Topic 10 - The Human Nervous System Flashcards
What is homeostasis?
Keeping the body in a steady state.
What is the advantage of homeostasis?
The body is kept at optimum conditions so that the metabolism is the most effective as possible.
What internal conditions need to be kept the same in the body?
1) Temperature - (37 degrees) so that enzymes don’t denature but work at optimum temperature.
2) pH - So enzymes don’t denature but work at optimum.
3) Water concentration - to keep an osmotic balance, so cells won’t burst or shrink.
4) Sugar + salt concentration - to maintain an osmotic balance.
What are the five stages of a reflex action?
1) Stimulus
2) Sensory Receptor
3) Co-ordinator (nervous system)
4) Effector
5) Response
Which neurones link the different stages of the reflex action?
1) The sensory neurone links the sensory receptor and the relay neurone in the central nervous system.
2) The relay neurone links the sensory neurone and the motor neurone in the central nervous system.
3) The motor neurone links the relay neurone with the effector (muscle or gland).
What two parts consist the nervous system?
1) Central Nervous System - brain + spinal cord (co-ordinators).
2) Peripheral Nervous System - goes to the furthest parts of the body (sensory + motor neurones).
What are neurones?
Long specialised cells that are normally found in bundles of hundreds or thousands of neurones called nerves.
What are receptors?
Cells that detect stimuli.
What are effectors?
Areas (muscles or glands normally) that bring about a response from the body.
What are coordination centres?
Areas that receive and process information from receptors.
What are reflex arcs?
They bring about a reflex action. They involve the sense organ, sensory, relay and motor neurones.
What are reflexes?
Rapid automatic responses of the nervous system that do not involve conscious thought.
What does the cerebral cortex do?
This is the region of the brain associated with consciousness, memory and language.
What does the medulla do?
This is the region of the brain concerned with unconscious activities like controlling heart or breathing rate. Additionally, the medulla controls long term memory storage.
What does the cerebellum do?
This is the region of the brain concerned with coordinating muscular activity and balance.
What does the hypothalamus control?
This is the region of the brain that controls body temperature.
What does the temporal lobe do?
Processing auditory information and with the encoding of memory.
What do the meninges do?
They are semi-permeable and prevent diseases from entering the brain.
What does the brain stem do?
Sends signals to the rest of the body.
What do MRI scans do?
They use magnetic resonance to scan different areas of brain for the different levels of activity.
What does electrically stimulating the brain do?
It can contract and relax muscles due to stimulating parts of the brain via electrodes.
What does the pituitary gland do?
Controls the release of hormones.