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biology 2022 paper 2 > Paper 2: Topic 5 Homeostasis & response - Hormonal coordination in humans (LV) > Flashcards

Paper 2: Topic 5 Homeostasis & response - Hormonal coordination in humans (LV) Flashcards

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1
Q

Describe the endocrine system (2)

A
  • Glands which secrete hormones directly into the bloodstream
  • Which travel in the plasma to their target organs
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2
Q

Define the term hormone (3)

A
  • A chemical messenger molecule
  • that is produced and secreted by an endocrine gland and
  • travels via the bloodstream to its target organ where it causes as response
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3
Q

Define the term endocrine gland (2)

A

An organ that produces a hormone which it secretes directly into the bloodstream

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4
Q

Define the term target organ

A

An organ made of cells who have receptors on their cell membranes that are complementary to specific hormones

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5
Q

State 6 differences between the nervous system and endocrine system

A
  1. Nervous system uses nerve impulse, endocrine system uses hormones
  2. Nervous system causes a quick response, endocrine system causes a slower response
  3. Effect of the nervous system is short-lived, effect of the endocrine system is longer-lasting
  4. Nervous system uses neurones, endocrine system involves glands and hormones
  5. Nervous system uses an electrical signal, endocrine system uses a chemical messenger
  6. Nervous system acts on a very precise area, endocrine system acts in a more general way
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6
Q

Name the master gland and exaplain why it is called this

A

Pituitary gland

Reason: It produces hormones which act on other glands to make them produce different hormones

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7
Q

Name 4 hormones produced and secreted by the pituitary gland

A
  1. Anti-diuretic hormone
  2. FSH (Follicle stimulating hormone)
  3. Luteinising hormone (LH)
  4. Thyroid Stimulating Hormone (TSH)
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8
Q

Why is the pituitary gland called the ‘master gland’

A

It produces several different hormones which act on other glands to stimulate other hormones to be released and cause different effects in the body

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9
Q

Describe the position of the pituitary gland

A

Specialised region of the brain

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10
Q

Describe the position of the pancreas

A

Part of the digestive system, located above the small intestine but below the stomach

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11
Q

Describe the position of the thyroid gland

A

Located in the neck region

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12
Q

Describe the position of the adrenal glands

A

Located just above the kidneys (one adrenal gland per kidney)

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13
Q

Describe the position of the ovaries

A

Part of the reproductive system, located in the pelvic region

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14
Q

Describe the position of the testes

A

Part the reproductive system, located in the scrotum

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15
Q

Describe the function/role of the pituitary gland

A
  • Produces and secretes several different hormones into the bloodstream
  • e.g. TSH, LH, FSH and ADH
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16
Q

Describe the function/role of the pancreas

A

Produces and secretes insulin and glucagon into the bloodstream

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17
Q

Describe the function/role of the thyroid gland

A
  • Produces and secretes thyroxine into the bloodstream
  • To regulate the heart rate, core body temperature and metabolic rate
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18
Q

Describe the function/role of the adrenal glands

A
  • Produces and secretes adrenaline into the bloodstream
  • To increases the heart rate for ‘flight, fright and fight’
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19
Q

Describe the function/role of the ovaries

A
  • Produces and secretes oestrogen into the bloodstream
  • To control puberty and the menstrual cycle
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20
Q

Describe the function/role of the testes (3)

A
  • Produces and secretes testosterone into the bloodstream
  • To control puberty
  • To control sperm production
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21
Q

Name the two hormones involved in regulating blood glucose levels

A

Insulin and glucagon

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22
Q

What is the difference between glucagon and glycogen?

