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
What is urine concentration controlled by?
ADH
How does ADH control urine concentration?
Causes kidneys to absorb more water.
What are 3 plant hormones?
1 - auxine
2 - ethene
3 - gibberelins
What does auxine do in shoots?
Causes the bottom cells of the plant to elongate so it stretches up to the sun?
What causes the movement of shoots towards the sun?
Auxines/phototropism
What does auxine do in roots?
Causes the upper cells to elongate to stretch the shoots down
What causes the downward movement of roots?
Auxines/gravitropism
What human organ does a dialysis machine assist/replace?
Kidneys
How does your body handle too much glucose?
Adds insulin, which converts excess glucose into glycogen)
How does your body handle too little glucose?
Adds glucagon
What are 5 glands within the body?
1 - pituitary 2 - thyroid 3 - adrenal 4 - pancreas 5 - ovaries/testes
What differentiates T1D from T2D?
In T1D, insulin isn’t produced at all, in T2D, blood becomes insulin resistant.
What do the blood vessels do when it is too hot?
Blood vessels near skin dilate (vasodilation)
What do the blood vessels do when it is too cold?
Blood vessels near skin constrict (vasoconstriction)
What is found at the back of your brain?
Cerebellum
What is found at the front of your brain (not frontal lobe)?
Medulla
What is the largest part of your brain called?
Cerebral cortex
