Topic 7 - Animal coordination , control and homeostasis

Question 1

Describe where hormones are produced and how they are
transported from endocrine glands to their target organs,
including the pituitary gland, thyroid gland, pancreas, adrenal
glands, ovaries and testes

Answer 1

• Hormones are produced in various glands , called endocrine glands. Which make up your endocrine system.
• Pituitary gland (brain)- produces many hormones, act on other glands
• Thyroid gland(neck)- regulates, heart rate, rate of metabolism, tem
• Adrenal gland- produces adrenaline, for ‘fight or flight response’
• The pancreas- produces insulin , which regulates blood glucose level
• Ovaries ( female )- produces oestrogen, progesteron , involved in menstrual cycle
• Testes(males)- produces testosterone , which controls puberty and sperm production

Question 2

Differences between neurons and hormones

Answer 2

Neurons;

• fast
• act for a short time
• act on a precise area

Hormones;

• slower
• act for a long time
• act in a more general way

Question 3

Explain that adrenaline is produced by the adrenal glands

to prepare the body for fight or flight, including:

Answer 3

• adrenaline binds to a specific receptors in the heart , which causes it to contrast more frequently with more force , so heart rate and blood pressure increases
• this increases blood flow to the muscles , so the cells receive more oxygen and glucose for increased respiration.
• adrenaline also binds to the receptors in the liver , causing the liver to break down its glycogen stores to release glucose
• This increase blood glucose level to be transported into the cells

Question 4

Explain how thyroxine controls metabolic rate as an

example of negative feedback, including:

Answer 4

Low thyroxine levels in the bloodstream stimulate the hypothalamus to release TRH (Thyrotropin releasing hormone ) and this causes the pituitary to release TSH (Thyroid stimulating hormone ) so the thyroid releases more thyroxine. So blood levels return to normal.

Question 5

Describe the stages of the menstrual cycle, including the roles
of the hormones oestrogen and progesterone, in the control of
the menstrual cycle

Answer 5

Stage 1:menstrual phase begins (1-7), the lining of the uterus breaks down and released
Stage 2: follicular phase(7-13) the uterus lining is repaired, until it becomes a thick spongy layer full of blood vesicles ready for a fertilised egg to implant there
Stage 3; ovulation phase (14-17)an egg develops and is released from the ovary
Stage 4;luteal phase (18-28) if no fertilised egg has landed on the uterus wall the cycle starts over, if the egg has been fertilized then it will implant there

Question 6

Explain the interactions of oestrogen, progesterone,
FSH and LH in the control of the menstrual cycle,
including the repair and maintenance of the uterus wall,
ovulation and menstruation

Answer 6

: follicle stimulating hormone (FSH ) causes the maturation of an egg in the ovary. luteinising hormone (LH ) stimulates the release of the egg. oestrogen is involved in repairing and thickening the uterus lining, progesterone maintains the uterine lining

Question 7

Explain how hormonal contraception influences the menstrual

cycle and prevents pregnancy

Answer 7

The synthetic oestrogen stops your body from producing two hormones that are involved in the menstrual cycle. This prevents ovulation (the release of an egg) each month. The synthetic progesterone thickens the mucus at the entrance of your womb so that sperm can’t get through to fertilise your eggs.