Nervous System Flashcards
What is your nervous system?
Your nervous system works by detecting changes in your external environment. This information is sent to your brain where it is processed. Your brain decides on an appropriate response and sends an impulse to another part of your body telling it how to respond.
What are the three main stages to a nervous response?
- There is a change in the environment. This is the stimulus. 2. Groups of cells detect the stimulus. These are the sensory receptors. 3. A response occurs from the effectors. These are muscles or glands.
How do muscles and glands respond to impulses?
Muscles respond to an impulse by contracting, which causes movement. Glands respond by releasing hormones.
What do receptor cells detect?
Receptor cells are found in your sense organs. Different receptors detect different stimuli. They change the stimulus into electrical impulses that travel along neurones to your central nervous system (CNS).
What is the central nervous system (CNS)?
The CNS is made up of the brain and spinal cord. These structures are made of delicate nervous tissue, so are protected by bones. The skull protects the brain, and the vertebral column protects the spinal cord.
What are the types of receptor cells and their stimuli?
Table 1 shows examples: Eye - light; Tongue - taste; Skin - pressure; Nose - smell.
How does the impulse travel to and from the CNS?
There are three types of neurones: 1. Sensory neurones - carry electrical impulses from receptor cells to the CNS. 2. Relay neurones - carry electrical impulses from sensory neurones to motor neurones. 3. Motor neurones - carry electrical impulses from the CNS to effectors.
What is the difference between a neurone and a nerve?
A neurone is a single nerve cell, while a nerve is a bundle of hundreds or thousands of neurones.
What is a coordinated response?
A coordinated response is when the brain processes huge amounts of information from sensory receptors and forms a response, resulting in a series of impulses sent to different parts of the body.
What is the flow of a nervous reaction?
Stimulus → Receptor cells → Sensory neurone → Spinal cord → Brain → Spinal cord → Motor neurone → Effector → Response.
How long does the whole nervous response process take?
The whole process takes around 0.7 seconds.
