B3.2 Flashcards
(62 cards)
What type of signal is used in the endocrine system?
Chemical
What type of signal is used in the nervous system?
Electrical
What is the transmitter in the endocrine system?
Hormones in bloodstream
What is the transmitter in the nervous system?
Nerve cells
What is the speed of response in the endocrine system?
Slower
What is the speed of response in the nervous system?
Very fast
What is the duration of response in the endocrine system?
Long
What is the duration of response in the nervous system?
Short
Where is adrenaline produced?
Adrenal glands above kidneys
What is the role of adrenaline?
Triggers ‘fight or flight’, increases heart rate and breathing rate, dilates pupils, makes hairs stand up (erect)
Where is thyroxine produced?
Thyroid gland in the neck
What does thyroxine control?
Metabolic rate, growth
What happens if thyroxine levels are low?
Hypothalamus releases TRH, pituitary releases TSH (thyroid stimulating hormone) → thyroid makes more thyroxine
What happens when thyroxine levels return to normal?
TRH and TSH secretion inhibited (negative feedback)
What does testosterone do?
Produced by testes, develops sperm and secondary sexual characteristics in males
What does oestrogen do?
Produced by ovaries, develops secondary sexual characteristics in females
What does oestrogen do in the menstrual cycle?
Thickens uterus lining for implantation
When do oestrogen levels peak?
Day 10
What does FSH (follicle stimulating hormone) do?
Matures egg in ovary
What does LH (luteinising hormone) do?
Stimulates ovulation
What causes FSH and LH to increase?
Drop in oestrogen levels
When does ovulation occur?
Day 14 – when FSH and LH peak
What does progesterone do?
Maintains thick uterus lining
What hormones does progesterone inhibit?
FSH and LH