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The human ear
Colour:
Green
Term:
3
Week:
Week 3
Language:
Introduction:
Focus on the aims of the lesson and use the resources available to understand the concepts and skills to be mastered.
Revise the ‘nervous system’ topic in Grade 9
Revise ‘nerve tissue’ covered in term 2 in Grade 10.
Hearing:
- The pinna traps and directs the sound waves into the external auditory canal/ear canal/meatus
- This causes the tympanic membrane to vibrate
- The vibrations are transmitted to the auditory ossicles
- The ossicles amplify the vibrations and transmit it to the oval window
- The oval window vibrates creating pressure waves in the fluid/endolymph of the cochlea
- This stimulates the organ of Corti to convert the wave into an impulse
- The impulse travels along the auditory nerve to the cerebrum where it is interpreted
Balance:
- The maculae in the utriculus and sacculus are stimulated by changes in the position of the head.
- The cristae in the semi-circular canals are stimulated by changes in the direction and speed of movement.
- When stimulated, the cristae and maculae convert the stimuli into nerve impulses
- The nerve impulses are transmitted through the auditory nerve to the cerebellum where they are interpreted
- The cerebellum then sends impulses via the motor neurons to the skeletal muscles to restore balance
Activities:
Answer the following questions:
1. Describe how the parts of the middle ear, including the membranes, assist with amplifying sounds.
2. Describe the role of the semi-circular canals in maintaining balance
Upload Audio Activities :
Conclusion:
By studying and learning about the human nervous system you will understand that organisms need to detect and respond to stimuli in order for them to survive in a continuously changing environment.
Introduction Heading:
Revision
Activities Heading:
Questions from past papers
Conclusion Heading:
Values
Grade:
12
Subject:
