The Nervous System Flashcards
Why must organisms be aware of what is going on around them?
Organisms must be aware of what is happening around them, as this affects their survival chances.
What is co-ordination of an organism’s activities carried out by?
Co-ordination of an organism’s activities is carried out by the nervous system and the endocrine system.
What does a nervous system allow an organism to do?
A nervous system allows an organism to detect and respond to stimuli in its internal or external environment.
What is a stimulus?
A stimulus is any change in your environment e.g. a flash of light, a noise, a fly landing on your nose.
What does the nervous system rely on and what is it involved in?
The nervous system relies on electrical signals, carried by specialised cells [neurons], and is involved in fast responses.
What is the central nervous system? + abbreviation
The central nervous system (CNS) is your brain and spinal cord.
What does the brain do?
The brain keeps a check on internal organs and activities, such as the level of carbon dioxide or water in the blood.
What is the peripheral nervous system? + abbreviation
The peripheral nervous system (PNS) is the nerves branching from the CNS to all parts of the body.
What are the cells involved in the endocrine system?
gland
What are the cells involved in the nervous system?
sense receptor
What is the message in the endocrine system?
chemical (Hormone)
What is the message in the nervous system?
electrical (impulse)
What is it carried by in the endocrine system?
blood
What is it carried by in the nervous system?
nerve cell
Where is the message sent to in the endocrine system?
cells throughout the body
Where is the message sent to in the nervous system?
specific cell or tissue
What is the message received by in the endocrine system?
target organ
What is the message received by in the nervous system?
effector (muscle/gland)
What is the speed of transition in the endocrine system?
usually slow
What is the speed of transition in the nervous system?
rapid
What is the effects of the endocrine system?
can be widespread
What is the effects of the nervous system?
localised usually
What is the duration of the endocrine system?
long-lasting (hours)
What is the duration of the nervous system?
usually brief (seconds)
What are the stages of coordination and response?
stimulus, receptor, process, effector, response
What is a stimulus?
a stimulus is any change in your environment
What is a receptor is a nerve cell that detects stimulus?
a receptor is a nerve cell that detects stimulus
what is a neuron?
a neuron is a specialised cell that carries electrical messages (impulses) around the body.
what is an impulse?
an impulse is an electrical message that is carried along a neuron.
Draw a motor neuron.
vrrrroooom
Which direction does the electrical signal go in?
from the cell body to the synaptic knob
Name the parts of a motor neuron?
Cell body, nucleus, dendron, dendrites, schwann cell, axon, myelin sheath, synaptic knob.
What is a cell body?
The cell body contains the nucleus and other organelles and produces neurotransmitter chemicals.
What is a dendron?
a dendron is a short fibre that receives information and carries it towards the cell body
What is an axon?
a very long fibre that conducts impulses away from the cell body.
What is a dendron?
a short fibre that receives information and carry it towards the cell body.
What are dendrites?
dendrites are small branches of a dendron
What is a schwann cell?
Many Schwann cells wrap their fatty cell membranes around an axon, forming a myelin sheath.
What is a myelin sheath made of?
Many Schwann cells wrap their fatty cell membranes around an axon, forming a myelin sheath.
What do many schwann cells wrap their fatty cell membranes around?
an axon
What does a myelin sheath do?
The myelin sheath insulates the neuron from electrical impulses flowing in other neurons.
How many types of neuron are there?
3
What is a sensory neuron?
sensory neuron carries messages from the sense organ to the central nervous system (CNS).
What is an interneuron?
an interneuron connects sensory and motor neurons and so carries messages within the CNS.
What is a motor neuron?
a motor neuron carries impulses from the CNS to muscles and glands.
Draw the sensory neuron, motor neuron, brain and spinal chord together
zap
What is a synapse?
a region where two neurons come into close contact.
What is a synaptic cleft?
the gap between two neuron, bridged by chemicals (neurotransmitters).
What is a neurotransmitter?
chemical released across a synaptic cleft to carry a signal from one neuron to another. The chemical is then destroyed or removed.
What happens to the chemical once it has carried a signal from one neuron to another?
the chemical is then destroyed or removed
Draw a synapse with dopamine and acetylcholine labeled.
zip
What are the parts of a synapse?
Impulse, transmitting neuron, mitochondrion, synaptic knob, vesicle with neurotransmitter, acetylcholine or dopamine, synaptic cleft (gap), neurotransmitter diffuses across synapse, receptor site, receiving neuron.