A
  • Glucagon is a hormone produced by the pancreas when blood glucose levels are low
  • Glycogen is a complex, insoluble carbohydrate that is used to store energy in skeletal muscles and the liver
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23
Q

Describe what happens to excess glucose absorbed into the bloodstream

A
  • The glucose is absorbed into the cells of the skeletal muscles and liver
  • And it’s then converted to glycogen for storage
  • This reduces the blood glucose levels
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24
Q

Name the organ that monitors and controls the blood glucose levels

A

Pancreas

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25
Q

Name the target organs for insulin

A
  • Liver
  • Skeletal muscles
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26
Q

Name the target organs for glucagon

A
  • Liver
  • Skeletal muscles
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27
Q

Describe what happens if the blood glucose level falls too low

A
  • The pancreas detects the fall in the blood glucose levels
  • The pancreas produces and secretes glucagon into the bloodstream
  • Glucagon travels in the bloodstream to its target organs, the liver and skeletal muscles
  • The cells of the liver and skeletal muscle respond to the glucagon by breaking down stored glycogen into glucose
  • The glucose is released from the liver and skeletal muscle cells into the bloodstream
  • This raises the blood glucose levels and restores the blood glucose level to normal
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28
Q

Describe what happens if the blood glucose level becomes too high

A
  • The pancreas detects the rise in the blood glucose concentration in the blood
  • The pancreas produces and secretes insulin into the bloodstream
  • Insulin travels in the bloodstream to its target organs, the liver and skeletal muscles
  • The cells of the liver and skeletal muscles respond to the insulin by absorbing more glucose from the blood plasma
  • The glucose converted into glycogen inside the liver and skeletal muscle cells
  • The glycogen is stored in the liver and skeletal cells
  • This removes glucose from the bloodstream
  • This lowers the blood glucose concentration and restores the blood glucose level to normal
  • This is an example of negative feedback
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29
Q

Name the term that describes how blood glucose levels are regulated by the body

A

Negative feedback

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30
Q

Describe a negative feedback loop/cycle

A
  • An internal factor e.g. blood glucose levels is elevated The elevated factor is detected by receptors
  • The co-ordination centre receives the information
  • The co-ordination centre co-ordinates a response
  • The body responds by casing internal changes that lower the internal factor
  • The internal factor is returned to its normal level

Remember the same happens when the internal factor is too low but the body responds causing internal changes that raise the internal factor

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31
Q

Explain why the negative feedback loop/cycle is referred to as a loop/cycle

A
  • The body constantly responds to fluctuations in the internal factors of the body
  • The process of detecting, responding and altering the internal factors is a continual process
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32
Q

Explain why the negative feedback loop/cycle is referred to as a negative process

A

The response that occurs is opposite to the change in the body’s internal factor

For example

  • if an internal factor becomes elevated the response is to lower it
  • if an internal factor becomes too low the body’s response it to raise it
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33
Q

State the two different types of diabetes

A
  • Type I
  • Type II
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34
Q

What causes type I diabetes?

A

The person’s pancreas fails to produce sufficient insulin for them to regulate their blood glucose levels

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35
Q

State the characteristics of type I diabetes

AND

Describe the symptoms of type I diabetes

A
  • Characteristic*:
  • Uncontrolled high blood glucose levels
  • Symptoms:*
  • Tiredness and fatigue
  • Breathlessness
  • Dizziness and fainitng
  • Frequent urination
  • Dry mouth
  • Weight loss
  • Nausea and vomiting
  • Blureed vision (which can lead to blindness)
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36
Q

Name the treatment given to type I diabetics

A

Insulin therapy

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37
Q

Describe insulin therapy

A
  • The type I diabetic is given insulin injections
  • Usually at mealtimes
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38
Q

Explain how insulin therapy works

A
  • Insulin is administered at meal times
  • This makes sure the blood glucose is removed from the blood as soon as the food is digested and glucose is absorbed
  • This prevents the glucose levels from becoming too high (spiking)
  • This form of treatment is very effective
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39
Q

State and explain 2 pieces of lifestyle advice is usually given to type I diabetics

A
  • To reduce their simple carbohydrate intake i.e. reduce their intake of sugars
  • To take regular exercise which will remove the excess glucose from the blood
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40
Q

What causes type II diabetes?

A

The person’s liver cells and skeletal muscle cells no longer responds to insulin produced by the pancreas

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41
Q

State the characteristics of type II diabetes

A

Uncontrolled high blood glucose levels

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42
Q

Describe how type II diabetes is normally treated

A

Follow a carbohydrate controlled diet and follow an exercise regime

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43
Q

Which type of diabetes increases the risk of obesity?

