[Part 3]- B11- hormonal coordination 🫥🚺🚹

Question 1

What’s are adrenal glands ?

Answer 1

• the adrenal gland, are located at the top of the kidneys, and they produce the hormone adrenaline during times of fear or stress
• this adrenaline, is then released into the blood

Question 2

How does adrenaline, provide the body for ‘flight or fight’ ?

Hint: why ?

Answer 2

• one of the main effects of adrenaline, is to increase the heart rate.
• ; as the heart is beating faster, more oxygen and glucose are delivered in the blood, to the brain and muscles.
• This is because, both oxygen and glucose are needed for aerobic respiration.
• and by doing this, the body is prepared with a flight or fight response [to fight or run away]

Question 3

RECAP: Why are both oxygen and, glucose needed for aerobic respiration ? [3]

Hint: breaks down

Answer 3

• they are the reactants of aerobic respiration.
• and during aerobic respiration, it breaks down glucose and then combines the broken down products with oxygen, producing carbon dioxide and water.
• ; because this glucose reacts with oxygen, glucose is then
  oxidised to release its energy- [which is then stored in ATP molecules]

Question 4

What’s the thyroid gland ?

Hint: growth

Answer 4

• the thyroid gland, is located at the bound of the neck and it releases the hormone: thyroxine
• ; thyroxine has two main effects- to stimulate the body’s basal metabolic rate [it makes the body’s chemical reactions take place, at a faster rate]
• and, it also plays an important role in growth and development

Question 5

Fill in the gap: the level of thyroxine in the blood, is controlled by ________ feedback but, the level of adrenaline in the blood isn’t controlled by ________ feedback.

Answer 5

• the level of thyroxine in the blood, is controlled by negative feedback but, the level of adrenaline in the blood isn’t controlled by negative feedback.

Question 6

What is negative feedback ?

Hint: any alteration from the

Answer 6

• negative feedback, is the process in which any alteration from the normal level sets in motion changes, which lead to a return to the original value

Question 7

Hard: Describe the negative feedback cycle, for adrenaline and thyroxine 🧠 [5]

Hint: monitored, stimulated, release, more thyroxine, brain, less

Answer 7

• the level of thyroxine in the blood, is monitored by the brain.
• when the thyroxine level falls, the hypothalamus will be stimulated to release Thyrotropin Releasing Hormone [TRH] the pituitary gland.
• this then will then release TSH [a hormone] into the bloodstream
• TSH will then trigger the thyroid gland, to release more thyroxine into the blood
• and this increased level of thyroxine is then detected by the brain- and this prevents the pituitary gland from releasing TSH
• ; as the TSH level falls, the thyroid gland now releases less thyroxine

Question 8

RECAP: What’s metabolism ?

Answer 8

• metabolism, is the sum of all the reactions in a cell or the body

Question 9

Give two examples of negative feedback cycles [2]

Answer 9

• the control of blood glucose
• and, in the menstrual cycle

Question 10

What’s some of the other effects, of adrenaline ? [3]

Answer 10

• adrenaline causes the pupils of your eye to dilate, to let in more light [pupil dilation]
• adrenaline increases your mental awareness
• ; adrenaline also causes blood to be redirected away from your digestive system, to the [big] muscles of the limbs,
  and to the brain- for increased oxygen delivery

Question 11

Hard: What’s the adrenaline pathway ? [4]🩸

Hint: reponse to a stimulus, secreted, dealt with, stop secreting

Answer 11

• in response to a stimulus [typically danger or excitement], the hypothalamus stimulates the adrenal glands, to secrete adrenaline.
• adrenaline is then secreted by the adrenal glands and, this releases [a high volume of] adrenaline into the blood
• the body now reacts to the stimuli, and is the threat or excitement is dealt with, so the hypothalamus then stops stimulating the adrenal glands.
• this causes the adrenal glands to stop secreting adrenaline, and the volume of adrenaline in the blood, returns to a low and normal volume.

Question 12

What’s TSH ?

Question 13

What’s the effect of having too much, or too little thyroxine ?

Question 14

What are the two reproductive hormones in men and women ?

Answer 14

• in men, testosterone is produced by the testes- this stimulates the testes, to produce sperm
• ; in women, oestrogen is produced by the ovaries

Question 15

compare and contrast the changes to girls and boys, during puberty

Question 16

Fill in the gaps: once puberty begins in girls, ____ in the ovaries start to ______

Answer 16

• once puberty begins in girls, eggs in the ovaries start to mature

Question 17

What is ovulation ?

Answer 17

• ovulation, is a process which causes the egg to be released from the follicle [an egg is approximately released, every 28 days]

Question 18

What is the menstrual cycle ?

Answer 18

• the menstrual cycle, is the period of time in which an egg develops and is released, ready for fertilisation

Question 19

What are the steps, of the menstrual cycle ? [5]

Answer 19

• the lining breaks down and, the egg starts to mature due to FSH.
• the uterus lining then builds up due to oestrogen.
• and, the egg is released due to high LH.
• the uterus lining is then maintained due to progesterone
• and, fertilisation may occur; it might not

Question 20

What are the four key hormones, in the menstrual cycle ? [4]

Answer 20

• follicle stimulating hormone [FSH]
• luteinising hormone [LH]
• oestrogen
• and progesterone

Question 21

What’s the role of follicle stimulating hormone [FSH] ?

Answer 21

• follicle stimulating hormone [FSH], causes an egg to mature in the ovary

Question 22

What’s the role of luteinising hormone [LH] ?

Answer 22

• luteinising hormone [LH], causes the egg [matured in the ovary] to be released- luteinising hormone [LH] causes ovulation

Question 23

What’s the role of oestrogen, and progesterone ?

Answer 23

• oestrogen and progesterone [is produced by the ovary], and is involved in: maintaining the uterus lining, in case the egg is fertilised and implants