Coordinate and Response

12.1 Coordinate and Response
 
  • Multicellular organisms need to respond to environmental changes
  • This response will be coordinated by organs and organ systems in the body
  • The changes in the environment are known as stimuli
  • External stimuli are changes in the external environment such as light, sound, smell, taste, the surrounding temperature, pain, pressure, and touch
  • Internal stimuli are changes in the internal environment in the body such as blood pressure, blood pH, body temperature, osmotic pressure, carbon dioxide partial pressure, and blood sugar level
  • The stimulus can be detected by an organism using receptors
  • Receptors are specialized cells in the sensory organs which detect stimuli and trigger nerve impulses
  • The nerve impulse will send to the integration centre via nerve for analysis
  • After analysis, the integration centre will send nerve impulses to the effector for producing appropriate responses toward that stimulus
  • Effectors consist of muscles (smooth, skeletal, and cardiac muscles) and glands (endocrine and exocrine glands)
  • Coordination is the corporation between several organs and organ systems in the body in order to function effectively by producing an appropriate response toward a stimulus
  • The nervous system and endocrine system are the two main organ systems in communicating and integrating towards the environment
 
Coordination and response in humans can be illustrated as below:
 
Stimulus
Sensory receptors
Integrating centre
Effector 
Response