In this Grade 7 Life Science lesson from Chapter 20, students learn how the nervous system responds to stimuli and controls the body, exploring how sense organs such as the eyes and ears detect environmental changes through structures like the retina, rods and cones, and the auditory canal. Students examine key vocabulary including stimulus, neurons, and the central and peripheral nervous systems to understand how sensory information is processed and interpreted by the brain. The lesson connects homeostasis to sensory function, showing how the nervous system works alongside other body systems to help the body survive and respond to its surroundings.
Section 1
Sense Organs Detect Environmental Changes
Our five senses—sight, hearing, touch, smell, and taste—capture stimuli from the environment. Each sense organ detects specific changes and sends signals to the brain for interpretation and response.
Section 2
The Central Nervous System Processes Information
The brain and spinal cord form the central nervous system, sending electrical signals through neurons. The brain controls voluntary behaviors while different areas manage specific functions like senses, posture, and breathing.
Section 3
Peripheral Nerves Connect Body to Brain
The peripheral nervous system includes sensory nerves that collect information from the environment and motor nerves that control movement. These nerves form a network throughout the body connecting to the central nervous system.
Section 4
Autonomic System Controls Involuntary Responses
Without conscious thought, the autonomic nervous system regulates heartbeat, digestion, and the fight-or-flight response. It maintains vital functions and prepares the body to respond quickly to danger or stress.
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Section 1
Sense Organs Detect Environmental Changes
Our five senses—sight, hearing, touch, smell, and taste—capture stimuli from the environment. Each sense organ detects specific changes and sends signals to the brain for interpretation and response.
Section 2
The Central Nervous System Processes Information
The brain and spinal cord form the central nervous system, sending electrical signals through neurons. The brain controls voluntary behaviors while different areas manage specific functions like senses, posture, and breathing.
Section 3
Peripheral Nerves Connect Body to Brain
The peripheral nervous system includes sensory nerves that collect information from the environment and motor nerves that control movement. These nerves form a network throughout the body connecting to the central nervous system.
Section 4
Autonomic System Controls Involuntary Responses
Without conscious thought, the autonomic nervous system regulates heartbeat, digestion, and the fight-or-flight response. It maintains vital functions and prepares the body to respond quickly to danger or stress.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter