Posts Tagged ‘rods’

How we see, how we hear

Friday, February 12th, 2010
Eye see you! by dotbenjamin on flickr

Eye see you! by dotbenjamin on flickr

We’ll start by looking at the different kinds of receptors that humans have, then focus on the photoreceptors in the eye and mechanoreceptors in the ear.  Click4biology is useful, as is this presentation by Mr Taylor in Bandung.

You need to be able to label a diagram of the eye like this one: Eye diagram

We’ll also do an eye dissection so you can relate the diagram to “reality”.  We’ll compare the different types of photoreceptors that are on the retina, namely rods and cones.  We’ll explain contra-lateral processing (right brain processing information from left eye, and vice versa). And finally we will explain certain kinds of optical illusions by looking at edge enhancement.

We’ll label a diagram of the ear and explain how sound is perceived.  Here are some questions for consideration:-

Why do we have two ears?  What role does the pinna play in other animals? Can fish hear? What range of sounds can the human ear hear? What is a cochlear implant and how does it work?  What does it mean to be tone deaf or have perfect pitch?

Option E – Neurobiology and Behaviour

Tuesday, January 26th, 2010
Mr Gray Eyes by Tim in sanhazzay on flickr

Mr Gray Eyes by Tim in sanhazzay on flickr

Here is the syllabus guide for this topic. Option E – syllabus guide

We’ll be using notes and resources from click4biology.

The first section is all about stimulus and response, so we’ll recap a bit of the nervous system, particularly the stuff on reflex arcs.  We’ll then move on to explain how animal responses can be affected by natural selection.  You need to investigate two examples of this.  Use can use the blackcap bird (Sylvia atricapilla) as one, and any other of your choosing.

Moving on to perception of stimuli, we’ll study both the eye and the ear.  You need to be able to label a diagram like this one: Eye diagram  We’ll then do a dissection so you can identify the parts properly.

You will also have to:

  • annotate a diagram of the retina to show cell types and direction of light movement
  • compare rods and cones
  • explain the processing of visual stimuli (edge enhancement and contralateral processing)

We’ll then move on to the ear, and you will need to be able to label a diagram and explain how sound is perceived.  Here is a good presentation to help you get through all that!