Recording-2025-03-13T03:49:53.395Z

Vibrations and Sound Waves

• Sound waves are made up of vibrations that travel through air.

• The ear detects these vibrations and converts them into electrical signals for the brain to interpret as sound.

• Sound waves can be compared to light waves in terms of frequency and amplitude; higher frequency results in higher pitch.

Structure of the Ear

External Ear

• Key components:

  • Auricle: Collects sound waves.

  • Helix: The outer rim of the auricle.

  • Lobule: The fleshy part of the ear; earlobes can be attached or unattached, a trait inherited genetically.

• These structures have folds that help to direct sound waves into the ear canal.

Middle Ear

• Contains the Tympanic Membrane (Eardrum):

  • Vibrates when sound waves hit it, similar to how a cymbal amplifies sound.

• Auditory Ossicles (three small bones):

  • Malleus (hammer): First bone in the chain.

  • Incus (anvil): Middle bone.

  • Stapes (stirrup): Final bone, amplifies vibrations to the inner ear.

• The function of these ossicles is to increase the amplitude of sound waves before they reach the inner ear.

Inner Ear

• Contains the Cochlea:

  • Shell-shaped structure filled with fluid that vibrates in response to sound waves.

  • Has structures called spiral organs and a cochlear duct inside.

• Vibrations in the cochlea lead to ion changes in membranes that activate nerves sensing sound and transmitting the electrical signals to the brain.

• Semicircular Canals (Ducts):

  • Involved in balance (equilibrium) while sound processing occurs in the cochlea.

Sound Testing

• Weber and Rinne Testing:

  • Used to assess hearing ability and detect any issues.

  • Weber Test: Conducted by placing a vibrating tuning fork on top of the head; sound should be equal in both ears.

  • Rinne Test: Involves placing the tuning fork on the mastoid process to check how sounds are conducted through bone vs. air.

Dissection and Lab Report Guidance

• Lab report focuses on comparing human anatomy with that of other organisms.

  • Hypothesis should explore comparative anatomical structures and their functions.

  • Introduction: Describe differences between humans and other organisms.

  • Methods: Steps for performing dissections to visualize structures.

  • Results: Present qualitative data with figures and comparisons.

  • Discussion: Importance of studied organisms and how they relate to human anatomy, including potential better-suited organisms for study.

Final Notes

• Review models and anatomy for practical exams post-spring break.

• Prepare adequately by taking pictures and using labeled structures from lecture materials.

• Reinforce knowledge of anatomical and physiological functions through studies with dissections.