Untitled Flashcards Set

What is the approximate number of nerve cells in the nervous system?

About 10 billion nerve cells.

What does the nervous system carry throughout the body?

Electrical messages.

What are the two main parts of the nervous system?

Central Nervous System (CNS) and Peripheral Nervous System (PNS).

What does the Central Nervous System consist of?

The brain and spinal cord.

What components make up the Peripheral Nervous System?

Cranial nerves, spinal nerves, plexuses, and peripheral nerves throughout the body.

What do cranial and spinal nerves carry?

Both sensory and motor nerves and fibers.

What do sensory nerves do?

Carry messages related to changes in the environment toward the spinal cord.

What do motor nerves do?

Carry messages from the brain to the muscles of the body.

How do motor nerves protect your hand from injury on a hot stove?

They tell the spinal cord instantly that the stove top is hot, activating muscles to pull the hand away.

What functions are associated with the spinal and cranial nerves?

Voluntary functions that involve sensations of smell, taste, sight, hearing, and muscle movements.

What is the role of the nervous system in the body?

The nervous system coordinates the body's actions and reactions to internal and external stimuli.

What are neuroglia?

Supporting cells in the nervous system that assist and protect neurons.

What is a reflex action?

An automatic response to a stimulus, processed without conscious thought.

What is the function of interneurons?

To connect sensory and motor neurons within the central nervous system.

What are neurotransmitters?

Chemicals that transmit signals across a synapse from one neuron to another.

What is the role of the brain in the nervous system?

The brain processes and interprets sensory information and coordinates higher functions such as thought, memory, and emotion.

What is the function of the spinal cord?

The spinal cord transmits messages between the brain and the rest of the body and also coordinates reflexes.

What are the functions of the autonomic nervous system?

Controls involuntary actions, regulating functions such as heart rate, digestion, and respiratory rate.

What is the difference between afferent and efferent nerves?

Afferent nerves carry sensory information to the central nervous system, while efferent nerves carry signals away from the central nervous system to effectors (muscles/glands).

What are the two divisions of the autonomic nervous system?

Sympathetic nervous system (activates 'fight or flight' response) and parasympathetic nervous system (activates 'rest and digest' functions).

What is myelin, and why is it important?

Myelin is a fatty substance that insulates nerve fibers, increasing the speed of electrical impulses along the nerve cells.

What are sensory receptors?

Specialized cells that detect stimuli and convert them into electrical signals for the nervous system.

How does the nervous system contribute to homeostasis?

By regulating internal conditions through feedback mechanisms, ensuring stability and proper functioning of the body.

What is synaptic transmission?

The process by which neurotransmitters are released from one neuron and bind to receptors on another neuron.

What are the potential effects of damage to the nervous system?

Effects can include loss of sensation, motor control issues, reflex abnormalities, and cognitive dysfunctions.