The Nervous System Flashcards
Name the type of particle whose movement in and out of neurons is an essential feature of nerve impulse transmission.
Ion
One of the roles of ions is the activation of neurotransmitters. Give an account of how neurotransmitters work.
1) an electrical nerve impulse arrive at the end of the first neuron
2) This results in the formation of vesicles containing a chemical called a neurotransmitter
3) these neurotransmitter vesicles burst at the end of the neuron and the neurotransmitter is released across the synaptic cleft
4) the neurotransmitter stimulates a new nerve impulse in the second neuron.
5) an enzyme breaks down the neurotransmitter within the synaptic cleft during the refractory period
Distinguish between the position of the cerebellum and the position of the cerebrum in the human brain.
Cerebellum is located in the hind brain.
Cerebrum is the largest part of the brain.
State three functions of the cerebrum.
1) vision
2) smell
3) hearing/ language
What is meant by the term “degnerative illness”?
Illness that gets worse
Is Alzheimer’s disease driven by a single gene or by many genes?
Many genes
What is thought to cause the disease Alzheimer?
A build up of protein-based plaques in the brain.
Suggest a possible symptom of Alzheimer disease?
Memory loss
How is the advance of technology helping in the fight against Alzheimer?
Can scan brain which helps to examine signs of trouble and defect.
There a probably more people suffering from Alzheimer than ever before. suggest a reason for that.
Larger population, which live longer.
Name another disorder of the nervous system than Alzheimer and give one possible treatment.
Parkinson/ Physiotherapy
Distinguish between the central nervous system and the peripheral nervous system.
CNS- brain and spinal cord
PNS - consists of nerves running out from the CNS
Give one way in which nervous response differs from a hormonal response.
Message is electrical- Hormone chemical
Give one function EACH of any two parts found ONLY in neurons.
1) Axon carries the impulse away from the cell body
2) schwann cells protect and insulate the axon
Name and state the role of any two types of neuron,other than the motor neuron.
SENSORY NEURON -carry impulses from receptors to the central nervous system
INTERNEURONS connect motor&sensory neurons
State one function of Hypothalamus.
Homeostatis
State one function of Cerebellum.
Balance/ responses are involuntary
State function of medulla oblangata.
Breathing
In relation to the nervous system, distinguish between grey matter and white matter.
WHITE MATTER contains axons
GREY MATTER contains cell bodies and dendrites;many axons
Name a possible cause for Parkinson other than accident.
Brain does not produce enough of the neurotransmitter dopamin
What is a reflex action?
An automatic response to a stimulus which is nit under conscious control
Give an example of a reflex action.
Sneezing
Suggest an advantage of refelx actions.
Protects the body
Write notes about Neurotransmitters.
Are chemicals which have been released from neurotransmitter swellings.
The end of a neuron consists of many synaptic knobs which contain numerous small vesicles filled with chemicals called neurotransmitters,e.g. Acetylcholine.
What is a neuron?
A neuron is a nerve cell.
Distinguish between SENSORY,MOTOR and INTERNEURONS
SENSORY: take messages from sense organs to the CNS
MOTOR: take messages from the CNS to muscles and glands, causing them to respond
INTERNEURONS: carry information between sensory and motorneurons.
only found in the CNS.
Briefly explain the role of neurotransmitter substances.
Neurotransmitter chemicals carry the impulse from one nerve cell to another.
State a function for Schwann cells.
Secrete a fatty insulating layer called the myelin sheet.
State a function of the Myelin sheat.
Insulates the electrical impulses.
What is a synapse?
A synapse is a region between 2 neurons or between a neuron and an effector
What do you understand under the term THRESHOLD ?
Minimum stimulus needed to cause an impulse to be carried.
What is the “all or nothing law” ?
States that if the threshold is reached an impulse is carried, but if the treshold is not reached no impulse is carried.
What do you understand under the term “refractory period” ?
Short timespan after a neuron has carried an impulse during which a stimulus fails to cause a response.
