and the excess is stored
5. As a result, the blood sugar levels increase and return to normal homeostatic levels
30
What happens when the glycogen stores in the liver and muscles are too full?
Any excess glucose is converted to lipids and/or stored.
31
What decreases the glucose levels in the blood?
Rigorous activity exercise - uses glucose for respiration and/or fasting - i.e. not eating.
32
How is the blood glucose concentration kept constant?
By producing insulin and glucagon constantly at a narrow concentration range.
33
Explain how the blood glucose concentration links to the negative feedback loop?
If the blood glucose level is too low, the pancreas releases the hormone glucagon. This travels to the liver in the blood and causes the break-down of glycogen into glucose. The glucose enters the blood stream and glucose levels increase back to normal. This is an example of negative feedback
34
What causes Type 1 diabetes?
The pancreas does not produce enough insulin - blood glucose concentration is not controlled or genetic
35
What are some symptoms of Type 1 diabetes?
- Frequent urination - glucose is excreted with urine
- Unusual thirst
- Extreme hunger
- Unusual weight loss - breaking down fat and protein to use as fuel instead
- Extreme fatigue - lack of energy - glucose cannot get to cells
36
When does type 1 diabetes develop?
During childhood or adolescence
37
What causes Type 2 diabetes?
- Body cells no longer respond to insulin or less insulin than the body needs
38
What dies Type 2 diabetes link to?
- Obesity
- Lack of exercise
- Unhealthy lifestyle
39
When does Type 2 diabetes develop.
It is more common as people get older
40
How do you treat Tyoe 1 diabetes with insulin injections?
1. insulin injection - replacement insulin before meals - insulin is a protein/hormone that would be digested in your stomach - so it is usually given as an injection because of its fast method to help lower blood sugar.
2. The injected insulin allows glucose to be taken into body cells and converted into glycogen in the liver --> This stops the glucose in the blood getting too high.
3. As the blood glucose levels fall, the glycogen is converted back into glucose and blood glucose levels are kept stable and returned to normal/optimum homeostatic levels in the body.
41
How else do you treat Type 1 diabetes?
- Caution about the levels of carbohydrates eaten
- A regular and balanced diet
- Exercise - keep the cardiovascular system healthy - which should be carefully planned to keep the blood glucose concentration steady
42
How have scientists and doctors attempted to cure Type 1 diabetes?
1. Transplanting pancreatic cells that make insulin from both dead and living donors - limited success so far.
2. Producing insulin - secreting cells from embryonic stem cells
3. Genetic engineering - genetically engineering oancreatic cells
4. These are all methods to minimise chances of rejection - so people (patients) are happy with the procedures, however, some people (for example, religious people or protestors) may think that the process is unethical.
43
How do you treat Type 2 diabetes if noticed early on?
- eating a balanced diet with carefully controlled amounts of carbohydrates
- losing weight
- doing regular exercise
- if on any medication, take it regularly in accordance with your schedule and doctors opinion
44
How do you treat more developed Type 2 diabetes?
There are drugs that:
- help insulin work better on the body cells
- help your pancreas make more insulin
- reduce the amount of glucose you absorb from your gut
- if these methods dont work (if its a severe case of Type 2 diabetes) then use insulin injections
45
What is negative feedback?
In negative feedback, the response will reverse or cause the opposite effect of the original stimulus. For example, internal regulation of body temperature
46
Where is thyroxine found?
The thyroid gland in your neck uses iodine from your diet to produce the hormone - thyroxine
47
What happens if levels of thyroxine in the blood begin to fall?
- Negative Feedback System
- the change/fall is detected by sensors in the brain --> so the amount of TSH released from the pituitary gland increases --> TSH stimulates production of thyroxine
48
What happens if levels of thyroxine in the blood begin to rise?
- Receptors in the brain (CNS) detect thyroxine --> this inhibits the release of TSH (Thyroid Stimulating Hormone)
-This means:
1. Lower metabolism rate
2. Lower levels of proteinsynthesis
49
Where are the adrenal glands located?
On top of the kidneys
50
When is the hormone - adrenaline - released?
