Nervous System Flashcards
What is a stimulus
A change in your surroundings that is detected by a receptor and produces a response
What is a receptor
Something that detects a stimulus.
Example of a receptor:
Eyes, ears, nose, tongue skin
What are the 2 main parts of the nervous system
Brain + Spinal cord
What does the cerebum do
Coordinates sensations, movements, memory, thought and intelligence
What does the cerebellum do
Coordinates balance and precise movements
Which is the big part of the brain ‘cerebrum’ or ‘cerebellum’
Cerebrum is the bigger part of the brain
The brain is enclosed in the cranium of the ________ while the spinal cord is enclosed in the ______________ column
Skull
Vertebral
What are the functions of cerebrospinal fluid
To act as a cushion for absorbing external shock
Nourishes neurons inside as it enables the diffusion of oxygen and food to nervous cells
Helps in preventing the collapse of the Central Nervous System
The ____________ is in control of breathing and beating of the heart
Medulla
Where is the medulla located
Low part of brain… near the spine lower than cerebellum, pituitary gland and obviously celebrum
How does information flow from one neuron to another
Across a synapse
One neuron can have thousands of ______________ on its body and dendrones
Synapses
An electrical impulse cannot cross a synapse. Instead, the nerve impulses is carried by chemicals called ___________________. These chemicals are made by the cell that is sending the impulse and stored in synaptic ____________ at the end of the _________. The cell that is receiving the impulse has __________________ on its surface
Neurotransmitters
Vesicles
Axon
Neuroreceptors
When the neurotransmitter diffuses across the gap and binds to these receptors, the nerve ____________ is carried on to the next ___________. After the impulse has been passed on, the _______________ is broken down by enzymes
Impulse
Neurone
Neurotransmitter
How do drugs affect synapses
Because the synapses are crossed by chemicals, it is easy for other chemicals (drugs) to interfere with them, they may mimic the neurotransmitter or block its action.
Stimulus-response pathways
Receptors –> Nerve impulses passed along sensory nerve to spinal cord –> nerve impulses pass across synapse and down a motor neuron –> nerve impulse reaches muscle –> muscle is moved accordingly.
How do nerve impulses work
- Electrical impulse travels along a nerve cell
- Electrical impulse reaches the end of the first nerve cell
- Neurotransmitter is released from the vesicles in the first nerve
- Neurotransmitter diffuses across the gap between the 2 nerve cells
- It attaches to special receptors on the second nerve cell
- This causes an electrical impulse to be set up in the second nerve cell
- Electrical _________ travels along a ________ cell
- Electrical _________ reaches the _____ of the first _________ cell
- ________________ is released from the vesicles in the first nerve
- ________________ diffuses across the gap between the 2 nerve cells
- It attaches to special receptors on the second _________ cell
- This causes an electrical _________ to be set up in the second _________ cell
Impulse Nerve Impulse End Nerve Neurotransmitter Neurotransmitter Nerve Impulse Nerve
A nerve impulse travels along a nerve cell as an _____________ impulse
Electrical
What is a connecting nerve cell
Cell which connects sensory and motor nerve cells in CNS. Also known as a relay or intermediate nerve cell.
What is an effector
Muscle or gland, which produce a response when stimulated by nerve impulses from motor nerve cells
What is a motor nerve cell
A cell which carries nerve impulses from the CNS to effector organs
What is a nerve impulse
A small but very rapid electrical charge carried along nerve fibres
From receptors to the CNS
And
From the CNS to effectors
What is the peripheral nervous system
All the nerve cells, fibres and nerve endings NOT in the CNS
What is the reaction rate
How quickly someone can respond to a stimulus
What is a sense organ
An organ full of specialised sensory receptors e.g eyes, ears
What is a sensory nerve cell
A cell which carries nerve impulses from receptors to the CNS
What is the spinal cord
Large bundle of nerve fibres running the length of the back inside the spinal column. Deals with the reflexes not involving the head.
What is a synapse
A tiny gap which carries nerve impulses from receptors to the CNS
What is a reflex (action)
A response to a receptor which does not include the brain
Why are reflexes important
They protect us
What is the generalised stimulus-response pathway in a reflex arc
Receptor –> Sensory nerve —. CNS —> Motor nerve —> Effector
