Biology Topic 5 - 1/2 Flashcards
Define Homeostasis
To be able to maintain a stable internal environment by regulating your conditions internally and externally
What is the function of your automatic control system in your body
Regulates your internal environment such as body temperature, blood glucose levels and water content
What three things is your automatic control system made up of
Receptors
Coordination centre
Effectors
Neurones
What happens during Negative Feedback
This is when your automatic control system keeps your internal environment stable. When the level of something gets too high or too low, your body uses negative feedback to bring it back to normal
What happens when a Stimulus detects that something is too high
- Receptor detects a stimulus as it is too high
- The coordination centre receives it and processes the information and organises a response
- Effectors produces a response which counteracts the change and restores back to optimum level
What happens when a Stimulus detects that something is too low
- Receptor detects a stimulus as it is too low
- The coordination centre receives it and processes the information and organises a response
- Effectors produces a response which counteracts the change and restores back to optimum level
What does the Nervous system do
Detects and reacts to stimuli
What does the Central Nervous System consist of
Consists of the brain and spinal chord
Define sensory neurone
This neurone carries information as electrical impulses from the receptors to CNS
Define motor neurone
This neurone carries information as electrical impulses from the CNS to effectors
Define Effector
It is where all your muscles and glands respond to electrical impulses
How does the muscles react to a stimulus
They contract in response to electrical impulses
How does the glands react to a stimulus
Glands secrete hormones
What is a synapses
the connection between 2 neurones where one neurone transmits impulses from electrical to chemical impulses as it diffuses across the gap then goes back to electrical impulse when it reaches the next neurone
What are reflexes and how is it helpful
Reflexes are rapid, automatic responses to certain stimuli that dont involve using the brain to think which can prevent injuries
What is a reflex arc
The passage of information from receptor to effector
Describe the 6 stages of the reflex arc of a bee stinging a finger
1) The bee stings the finger
2) The receptor detects the stimulus
3) The information is sent along the sensory neurone to the CNS where it reaches a synapse and electrical impulses is transferred to chemical impulses as it diffuses through the gap to the relay neurone and then transfers back to electrical impulses
4) Then the information is sent from the relay neuron to motor neurone where electrical impulses transfer to chemical impulses as it diffuses through the gap then reaches the motor neurone as electrical impulse
5) Information is sent from motor neurone to effector (muscle)
6) The muscle then contracts and moves hand away from bee
What makes your reaction time faster
Caffeine is a drug that can speed up a persons reaction time
How can you investigate reaction time using a ruler drop test
1) person tested sits with arm resting on edge of table
2) Hold a vertical ruler between their thumb and forefinger with it in line with 0cm
3) let go without giving a warning
4) The person should catch it ASAP
5) The smaller the number they catch it on the faster their reaction time
6) Repeat several times and calculate mean distance
What are 3!control variable should you control
Use same hand when catching
Use same person catching ruler
Ruler should be dropped from same height
How can you investigate reaction time using a computer test
The person being tested has to click a mouse or press a key as soon as they see a stimulus on the screen like a change in colour
How is computer test more precise
1) It gives more precise reaction time as it removes possibility of human error
2) Computer can record the reaction time in milliseconds
3) Removes possibility that the person can predict when the dropper is going to drop the ruler by reading body language
