B3.1 Control Systems Flashcards
What are the three main functions of the kidneys?
Removal of the urea from the blood
Adjustment of the ion levels in the blood
Adjustment of water content in the blood
Which substances are squeezed out of the blood by high pressure?
Water
Urea
Ions
Glucose
Which substances are not filtered out by the kidneys?
Proteins and blood cells
Which substances are selectively reabsorbed?
Glucose
Sufficient water
What is water content controlled by?
Negative feedback
What hormone controls water content?
Anti-Diuretic-Hormone (ADH)
If you are dehydrated, how is it adjusted?
Brain detects water loss
Pituitary gland releases more ADH
ADH makes kidneys absorb more water
Hydrated
What is the function of a dialysis machine?
To filter blood for patients who have kidney failure.
What is an alternative solution to dialysis for patients with kidney failure?
A kidney transplant
What is the danger of a kidney transplant?
They can be rejected by the patients body.
What are the adaptations of an egg that suit it?
Contains nutrients to nourish the developing embryo
After fertilisation, the membrane changes its structure to stop more sperm getting in
What features does a sperm cell have?
Long tails to swim
Lots of mitochondria to respire when swimming
They store enzymes to break through the egg
What is FSH and its uses in the menstrual cycle?
Follicle-stimulating hormone causes a follicle to mature in an ovary and it stimulates oestrogen production.
What is the purpose of Oestrogen in the menstrual cycle?
It causes the lining of the uterus to thicken and grow, as well as stimulating an LSH surge.
What is LH and its purpose in the menstrual cycle?
Luteinising Hormone stimulates the follicle to rupture and release the egg. It also stimulates the remainder of the follicle to develop into a structure called a corpus luteum which secretes progesterone.
What is the purpose of Progesterone in the menstrual cycle?
Maintains the lining of the uterus
Prevents the production of FSH and LH
When progesterone levels fall and theres a low oestrogen level, the lining of the uterus breaks down
A low progesterone level allows FSH to increase, which starts the cycle again.