Hormones and Fertility - TOPIC 7 Flashcards
1
Q
what are hormones
A
chemical messengers which travel in the blood to activate cells in target organs
2
Q
where are hormones produced
A
endocrine glands
3
Q
what is the endocrine system using hormones for
A
to react to changes in the environment or changes inside the body
4
Q
what are the six glands in the endocrine system
A
pituitary gland
thyroid gland
pancreas
adrenal glands
ovaries
testes
5
Q
what does the thyroid gland do
A
produce thyroxine which is involved in regulating things like rate of metabolism and heart rate
6
Q
what does the pancreas produce
A
insulin
7
Q
what do adrenal glands produce
A
adrenaline which is used to prepare the body for a flight or fight response
8
Q
what do the ovaries do
A
produce oestrogen which is involved in the menstrual cycle
9
Q
what do the testes do
A
produce testosterone which controls puberty and sperm production in males
10
Q
differences between nerves and hormones
A
nerves are faster
nerves act for a shorter time
nerves act on a precise area
11
Q
when and how is adrenaline released
A
in response to stressful or scary situations. The brain detects fear or stress and sends nervous impulses to the adrenal glands which respond by releasing adrenaline
12
Q
how does adrenaline get the body ready for flight or fight
A
by triggering mechanisms that increase the supply of oxygen and glucose to cells
13
Q
what happens when adrenaline binds to specific receptors in the heart, to heart rate and blood pressure
A
heart muscle contract more frequently and with more force so the heart rate and blood pressure increase
14
Q
what happens when heart rate and blood pressure increases from adrenaline
A
increase in blood flow to muscles, so cells receive more oxygen and glucose for increased respiration and this gives the muscles extra energy for muscle contraction
15
Q
how does adrenaline cause increase in glucose
A
adrenaline binds to receptors in the liver and this causes liver to break down its glycogen stores to release glucose.
16
Q
what is glucose released from adrenaline used for
A
it is used to fuel muscle contraction in the fight or flight response
17
Q
what does thyroxine do
A
regulate basal metabolic rate
18
Q
what is negative feedback
A
when levels of certain substance in the body go above or below a normal level, the body triggers responses that help to bring these levels into a normal range
19
Q
what does negative feedback system do to amount of thyroxine in blood
A
keep it at the right level
20
Q
what happens when level of thyroxine in blood is lower than normal
A
The hypothalamus is stimulated to release TRH
TRH stimulates the pituitary gland to release TSH
TSH stimulates thyroid gland to release thyroxine
So, blood thyroxine level rises back to normal
21
Q
what happens when level of thyroxine in blood is higher than normal
A
release of TRH from hypothalamus is inhibited (stopped) and this reduces the amount of thyroxine released form thyroid gland and so level of thyroxine falls.
22
Q
what is the menstrual cycle
A
monthly sequence of events in which the female body releases an egg and prepares the uterus in case the egg is fertilised
23
Q
how long is the menstrual cycle
A
28 days
24
Q
what happens in stage 1 of the menstrual cycle (day 1 to 4)
A
day 1 is when menstruation/ bleeding starts and uterus lining breaks down and is released
25
what happens in stage 2 of the menstrual cycle
lining of uterus is repaired, from day 4 - 14, and ready for a fertilised egg to implant there
26
what happens in stage 3 of the menstrual cycle
an egg is released from the ovary at day 14 which is also known as ovulation
27
what happens in stage 4 of the menstrual cycle
lining is then maintained for about 14 days until 28 days.
