Nerves and Homoeostasis Flashcards
What are the 5 sense organs?
Tongue, Nose, Ears, Eyes, Skin
What is a stimulus?
A change in environment
What is a receptor?
Something sensitive to a stimuli
How do receptors work?
They change stimulus energy into electrical impulses
Name examples of stimuli
Light, Sound, Touch, Pressure, Pain, Chemical
What receptors are in your eyes and what do they contain?
Light receptors - Have nucleus, Cytoplasm, Cell membrane
What receptors are in your ears and what do they contain?
Sound and balance receptors - Sensitive to change in position
What receptors are in your nose and what do they contain?
Smell receptors - Sensitive to chemical stimuli
What receptors are in your tongue and what do they contain?
Taste receptors - Sensitive to bitter, salt, sweet tastes (chemical stimuli)
What receptors are in your skin and what do they contain?
Sensitive to touch, pressure and temperature change
What are sensory neurons?
Nerve cells which carry electrical impulses from receptors to organs in the CNS
What are relay neurons?
Nerve cells which carry signals from the sensory neurons to the motor neurons
What are motor neurons?
Nerve cells which carry signals from the CNS to effector muscles or glands
What does the CNS consist of?
Spine and brain
What happens at the CNS?
Coordination centres - Where information from the receptors in sense organs is sent to and where responses are coordinated e.g to effector muslces
What do control systems consist of?
Receptors -> coordination centres -> effectors
What is the role of a control system in your body?
To keep conditions constant by responding to stimuli
What is the connection between 2 neurons called?
Synapse
How is the nerve signal transferred across a synapse?
By the chemicals which diffuse across the gap
What happens next after the chemicals have diffused across a synapse?
The chemicals set off a new electrical signal in the next neurons
What is a reflex?
A response to a stimuli
What is the passage of information in a reflex called?
A reflex arc
Where does a reflex arc go through in your body?
CNS
What is the brain responsible for in terms of behaviour?
Complex behaviours
What is the function of the cerebral cortex in your brain?
Consciousness, memory, language and intelligence (-> If you’re reading this, you need more)
What is the function of the medulla in your brain?
Controls unconscious activities e.g heart rate and breathing
What is the function of the cerebellum in your brain?
Muscle coordination
What is the function of your spinal cord (top end which connects to your brain)?
Part of the CNS
What are methods to see which part of the brain has been damaged?
Ask patient what effect he is having e.g blind
MRI scans
Electrically stimulating the brain
What needs to be kept constant in your body?
Water levels, glucose levels, temperature, ion content
What is the system called which keeps levels constant in your body?
Automatic control systems
What is a hormone?
Chemical substances secreted by glands
Where do hormones travel?
In the bloodstream to other parts in the body, but only effect particular cells
What is responsible to keep your ion content constant?
Kidneys
What happens if you eat a food with too much of an ion?
You shit, or piss it out