Biological Influences Flashcards
Function of the Brain
Maintains the body in an optimal state relative to the environment
Brain Plasticity
The ability for the brain to change by forming new connections between neurons
Location of the Hindbrain
Base of the brain - above the brain stem
Function of the Hindbrain
Part of the ANS; controls heart rate, breathing, sleep, arousal
Coordinates reflexive actions; swallowing, coughing, vomiting
Divisions of the Hindbrain
Metencephalon and Myelencephalon
Parts of the Metencephalon
Contains pons and cerebellum
Parts of the Myelencephalon
Contains the medulla oblongata
Location of the Midbrain
Between the forebrain and hindbrain
Function of the Midbrain
Keeps us awake, alert, vigilant
Parts of the Midbrain
Middle part of the Reticular Formation
Structure of Reticular Formation
Network of nerve pathways connecting the spinal cord, cerebellum, and cerebrum
Extends into hindbrain and thalamus
Function of Reticular Formation
Mediates overall levels of consciousness
Location of the Forebrain
Above the midbrain, divided into two hemispheres
Function of the Forebrain
Complex processes - emotions, motivations, sensations, perceptions, learning, memory, reasoning
Function of the Cerebrum
Contains cerebral cortex (higher mental functions), basal ganglia (selection action, learning, motor control), Limbic system (autonomic functions - sleep, sex, eating)
Functions of the Cerebral Cortex
Information processing activities - language, learning, thinking, memory, perception, problem solving
Planning and control of voluntary body movements, learning, time, recognition, recall, planning
Functions of the Left Hemisphere
verbal, language and analytical thinking
- Broca’s and Weirnicke’s area
Functions of the Right Hemisphere
Non-verbal, spatial activities, emotion, facial recognition
Function of the Thalamus
Processes and sends sensory info to higher brain areas
Functions of the Hypothalamus
Temporal control and basic behavioral drives
Functions of the Cerebellum
“little brain” - posture, balance, coordination
Connected to brainstem by cerebellar peduncles
Function of the Pons
Relays signals to and from the cerebellum
Sensory Neurons
Afferent - transmits impulses from sensory receptors
Interneurons
Connects afferent and efferent neurons in the CNS
Motor Neurons
Efferent - Transmits impulses for a response
Neural Impulses and Learning
Neurotransmitters repeatedly sent across a synapse lead to a change in the chemistry of the synapse - strengthening impulse
Serotonin
Biological functions - sex, sleep, appetite, aggression, mood
Has an inhibitory effect
Affect of Serotonin Levels
Deficiencies = anxiety, mood disorders,insomnia
Elevated levels = other mood disorders, autism
Dopamine
Attention, initiation of voluntary movement, pleasure
Formation of long term memory
Both inhibitory and and excitatory
Affects of Dopamine
Inhibits certain synapses, might be partially responsible for Parkinson’s Disease
The Frontal Lobe
Planning and carrying out movements, personality, language, judgement, emotional control
Primary Motor Cortex
Found in frontal lobe - carries out the initial processing of motor information
The Motor Homunculus
Amount of cortex devoted to body part = complexity of movements
Association in Prefrontal Cortex
Receive and combine info from other lobes to perform complex mental functions
Broca’s Area
Found in left frontal lobe - involved in the production of articulate speech
Coordinating movement of muscles for speech, relaying info to other motor cortex areas
Understanding grammatical sentence structure
Broca’s Aphasia
Damage to Broca’s area - able to understand, formulate a response but can’t articulate it
The Parietal Lobe
Touch, motion detection, object location, location of body
Processes sensory information
Primary Somatosensory Cortex
Left Parietal lobe -
Receives and processes sensory info to perceive bodily sensations - touch pressure, temperature, muscle movement and positioning
Amount of cortex devoted to body part dictates sensitivity
Damage to Parietal Lobe
Unable to sense stimuli, unable to recognise texture of stimuli, understand it’s use, clumsiness, confuse right and left, spacial neglect
