unit 1 aos 1 the role of the brain in mental processes and behaviour Flashcards
the central nervous system CNS (4 points)
main function - process info received from sensory systems and other body parts and activate appropriate responses.
- consists of the brain and spinal cord
- brain is the centre for cognition, processing and responding
- spinal cord is a route for messages to and from the brain
the peripheral nervous system PNS (x3)
responsible for carrying information to and from the CNS
- made up of every nerve in the body outside of the CNS.
- divided into the somatic and autonomic nervous systems.
the somatic nervous system SNS
Network of nerves that
- carry sensory information to the CNS
- motor information from the CNS.
controls the skeletal muscles attached to our bones, which produce observable bodily movement
sensory messages
transmit information about the body’s sensations, to the CNS so as it can coordinate a response.
motor messages
transmitted from the brain (via the spinal cord) to the skeletal muscles, giving instructions on how to move.
how is a response coordinated? 4 steps
1 body registers something,
2 SNS sends sensory messages about these sensations to the CNS
3 CNS processes this information and coordinates a response if necessary.
4 CNS sends a motor message to the skeletal muscles through SNS, telling them to respond
autonomic nervous system ANS
responsible for initiating the responses of the body’s visceral muscles, organs, and glands, such as the heart, stomach, and liver.
mostly self-regulating
ANS is further divided into sympathetic and parasympathetic
sympathetic nervous system
(branch of ANS) FIGHT OR FLIGHT
responsible for activating the body’s visceral organs, muscles and glands in order to prepare the body for dealing with high levels of activity, such as exercise or escaping a threat.
examples of responses - heart rate increase, blood flow increases, dilates pupils
parasympathetic nervous system
(a branch of the ANS) responsible for returning the body to and maintaining homeostasis of the body after heightened arousal of sympathetic response.
examples of responses - constricts pupils, heart rate decreases, blood flow is regular
homeostasis
an equilibrium in the body where all systems are at a stable level of functioning
the role of a neuron
responsible for transmitting, receiving, and processing information in the form of neuronal messages.
form of neuronal messages
sent electrochemically
chemically between neurons
electrically throughout a single neuron
types of neurons
sensory neurons - communicate info about body’s sensations
motor neurons - communicate info about how to move
interneurons - function to relay neuronal messages between motor and sensory neurons (because motor and sensory don’t communicate with eachother)
synaptic gap
the space between two neurons into which a neuronal message is transmitted
dendrites
are the bushy branches at the receiving end of a neuron
axon
long stick-like part of the neuron that conducts electrical impulses away from the cell body of the neuron to the sending end
myelin sheath
the fat and protein substance that surrounds, insulates and protects the axon of a neuron
axon terminals
are at the sending end of the neuron
they are responsible for the release of the neuronal message into the synapse
glial cells (x5)
a specialised cell that protects and supports neurons and their functioning • provides nutrients and oxygen • repair neurons • insulate neurons • produce myelin • aid neurons in neurotransmission.
hindbrain
an area at the base of the brain, including the medulla and pons (in the brain stem) and the cerebellum
responsible for some of our most fundamental functions, such as autonomic regulation of breathing and basic movement
cerebellum
the cerebellum is a ball-of-wool-like structure located at the back and base of the brain.
- posture and balance
- muscle movement
- procedures and sequences
medulla
located at the very bottom of the brain stem
functions to regulate our autonomic functions, such as breathing, heart rate, digestion, blood pressure, sneezing etc
pons (x4)
located directly above the medulla in the brain stem • relays information • regulates the respiratory system • involved in sleep • involved in some involuntary movements
midbrain
located in the middle of the brain between the hindbrain and the forebrain.
consists of the reticular formation
reticular formation
has pathways that project into various parts of the brain.
functions to
• filter information to relevant parts of the brain,
• regulating the sleep-wake cycle and consciousness
• regulating physiological arousal and alertness through the reticular activation system (RAS).
reticular activation system
a network of neurons that has pathways through the brain and down toward the spinal cord, telling the body to either increase or decrease arousal/alertness in response to information about the body’s state and environmental stimuli.
forebrain
the largest area of the brain is responsible for our most sophisticated functions such as - memory - learning - perception - cognition.
thalamus
part of the forebrain. the “relay centre”
- functions to regulate arousal, attention and activity
- filters sensory and motor signals
hypothalamus
primarily involved in homeostatic functions as well as motivated and emotional behaviours
cerebrum
largest expanse of brain matter including the outer cerebral cortex and inner tissue of the forebrain.
responsible for our most sophisticated, higher order functions like language, perception and evaluation
left and right hemispheres
left = verbal and analytical functions right = non-verbal functions and creativity and facial recognition
frontal lobe
responsible for high-order mental processes, regulation and expression of emotions, voluntary movement and speech production.
cerebral cortex
the thin outer layer of the cerebrum
pre-frontal cortex of the frontal lobe
an area of the frontal lobe responsible for higher-order cognitive processes such as decision making and planning
reaches maturity at 25 y/o
pre-motor cortex
an area of the frontal lobe responsible for planning necessary sequences for motor movements
primary-motor cortex
an area of the frontal lobe that initiates and controls voluntary movements
broca’s area
area of the frontal lobe responsible for production of clear and fluent speech
parietal lobe (x3)
- processing bodily functions such as touch and temperature
- information about muscle movement
- attention and spatial reasoning
somatosensory cortex
responsible for receiving and processing sensory information from the skin and body.
occipital lobe
organisation and interpretation of visual stimuli
primary visual cortex
major destination for visual information.
the information comes in from the sensory receptors located on the retina of the eyes.
temporal lobe (x3)
- hearing
- decisions made about which features of environments we will remember
- facial recognition
primary auditory cortex
temporal lobe - receives and processes sound from both ears so that we can perceive and identify different types of sounds
wernicke’s area
temporal lobe - speech comprehension and interpreting human speech. you cannot understand words until processed here
plasticity
our brain’s ability to physically change in response to experience and learning
developmental plasticity (what and when)
changes in the brain that occur in response to ageing and maturation
- begins when we are a fetus and ends when we are in our mid-twenties.
adaptive plasticity
changes in the brain that occur in response to injury or trauma
myelination (what and when)
the process of coating neurons axons’ with a fatty protein substance (myelin sheath) to ensure neuronal communication is fast and efficient. occurs largely during infancy and then further in adultolesence
Synaptic pruning
The elimination of underused synapses.
- To ensure the brain can function efficiently as only necessary connections are kept.
- Some pruning occurs after infancy but it occurs most intensely during adolescence.
Frontal lobe development
The development of the frontal lobe, including its growth in size and the maturation of its neuronal connections.
- To allow for the functioning of any task the frontal lobe is responsible for, such as movement, language and decision making.
- The frontal lobe develops from when we are a fetus until about the age of 25 through changes to our neuronal connections.
proliferation
the forming of neurons in infancy
Migration
when neurons migrate from where they were formed, to where they will stay in the nervous system
synaptogenesis
The axons of neurons grow and form connections to nearby neurons creating synapses. This can occur throughout the lifespan but is most intense in infancy.
