Homeostasis and the Nervous System Module 3 Quiz

Reflexes

• A reflex is an involuntary muscle response to a stimulus without input from the brain.
• The pathway a reflex takes is called a reflex arc, which connects to the spinal cord, bypassing the brain.
• The pathway of the reflex arc is: stimulus -> sensory neuron -> motor neuron -> reflex muscle movement.
• Examples of reflexes include: pulling your hand back when you touch something hot, jumping when you hear a loud sound, and the knee-jerk reflex.
• Reflex arcs that affect inner organs are called autonomic reflex arcs, while those that affect muscles are called somatic reflex arcs.

Neurons

• Neurons are cells with the special ability to carry signals or impulses.
• Thoughts, emotions, learning, and many body functions are carried by nerve impulses in the neurons.
• A nerve impulse is not a flow of electricity, but an electrochemical signal moving along a neuron.
• Neurons that receive messages from the senses and send them to the central nervous system are called afferent neurons.
• Motor neurons transmit impulses from the brain to muscles, glands, or other neurons in the Peripheral Nervous System (PNS).
• Sensory neurons transmit impulses from sensory nerves (receptor cells) to the Central Nervous System (CNS).

Homeostasis and the Nervous System

• The nervous system coordinates and regulates feedback mechanisms to maintain homeostasis.
• Homeostasis is the ability of the body to maintain a stable internal environment despite changes in the external environment.
• The nervous system helps to maintain homeostasis by regulating body systems within certain limits.

Nervous System Functions

• The nervous system coordinates the body's functions.
• The building blocks of the nervous system are neurons.
• Voluntary movements, such as walking, are controlled by the nervous system.
• The peripheral nervous system includes nerves and senses.