Spacial Neglect
Can’t recognise own body parts
Temporal Lobe
Auditory perception, memory, identifying and recognising visual stimuli, emotional responses to stimuli and memories
Primary Auditory Cortex
Processes incoming auditory sense information
Receives electrical signals from ear receptors - transforms them to meaningless sound sensations
Organisation of the Primary Auditory Cortex
Tonotopically organised - neurons in different parts respond to different frequencies
- Low frequencies (500 hertz) at the front
- High frequencies (1000 hertz) at the back
Verbal sounds - right hemisphere
Non-verbal - left hemisphere
Medial Temporal Lobe
Contains hippocampus, amygdala; formation of long tern memory, linking emotion to memories
Auditory Association Areas
Meaningless sound from primary auditory area processed into recognisable auditory information
Sounds are then given meaning
Wernicke’s Area
Connected to Broca’s area by bundle of nerves
Involved in speech production, interpreting speech
Coordinates muscles to produce sounds, relays info to facial area
Damage to Wenicke’s Area
Inability to recognise a person, but can describe them etc
Occipital Lobe
Sense of vision
Divided into different visual areas that process different elements - texture, line etc
Primary Visual Cortex
Largest visual area, receives info from photoreceptors
Each hemisphere receives 1/2 of the visual information
Neurons respond to different visual elements
Association areas select, organise, integrate and assign meaning/memory
Effect of Genetics
Dictate individual development
Epigenetics
Study of the transmission of genetic information without any alteration to the genes
Behavioral Epigenetics
Environmental factors such as child neglect and drug use changing the neurons without changing the DNA
Cognitive Epidermiology
Concerned with the heritability of intelligence
- semen and intelligence are related (Arden et al, 2009)
- genetics influence a child’s drawing, later intelligence (Arden et al, 2014)
Hormones
Chemical messengers produced by endocrine glands that travel through the blood stream to affect specific body parts
Adrenal Glands
Secretes adrenaline, noradrenalin
- Sympathetic nervous system
- localised functions
Thyroid Gland
Secretes thyroxine (regulation of metabolism)
- brain and nervous system development
- deficiency = intellect difficulties (during brain development), slowed growth
Pituitary gland
Triggers the release of hormones from other endocrine glands
- growth hormone; deficiency = height of 130cm
Drugs
Any substance taken/given for medicinal purposes; for euphoriant, relaxant purposes
Depressants
Calms the nervous system
- Alcohol
- Heroin
Herion
Mimics endorphines; alters reaction to pain
Euphoria followed by calmness
Withdrawal - fevers, cramps, gastro-intestinal problems
Stimulants
Excites the nervous system
- Cocaine
- Ecstasy
- Ice
Cocaine
Suppresses appetite, elevates mood, increased mental awareness, self-confidence
Prolonged use - psychosis; auditory hallucinations, paranoia
Ecstasy
Causes dehydration, deflated mood, memory loss, damage to immune system
- higher depression rates, difficulty with long term memory, distracted (McCardle et al, 2004)
- loss of mental flexibility >50 tablets (Dafters, 2006)
Ice
intense high lasting for 4-12 hours; increased arousal and activity (Australian National Council on Drugs, 2014)
Prolonged use - brain and mental health conditions (depression, memory loss, psychosis)
- 2.1% aus pop. users in the past 12 months (Australian Institute of Health and Welfare, 2014)
Hallucinogens
Stimulates receptors in the serotonin system (serotonin 1A and 2A receptors)
Changes perceptions, creates sensory images without input from the senses
- Marijuana
- LSD
Marijuana
increased sensitivity to sounds, colours, tastes, smells - cannabinoid CB1 receptor; activating the receptor blocks neurons that inhibit dopamine release
LSD
Induces trips
increased use destroys receptors in brain - flooded by monoamines; can’t feel pleasures without the drug (Australian National Council on Drugs, 2013)
Prolonged use - memory loss, depression, psychosis
Affects family and social relations, family problems
