Introduction
Observe the ´Rubber Hand´experiment?
A) Reflect on the experience.
What did you see?
What did you think?
What did you wonder?
Think of some specific questions that you would like to ask, after witnessing this experiment?
Take one of the questions, and try to phrase it as a viable IA question?
The Homonculus
The Homonculus is a proportional drawing showing how much of the cerebral cortex in the brain is taken up by neural connections with certain parts of the body. If there are more neural connections to that part of the body, the part is shown to be larger. If there are few neural connections, that body part is smaller. Explore this Link
Q) Which parts of the body contain the most connections to the cerebral cortex?
Hearing
Introductry Activity: try the Ear funnel demonstration.
Q) What conclusions can you draw about the role of the inner ear?
Exploration: Use this link to explore the Inner ear
Download the worksheet (printed copies available).
WS – Ear Structure and Function WORD
The human ear can detect sound because of a the sensory cells in the cochlea, which detect vibrations passed through the oval window into the inner ear.
These cells are a kind of mechanoreceptor because they can detect physical movement of vibrations.
Different hairs vibrate to each specific frequency of sound.
These cochlear hair receptor cells are connected by synapses to the auditory nerve. When a cochlea is depolarised by vibrations in the hair, a neurotransmitter is released that triggers an action potential in the auditory nerve. In this way, the information is carried to the brain (temporal lobes).
Reflect on the video prompt The effect of music on the brain.
Challenge: What aspects of the video changed the way you thought, or offered fresh ideas about music?
Connect: What aspects of the video connected to things you already knew, or what we have learned in class about hearing
Extend: What would you like to find out about, relating to the effect of music on the brain. Write two or three questions. Select one, and rephrase it into a research question that might be linked to an IA.
How do Cochlear implants work
Cochlear implants are used when a hearing impairment is not simply caused by the poor transmission of vibrations from the outer ear, to the inner ear. They are used when the cochlear is not functioning properly.
In a cochlear implant, the human ear is bypassed almost entirely in that:
- An external microphone is set up to detect sounds (in place of the pinna, which normally funnels sound into the auditory tube.
- A transmitter and stimulator is implanted into the cochlea, which is designed to stimulate the auditory nerve directly and stimulate the correct impulses related to the sound detected.
Cochlear implants cannot completely restore hearing, but they will allow for a great improvement in hearing in cases of severe impairment.
Lesson 2: The Human Eye
Keywords:
Receptor cell: a cell which is capable of sensing stimuli from the environment. Common Receptor cells include thermoreceptors, chemoreceoptors, mechanoreceptors, and photoreceptors.
Rods and cone cells: Are photoreceptors in the human eye (rods detect more efficiently in dim light, and more black and white. cones detect more in colour, and more in bright light)
Ganglion cell: A cell which conducts electricity to the optic nerve, in the eye.
Optic nerve: A nerve which runs to the brain (to the visual processing centre, in the occipital lobe).
Introduction:
Receptors are cells that can detect stimuli from the environment, creating an electrical impulse which passes along a sensory neurone.
Kinds of receptors:
- Thermoreceptors, detect heat.
- Photoreceptors, detect light
- Mechanoreceptors, detect forces eg. pressure, or stretching
- Chemoreceptors detect chemicals
Q) Make a table for the ´five senses´, that you would have heard of, and determine through discussion the sense organ involved, the relevant receptor cells (if you know them), and the kind of receptor cell they are.
Q) Explain succinctly to the person sitting next to you what is meant by the blind spot for the human eye? What are the implications for everyday life?
How does the human eye detect light?
Task Develop a table stating the function of the following parts of the eye: lens, choroid, retina, sclera, pupil, ciliary body, aqueous and vitreous humor, iris. Generate this through the video discussion.
Q) Where are the receptor cells found in the eye, what are there names and what kind of receptor cells are they?
Generating an image from light
Task: Watch the video, and draw flow charts to show the pathway of light, and the pathway of an electrical impulse, in the retina.
Rods and Cone cells are different photoreceptors
Cones: Distinguish colours, function better in bright light as they are less light sensitive. Exist as either red, blue, or green cones.
Rods: Do not distinguish colours, are more light sensitive.
Discussion Q. Which photoreceptors are more useful at night, and which are more useful during the day?
The fovea – the area of the retina that contains the greatest density of rods and cones
Rhodopsin is a pigment that absorbs light, and is broken down in the process. If a light is shone in your eye, the rhodopsin is completely broken down (especially in rod cells), and this causes you temporary blindness as without rhodopsin light stimulus cannot be detected.
Rods and Cone cells are different photoreceptors found in the retina.
Cones: Distinguish colours, function better in bright light as they are less light sensitive. Exist as either red, blue, or green cones.
Rods: Do not distinguish colours, are more light sensitive.
Discussion Q. Which photoreceptors are more useful at night, and which are more useful during the day?
The fovea – the area of the retina that contains the greatest density of rods and cones
Rhodopsin is a pigment that absorbs light, and is broken down in the process. If a light is shone in your eye, the rhodopsin is completely broken down (especially in rod cells), and this causes you temporary blindness as without rhodopsin light stimulus cannot be detected.
Rods and Cone cells are different photoreceptors
Cones: Distinguish colours, function better in bright light as they are less light sensitive. Exist as either red, blue, or green cones.
Rods: Do not distinguish colours, are more light sensitive.
Discussion Q. Which photoreceptors are more useful at night, and which are more useful during the day?
The fovea – the area of the retina that contains the greatest density of rods and cones
Rhodopsin is a pigment that absorbs light, and is broken down in the process. If a light is shone in your eye, the rhodopsin is completely broken down (especially in rod cells), and this causes you temporary blindness as without rhodopsin light stimulus cannot be detected.
Visual processing
The visual processing centre in the occipital lobe processes the information from both eyes to create an image (it needs to be flipped and cross-referenced). The brain is interpreting information – how do we know if we see the same thing?
The brain processes the information from both eyes to create an image (it needs to be flipped and cross-referenced).
Q) The brain is interpreting information – so how do we know if we see the same thing as another person?
