BIO101 – Topic 17: Coordination and Response in Living Organisms
Course Code: BIO 101
Course Name: General Biology
© Lesuyai Organic Guides 2025
(Original | Educational | Professional | Plagiarism-Free | A4 Format)
17.1 Introduction to Coordination and Response
Living organisms constantly receive and react to changes (stimuli) in their internal and
external environments to maintain stability and survival.
Coordination ensures that various organs and systems work together harmoniously.
Response is the reaction of an organism to a stimulus.
In animals, coordination involves the nervous system and endocrine system.
In plants, coordination occurs through growth substances (hormones).
17.2 Importance of Coordination
- Enables organisms to respond to environmental changes.
- Maintains internal balance (homeostasis).
- Ensures smooth functioning of body systems.
- Supports survival and adaptation.
17.3 Components of Coordination
1. Stimulus – change that triggers a response.
2. Receptor – detects the stimulus.
3. Effector – carries out the response.
4. Coordinator – processes information and sends instructions.
17.4 The Human Nervous System
The nervous system controls body activities through electrical impulses.
Divisions:
1. Central Nervous System – brain and spinal cord.
2. Peripheral Nervous System – nerves.
3. Autonomic Nervous System – involuntary control.
17.5 Structure and Function of a Neuron
A neuron (nerve cell) is the functional unit of the nervous system.
Parts:
Dendrites – receive impulses.
Cell body – contains nucleus.
Axon – carries impulses away.
Course Code: BIO 101
Course Name: General Biology
© Lesuyai Organic Guides 2025
(Original | Educational | Professional | Plagiarism-Free | A4 Format)
17.1 Introduction to Coordination and Response
Living organisms constantly receive and react to changes (stimuli) in their internal and
external environments to maintain stability and survival.
Coordination ensures that various organs and systems work together harmoniously.
Response is the reaction of an organism to a stimulus.
In animals, coordination involves the nervous system and endocrine system.
In plants, coordination occurs through growth substances (hormones).
17.2 Importance of Coordination
- Enables organisms to respond to environmental changes.
- Maintains internal balance (homeostasis).
- Ensures smooth functioning of body systems.
- Supports survival and adaptation.
17.3 Components of Coordination
1. Stimulus – change that triggers a response.
2. Receptor – detects the stimulus.
3. Effector – carries out the response.
4. Coordinator – processes information and sends instructions.
17.4 The Human Nervous System
The nervous system controls body activities through electrical impulses.
Divisions:
1. Central Nervous System – brain and spinal cord.
2. Peripheral Nervous System – nerves.
3. Autonomic Nervous System – involuntary control.
17.5 Structure and Function of a Neuron
A neuron (nerve cell) is the functional unit of the nervous system.
Parts:
Dendrites – receive impulses.
Cell body – contains nucleus.
Axon – carries impulses away.
