Control of behaviour Flashcards
What are some simple behaviours?
What can controls behaviour?
Simple behaviours:
Reflexes
Kinesis
Taxis
Neural control
Hormonal control
Diurnal and tidal cycles
Social control
Name some simple reflexes and the link between them
What is the simple pathway for reflexes naming neurons
Automatic response to an external signal.
Blinking eye.
Sneeze.
Pupil dilation.
Knee-jerk.
They are all automatic and almost impossible to override. The reasons for these behaviours is for protection and quick signals
Sensory neuron–> (interneuron)–> motor neuron
Describe kinesis
Change in activity rate in response to a stimulus.
Very simple orientation behaviour.
No orientation with respect to gradient.
Describe taxis
Movement towards or away from a stimulus.
Many marine plankton alternate between positive and negative phototaxis such as barnacles
Neural control of behaviour and give an exampe
Integrating information and producing a coordinated response requires a complex nervous system.
Feedback usually involved – “closed loop” not “open loop” like reflexes.
Simple internal feedback: stretch receptors in stomach controlling food intake.
More complex behaviour uses feedback and control from CNS and PNS.
ganglia allows integration of information and send messages from one part to another o be processed. coordination
human cerebral cortex
The primary motor complex situated in the frontal lobe and the primary somatosensory cortex situated in the parietal lobe
The brain has invaginted surfaces to increase surface area, the connections of the brain and the connections between neurones are on the surface.
Larger invagination means we have devoted a larger importance to this function.
Hormonal control of behaviour
Name some examples
Hormones provide proximate control.
E.g. High levels of testosterone in mammals often associated with courtship displays or male–male aggression.
Hormones influence development.
E.g. Androgenisation of male foetus depends on testosterone levels.
Many sex differences in morphology and behaviour are related to hormonal differences.
Hormonal control of behaviour in Blue-headed wrasse
Males defend patches of coral reef.
sex is socially controlled by testosterone levels not by genes and they can switch from producing eggs to sperm
Females lay eggs in the males’ territories.
Sex of individuals is socially controlled
Testosterone controls the sex, colour, and behavioural traits.
Temporal patterns of behaviour
Seasonal patterns (year).
E.g. Breeding and migration in birds.
Lunar cycles and tidal cycles (month).
E.g. Behaviour of many marine organisms.
Circadian rhythms (day).
E.g. Daily patterns of activity and rest.
Activity rhythms in Horseshoe Crabs Limulus polyphemus
In late spring, adults move inshore from deep waters to spawn on sandy beaches.
Peak in spawning activity coincides with the full moon and evening spring tides.
Synchronises breeding.
Social control of behaviour use an example
Courtship behaviour in sticklebacks.
Female behaviour depends on:
Male’s behaviour
Male’s appearance
Nest quality
Controlling others
Male fiddler crabs signal
Male fiddler crabs signal to rival males and potential mates.
Colourful enlarged claws may have evolved to exploit existing sensory biases.
Name what controls behaviours
Behaviour may be controlled by:
Internal factors such as hormones, learning.
External factors such as food availability, competitors, tides.
Most behaviours involve control at a range of levels.
Animals with complex behavioural traits usually have complex nervous systems.
Diversity in nervous systems
*coral polyp= No CNS nerves are diffuse, nerve depch through body. They can learn and show simple behaviours but their ability to coordinate behaviour is very limited
*starfish= It has a nerve ring around body, not a brain but centralisation of a processing power so if its prey released chemicals e.g a scallop, the starfish can detect it from one arm and coordinate a response to move in that direction
leech/worm=More involved integration of nerves, some degree of brain formation (swelling) they have ganglia which are bulges in PNS which allow integration of info from one part of the body to the next with processing
insects, locust= Large brain and big ganglia’s throughout body so can coordinate the movement of six legs without thinking, it can process feedback from each leg due to ganglia along spine and well developed CNS. Its brain can also process external and visual information rapidly
cephalopods octopus= well developed brain, large nerves and ganglia’s for processing information,
