nervous system

What is the main function of the nervous system?

The main function of the nervous system is to coordinate all of the body's activities.

What is a cerebrovascular accident? What are the causes, symptoms and treatments?

A cerebrovascular accident (CVA) is also known as a stroke, or "brain attack." It occurs when there is a loss of blood flow, and in turn oxygen, to the brain.

What are afferent, efferent, and associative neurons?

Afferent neurons are also called sensory neurons. They carry messages from all parts of the body to the brain and spinal cord. Efferent neurons are also called motor neurons. They carry messages from the brain and spinal cord to the muscles and glands. Associative neurons are also called interneurons. They carry messages from afferent neurons to efferent neurons.

What is Alzheimer's?

Alzheimer's disease is a progressive neurodegenerative disease that occurs when nerve cells in the brain die.

What is autism?

Autism, or autism spectrum disorder, refers to a broad range of conditions characterized by challenges with social skills, repetitive behaviors, speech, and nonverbal communication.

What is cerebrospinal fluid and what is its function?

Cerebrospinal fluid flows throughout the brain and around the spinal cord for further protection. This watery liquid fills the brain's four ventricles, or hollow spaces, and acts as a shock absorber.

Myelin sheath

Many axons are covered by a fatty tissue called the myelin sheath. This sheath protects the axons and speeds up the impulse as it travels.

What is multiple sclerosis? What are the causes, symptoms and treatments?

Multiple sclerosis (MS) is a disease of the central nervous system that results in progressive loss of muscle control. The myelin sheath is slowly destroyed. The exact cause of this disease is not known, but it is thought that it may be related to a virus or an autoimmune process.

What is myasthenia gravis? What are the causes, symptoms and treatments?

Myasthenia gravis is a disease where the proper nerve pulses are not sent to the muscles. As a result, progressive muscle weakness and paralysis occur. If the respiratory system muscles are affected, the disease can be fatal.

What is a neuron? What is its job?

The basic element of the nervous system is the neuron, or nerve cell. Its job is to transmit a message from one cell to the next.

How is the brain stem separated and what is its function of each part?

The brain stem includes three parts. The midbrain conducts impulses between the brain parts and for certain eye and auditory reflexes. The pons directs messages to other parts of the brain and for chewing, tasting, and saliva production. It also helps with respiration. The medulla oblongata connects with the spinal cord and regulates heartbeat, respiration, swallowing, coughing, and blood pressure.

What is the function of the cerebellum?

The cerebellum is responsible for coordination of muscle movements, balance and posture, and muscle tone.

How is the cerebrum separated and what is its function?

The cerebrum is the largest and highest section of the brain. It is separated into four lobes: frontal, parietal, temporal, and occipital. It is concerned with reasoning, the senses, speech, and voluntary body movement.

How is the diencephalon separated and what is its function of each part?

The diencephalon includes two parts. The thalamus directs sensory impulses to the cerebrum. The hypothalamus controls the autonomic nervous system, body temperature, appetite, water balance, sleep, and blood vessel constriction and dilation. The hypothalamus also plays a role in emotions such as anger, fear, pleasure, pain, and affection.

Synapse

The space between a dendrite and an axon

What are the divisions of the autonomic nervous system? What is the each division responsible for?

The two divisions of the autonomic nervous system are the sympathetic and parasympathetic systems. In times of emergency, the sympathetic system prepares the body for action with the "fight or flight" response. It increases heart rate, respiration, and blood pressure and slows the rate of digestion. After the stress is over, the parasympathetic system reverses these actions to counteract the effects and return the body to normal working conditions.

What are the two main divisions of the nervous system?

The two main divisions of the nervous system are the central nervous system and the peripheral nervous system.

Axon

conduct impulses away from the cell. Each nerve cell has only one axon.

Dendrite

conduct impulses toward the cell. A nerve cell may have several dendrites

Neurotransmitters

help impulses "jump" the synapse to pass the message from cell to cell.

List the three meninges covering the brain and spinal cord from the innermost to the outermost layer.

midbrain, pons, and medulla oblongata