The Neevous System Flashcards
What is the main function of the nervous system?
To react to what goes on around you
The nervous system allows organisms to respond to environmental changes.
What are the two main components of the Central Nervous System (CNS)?
Brain and spinal cord
The CNS coordinates responses and processes information.
What are sensory receptors?
Groups of cells that detect changes in the environment
Different receptors are specialized for different stimuli, such as light or touch.
What happens when a stimulus is detected by receptors?
The information is converted to a nervous impulse and sent to the CNS
Sensory neurones transmit this information.
What is the role of the CNS in response coordination?
Decides how to respond to a stimulus and sends signals to effectors
Impulses travel through relay neurones within the CNS.
What is an effector?
A muscle or gland that responds to signals from the CNS
Effectors carry out the response to a stimulus.
What is reaction time?
The time it takes to respond to a stimulus
Reaction time can vary based on several factors including the type of stimulus.
What are the main structural components of neurones?
Cell body, dendrites, and axon
Neurones transmit information as electrical impulses.
What is the function of dendrites in neurones?
Carry nerve impulses towards the cell body
Dendrites are extensions of the neurone that receive signals.
What is the function of axons in neurones?
Carry nerve impulses away from the cell body
Axons can be long and may be surrounded by a myelin sheath.
What is the myelin sheath?
An electrical insulator that speeds up electrical impulses
Myelinated neurones transmit signals more quickly than unmyelinated ones.
What are sensory neurones responsible for? What is their structure?
Carrying nerve impulses from receptor cells to the CNS
They have one long dendron and a short axon.
What is the structure of a motor neurone?
Many short dendrites and one long axon
Motor neurones transmit impulses from the CNS to effectors.
What is the role of relay neurones?
Carry nerve impulses from sensory neurones to motor neurones
They play a crucial role in processing information within the CNS.
Fill in the blank: In a relay neurone, the _______ carries nerve impulses from the cell body to motor neurones.
axon
Axons are essential for transmitting signals away from the neurone’s cell body.
True or False: All neurones are myelinated.
False
Some neurones can be unmyelinated, affecting the speed of impulse transmission.
What is the direction of impulse flow in sensory neurones?
From receptor cells to the cell body
The cell body of sensory neurones is typically located in the middle.
What is the direction of impulse flow in motor neurones?
From the cell body to effector cells
This is essential for executing responses to stimuli.