28
what happens if no fertilised egg has landed on the uterus wall by day 28
spongy lining starts to break down again and the whole cycle starts again
29
hormones in the menstrual cycle
oestrogen and progesterone
30
what does oestrogen do
stimulate the growth of the uterus lining during stage 2 of the menstrual cycle
31
what does progesterone do
maintain the uterus lining during stage 4 and stops the release of FSH and LH
32
what does follicle stimulating hormone (FSH) do
causes a follicle to mature in one of the ovaries and stimulates ovaries to produce oestrogen
33
what does luteinising hormone (LH) do
stimulate the release of an egg at day 14 / ovulation
34
what happens when the level of progesterone falls and there is a low oestrogen level
uterus lining breaks down and low progesterone level allows FSH to increase and therefore allows the whole cycle to start again
35
why does level of progesterone stay high during pregnancy
to maintain the lining of the uterus during pregnancy
36
what does infertile mean
they cannot reproduce naturally
37
what happens if women have FSH level that is too low
eggs cannot mature and therefore no eggs are released and women can't get pregnant
38
what are the 2 hormonal ways people can use to get pregnant
clomifene therapy
IVF ( in vitro fertilisation)
39
what does clomifene do
it is a drug, which works by causing more FSH and LH to be released by the body, which stimulates egg maturation and ovulation
40
how does IVF work
it involves collecting eggs from the woman's ovaries and fertilising them in a lab using the man's sperm. Fertilised eggs are then grown into embryos and once they are tiny balls of cells, one or two of them are transferred to the womens uterus
41
why is FSH and LH given before egg collection in IVF
to stimulate egg production so more than one egg can be collected
42
what are contraceptives used for
preventing pregnancy
43
why is oestrogen and progesterone used as contraceptives
they reduce the fertility
44
how does oestrogen prevent egg release and pregnancy
if taken every day to keep the level of oestrogen permanently high, it stops FSH production and after a while egg maturation and therefore egg release stop and stay stopped
45
how does progesterone reduce fertility
stimulates production of thick cervical mucus which prevents any sperm getting through the entrance to uterus and reaching an egg and it can also stop egg maturation
46
forms of hormonal contraceptive
the combined pill is an oral contraceptive
mini pill which is oestrogen only pill
contraceptive patch
contraceptive injection
47
what does barrier forms of contraceptive mean
there is a barrier between sperm and egg so they do not meet
48
different barrier methods of contraception
condoms (male and female)
diaphragm
49
why are hormonal methods more effective than barrier methods at preventing pregnancy
more effective when used correctly and people do not need to think about contraception every time they have intercourse
50
why are hormonal methods bad
they have unpleasant side effects such as headaches and acne and mood change and they do not protect against STI
51
what is homeostasis
the regulation of the conditions inside your body to maintain a constant internal environment, in response to changes in both internal and external conditions
52
examples of homeostasis
osmoregulation
thermoregulation
blood glucose regulation
53
what do negative feedback systems do
help to keep conditions in your body steady.
54
what monitors blood glucose levels
the pancreas, by producing hormones
55
what hormone is produced by the pancreas
insulin
56
what does insulin do to blood glucose levels
decreases blood glucose levels when they get too high
57
describe how insulin decreases blood glucose levels when they get too high
when blood glucose levels rise, the pancreas detects this rise.
the pancreas responds by producing insulin, which is secreted into the blood
insulin causes the body cells to take up more glucose from the blood. Cells in the liver and muscles can take up glucose and convert it into glycogen
this causes the blood glucose level to fall
58
where is glycogen produced
by the pancreas
59
what does glycogen do
it increases the blood glucose level when it gets too low
60
describe how does glucagon cause blood glucose level to increase
the fall in blood glucose level is detected by the pancreas
the pancreas responds by producing glucagon, which is secreted into the blood
glucagon causes the glycogen stored in the liver and muscles to be converted back into glucose, which enters the blood
this causes the blood glucose level to rise
61
what is type 1 diabetes
a condition where the pancreas produces little or no insulin which can make the blood glucose level rise to a level which can kill the person
62
how is type 1 diabetes treated
with insulin injections and their doses depend on their diet and activity levels
63
what is type 2 diabetes
a condition where the pancreas does not produce enough insulin or when a person becomes resistant to their own insulin
64
what is the risk factor of type 2 diabetes
being overweight and obese
65
how to control type 2 diabetes
eating a healthy diet, regular exercise and losing weight if needed
66
what is the equation for BMI
mass / (height)^2
67
what is the equation for waist to hip ratio
waist circumference / hip circumference
68
what is the importance of homeostasis
it constantly balances the amount of energy gained and lost to keep the core body temperature at 37 degrees celsius
69
how is the temperature of the body kept around a constant level
due to a negative feedback system which make the body bring the temp of the body back to the optimum if it gets too high or low
70
what does the thermoregulatory centre do
it acts as your own personal thermostat
71
what do the epidermis and dermis do
receptors are found in them, which send information about skin temperature via nervous impulses
72
what does the hypothalamus do
it processes the information from the temperature receptors and triggers the effectors immediately
73
what is vasodilation
when the blood vessels supplying the skin capillaries get wider so more blood flows close to the surface of the skin
74
what are the ways your body respond when your core body temperature gets too high
1. Erector muscles in the dermis relax
2. Sweating
3. Vasodilation
75
how does the body respond to a rise in body temp
when temperature receptors detect that core body temp is too high , they send inpulses to the hypothalamus, which coordinates the response.
