SB2e-f Flashcards
What does the brain consist of? (4)
- Cerebral cortex, divided into two cerebral hemispheres
- Cerebellum
- Medulla oblongata
- Spinal cord
What does the cerebral cortex do?
It is divided into 2 cerebral hemispheres and makes up 80% of the brain. The right hemisphere communicates with the left side of the body and vice versa. It is used for most our senses, language, memory, behaviour and consciousness.
What does the cerebellum do?
It is divided into 2 halves and controls balance and posture. It also coordinates the timing and fine control of muscle activity to make sure the movements are smooth.
What does the medulla oblongata do?
Controls heart rate and breathing rate. Also responsible for reflexes such as vomiting, sneezing and swallowing.
How is the brain connected to the spinal cord?
The mass of neurones that make up the medulla oblongata connect the brain to the spinal cord.
What does the spinal cord consist of?
What does a nerve consist of? (3)
- Long neurones
- Blood vessels
- Outer covering of the nerve
What does a CT scan show?
A CT scan shows the shapes of structures in the brain.
How does a CT scan work?
Detectors measure the absorption of the X-rays from an X-ray beam that moves in a circle around the head. A computer uses this information to build up a view of the inside of the body as a series of slices.
Check Biology page 40.
What do we understand from differences in the shapes of the brain?
Can be linked to differences in the way people think and act, suggesting the functions of those parts.
What does a PET scan show?
A PET scan shows brain activity.
How does a PET scan work?
The patient is injected with radioactive glucose. More active cells take in more glucose than less active ones (for respiration). The radioactive atoms cause gamma rays that the scanner detects. More gamma rays come from parts containing more active cells.
Check Biology book page 41.
What can spinal cord damage cause?
Reduced flow of information between the brain and parts of the body.
What can nerve damage in the lower spinal cord cause?
Loss of feeling in and use of the legs.
What can neck damage cause?
Quadriplegia (loss of use of both arms and legs).
Why can damage not be repaired in the spinal cord?
No adult stem cells can differentiate into neurones in the spinal cord, so new neurones cannot be made to repair damages.
What damages can brain tumours cause?
They can squash parts of the brain and stop them from working.
How can tumours be cut out, and what are some issues with these solutions?
Tumours can be cut out or the cells can be killed using radiotherapy (high-energy X-ray beams) and chemotherapy (injecting drugs that kill actively dividing cells).
These methods can damage the body and brain. Chemotherapy may not work due to the blood-brain barrier.
What is the blood-brain barrier?
A natural filter that only allows certain substances to get from the blood into the brain, mainly due to cells in the capillary walls in the brain fitting together very closely.
