The Nervous System PMT Flashcards
What is the central nervous system?
Brain and spinal cord
What is the spinal cord?
A long, thin structure composed of neurons that extends from the medulla oblongata down the spine
What is the function of the spinal cord?
Connect the peripheral nervous system to the brain
What are the main structures of the brain
- Cerebrum
- Cerebellum
- Medulla Oblongata
Describe the structure of the cerebrum
- Largest region of the brain
- Divided into two hemispheres
What is the function of the cerebrum?
- Intelligence
- Language
- Memory
- Emotion
- Visual and sensory processes
What is the function of each cerebral hemisphere?
- The left hemisphere receives sensory information from the right side of the body and controls muscle coordination on the right.
- The right hemisphere receives sensory information from the left side of the body and controls muscle coordination on the left
What is the cerebellum located?
Lower region of the brain
What is the function of the cerebellum?
- Coordination of muscles
- Voluntary movement
- Non-voluntary movement
What is the function of the medulla oblongata?
Controls automatic processes in the body
What methods other than surgery are used by doctors to observe the brain?
- CT scan
- PET scan
What is a CT scan?
A procedure that uses x-rays to produce 3D cross-sectional images of the brain
Describe how CT scans are useful to investigate brain function
- CT scans show damaged regions of the brain
- Observations of the patient’s symptoms can enable scientists to determine the function of the damaged region
What does a PET scan involve?
- Radioactive substance injected into a patient’s bloodstream and taken up by tissues in the brain
- Radiation emitted by tissues detected, enabling the identification of active and inactive regions of the brain
Describe how PET scans are used to investigate brain function
- Show which areas of the brain are active and which areas are not
- Comparisons of brain activity in healthy patients and patient with brain damage allow scientist to determine the functions of inactive regions
Why is it difficult to treat damage to the CNS?
- Damage to the neurons is permanent and cannot be repaired
- Hard to reach some areas of the brain
- Risk of further permanent damage to other areas of the CNS during surgery
What is the function of the nervous system?
Allows an organism to rapidly react to environmental and internal changes
What are neurons?
Nerve cells adapted to quickly transmit nerve impulses. They are the functional unit of the nervous system.
What is the function of the axon?
- Carries impulses away from the cell body
- Enables the transmission of nerve impulses over long distances
What is the function of the dendrites and dendrons?
- Carries impulses towards the cell body
- Dendrites provide a large surface area to receive impulses
What is the role of the myelin sheath?
- Electrically insulating layer
- Surrounds the axon and increases the speed of impulses
Describe the function of a sensory neuron
It carries impulses from receptors to the central nervous system
Describe the structure of a sensory neurone
- Long dendron carries impulses from receptors to the cell body
- Cell body found part way along the neurone
- Short axon carries impulses from the cell body to the central nervous system
Describe the function of a motor neuron
Carries impulses from the central nervous system to effectors
