Biology And Behaviour Flashcards
What are the three major parts of the brain and their embryonic brain subdivisions
Hindbrain (rhombencephalon) - divides into metencephalon (pons and cerebelllum ) and myelencephalon (medullla oblongata )
Midbrain (mesencephalon ) - contains superior and inferior colliculus
Forebrain (prosencephalon) - telencephalon (cerebral cortex, basal ganglia, lambic system) and diencephalon (thalamus, hypothalamus, posterior pituitary and pineal glands)
Superior collliculus
Receives visual sensory input
Inferior collliculus
Receives auditory sensory input
What are two non invasive ways to study brain activity and how do they work?
EEG (electroencephalogram)- places electrodes on scalp and measures patters on electrical activity
Regional cerebral blood flow (rCBF) - inhale harmless radioactive gas and then look at regions where we have increased blood flow
Thalamus
Part of the forebrain that acts as relay station for incoming sensory information for all senses but smell and send them to the cerebral cortex
Hypothalamus
Subdivided into the lateral hypothalamus, ventromedial hypothalamus, and anterior hypothalamus
Important for homeostasis, emotional experience, high arousal states, aggressive behaviour, sexual behaviour, hunger and thirst
Lateral hypothalamus
Hunger center - has receptors that detect when the body needs more food or fluids
If this part of the brain does not work you lack hunger - would not eat or drink
Ventromedial hypothalamus
Satiety centre - provide signals to stop eating - if this is part of the brain is not working you are “VMH - very much hungry - would lead to obesity
Anterior hypothalamus
Controls sexual behaviour - damage would cease sexual activity
Also regulates sleep and body temperature
Basal ganglia
In middle of brain - coordinate movement and received information from cortex and relays to spinal cord via extrapyramidal motor system
Makes our movements smooth and posture steady
Parkinson’s disease has destruction of basal ganglia
Limbic system
Interconnected structures looping around central portion of the brain - controls emotion and memory - includes septal nuclei, amygdala and hippocampus
Septal nuclei
Primary pleasure centres in the brain - can cause addictive behaviour
Amygdala
Defensive and aggressive behaviour, fear and rage - aggression and fear greatly reduced when amygdala not functioning
Hippocampus
Learning and memory, consolidate information to form long term memory, redistributes memory to cerebral cortex
Communicates w/ limbic system through fornix
Anterograde amnesia
Not being able to establish new memories
Retrograde amnesia
Memory loss of events that transpired before brain injury
Cerebral cortex
Aka neocortex - outer surface of brain - most recent to evolve - has many gyri (bumps) and sulci (folds)
Four lobes - frontal, temporal, parietal , occipital
Prefrontal cortex
Manages executive function by supervising and directing operations of processes for perception, memory (does not store memories itself but let us know we have them), emotion, impulse control and long term planning
Communicates with reticular formation in the brain stem controlling alertness or attention - wake up or relax
Association area
Integrates input from diverse brain regions
Eg. Many different inputs needed to solve a puzzle
Projection area
Perform more rudimentary or simple perceptual motor tasks
Eg. Visual cortex
What may happen if a person had a prefrontal legion
Impulsive, less in control of behaviour , depressed
Primary motor cortex
Located on the precentral gyrus - initiates voluntary motor movements by sending impulses down the spinal cord towards the muscle
Is a projection area
Motor homunculus
Neutrons in motor cortex area arranged systematically - size in cortex based in need for finer motor control
Area in the frontal lobe that is vital for speech production
Broca’s area- only found in 1 hemisphere
Parietal lobe
Located to the rear of the frontal lobe
Contains the somatosensory cortex which is a projection area for sensory signals for touch, pressure, temperature and pain
Also associated with spatial processing and manipulation - orient of self and others in 3D space
Occipital lobe
At the rear of the brain and contain the visual/striate cortex
Also has role in learning and motor control
Temporal lobe
Contains the auditory cortex, wernicke’s area and hippocampus (memory processing, emotion, language)
Auditory cortex
Part of the temporal lobe - sound processing - speech and music
Wernicke’s Area
Language reception and comprehension
Contralateral
Cerebral hemisphere will cause action in the side of the body opposite to it
Opposite is ipsilateral (eg. Hearing )
Dominant hemisphere
Usually the left - the one that is more heavily stimulated during language reception and production
Analytic , good for managing details, language, logic, math
Contains Broca’s area dnd wernicke’s area
[letters, words, language sounds, speech, reading, math, complex voluntary movement ]
Non dominant hemisphere
Usually the right - intuition, creativity, music cognition, spatial processing
Holistic image, less prominent role in language,
More sensitive to tone of language or mood
[faces, music, emotions, geometry, sense of direction ]
Acetylcholine
In peripheral nervous system it transmits nerve impulses to muscles
Uses mainly in parasympathetic system, but inner ages sweat glands in sympathetic
CNS linked to attention and arousal - loss of cholinergic neutrons can lead to Alzheimer’s
Epinephrine and norepinephrine
Are catecholamines and are important in experience of emotions
Control alertness and wakefulness, primary NT. Of sympathetic nervous system
NE usually more local NT while epinephrine is secreted from adrenal medulla to act systemically as a hormone
What is associated with low levels of NE? High levels?
Depression
Anxiety and mania
Dopamine
Catecholamine important for movement and posture - high levels usually found in basal ganglia to help with movement and postural stability
Dopamine hypothesis of schizophrenia
Too much dopamine or an over sensitivity to dopamine can cause delusions, hallucinations and agitation
Loss of dopaminergic neutrons in the basal ganglia
Parkinson’s - resting tremor, jerky movements and postural instability
Serotonin
Monoamine catecholamine
Regulates mood, eating, sleeping and dreaming
Depression and mania
GABA
Produces inhibitory post synaptic potentials - stabilizes neural activity in the brain - causes hyperpolarization of postsynaptic neutrons
Neormodulators
Aka neuropeptides
Slower and longer effects
Eg. Natural pain killers endorphins and enkephalins
Reflex
A behaviour that occurs automatically in response to a given stimulus
Primitive reflexes
Reflexes that we have when we are young but typically disappear at a distinctive time - retention of these can indicate issues with neurological development
Rooting reflex
Automatic turning of the head when a stimulus brushes the cheek
Moro reflex
Infants react to abrupt movements of their heads by flinging out arms, slowly retracing and crying
-usually disappears after 4 months - continuation at 1 year is strong indicator of developmental difficulties
Babinski reflex
Toes spread apart automatically when the sole of the fooot is stimulated
Grasping reflex
Occurs when infant closes fingers around an object when put in hand
Gross motor skills
Movement from large muscle groups and whole body movement
Fine motor skills
Smaller muscles such as fingers eyes and toes
Tracking motion, drawing, catching and waving
Stranger anxiety
Fear or apprehension of unknown individuals - develops at 7 months
Separation anxiety
Fear of being away from parent figure - begins at 1 year
Parallel play
Begins at age 2 - children will play alongside each other without influencing one anthers behaviours
Before this it was solitary to onlooker
