Lecture 19 senses Flashcards
What senses are part of Chemoreception?
smell
taste
What senses are part of Mechanoreception?
Touch
Proprioception
Lateral line system
Balance
What is the threshold membrane voltage?
Voltage at which the action potential is triggered (55mV)
The vertebrate nervous system transmits
information in what aspect of action potentials?
Frequency(number per second).
What is an afferent neuron?
the sensory neuron
describe the sensory - Motor response pathway?
Sensory (afferent) neuron -> receptor
Interneurons
Motor (efferent) neuron -> effector
what are the types of Detectable information?
Light
Chemicals
Temperature
Movements
What is transduction?
The process of converting one form of energy into another form i.e converting information into the Language of the nervous system.
What are the steps in a stimulus response?
Detection Transduction Amplification Transmission Integration Response
What are the different types of sensory cells?
Neurons
- Short single dendrite
-Long branched dendrites
Specialised epithelial cells
What types of receptors are present internally?
Enteroceptors
What is the most widespread sense?
Chemoreception
What are the two primary forms of chemoreception?
Taste (gustation)
Smell (olfaction)
What are the areas of the brain specialised for olfaction in insects and vertebrae?
Antennal lobe (insect) Olfactory bulb (vertebrate)
What are the sensory structures of insect olfaction?
Sensory ‘hairs’ or sensilla, on their antenna.
Three main components of insect olfaction
Cuticular structure (hair) with many small pores Support cells produce lymph (mucus) Sensory neurons with cilia
how do male moths increase olfaction?
Larger surface area through:
Antennal branches
Longer sensilla
What are the parts of the Olfactory epithelium?
Mucus
Sensory neurons
Cilia
How do axons reach the olfactory bulb in brain?
they pass through cribriform plate
What are the Glomeruli?
processing areas
Where is the Shortest cranial nerve?
Olfactory epithelium
how many different odours can Mammals differentiate?
~10,000
How are the chemicals differentiated in olfaction?
Its unique combination of
receptors
Where are Olfactions primary receptor cells located?
Olfactory epithelium
What are the Receptor proteins on?
The cilia of olfactory neurons
How may traduction methods does Olfaction have?
one
do molecules bind to multiple or single receptors?
Each molecule can bind to
several different receptors
Each receptor detects several
different odorants
what is Gustation?
Contact chemoreception (Taste)
is taste more or less sensitive to than smell?
less
What kind of receptor cells does Gustation (Taste) have?
Epithelial receptor cells (not neurons)
What locations on the body does Taste occur?
Taste buds in oral cavity (amniotes)
Also on rest of the body in fish (e.g. barbels) and aquatic amphibians
What tastes can be discriminated?
Five tastes: Salty, Sour, Bitter, Sweet and Umami
How many tastes can each receptor detect?
one
What are the components of flavour?
taste and smell
What are the Distinctions between taste & smell in vertebrates?
Smell: Distance, many qualities, centralised location (nose)
Taste: Contact, only five qualities, diffuse location
What are the Specialised Mechanoreception systems?
Lateral line system
Hearing
Equilibrium
Echolocation
What sensations are included in Mechanoreception?
touch, vibration, pressure & pain
how do Mechanoreception receptors function?
Receptors are ion channels
respond to physical motion of cell membrane
changes membrane permeability to Na+ & K+
how do Insect bristle function?
Hard exoskeleton impedes mechanical deformation
Movement of bristle in socket
Signal depends on direction
of bend
What is Somatosensory?
Touch
how is the Depth of pressure recognised?
Light touch: outer
layers deform
Strong pressure: deep
layers deform
What are Proprioceptors used for?
What is the body doing?
Orientation and movement of own body
What does the Lateral line systems detect?
how body is positioned relative to water flow
What does Electroreception detect?
muscle potentials