A

Type II

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44
Q

State 3 organs involved in the removal of waste materials/products from the body

A
  1. Skin
  2. Kidney
  3. Lungs
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45
Q

State 4 waste products that must be removed from the body

A
  • Carbon dioxide
  • Excess water
  • Urea
  • Excess ions
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46
Q

State 3 ways water is removed from the body

A
  • During exhalation as water vapour
  • As the solvent that forms urine via the kidneys
  • As sweat from the skin
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47
Q

State 2 ways ions are lost from the body

A

From the skin as sweat In the urine via the kidneys

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48
Q

State 2 ways urea is lost from the body

A
  • In the urine via the kidneys
  • A small (uncontrolled) quantity is lost from the skin as sweat
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49
Q

Explain why the skin and lungs are less efficient as excretory organs than the kidneys

A
  • The skin and lungs have no control over water, ion or urea lost
  • The kidney has a high degree of control over how much water, ions and urea is removed from the body
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50
Q

Explain why it is important to regulate the internal water content of the body

A
  • If animal cells contain too much water they will rupture
  • This is called cytolysis
  • If animal cells contain too little water they will crenate
  • In both case this will cause the cells to fail to function correctly
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51
Q

Explain how urea is formed

A
  • Excess proteins in the diet are broken down during digestion
  • By protease to amino acids
  • The excess amino acids are deaminated in the liver
  • To form ammonia
  • Ammonia is highly soluble and toxic
  • So it is immediately converted to urea
  • So that it can be safely excreted
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52
Q

Explain the term excretion

A
  • The removal of waste products from the body that have been produced by cells during metabolism e.g.
    • carbon dioxide (from respiration)
    • urea (from deamination)
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53
Q

Explain the term egestion

A
  • The removal of dead cells and undigested food from the body
  • E.g. dead bacteria from the gut
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54
Q

State the two main processes that occur in the kidney to produce urine

A
  1. Filtration
  2. Selective reabsorption
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55
Q

State 4 molecules that are filtered out of the blood plasma into the filtrate in the kidneys

A
  1. Water
  2. Ions
  3. Glucose
  4. Amino acids
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56
Q

Explain why cells are not filtered out of the blood plasma into the filtrate during urine formation

A

The cells are too big to pass through the membrane that filters the blood

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57
Q

State 3 molecules that are selectively reabsorbed back into the blood in the kidney

A
  • All the glucose
  • The required quantity of ions
  • The required quantity of water
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58
Q

State 3 molecules that are excreted in the urine

A
  • Excess ions
  • Excess water
  • The majority of the urea
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59
Q

Explain why it is important to regulate the ion level of the blood

A
  • If the ion content of the blood changes it alters the water potential of the blood
  • This causes the cells to become crenated or to rupture
  • This then prevents the cells from functioning correctly
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60
Q

Name the hormone involved in regulating the water content of the blood

A

Anti-diuretic hormone (ADH)

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61
Q

Name the part of the body that monitors the water content of the blood

A

The osmo-regulatory centre of the brain

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62
Q

Name the receptors in the brain that detect changes in the water level of the blood

A

Osmoreceptors

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63
Q

Describe the events that occur if the water content of the blood is too high

A
  • Osmoreceptors in the osmo-regulatory centre of the brain detect changes in the water level of the blood following through the brain
  • The co-ordination centre in the brain receives the information and co-ordinates a response
  • The pituitary gland releases less ADH
  • This causes less water to be reabsorbed from the filtrate back into the blood
  • This causes the water volume of the blood to decrease
  • A greater volume of urine is produced
  • The urine is more dilute
64
Q

Describe the events that occur if the water content of the blood is too low

A
  • Osmoreceptors in the osmo-regulatory centre of the brain detect changes in the water level of the blood following through the brain
  • The co-ordination centre in the brain receives the information and co-ordinates a response
  • The pituitary gland releases more ADH
  • This causes more water to be reabsorbed from the filtrate back into the blood
  • This causes the water volume of the blood to increase
  • A smaller volume of urine is produced
  • The urine is more concentrated
65
Q

Describe the effect ADH has on the kidney tubules (2)