- fight or flight --> adrenaline boosts the delivery of oxygen and glucose to the brain and muscles
- when someone is stressed, angry, excited or frightened
51
What does adrenaline cause? (5 marks)
-heart rate and breathing rate increases
-stored glycogen in the liver converted to glucose for respiration
-pupils of eyes dilate to let more light in
-mental awareness increases
-blood diverted away from digestive system to big muscles of the limbs
52
What do the reproductive hormones control?
The development of secondary sexual characteristics
53
What are primary sexual characteristics?
- reproductive organs (present at birth)
-ovaries in girls
- testes in boys
54
What do reproductive organs produce?
- sex hormones
- special sex cells + gametes that join in reproduction
55
What is the fallopian tube?
Oviduct, where the egg travels to the uterus and may be fertilised
56
What is the ovary?
The female sex gland that contains the egg (gametes) eggs mature here (via. FSH)
57
What are sperm ducts?
Tubes that carry sperm
58
Where is the male hormone - testosterone - produced and what does it do?
Testosterone is produced in testes and stimulates sperm production
59
What are examples of secondary sexual characteristics in males?
- pubic hair
- facial hair
- testes grow and become more active
60
Where is the female sex hormone - oestrogen - produced and what does it do?
Oestrogen is produced by ovaries produces physical changes and is involved in the menstrual cycle, as well as maturing/developing the egg (gamete)
61
What are examples of secondary sexual characteristics in females?
- pubic hair
- growth spurt
- breasts develop/grow
62
Define the term puberty?
Period in which adolescents start to develop secondary sexual characteristics
63
What is the menstrual cycle coordinated by?
Coordinated by hormones from pituitary gland in brain --> starts egg maturation
64
Where is oestrogen secreted?
It is secreted by the/at ovaries
65
What does oestrogen do?
- Stimulates the lining of the uterus to grow/'build up' again after menstruation in preparation for pregnancy.
- Stimulates the pituitary gland to release LH.
- Inhibits the release of FSH, so that only one egg matures in a cycle.
66
What is LH?
Luteinising hormone
67
Where is LH secreted?
Pituitary gland
68
What does LH do?
- Stimulates the release of a mature egg from the ovary.
- Stimulates the ovaries to release progesterone.
-Inhibits the release of Ostrogen
69
What does progesterone do?
- Maintains the lining of uterus during second half of menstrual cycle and during pregnancy
- Inhibits both FSH and LH
70
Where is progesterone secreted?
Progesterone is produced in the ovaries and secreted from the egg follicle
71
What is Stage 1 of the menstrual cycle?
Menstruation starts (periods). The uterus lining breaks down for 4 days.
72
What is Stage 2 of the menstrual cycle?
The uterus builds up again (oestrogen) from day 4 - 14, into a thick spongy layer full of blood vessels, ready to recieve a fertilised egg.
73
What is stage 3 of menstrual cycle?
Ovulation - day 14 - egg is released - ready for fertilisation and if not done within 48 hours (2 days), the egg will be flushed out of the vagina. However, some women's ovulation may vary with the ovulation occuring at day 6 instead of day 14.
74
What is stage 4 of the menstrual cycle?
The lining of the uterus is maintained from 14 - 28 days. If no fertilised egg by day 28 --> lining starts to break down/shed --> cycle starts again.
75
Why is a thick lining of a uterus needed for foetus'?
To provide protection and food for developing embryo
76
Explain the Menstrual Cycle in terms of hormones. (4 marks)
1. FSH stimulates ovaries to produce oestrogen --> higher levels of FSH just before oestrogen starts to increase
2. Oestrogen levels increase and inhibits release of FSH - negative feedback
3. Oestrogen stimulates the release of LH --> this causes a spike in LH --> this is known as the period of ovulation
4. Progesterone builds up then inhibits both LH and FSH
77
What is contraception?
The prevention of pregnancy by stopping the egg and sperm from meeting and therefore stopping a fetilised egg implanting into the uterus
78
Name all different methods of contraception. (6 marks)
- Abstinence (rhythm method)
- Surgical methods
- Hormone based methods
- Barrier methods
- Chemical methods
- Intrauterine devices (i.e. coil, etc.)
79
What are the two kinds of oral contraceptives and what is their success rates?
- The contraceptive pill (progesterone only) - uses female hormones to prevent pregnancy - 99% success rate IF TAKEN PROPERLY.
