Chapter 2 - The Nervous System and Hormones Flashcards
How does the nervous system work?
Impulses from the receptors pass along the sensory neurones to the brain and spinal cord, impulses are sent along the motor neurones from the brain to the effector organs.
Receptor–>Sensory Neurone–>Cns–>Motor Neurone–> Effector
What are impulses?
Electrical signals carried along the neurones
How does the synapses work?
When an impulse from the sensory neuron arrives in the synapse a chemical is released, the chemical passes through the synapse to the relay neuron.
Why do we need the nervous system?
To be aware of our surrounding and to communicate and interact with others.
What are the 5 senses?
Taste Smell Touch Sight Hearing
What are receptors?
Cells that detect stimuli (change in the environment).
What are hormones?
Chemical messengers transported in the blood.
Where can you find hormones?
The pituitary glands.
What does Fsh do in the Menstrual Cycle?
Fsh is secreted by the pituitary glands, it matures the egg in the ovaries and stimulates the release of Oestrogen.
What does Oestrogen do in the Menstrual Cycle?
Oestrogen causes the lining of the uterus to thicken, it slows the production of Fsh and stimulates the release of LH.
What does LH do in the Menstrual Cycle?
LH stimulates the release of a mature egg.
How is Fsh used in IVF treatments?
Fsh can be used as a fertility drug to stimulate the eggs to mature in the ovaries.
What is Gravitropism?
The uneven distribution of the plant hormone ‘Auxin’.
How does Gravitropism work in plants?
In the stem of a plant auxin grows on the lower side, the stem grows on the side with more auxin making it bend and grow upwards away from the force of gravity.
In the roots of a plant auxin grows on the lower side, the root grows on the side with less auxin making it bend and grow downwards towards the force of gravity.
Pros and cons of plants hormones as weed killers?
Plant hormones are very useful as weed killers, however can damage the environment, due to their powerful chemicals.
