The Human Nervous System Quiz

The Human Nervous System

• The nervous system is constantly working, detecting and responding to environmental changes via senses.
• It interacts with other systems, especially during stress or competition.
• Information is sent as electrical signals through nerves to the brain.
• The brain interprets the information and sends further signals to muscles for a response.
• This entire process occurs quickly, thanks to the nervous system.

How the Nervous System Works

• Electrical impulses, or messages, travel through neurons, specialized cells in the nervous system.
• Neurons connect end-to-end, forming chains called nerves.
• These nerves transmit messages throughout the body.
• Messages are transmitted from nerves to the brain and back through the body using two systems, the CNS and PNS.

CNS - Central Nervous System

• Consists of the brain and spinal cord.
• The brain is the ultimate processing center, divided into hemispheres.
• It receives and interprets information, controlling many bodily functions.
• The spinal cord relays messages between the brain and nerves, controlling reflex activities.

Brain Structure and Function

• The brain has two hemispheres, divided into four lobes.
• The brain contains approximately 9 billion neurons.
• The brain receives 25% of the blood pumped by the heart.
• The left side of the brain controls the right side of the body, and vice versa.
• The brain weighs approximately 1.2 kg.

Cerebral Cortex

• Different regions of the cerebral cortex are responsible for specific functions like motor control, touch, taste, body awareness, language, reading, smell, hearing, facial recognition, and coordination.

PNS - Peripheral Nervous System

• Sends messages to and from the CNS.
• Sensory neurons detect environmental changes, and motor neurons respond, causing muscles and glands to react.
• For example, smelling a delicious Big Mac combo (stimulus) can cause you to turn your head (response).
• The PNS has two main divisions:
  • Autonomic (involuntary control of internal organs and glands):
    • Sympathetic division ("fight or flight")
    • Parasympathetic division ("rest and digest")
  • Somatic (voluntary control of skeletal muscles). Motor neurons influence movement of skeletal muscles via nerve impulses.

Neural Pathway Summary

• Stimulus detected by a receptor (e.g., a visual stimulus).
• Sensory neurons carry the message to the CNS.
• The CNS processes the message.
• Motor neurons carry responses back to effectors (e.g., muscles or glands).
• A response is carried out.

Reflex Arc

• An involuntary, rapid automatic response to a stimulus.
• Involves sensory neurons, spinal cord (reflex arc), and motor neurons.
• It helps to protect the body from harm.

Homework

• Complete a glossary of terms and answer questions #1-6 on page 417.

Activity

• Group activity to test reaction time using a stopwatch and meter stick.

Test your knowledge on the human nervous system, including its structure and function. This quiz covers the roles of neurons, the central and peripheral nervous systems, and how the brain processes information. Perfect for students studying biology or anatomy.