Sensory receptors 0.0 / 5 ? BiologyCellular processesA2/A-levelOCR Created by: Steff06Created on: 17-05-16 10:03 What are the receptors in the retina of the eye called and what energy change do they detect? Light sensitive cells (rods+cones). Detect light intensity and range of wavelengths. 1 of 23 Where are the olfactory cells and what energy change do they detect? Lining the inner surface in the nasal cavity. Detect presence of volatile chemicals. 2 of 23 Where are the taste buds and what do they detect? In tongue, hard palate, epiglottis, 1st part of oesophagus. Detect pressure on skin. 3 of 23 What are the pressure receptors in the skin known as and what do they detect? Pacinian corpsules. Detect pressure on skin. 4 of 23 Where are the sound receptors and what do they detect? In the cochlea (inner ear). Detect vibrations in the ear. 5 of 23 What do the muscle spindles detect? The length of muscle fibres. 6 of 23 What do sensory receptors detect? Changes in our surroundings. 7 of 23 Why are the known as energy transducers? They convert one form of energy to another. 8 of 23 What is a change in the environment known as? A stimulus. 9 of 23 What are the specialised channel proteins in neurones specific to? Either sodium or potassium ions. 10 of 23 What can the gate on the channel proteins do? Open or close the channel. 11 of 23 What is the permeability when the gate is open? Permeability of the membrane is increased. 12 of 23 What happens to the permeability when the gate is closed? It is reduced. 13 of 23 Are the channels usually kept open or closed? Usually closed. 14 of 23 What pumps do nerve cell membranes also contain and what is the function of these? Contain sodium-potassium ion pumps that actively transport 3Na+ sodium ions out of the cell and 2K+ potassium ions into the cell. 15 of 23 What does this ion movement mean? The inside of the cell is more negative than the outside of the cell (membrane is polarised). 16 of 23 What produces the voltage? The difference in charge. 17 of 23 How is a nerve impulse created? By altering the permeability of the nerve cell membrane to sodium ions. 18 of 23 What happens as the sodium ion channels are opened? The membrane permeability is increased and sodium ions can move across the membrane down their concentration gradient into the cell. 19 of 23 What happens to the charge inside the cell and what is this caused? Inside of the cell becomes less negative compared to the outside. This is called depolarisation. 20 of 23 What is a generator potential? A small change in potential caused by 1 or 2 sodium ion channels opening. 21 of 23 What is the effect if the stimulus is larger? More sodium ion channels will open. 22 of 23 When will an action potential only be produced? If the generator potential reaches a certain threshold. 23 of 23
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