Homeostasis & Response Flashcards
What’s homeostasis?
The regulation of internal environment/conditions in cells and organisms.
What are the 3 conditions in humans?
- Blood & glucose concentration
- Water Levels
- Temperature
What is a stimulus?
A change in the environment
Name 2 automatic control systems
- Nervous
* Hormonal
What are automatic control systems made of?
Receptors, coordination centres and effectors.
What’s the process of negative feedback?
The receptor detects the change.
The coordination centre receives and processes the information and organise a response.
The effector produces the response that will restore the optimum level.
What are two examples of coordination systems?
Brain and Pancreas
What are two examples of effectors?
Muscles and Glands
What’s the central nervous system made of?
Brain and Spinal Cord
What’s the path of the nervous system?
The stimulus is detected by the receptor.
An electrical impulses is passed to the sensory neuron, then to the relay neuron and then to a motor neuron.
The motor neuron triggers the effector to give a response.
What are neurons?
Individual nerve cells
What are the 4 parts of the nervous system?
The CNS
Sensory Neurones - neurones that carry information as electrical impulses from receptors to the CNS.
Motor Neurones - neurones that carry information as electrical impulses from the CNS to effectors.
Effectors - muscles and glands responding to nervous muscles impulses
What are relay neurones?
Neurones in the CNS
What’s a synapse?
The connection between two neurones
How is the nerve signal transferred?
Chemicals diffuse to move across the gap.
What are reflexes?
Rapid, automatic responses that don’t require the brain.
What’s the pathway of a reflex?
The neurones in reflex arcs go through the spinal cord or the unconscious part of the brain (the CNS).
The receptor detects the stimuli and the sensory neurones sends an impulse to the CNS.
Then the impulses passes on a relay neurone and then a motor neurone on a synapse.
The motor neurone sends the impulse to the effector.
How do you investigate reaction time?
Rest your arm on a table and have someone hold a ruler with zero at your thumb and forefinger.
The person holding the ruler should drop it unexpectedly and the other person should catch it as fast as they can.
The higher the number, the slower their reaction time.
Repeat several times and find a mean.
What factors can affect reaction time?
Age, gender, drugs
What is the brain made of?
Billions of interconnected neurones
What does the brain do?
It’s in charge of all of our complex behaviour.
What’s the cerebral cortex?
The outer wrinkly part of the brain and it controls consciousness, intelligence, memory and language
What does the medulla do?
Controls unconscious activities like breathing.
What is the cerebellum responsible for?
Muscle coordination
What methods can you use to study the brain?
Studying patients with brain damage
MRI Scans
Electrically stimulating the brain
What’s the sclera?
The supporting wall of the eye