A
  • The more ADH the more permeable the kidney tubules are to water
  • So more water is reabsorbed
66
Q

Name the term that describes how blood water levels are regulated by the body

A

Negative feedback

67
Q

State 2 possible forms of treatment for a patient whose kidneys have stopped working

A
  1. Kidney dialysis
  2. Kidney transplant
68
Q

Describe why kidney failure can be fatal

A
  • The function of the kidneys is to remove waste products from the blood
  • If they stop working (fully) the waste products accumulate
  • The waste products can become toxic
  • Causing cell damage and failure of the cells to work correctly
  • This can then lead to multiple tissue and multiple organ failure potentially resulting in death
69
Q

Describe the function of a dialysis machine

A
  • To carry out the same function that would be carried out by healthy kidneys
  • To remove waste products from the blood plasma
  • This then maintains dissolved substances in the blood at their normal levels
70
Q

Describe the properties of the membrane used in a dialysis machine

A

Partially permeable

71
Q

What does the term ‘partially permeable membrane’ mean?

A

The membrane allows certain molecules to pass through but not others

72
Q

Describe 3 dissolved substances that are removed from the blood plasma by a dialysis machine

A
  • Excess ions
  • Excess water
  • All the urea
73
Q

Describe how blood glucose levels are kept at the correct level when a patient has dialysis

A
  • The dialysis fluid as glucose dissolved in it
  • The concentration of the glucose in the dialysis fluid is the set at the level that the person requires
  • This means only excess glucose is filtered out by dialysis
  • As only the extra glucose will diffuse from the blood plasma into the dialysis fluid
74
Q

How frequently must a patient have dialysis?

A
  • 3 times a week
  • Each session lasts 3-4 hours
75
Q

State 2 risks of dialysis

A
  1. Risk of infection
  2. Risk of blood clots (thrombus) forming
76
Q

State 4 advantages of dialysis compared to a kidney transplant

A
  1. No risk of rejection
  2. No need for immunosuppressant drugs for the rest of life
  3. Readily available – new kidneys are rare
  4. Can ‘buy time’ until a donor kidney becomes available
77
Q

State 5 advantages of a kidney transplant compared to a dialysis

A
  1. Lifestyle no longer restricted by dialysis
  2. Life returns to completely normal
  3. Diet is normal – no need for special food regime
  4. Cheaper than long-term dialysis (although single one off operation is costly, the life-long cost of dialysis is much higher overall)
  5. Recipient can return to a ‘normal’ lifestyle e.g. return to work
78
Q

State 5 disadvantages of a kidney transplant

A
  1. Lack of donor kidneys – so long waiting list
  2. Risk associated with general surgery e.g. reacting to the anaesthetic
  3. Risk of kidney rejection
  4. Patient must take immune-suppressants for life
  5. Operation itself is a high cost
79
Q

State 3 disadvantages of dialysis

A
  1. Very intrusive – lifestyle is seriously affected
  2. Patient unlikely to be able to work (due to long and frequent trips to hospital)
  3. Risk of infection is high It is not a ‘cure’ – can’t be used indefinitely
80
Q

Describe the changes that occur to a female during puberty

A
  • Menstrual cycle starts
  • Breast tissue develops
  • Hips widen
  • Pubic hair grows
81
Q

Describe the changes that occur to a male during puberty

A
  • Pubic hair grows
  • Facial hair grows
  • Shoulders broaden
  • Muscle development increases
82
Q

Name the term that describes the physical changes that occur during puberty

A

Secondary sexual characteristics

83
Q

Name the male hormone responsible for secondary sexual characteristics

A

Testosterone

84
Q

Name the female hormone responsible for secondary sexual characteristics

A

Oestrogen

85
Q

Name the organ that produces testosterone

A

Testes

86
Q

Name the organ that produces oestrogen

A

Ovaries

87
Q

State the 4 main stages that occur during a menstrual cycle

A
  • Stage 1: menstruation occurs
  • Stage 2: the uterus lining is rebuilt
  • Stage 3 Ovulation occurs
  • Stage 4: Implantation occurs if the woman has conceived or the lining of the uterus begins to break down again
88
Q

