Senses Flashcards
What is the function of sensory receptors?
To convert physical and chemical stimuli to neural signals.
What are the three types of ionotropic sensory receptors?
Mechanoreceptors, thermoreceptors and electroreceptors.
What opens the ion channels of mechanoreceptors?
Pressure
What influences the cation channel of thermoreceptors?
Temperature
What opens the ion channels of electroreceptors?
Electric charge
What are the two types of metabotropic sensory receptors?
Chemoreceptors and photoreceptors
What causes the opening of ion channels in chemoreceptors?
Ligand binding
What causes photoreceptor ion channels to open?
Light that alters the receptor protein and initiates a signal cascade.
What is receptor potential?
Changes in resting membrane potential of the sensory receptor cell.
What does the type of sensation experienced depend on?
Which neurons receive APs from sensory cells.
How do all sensory systems process information?
As action potentials.
Why do sensations differ?
As it is dependent on which area of the CNS the AP arrives.
What is adaptation?
When sensory cells give gradually diminishing responses to maintained or repeated stimulation.
When do rapid adapting cells produce signals?
When stimulus turns on and then off, not in the middle.
What responses can ligand binding to chemoreceptors result in?
Feeding, fighting and recognising individuals.
What coordinates mating in silkworms?
The pheromone bombykol.
What structures are involved in mosquito olfaction?
Antennae, maxillary palps and the proboscis.
What is the Aedes aegypti aegypti preference for humans linked to?
Ligand sensitivity of the odorant receptor Or4.
How does Or4 help mosquitos distinguish humans?
By increasing perception of sulcatone.
How does the olfaction system in mosquitos function?
Odorants bound by ODP in microscopic hairs are transported to receptors which generate a receptor potential.
What is gustation responsible for?
Taste
What is the process of gustation?
Sensory cells are found in the papilla on the tongue. Molecules bind to receptors on microvilli sensory cells in the papilla. Sensory cells release neurotransmitters which depolarises dendrite sensory cells.
What are the functions of mechanoreceptors?
Interpreting skin sensations, sensing BPs, hearing and maintenance of balance.
Where are mechanoreceptors found?
In muscles, tendons and ligaments.
Where are golgi tendon organs found?
In tendons and ligaments
What is the function of golgi tendon organs?
To provide information about force generated by contracting muscles.
When are stretch receptors initiated?
When muscle spindles are stretched.
What happens when contraction becomes too forceful?
Sensory neurons send APs to the CNS that inhibit motor neurons and the muscle relaxes.
What is responsible for hearing?
Pressure waves that are converted to receptor potentials by mechanoreceptors.
What detects gravity and momentum?
Hair cells.
What does photosensitivity allow simple organisms to do?
Orient themselves to the sun and sky.
What does photosensitivity allow complex organisms to do?
Obtain rapid and detailed information on their environment.
What is the main structure in photosensitivity?
Rhodopsin
What kind of eyes are found in Arthropods?
Compound eyes
What are compound eyes?
Eyes that consist of many units called ommatidia.
What structures are contained in the ommatidium?
The corneal lens, crystalline cone, pigment cell and photoreceptor.
What is the function of Ampullae of Lorenzini?
To detect small electrical fields generated by prey.
