The Nervous System

What enables humans to react to their surroundings and coordinate their behavior?

The nervous system.

What are electrical impulses in the nervous system known as when sent along nerve cells?

Neurones.

What is a nerve?

A bundle of neurones.

What is a stimulus?

A detectable change in the internal or external environment of an organism.

What is the role of a receptor?

To detect a stimulus.

What does a sensory neurone do?

Carries nerve impulses from receptors to the central nervous system (CNS).

What is the function of a motor neurone?

Carries nerve impulses from the CNS to effectors.

What does a relay neurone do?

Receives signals from sensory neurons and passes them on to motor neurons.

What produces a conscious response to a stimulus?

Voluntary response.

What produces an automatic response to a stimulus?

Reflex response.

What is a synapse?

The gap between two neurones.

What is the function of an axon?

To transmit electrical impulses away from the cell body.

What is the central nervous system (CNS) composed of?

The brain and spinal cord.

What does the peripheral nervous system (PNS) consist of?

All nerves outside the CNS that connect it to limbs and organs.

What is the process of a reflex arc?

A quick involuntary response involving receptors, sensory neurones, relay neurones, motor neurones, and effectors.

What are rod cells responsible for?

Sensitivity to light.

What are cone cells responsible for?

Sensitivity to color.

What controls how much light enters the eye?

The iris.

What is the function of the lens in the eye?

To change shape and focus light onto the retina.

What happens when focusing on a distant object?

Ciliary muscle relaxes, suspensory ligaments contract, and the lens becomes thinner.

What happens when focusing on a near object?

Ciliary muscle contracts, suspensory ligaments slacken, and the lens becomes fatter.

What is myopia?

Short-sightedness; cannot see distant objects.

What is hyperopia?

Long-sightedness; cannot see close objects.

What is the function of the cerebrum?

Responsible for memory, intelligence, language, and consciousness.

What does the medulla control?

Unconscious activities like heart and breathing rate.

What regulates body temperature in the brain?

The hypothalamus.

What is the role of the cerebellum?

Balance, muscle coordination, and movement.

What are the challenges of studying the brain?

Complexity, ethical considerations, and complicated MRI interpretations.

What is the pituitary gland responsible for?

Producing hormones, including those used in the menstrual cycle.