The Nervous System
Ramona, Sarah, Laura, Zunaira & Hibba
Sends signals around your body.
Lets you respond to everything around you.
Coordinates movement and processes senses.
Peripheral Nervous System
- Nerves that connect the rest of your body to the CNS
- Relays information from a part of your body, up through your spinal cord, and registers it in your brain
- Autonomic sub-system responsible for functions you don't think about, e.g., blood pumping
- Somatic sub-system responsible for things you control at will
#1: Contact with the "stimulus" - the object that endangers us.
#2: Reception - the nerve ending registers the information
#3: Transmission - the nerve relays this to the spinal cord
#4: Pain reception - the brain registers this information, and decides what to do, such as moving your hand away from the hot object you just touched
A problem concerning nerve damage is the body's inability to react to pain.
Nerves and Neurons
- A neuron is an individual cell, and a nerve is a group of neurons
- Sensory neurons send signals to the CNS
- Motor neurons receive signals from the CNS
- Neurons are the longest lived cells in your body
- Dendrites receive information from other neurons, or surrounding area
- Axons transmit electrical impulses away from cell body to other cells
- Information travels down axon, and hops from cell to cell
- This process is called 'synapse'
- Myelin sheath surrounds axon and transmits nerve impulses
- mass of soft nerve tissue protected by the skull
- made up of neurons (grey matter) and cell processes (white matter)
- grey matter found at periphery of brain and centre of spinal cord
- white matter found deep within brain
- very compact, and weighs about three pounds
- largest part of the brain
- centre for thought and intelligence
- divided into right and left hemispheres
- right hemisphere controls the movement on the left side of your body, and vice versa
- responsible for senses, learning, and motor functions
- cerebral cortex is outside of cerebrum
- function is learning, reasoning, knowledge, and memory
- controls heart rate, breathing, swallowing, coughing, and vomiting
- forms brainstem that connects cerebrum to spinal cord
Breakdowns of the System
Charcot-Marie Tooth Syndrome
- risk increases with age
- symptoms include progressive inability to remember facts or events, and later even friends and family
- runs in families
- lesions of proteins are found in the brain
- individuals are extremely drowsy at all times
- weakness in muscles is experienced
- occurs at random
- dream stage of sleep can occur when person is awake, resulting in temporary paralysis
There are more nerve cells in the human brain than there are stars in the milky way
Your brain loses a gram of weight per gear
The nervous system relays information at about 100 metres per second
A baby's brain triples in size in its first year
If injured, nerves at the bottom of the spinal cord can cause paralysis
An octopus, an invertebrate, has 500 million neurons
What you're seeing here...
- Immune system has begun to erroneously attack myelin, or protective sheath that covers neurons, causing damage in the brain.
- This damages nerve signals in the brain! No wonder Ramona was experiencing forgetfulness and mood swings.
- Inflammation has occurred, preventing the brain from communicating with the rest of the body.
- Hint: you now know which part of the nervous system the disease affects.
- Hint #2: we prescribed corticosteroids to stall inflammation of the brain.
What You're Seeing Here...
- The x-rays are in... And it has been confirmed. Only the patient's central nervous system has been affected by whatever it is she has.
- Here, the spinal cord has been slightly impacted due to myelin sheaths in its neurons being worn away.
- The extent of her symptoms show that her disease has progressed really far!
What you're seeing here...
- More scans of the brain showing how warped it is.
- You can see how poor her immune system is at defending against... Something.