B5 - Homeostasis Flashcards
What does a negative feedback system do?
Counteract change
What are the 4 components of the nervous system?
CNS
Sensory neurones
Motor neurones
Effectors
What are 3 ways to correct vision defects?
1 - contacts
2 - laser eye surgery
3 - replacement lens surgery
What are the 3 ways to study the brain?
1 - studying patients with brain damage
2 - electrically stimulating the brain
3 - MRI scans
What happens at the synapses between neurones?
Diffusion of chemicals
How do the lenses adjust to view near objects?
Cillary muscles tighten, suspensory ligaments relax.
How do the lenses adjust to view far objects?
Cillary muscles relax, suspensory ligaments tighten.
How many stages does the female menstrual cycle have?
4
What are the 4 hormones involved in the menstrual cycle?
FSH, LH, Oestrogen, Progesterone
What does FSH do?
Stimulate oestrogen production
What does oestrogen do?
Growth of lining + stims LH
What does LH do?
Stims egg release
What does progesterone do?
Inhibits LH + FSH
What do kidneys filter from the blood?
Urea, ions/salts, water
What does thyroxine do?
Controls metabolism