Nervous System Flashcards
What does the nervous system do?
A: control and coordinate all functions of the body
What are the two main subdivisions of the nervous system?
- Central nervous system
- Peripheral nervous system
What is a neuron?
A: the scientific name for a nerve cells
What are the three basic structures of a neuron?
- Cell body
- Dendrites
- Axon
What two things does the cell body contain?
- Cytoplasm
- Nucleus
What do dendrites do?
A: receive messages, impulses, and send them through the cell body and the axon.
What is an axon? What does it do?
A: a single long fibre. Sends messages away from the cell body
What is the axon covered with?
A: a myelin sheath
What does the myelin sheath do?
A: increase speed of the nerve signals
How do impulses travel from one neuron to another?
A: across synapses
What are synapses?
A: spaces between the nerve cells
What is the jumping across synapses helped by?
A: neurotransmitters
Where do drugs affect the nervous system?
A: synapses
What are the three types of neurons?
- Sensory
- Motor
- Interneurons
Sensory neurons send information from where to where?
A: sensory receptors to the CNS
Where do motor neurons send information to?
A: away from the CNS to muscles or glands
Where do interneurons send information?
A: in between sensory neurons and motor neurons
Where are most interneurons located?
A: in the central nervous system
What is a stimulus?
A: a detectible change in the environment
What is response/reaction?
A: how the body reacts to a stimulus
What is reflex arc?
A: the pathway that is signal follows to produce a quick response to a stimulus
Do reflexes have to travel to the brain before causing a response?
A: no
What are the two parts of the central nervous system?
- Brain
- Spinal cord
What does the brain do?
A: coordinates body activities
How many neurons is the brain made up of?
A: 100 billion
What percent of oxygen and energy does the brain use?
A: 20%
What are the three major parts of the brain?
- Cerebrum
- Cerebellum
- Brain stem
What is the cerebrum? What is it responsible for?
A: the largest part of the brain. It’s responsible for thinking movements and storing memories.
What does the cerebellum do?
A: coordinate muscles for balance
What does the brain stem control?
A: involuntary actions, such as blood pressure, heart rate, breathing and swallowing
What is the spinal cord?
A: an extension of the brainstem
What does the spinal cord do?
A: it is bundles of neurons that carry impulses from all parts of the body to the brain and from the brain to all parts of the body
What is the peripheral nervous system?
A: all of the nerves that are not part of the brain and the spinal cord
What does the peripheral nervous system do?
A: it connects the body to the brain and spinal cord
What are the two divisions of the peripheral nervous system?
- Somatic
- Autonomic
What is the somatic division do?
A: controls voluntary actions by controlling your skeletal muscles
What does the autonomic division do?
A: controls involuntary actions, such as your heart rate, breathing, and digestion
What is dementia?
A: a general term for the impaired ability to remember think or make decisions that interferes with doing every day activities
What is Alzheimer’s disease?
A: a specific type of dementia that affects most of the brain
What is the most common cause of dementia?
A: Alzheimer’s disease
What is the cause of Alzheimer’s disease?
A: an abnormal buildup of proteins and around the brain cells
What eventually happens to the brain in the last stages of Alzheimer’s disease?
A: it shrinks as brain cells die
What is a stroke? What does this do? What happens?
A: a disease in which of blood clot blocks an artery or a blood vessel breaks. Prevent blood from reaching the brain. Brain cells, die, causing brain damage.
What is the fifth leading cause of death in the USA?
A: strokes
What is Parkinson’s disease? How does it develop? What causes the symptoms?
A: a brain disorder that leads to shaking stiffness and difficulty with walking balance and coordination. A certain neurons in the brain gradually break down or die. A loss of neurons that produce a chemical mass in the brain called dopamine.
What is epilepsy? What is the cause of epilepsy?
A: a condition in which brain activity becomes abnormal, causing seizures or periods of unusual behavior, sensations, and sometimes the loss of awareness. The cause is not known, but it is often triggered by stress.
What is multiple sclerosis? What does it cause? What are some symptoms?
A: the immune system attacks, the protective myelin sheaths that covers nerve fibres. Communication problems between the brain and the rest of the body. Numbness, electrical shock sensations, and the loss of coordination.
What is the cause of carpal tunnel syndrome? What happens?
A: a nerve in the wrist becomes pinched or compressed. It reduces blood flow, causing nerve damage that leads to tingling and numbness of the thumb, index, and middle fingers.