Describe the events that occur during stage 1 of the menstrual cycle, menstruation

A
  • The lining of the uterus breaks down
  • The blood is lost from the female body via the vagina
  • This stage lasts ~4 days
89
Q

Describe the events that occur during stage 2 of the menstrual cycle

A
  • The uterus lining is rebuilt It becomes thick and full of blood vessels
  • This stage lasts from day 4 to day 14
90
Q

Describe the events that occur during stage 3 of the menstrual cycle, ovulation

A
  • An ovum is released from an ovary
  • The ovum is moved down the fallopian tubes towards the uterus
  • This occurs on ~day 14
91
Q

Describe the events that occur during stage 4 of the menstrual cycle

A
  • If fertilisation occurs the zygote implants in the uterus lining
  • If fertilisation has not occurred the spongy lining of the uterus breaks down
  • The cycle repeats itself
92
Q

What event marks the start of a menstrual cycle?

A

The first day of menstruation (period)

93
Q

Name the 4 hormones that control the menstrual cycle

A
  1. Follicle stimulating hormone (FSH)
  2. Oestrogen
  3. Progesterone
  4. Luteinising hormone (LH)
94
Q

Describe the role/function of FSH in the menstrual cycle

A
  • Causes an ovum to mature into a follicle in one of the ovaries
  • Stimulates the ovaries to produce oestrogen
95
Q

Describe the role/function of oestrogen in the menstrual cycle

A
  • Causes the lining of the uterus to thicken
  • Stimulates the release of LH
  • Inhibits the release of FSH
96
Q

Describe the role/function of progesterone in the menstrual cycle

A
  • Maintains the lining of the uterus during the 2nd half of the menstrual cycle
  • Low levels of progesterone cause the uterus lining to break down
  • Inhibits the release of LH
  • Inhibits the release of FSH
97
Q

Describe the role/function of LH in the menstrual cycle

A

Stimulates ovulation on day 14

98
Q

State where FSH is produced

A

Pituitary gland

99
Q

State where oestrogen is produced

A

Ovaries

100
Q

State where progesterone is produced

A
  • Ovaries
  • By the follicle cells left in the ovary after ovulation
101
Q

State where LH is produced

A

Pituitary gland

102
Q

Describe the term contraception

A

A method for reducing the chance of fertilisation (and hence pregnancy)

103
Q

State the 2 main ways contraceptives work

A
  • Reduce fertility
  • Preventing fertilisation
104
Q

Why is it incorrect to refer to surgical sterilisation as a contraception

A
  • Surgical sterilisation is (generally) permanent
  • When a woman has her fallopian tubes tied or a man has a vasectomy it is (very) rare for these operations to be reversed successfully
  • Hence neither form of sterilisation can be used for a short period of time and then stopped
105
Q

State the 2 hormones found in most combined oral contraceptive pills

A
  1. Oestrogen
  2. Progesterone
106
Q

Describe how oestrogen can be used in a contraceptive pill to reduce fertility

A
  • Oestrogen can be used to prevent ovulation
  • Permanently high levels of oestrogen inhibits the release of FSH
  • The absence of FSH stops the maturation of an ovum into a follicle
  • So no ovulation occurs
107
Q

Describe how progesterone can be used in a contraceptive pill to reduce fertility

A
  • Progesterone stimulates the production of thick mucus
  • This thick mucus prevents the sperm travelling through the cervix to meet the ovum
  • So no fertilisation can occur
108
Q

State 4 disadvantages of taking combined oral-contraceptive pills to reduce fertility in females

A
  • Risks of blood clots (thrombus)
  • Can cause headaches
  • Can cause nausea
  • It does not protect against sexually transmitted diseases
109
Q

State the advantage of using a progesterone-only contraceptive pill

A

It has fewer side effects than the combined pill (and it still just as effective!)