- The mixed pill - same as the normal contraceptive pill but contains low doses of pestrogen as well as the usual - progesterone - 99% success rate
80
How doe these oral contraceptives work?
- The hormones inhibit the production of FSH by the pituitary gland, affecting the ovaries --> leading to no eggs maturing --> comsequently preventing pregnancy
OR
- It stops the lining of the uterus from developing --> preventing implantation (by making the mucus in the cervix so thick, its enough to prevent sperm from getting through and fertilising the egg) --> thus, preventing pregnancy.
81
Advantages of mixed oral contraceptive pill?
- doesnt affect sexual intercourse
- easy to use
- usually high successful contraceptive rates
82
Disadvantage of the mixed oral contraceptive pill?
More side effects:
- raised blood pressure
- breast cancer
- thrombosis
83
What are the advantages of the PROGESTERONE ONLY contraceptive pill?
- fewer side effects
- reduces acne in some women
- sometimes it may help some people with their periods and muscle cramps/spasms
84
What are the disadvantages of the PROGESTERONE ONLY contraceptive pill?
- has to be taken regularly, if not: artificial hormones drop and the body's own hormones can take over --> resulting in the unexpected realease of an egg.
- doesnt protect against STI's/STD's
85
What are alternative methods of contraceptives instead of oral pills and what are their success rate?
- A contraceptive implant: can last up to 3 years, via. A tiny tube inserted under the skin which slowly releases progesterone --> and is very effective with a success rate of 99%
- Contraceptive injections - injections of progesterone that are effective with a success rate of 99% but they only last for short periods of time.
86
How do some chemical methods of contraception work and what is the success rate?
An example of a chemical contraceptive is a:
- Spermicide - it is a gel placed on a femidom/comdom to kill/disable sperm. It has a success rate of 87%
87
What is an advantage of spermicides?
They are readily available without prescription
88
What is a disadvantage of spermicides?
efficacy of preventing pregnancy is low and inconsistant
89
How do barrier methods of contraception work?
They prevent soerm from reaching the egg as it faces a BARRIER
90
What is an example of a barrier method used as contraception for men and what is its success rate?
- condom - a thin latex/non-latex sheath placed over penis during intercourse to collect the semen and prevent egg and sperm from meeting. It is usually effective with a success rate of 98%.
91
What are some advantages of condoms?
- no side effects and do not need medical advice
- offer some protection against sexually transmitted diseases/infections (STD/I's) - for example: syphillis and AIDS.
92
What are some disadvantages of condoms?
- can easily be damaged or can break
- can maybe affect sexual intercourse
- the latex in the condom may affect the sexual performance as they may be allergic to that latex.
93
What is an example of a barrier method used as contraception for women and what is its success rate?
- A diaphragm/cap or femidom - is a thin rubber diaphragm placed over the cervix before sex to prevent entry of sperm. It is usually effective with a success rate of 98%.
94
What is the advantage of diaphragm/femidom/cap?
No side effects
95
What are some disadvantages of a diaphragm/cap/femidom?
- has to be fitted by a doctor initially and if incorrectly placed - it is not effective
- maybe uncomfortable and may affect sexual intercourse
96
What are intrauterine devices (IUD's)
IUD's are small structures inserted into the uterus by a doctor
97
How do IUD's (intrauterine devices) work and what is the success rate?
- IUD's contain copper (a natural spermicide) - which pervents any early embryos implanting in lining
OR
- Contain progesterone and release it slowly to prevent the build-up of uterus lining, in order to thicken the mucus of the cervix.
- IUD's usually are very effective with a success rate of 99%.
98
What are some advantages of IUD's?
- they last for a long time (5-10yrs) and can be removed at any time if a women does change her mind and wants to get pregnant
- very effective - 99% success rate
99
What are some disadvantages of IUD's?
- can cause period problems or infections (longer, heavier and more painful periods)
- can be very painful for the women to endure as they go along their usual routine due to the interuterine change.
100
How does abstinance work?
If a woman doesn't have sex during ovulation, she wont get pregnant - egg won't be fertilised - also known as the rhythym method
101
What are some advantages of abstinence?
