Brain and Behaviour Flashcards
What is the aim of psychobiology?
Psychobiology aims to understand the biological basis of behaviour. There are two schools of thought:
-> Dualist (Mind is different from matter)
-> Materialist (Mind is what brains do)
What are the different biological systems that are studied in psychobiology?
Biological systems studied in psychobiology:
-> Immune System
-> Endocrine System (the body’s internal state, growth, development, reproduction)
-> Nervous System (coordinates response to stimuli + biological basis of cognitive functions
What is the evolutionary history of the nervous system?
Evolutionary history of the nervous system:
-All animals have nervous systems, except sponges
-Electrochemically-active cells specialised to communicate with eachother (chemical change in one cell causes chemical change of another)
-Simplest forms of NS are uncentralised
-Simple organisms have centralised NS with seperate CNS + PNS systems
-Vertebrate NS are more complex, and CNS + PNS systems more seperated
Organisation of the nervous system
-CNS is split into the brain and spinal cord
-PNS is made up of somatic (voluntary control of skeletal muscles) systems and autonomic systems (involuntary control of muscles and glands)
-The autonomic system is made up of the sympathetic (fight/flight) and parasympathetic (rest/maintenance)
Spinal Cord link between PNS and CNS
-Sensory signals from body enter CNS via spinal cord
-Motor signals to body leave CNS via spinal cord
Outline the monosynaptic reflex arc (eg knee-jerk reflex)
Monosynaptic Reflex Arc:
1. Specific sense organs in muscle fibres (called muscle spindles) activates sensory neurone
2. Axons enter spinal cord (via dorsol root), connecting directly with motor neurones which send their axons out (via central root)
3. This therefore activates the same muscles from which signals originated (causing it to contract)
What are monosynaptic reflexes?
Monosynaptic reflex resist skeletal muscle stretching, enabling smooth and stable movement
-> These can have additional synaptic connections
What is the polysynaptic reflex arc?
Polysynaptic reflex arc:
-Sensory and motor neurones connected via one or more interneurons
-Sensory and effector in different locations
-More flexible arrangement
-Can show simple forms of learning
What are central pattern generators?
Central pattern generators:
-Spinal cord neurones generate complex movement patterns
-Cannot voluntarily initiate movements - only in response to stimulation
Monosynaptic and Polysynaptic synapse functions
-Monosynaptic synapse = Functionally, only one synapse links between sensory and motor neurones
-Polysynaptic synapse = Functionally, multiple synapses between neurones (bi-synaptic and tri-synaptic)
‘What does it take for an organism to ‘behave’?
1 -> Information from the environment is registered
2-> Resulting in an internal change (‘transform’ or ‘process’ the info)
3->Generate an appropriate response
What does an ‘uncentralised’ nervous system mean, as found in the simplest forms of nervous systems?
Uncentralised nervous systems = no ‘nerve centre’ that controls the activity of large numbers of other neurons and the actions of distant body parts
Vertebrate nervous systems
-More complex than simple
-Structurally = CNS and PNS more seperated
-Hierarchically organised with brain specialised to organise and communicate between neurones as well as control the action of distant body parts
Autonomic nervous system input (resulting in involuntary control)
Autonomic NS receives input from CNS only whereas Somatic nervous system receives input from both sense organs and CNS
3 basic processes of the nervous system
Sensory signals detected
Signals interpreted
Motor signals sent to muscles and glands
Why are monosynaptic reflex arcs important?
Monosynaptic reflex arcs are important because it resists or dampens stretching of skeletal muscles, providing smooth and stable movements.
Differentiate monosynaptic and polysynaptic reflex arcs
Monosynaptic reflex arc activates the same muscle the signal is originated from, whereas polysynaptic reflex arc has the receptor and effector in different places
CNS anatomy
Anatomically, CNS is a delimited nervous tissue that is compromised of functionally specialised neurons interconnected by axon tracts (neuropil)
What are ganglia in the nervous systen?
Ganglia are groups of brain cells or nerves that are closely related and work together as part of the nervous system
->Also known as the relay stations in the PNS
->CNS is subdivided into ganglia
Define the uncentralisation of nervous systems, as found in simpler organisms
Uncentralised nervous systems = recieves sensory input and output only locally, without central intergration -> this is achieved by direct interconnection of sensory neurons and effector neurons
Determination of the cell becoming active
The combined input of the signal integration at relay stations determines if the cell becomes active
Location of which precisely localised information is sent
Neurons transmitting precisely localised information send axons to the top of the spinal cord (medulla)
What is sensory adaption?
Sensory adaption = refers to neurons getting used to a specific stimulus -> this means that a constant stimulus would not be felt (only changing stimuli)
Transmission of poorly localised information
Neurons transmitting poorly localised information (eg temperature and pain) synapse immediately with other neurons upon entering the spinal cord
What are relay stations?
Relay stations = where all signals are integrated -> the combined input of the signal integration determines if the cell becomes active
->A lot of information processing takes place before a signals has reached the brain
What structures do the hindbrain consist of?
The hindbrain consists of the medulla, pons and cerebellum
Hindbrain - function
->Medulla and Pons = where the spinal cord enters the brain (functions: contains several nuclei/clusters of cell bodies, connected to the autonomic nervous system)
->Cerebellum: not part of the brain stem (function = balance and motor learning)