110
Q

Other than pills, state 4 other hormonal contraception methods

A
  1. Contraceptive patch
  2. Contraceptive implant
  3. Contraceptive injection
  4. Intrauterine device
111
Q

Describe how the contraceptive patch works

A
  • A small (5cm x 5cm) patch is stick to the female’s arm
  • The patch contains both oestrogen and progesterone
  • The hormones are slowly released into the bloodstream
  • Each patch lasts one week
112
Q

Describe how the contraceptive implant works

A
  • A small implant is inserted under the skin in the female’s arm
  • It releases a continual quantity of progesterone into the bloodstream
  • The progesterone prevents ovulation and makes it harder for the sperm to pass through the cervix to reach the ovum
  • So fertilisation is prevented
  • Each implant can last ~3 years
113
Q

Describe how the contraceptive injection works

A
  • The injection contains progesterone
  • The progesterone prevents ovulation and makes it harder for the sperm to pass through the cervix to reach the ovum
  • So fertilisation is prevented
  • Each does lasts 2-3 months
114
Q

Describe how an intrauterine device works

A
  • These can be made from plastic or copper
  • The t-shaped device is inserted into the uterus
  • Plastic IUD release progesterone
  • Copper IUD prevent the sperm surviving in the uterus
  • They prevent the embryo from implanting in the uterus
115
Q

State 4 examples of barrier contraceptives

A

Condoms

Femidoms

Diaphragm

Spermicide

116
Q

Describe how barrier contraceptives work

A

Non-hormonal contraceptives prevent the sperm from reaching the ovum

117
Q

Describe how condoms are used to prevent fertilisation/pregnancy

A
  • Condoms are worn over the penis during sexual intercourse
  • The condom collects the sperm that are ejaculated
  • This prevents the sperm from entering the vagina
118
Q

Describe how femidoms are used to prevent fertilisation/pregnancy

A
  • Femidoms are worn inside the vagina
  • They prevent the sperm moving through the vagina and the cervix to the fallopian tubes
  • This prevents the sperm from reaching an ovum
119
Q

Describe how diaphragms are used to prevent fertilisation/pregnancy

A
  • A diaphragm is a plastic cup that sits over the cervix
  • This must be used with a spermicide
  • They prevent the sperm moving through the vagina and the cervix to the fallopian tubes
  • This prevents the sperm from reaching an ovum and the spermicide kills or disable any sperm that reaches the diaphragm
120
Q

Describe how spermicides are used to prevent fertilisation/pregnancy

A
  • A spermicide can be used on its own but it is NOT very effective (~70%)
  • The spermicide kills or disables the sperm
121
Q

Describe the two forms of surgical sterilisation

A
  • Tubal ligation
  • Vasectomy
122
Q

Explain how tubal ligation can be used as a form of preventing pregnancy

A
  • Cutting or tying the fallopian tubes will prevent the ovum from passing to the uterus
  • So no fertilisation and implantation can occur
123
Q

Explain how a vasectomy can be used as a form of preventing pregnancy

A
  • Cutting or tying the sperm ducts will prevent the sperm passing into the urethra and being ejaculated
  • So no fertilisation and implantation can occur
124
Q

Explain the ‘natural’ method of contraception

A
  • This is when a couple avoid sexual intercourse during the most fertile days of the menstrual cycle

Please note: this is NOT a reliable or effective form of contraception

125
Q

State the most effective way to avoid pregnancy

A

Abstinence – avoid having sexual intercourse!

126
Q

Describe how hormones can be used to increase fertility

A
  • FSH and LH can be prescribed to a woman who has low fertility
  • These hormones will stimulate ovulation
127
Q

State an advantage of prescribing a woman fertility drugs

A

It helps a lot of women who have naturally low levels of FSH to become pregnant

128
Q

State 4 disadvantages of prescribing a woman fertility drugs

A
  1. It is not always successful
  2. It may have to be repeated several times
  3. It is costly
  4. Too many ova may be stimulated which can cause unexpected multiple pregnancies
129
Q

State what IVF stands for

A

In-vitro fertilisation

130
Q

Describe the 5 key stages in IVF

A
  1. The woman is prescribed FSH and LH to stimulate several ova to mature
  2. Ova are collected from the woman’s ovaries
  3. The ovum is fertilised in a lab using a man’s sperm OR a sperm can be injected directly into an ovum using a technique called ICSI
  4. The zygote is grown into an embryo in a lab incubator
  5. The embryo is transferred into the woman’s uterus
131
Q

