Homeostasis Flashcards
Homeostasis
The regulation of the internal conditions of a cell or organism to maintain optimum conditions for function in response to internal and eternal changes
What does homeostasis regulate?
- Blood glucose concentration
- Body temperature
- Water levels
What are receptors?
Detect stimuli
What are coordination centres?
Receive and process information from receptors
- Brain
- Spinal cord
- Pancreas
What are effectors?
Muscles or glands which bring about responses to react to environment (restore optimum levels)
What is the central nervous system?
BRAIN and SPINAL CORD
What is the peripheral nervous system?
ALL the NERVES in your body
What does the nervous system do?
Allows humans to REACT to their surroundings and to COORDINATE behaviour
How is information sent through the nervous system?
Through ELECTRICAL IMPULSES that pass along nerve cells called NEURONES
What is a nerve?
A bundle of neurones
What is the actual function of the CNS?
CNS coordinates the response of receptors
What are neurones made up of?
- A cell body (nucleus and main organelles are found here)
- Cytoplasmic extensions from this body called AXONS and DENDRITES
What is adaptation of a neuron?
- Some human neurones are 1m long
- Much more effective than having multiple neurons which wastes time transferring electrical impulses from one cell to another
What is an adaptation of the axon?
Fatty sheath acts as an insulator
What is the path of response in the nervous system?
Stimulus, receptor, coordinator, effector, response
What is a reflex?
An involuntary, rapid action which does not involve the conscious part of the brain
What does the reflex arc involve?
- Stimulus
- A sensory neurone sends electrical impulses to the spinal cord (COORDINATOR)
- An electrical impulse is passed to a RELAY NEURONE in the spinal cord
- Relay neurone synapses with a motor neurone
- A motor neurone carries an impulse to a muscle (THE EFFECTOR)
- The muscle pulls the body part away from the dangerous stimulus
What is the sensory neurone?
Carry impulses from sense organs to CNS (brain or spinal cord)
What is the relay neurone?
Found inside the CNS and connect SENSORY and MOTOR neurones
What are motor neurones?
Carry impulses from the CNS to the effectors (muscles) where the action is carried out
What is the brain
- Part of the central nervous system
- Made of billions of interconnected neurones
- Responsible for controlling complex behaviours
Where is the cerebral cortex
Front of brain
Where is the cerebellum?
Back of brain (bottom)
Where is the medulla?
Bottom, connecting to spinal cord
What does the Cerebral cortex control?
Responsible for
- Intelligence
- Memory
- Consciousness
- Personality
What does the Cerebellum control?
Responsible for
- Balance
- Muscle coordination
- Movement
What does the medulla control?
Responsible for
- Unconscious activities
- Such as heart rate or breathing
Why is it so difficult to study the brain?
- Very delicate
- High risk of damage if studying a living brain
- Accidents could lead to speech or motor issues