- no side effects
- suited for religious groups that condone the use of artificial contraception
102
What are some disadvantages of abstinence?
- may not be effective if not followed properly
- unreliable as some women's menstrual cycle differ (average period of ovulation is day 14 but some women may have the period of ovulation at day 6)
103
What do surgical methods of contraception involve?
Surgical sterilisation
104
How do surgical methods of contraception work in men and what is the success rate?
- a vasectomy - sperm ducts are cut and tied to prevent sperm getting into semen. It is very effective and is shown with a success rate of 99-100%.
105
How do surgical methods of contraception work in women and what is the success rate?
- tubal ligation - oviducts are cut or tied to prevent egg reaching the uterus and sperm reaching the egg. It is very effective and is shown with a success rate of 99-100%.
106
What is an advantage of a man getting a vasectomy?
Vasectomy doesn't affect your hormone levels, sex drive or general health
107
What is a disadvantage to a man getting a vasectomy?
It is very difficult to reverse a vasectomy if you do change your mind and it still doesnt protect men from STI/D's
108
What is an advantage of a woman getting a tubal ligation?
It is an effective and permanent contracption with no risk of human error
109
What is an disadvantage of a woman getting a tubal ligation?
Women may need general anaesthetic for surgery and they are still prone to STI/D's
110
What are possible reasons for infertility?
-lack of female hormones
-damaged oviducts
-lack of sperm in semen
-obesity
-eating disorders
-age --> ageing --> getting closer to menopause --> perimenopausal
111
How do artificial FSH drugs aid ovulation?
- stimulates eggs in ovaries to mature and triggers oestrogen --> thus stimulating ovulation
112
What does IN-VIVO mean?
In-vivo means 'in the body' - hence in vivo fertilisation would be sexual intercourse as its 'in-vivo'
113
What does IN-VITRO mean?
In-vitro means 'outside the body' - hence IVF - In Vitro Fertilisation treatment
114
What is IVF treatment?
In - vitro fertilisation treatment:
- IVF is a form of fertility treatment used if the oviducts have been damaged or blocked by an infection or if a donor egg has to be used
- However, if a man produces very few sperm or if they do not mature properly- individual sperm injected into egg through IVF
115
How does the IVF process work? (5 marks)
-mother given synthetic FSH to stimulate the maturation of a number of eggs at the same time followed by LH to bring the eggs to a point of ovulation- fertility drugs
-They collect the eggs from the ovary of the mother and fertilise them with a sperm from the father outside the body in a lab on a Petri dish- sperm and egg mix
-The fertilised eggs are kept in special solutions in a warm environment to develop into tiny embryos and checked to see if properly developed
-At the stage when they have formed tiny balls of cells- one or two embryos inserted back into uterus of mother --> so they bypass the faulty tubes
116
What are some advantages of IVF treatment? (4 marks)
-The use of hormones to help overcome infertility gives people chance to have baby of their own
-People can remove single cells from embryo's and choose their baby's gender and eye colour (designer babies)
-Embryos can be genetically tested before implantation
-People can chose when to have children
117
What are some disadvantages of IVF treatment? (5 marks)
- expensive
- not always successful- The older the parents get- less likely it becomes--> using donor eggs or donor sperms from younger people can help the success rate- but baby not biologically the parent's child
- can have some health risks for mother-can be emotionally and physically stressful/ painful (vomiting)
- increase chances of a multiple pregnancy--> which increase risk-- can lead to stillbirths and premature births-- if babies survive can have disabilities
- ethical problems if mature eggs produced by a women in IVF is stored and later on discarded
118
What is the FOLP anagram and explain each letter in terms of its role in the menstrual cycle.
F - Follicle Stimulating Hormone - stimulates an egg to mature in an ovary
O - Oestrogen - stimulates the lining of the uterus to grow 'build up' again after menstruation in preparation for pregnancy.
L - Leuteinising Hormone - stimulates the release of a mature egg from the ovary.
P - Progesterone - maintains the lining of uterys during second half of menstrual cycle and during pregnancy
119
How do the hormones interact?
- Stimulates the release of...
FSH --> Oestrogen --> LH --> Progesterone
- Inhibits...
Progesterone --> LH --> Oestrogen --> FSH
