B1.2 Nerves and Hormones Flashcards
What is a vaccine?
A weakened or dead pathogen that induces immunity. White blood cells recognize the pathogens antigens. White blood cells then produce specific antibodies.
What is the nervous system sequence?
RECEPTOR → SENSORY NEURONE → CNS → MOTOR NEURONE → EFFECTOR
What is the CNS?
Central Nervous System
Where is FSH produced and what does it do?
Pituitary gland
stimulates egg to develop
stimulates ovaries to produce oestrogen
Where is Oestrogen produced and what does it do?
Ovaries
inhibits FSH
uterus lining thickens
stimulates the release of LH
Where is LH produced and what does it do?
Pituitary gland
stimulates release of an egg at day 14
What is a reflex action?
A rapid, automatic response of the nervous system that requires no conscious thought
What is the reflex action sequence?
STIMULUS → RECEPTOR → SENSORY NEURONE → SYNAPSE → RELAY NEURONE → SYNAPSE → MOTOR NEURONE → EFFECTOR → RESPONSE
What is homeostasis?
The control of a constant internal enviroment
How does gravitropism work?
Where there is least auxin there is poor growth - in the root (grows down most on the bottom)
The lower half of the shoot grows more (because there is more auxin)causing upward growth
How does phototropism work?
There is more growth where there is more auxin.
More auxin on the darker side (away from sun) so there is more growth.
The plants tilts towards the sun.
Describe the process of IVF (In Vitro Fertilisation) ?
> fertility drugs can be used to make lots of eggs mature
the mature eggs are collected
the eggs are put in a special solution in a petri dish
a sample of semen (with sperm) is collected
when eggs are fertilised 1-2 embryos are placed in the mother’s uterus
the embryo will grow and develop
What is the oral contraceptive pill?
Pill that contains female hormones. It prevents the egg release and inhibits FSH productions
What are the advantages and disadvantages of the oral contraceptive pill?
ADVANTAGES: reduces some cancer risks family planning avoids unwanted pregnancy over 90% effective
DISADVANTAGES: blood clots no STI protection not 100% effective strict consumption rules
What do humans control and maintain levels of?
Water
Ions (in water)
Blood sugar
Temperature