State what ICSI stands for

A

Intra-cytoplasmic sperm injection

132
Q

Describe a situation where a couple may be advised to consider using ICSI

A

When the male has a low/no sperm count

133
Q

State an advantage of IVF

A

It enables infertile couples to conceive and have their own biological children

134
Q

State 6 disadvantages of IVF

A
  1. Multiple births can happen
  2. Multiple births are risky for the unborn babies and the mother e.g. higher risk of miscarriage, higher risk of the babies being still born
  3. The success rate of IVF is low
  4. The procedure is very emotionally stressful and upsetting for the couple as it often ends with multiple failures
  5. The procedure is physically stressful for the woman
  6. Some women have side effects to the hormones e.g. vomiting, abdominal pain, dehydration
135
Q

Give 3 reasons why some people object to IVF

A
  1. IVF often produces several embryos that are unused which just get destroyed
  2. People object to unused embryos being destroyed as they think it is unethical to destroy a potential human life
  3. It is possible that through genetic testing of embryos certain characteristics could be selected e.g. hair colour which is unethical
136
Q

State where adrenaline is produced

A

Adrenal glands

137
Q

State 3 situations where adrenaline secretion is increased

A

When the body is preparing for

  • Flight
  • Fright
  • Fight situations
138
Q

State 3 effects of the increased secretion of adrenaline

A
  1. Increased heart rate
  2. Increased supply of oxygen to the brain and skeletal muscles
  3. Increases supply of glucose to the brain and skeletal muscles
139
Q

Name the hormone that regulates metabolism

A

Thyroxine

140
Q

State where thyroxine is produced

A

Thyroid gland in the neck

141
Q

State 2 effects of increased thyroxine secretion

A
  1. Increasing metabolic rate
  2. Stimulating protein synthesis
142
Q

Name the hormone that stimulates the production and secretion of thyroxine

A

Thyroid stimulating hormone

143
Q

Name the term that describes how thyroxine levels are regulated by the body

A

Negative feedback

144
Q

Label the endocrine glands

A
145
Q

Complete the table to compare the endocrine system and the nervous system

A
146
Q

Distinguish between these three terms:

  • Glucose
  • Glycogen
  • Glucagon
A
147
Q

Describe the role of thyroxine (2)

A
  • Thyroxine controls cell metabolism
  • Thyroxine ensures metabolism occurs at the correct pace
148
Q

What is thyroxine? How is it transported around the body?

A

What is thyroxine?

  • Thyroxine is a hormone (chemical messenger)
  • It is produced by the thyroid gland (an endocrine gland) located in the neck

How is it trasnported?

  • Like all hormones, thyroxine is transported around the body in the blood plasma
149
Q

Explain how thyroxine levels are regulated (controlled) in the body

A
  • Negative feedback controls the levels of thyroxine
  • Negative feedback ensures that any changes are reversed and returned back to the normal level
  • As levels of thyroxine increase in the bloodstream TSH is inhibited
  • This stops the thyroid gland producing thyroxine
150
Q

What is adrenaline and when is it produced?

A
  • Adrenaline is produced by the adrenal glands
  • It is produced in times of fear or stress.
151
Q

Describe the body’s responses to adrenaline

A

It causes the following responses:

  • increases the heart rate
  • increases breathing rate
  • stimulate the liver to break down glycogen to glucose
  • increases the delivery of oxygen and glucose to the brain
  • increases the delivery of oxygen and glucose to the muscles
  • causes the pupils to dilate
  • increases the person’s mental awareness i.e. increased sensitivity

i.e. this prepares the body for ‘flight or fight’.

152
Q

Label frontal view of the female reproductive system

A
153
Q

Label the side view of the female reproductive system

A
154
Q

Label the frontal view of the male reproductive system

A
155
Q

Label the side view of the male reproductive system

A
156
Q

Label the 4 different stages of the menstrual cycle

A
157
Q

Label the 4 different hormones involved in the menstrual cycle and identify the point of ovulation

A

biology 2022 paper 2 (6 decks)

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