Communication Flashcards
What are the lowest and highest frequencies detected by humans?
20 Hz and 20,000 Hz
What is the reason for the range of frequencies detected by humans?
Humans have excellent vision and therefore do not require the ability to detect high frequency sounds. Human voices are well within the range of human hearing so effective communication is possible.
What is the range of frequencies that bats can detect?
100,000 to 120,000 Hz
What is the reason for the range of frequencies detected by bats?
Bats are nocturnal animals so have limited vision and rely on their hearing heavily.
Low frequency sound detection is unnecessary and the very high frequency sounds allow for precise echolocation: allows them to locate obstacles as they fly by emitting ultrasound’s which bounce off objects and return as an echo to the bats ear allowing them to locate objects.
What are dendrites?
These give the cell a large surface area for the collection of signals from other neurons.
What is the cell body of a neurone?
Contains the nucleus and other organelles.
What is the axon of a neurone?
Takes the electrical messages from the cell body to the synaptic knobs. It is surrounded by a myelin sheath made up of Schwann cells. This sheath insulates the axon preventing any charge from leaving.
What are the synaptic knobs of a neurone?
These are found at the end of the branches at the end of the axon. They contain neurotransmitters (chemicals) that allow the electrical impulse to be converted into a chemical message so it can cross the gap (synapse) between the neurones by diffusion and generate another electrical signal in the next neuron by allowing sodium ions to enter the next neurone.
What is a neurone?
A nerve cell that transmits a signal or impulse from one part of the body to another.
What is a nerve impulse?
A nerve impulse can be detected as a change in voltage. The impulse is transmitted as a wave of electrical changes that travel along the cell membrane of the neurone.
What happens when a neurone is at rest and why?
When a neurone is at rest (resting potential), they have a negative charge inside and positive charge outside the membrane. This is due to the sodium ions (Na+) being pumped out actively and the sodium channels being closed so they can’t re-enter. A negative charge builds up inside the neuron. Resting potential: -50mV to -100mV
