B6 Flashcards
An animals response is coordinated by what?
The central nervous system
What is the central nervous system also known as?
The processing centre
The brain and spine are connected to the body by which system?
The peripheral nervous system
What does the peripheral nervous system consist of?
Sensory neurons that carry impulses from receptors to the brain and spine
Motor neurons that carry impulses from the brain and spine to effectors
Receptors and effectors can form part of complex organs, such as…?
Muscle cells in a muscle
Light receptor cells in the retina of the eye
Hormone secreting cells in a gland
Muscle cells in a muscle…?
Impulses travel along motor neurons and stop at the muscle cells, causing the muscle cells to contract
Light receptor cells in the retina of the eye…?
The lens focuses light onto receptor cells in the retina. The receptor cells are then stimulated and send impulses along sensory neurons to the brain
Hormone secreting cells in a gland…?
An impulse travels along a motor neuron and stops at the hormone secreting cells in glands. This triggers the release of the hormone into the bloodstream
Neurons are specially-adapted cells that carry an electrical signal when stimulated…
They are elongated to make connections between different parts of your body
They have branched endings so that a single neuron can act on many other neurons or effectors
In motor neurons the cytoplasm forms a long fibre surrounded by a cell membrane called an…?
Axon
Some axons are surrounded by a fatty sheath which…?
Insulates the neuron from neighbouring cells
Increases the speed at which which the nerve impulse is transmitted
What is a stimulus?
A change in an organisms environment
What are synapses?
The gaps between adjacent neurons
What is a reflex action?
A fast, automatic, involuntary response to a stimulus
What do simple reflexes help animals to do?
Find food, shelter from predators and finding a mate