The hypothalamus processes the information from the temp receptors and triggers the effectors immediately
The effectors produce a response that increases the amount of heat lost from the body and cools it down
76
how does the body respond to a fall in body temp
when the temp receptors detect that body temp is too low, they send impulses to hypothalamus
This processes the info and triggers the effectors to reduce the amount of heat lost from the body
the effectors produce a response that counteracts the change and the body warms up
77
what are the different responses that increase core body temperature
1. erector muscles in dermis contract
2. very little sweat is produced
3. Vasoconstriction
4. shivering
78
why must water content of the blood be controlled
in order to keep the cells functioning normally
79
what happens if the conc of water in the blood is too high
water will move into the body cells by osmosis and if too much water moves into cells, they may burst
80
what happens if the concentration of water in the blood is too low
water will move out of cells and into the blood by osmosis which will cause the cells to shrink
81
how does the kidney help regulate the water content
by controlling how much water is reabsorbed and how much water is lost in urine
82
how is urea produced
from the breakdown of excess amino acids in the liver
83
what is ultrafiltration
when substances are filtered out of the blood as it passes through the kidneys
84
what is selective reabsorption
useful substances including all the glucose, some ions and right amount of water are then reabsorbed back into the blood
85
what are nephrons
structures in the kidneys where ultrafiltration and selective reabsorption takes place
86
how is the structure of the nephron related to filtration
filtration takes place in the glomerulus which is found at the start of the nephron.
Urea, water, ions and glucose are small enough to pass out of the capillaries into the Bowman's capsule however proteins and cells are too big and stay in the blood
87
how is the structure of the nephron related to its function of selective reabsorption of glucose and ions
the substances in the bowman's capsule move into the tubule. At the proximal convoluted tubule, the amount of glucose lost in filtration is selectively reabsorbed back into the blood
88
how is the structure of the nephron related to its function of reabsorption of water and ions
water and ions are reabsorbed at the loop of Henle and collecting duct areas of the tubule
89
how is urine released
the urea, excess water and ions which aren't reabsorbed from the nephron into the blood continues out of the nephron via the collecting duct.
It then passes into the ureter and down to the bladder as urine and urine is released from the bladder through the urethra
90
what happens to ADH if water potential of the blood is too high
less ADH is released from the pituitary gland and the collecting duct becomes less permeable to water and this leads to more water being released in urination
91
what happens to ADH if water potential of the blood is too low
more ADH is released from the pituitary gland and the collecting duct becomes more permeable to water and so less water is released in urination.
92
what are the treatments for kidney failure
kidney dialysis and kidney transplants
93
what does a dialysis machine do
it takes over the role of the failing kidneys and filters the blood.
94
why does dialysis have to been done regularly
to keep the concentrations of dissolved substances in the blood at normal levels and to remove waste products
95
how does a dialysis machine work
in the machine, the persons blood flows along a partially permeable membrane, surrounded by dialysis fluid.
The membrane allows things like ions and waste products through but not big molecules.
The dialysis fluid has the same conc of ions and glucose as healthy blood so that useful dissolved ions and glucose wont be lost from the blood and only waste substances and excess water and ions
96
what is the problem with kidney transplants
the donor kidney can be rejected by the recipients immune system
97
why does kidney rejection happen
antigens on the donor kidneys are not recognised as being part of the body by the recipients white blood cells and so the WBC produce antibodies to attack the donor cells
98
how can you prevent rejection of the donor kidney
the recipient is treated with drugs that suppress the immune system as they reduce the production of antibodies by the WBC's
a donor with a tissue type that closely matches the patient's is chosen
99
how does shivering increase core body temperature
increased muscle contractions which generates more heat from respiration
100
how does vasoconstriction increase core body temperature
it reduces the amount of blood that flows close to the surface of the skin and so less energy is transferred from skin to environment
101
how does erector muscles in dermis contracting increase core body temperature
it makes hairs on skin stand up. This traps insulating layer of air next to skin reducing energy transferred to environment
102
how does Erector muscles in the dermis relaxing decrease core body temperature
makes hairs on the skin lie flat and this means less air is trapped near the surface of the skin. This allows heat to be transferred to the environment easily
103
how does sweating DECREASE core body temperature
Sweat is produced by sweat glands in the dermis and released onto the surface of the skin through pores in the epidermis. When sweat evaporates from the skin, it transfers energy to the environment, reducing body temp
104
positives of kidney dialysis
no shortage of dialysis machines
105
negatives of kidney dialysis
requires frequent treatment
have to eat controlled diet
expensive in the long term
106
positives of kidney transplant
patients can lead a normal life
only expensive initially
107
negatives of kidney transplant
shortage of kidney donors
have to take anti rejection drugs for the rest of your life
108
What happens in filtration
filtration, or ultrafiltration, occurs in the glomerulus, a collection of capillaries at the start of the nephron. Urea, water, ions and glucose are small enough to pass out of the capillaries and through the membrane into the Bowman's capsule - however proteins and cells are too large, and remain in the blood)
109
What happens in selective reabsorption
The substances in the Bowman's capsule move into the tubule. At a point called the proximal convoluted tubule (the first 'bend' in the tubule), as much glucose as was lost during ultrafiltration is selectively reabsorbed into the blood.
This is important, as glucose is valuable to the body for energy (from respiration) and we do not want it to be excreted.
110
What happens in reabsorption of water and ions
water and ions are reabsorbed at the Loop of Henle and collecting duct areas of the tubule.
