Biological Influences Flashcards
nervous system
vast and complex communication system that monitors and controls all that we do
central nervous system
- integrates and coordinates all incoming neural information and initiates messages sent to different parts of the body
- comprises of the brain and spinal cord
peripheral nervous system
- consists of all other nerves
- involved in transmitting information to and from the spinal cord
- connects the CNS to the rest of the body, serving as a communication system that goes back and forth between the brain and extremities
spinal cord
- runs down the brainstem and is a major thoroughfare for messages between the brain and rest of the body
- consists of efferent/motor neurons that transmits impulses away from the brain and afferent/sensory neurons that transmits impulses towards the brain
features of spinal cord
- organised 31 segments with sensory nerves leading into the dorsal side of each segment and motor nerves exiting the ventral side
- between the sides is grey matter surrounded by neural pathways which characterises humans
- PNS originates from the 31 pairs of spinal nerves and 12 cranial nerves that leaves the brainstem at the top of the spinal cord
reflex arc
connection of the afferent neurons to the interneurons to the efferent neurons, resulting in a reflex action
autonomic nervous system
- network of nerves that connects the CNS to the body’s internal organs and glands
- neurons that transmits messages between the brain via the spinal cord and smooth muscles found in the heart, lungs, blood vessels and glands
- actively involved in experiencing emotions such as fear and excitement at very intense levels
- functions continuously to maintain our survival as many organs are self regulating
somatic nervous system
network of sensory nerves that carries information received by sensory receptors in the body to CNS and motor nerves that carries information from CNS to control voluntary movements of skeletal muscles
motor and sensory function
- motor function: controls skeletal muscles attached to our bones that produce observable movements
- sensory function: processes sensory information
sympathetic nervous system
- responsible for increasing the activity of most muscles, organs and glands in times of vigorous activity
- prepares body for fight or flight response
- physiological responses: pupils dilate, body temperature increases, breathing rate increases, heart rate increases, secretion of adrenaline
parasympathetic nervous system
- responsible for decreasing the activity of most muscles, organs and glands and keeps the body functioning in its normal state
- where the body starts to relax itself
- physiological responses: pupils constrict, breathing rate decreases, heart decreases, body temperature decreases, muscles relax
neuron
individual nerve cells that receives, transmits and processes information
dendrites
receives neural impulses from other neurons
soma
- receives information from dendrites
- controls maintenance and metabolic functions of the cell
axon
carries information away from soma towards other neurons, muscles and gland cells
myelin sheath
- helps insulate axon and speed up neural impulses
- loss can lead to disruption of flow of information
synaptic knobs
forms junction with other cells and releases neurotransmitters
synapse
- junction where information is transmitted from one neuron to another
- slight gap between the terminal button of the pre synaptic neuron and dendrite of the post synaptic neuron
how neurons communicate
- action potential reaches axon terminal buttons
- it triggers the vesicles in the axon terminal to release neurotransmitters
- the neurotransmitters travel across the synapse and binds with the receptors of the dendrite of the post synaptic neuron, creating an electrochemical signal
- if the signal is strong enough, it will spread down the dendrite and begin another action potential
neurotransmitters
chemicals that enables activities to travel across synaptic gap between neurons
dopamine
involved with control of movement, sensations of pleasure, learning and attention
serotonin
regulates sleep, mood and appetite
noradrenaline
involved in arousal, memory retrieval and helps body deal with danger
endorphin
regulates feelings and perception of pain
corticalisation
- enlargement of the cerebral cortex
- greater amount of corticalisation is associated with increased size and complexity
cortical localisation
specific behavioral functions that are located in specific areas of the brain
forebrain consists of
- limbic system
- cerebrum
- thalamus
- hypothalamus
areas of forebrain
- lateral brain areas are involved in perception, learning, motor and conceptual activities
- medial brain areas are involved with internal and automatic bodily functions
cerebrum
- mainly associated with cerebral cortex
- divided into left and right hemisphere which is connected by corpus callosum
left hemisphere
- associated with language processes and controls movements in the right side of the body
- receives sensations from the right side of the body
- functions: language comprehension, speech production, analytical thinking, logical reasoning
right hemisphere
- associated with visual imagery and emotions and controls movements in the left side of the body
- receives sensations from the left side of the body
- functions: emotion regulation, detection of emotion, facial recognition
contralateral
effects on the opposite side of the body
ipsilateral
controls on the same side of the body
corpus callosum
thick band of fibres that transfers information registered in one hemisphere to the opposite hemisphere
cerebral cortex
- outer layer of the cerebrum
- divided into lobes, each of which is associated with different functions
frontal lobe
- plans and controls execution of voluntary movements
- involved with higher order thinking, emotion regulation and expression of personality
- Broca’s area: speech production; combining sounds into words and arranging words into sentences
- primary motor cortex: controls voluntary body movements through control of skeletal muscles
temporal lobe
- involved with auditory perception, memory formation and language comprehension
- Wernicke’s area: language comprehension; responsible for speaking in coherent sentences and coherent speech
- amygala
- hippocampus
- limbic system
parietal lobe
- involved with spatial awareness, bodily sensations and self recognition
- primary somatosensory cortex: processes sensory stimuli via body parts
- damage to left hemisphere results in problems in math, reading and writing
- damage to right hemisphere results in loss of imagery and visualisation of spatial relationships
occipital lobe
- involved with visual perception and visual processing
- primary visual cortex: received visual information from the retina and is involved with visual perceptions and colour recognition
- damage to this lobe can lead to full or partial blindness or word blindness
role of genetics
- genes inherited from parents guides how we develop physically
- ensures that some of our cells become brain cells, skill cells and bone cells and so on
- regulates production of pigmentation in our bodies
- regulates pace and timing of development
chromosome
threadlike bodies within a cell that consists of thousands of genes
genes
basic unit of heredity
zygote
new egg formed when a sperm penetrates an ovum
epigenetics
the study of the transmission of information from one generation to the next through genetic inheritance which affects the traits of the offspring without alteration of DNA or alteration that comes from the environment
monozygotic twins
- develops from the same fertilised egg that has split
- share 100% DNA
dizygotic twins
- develops from 2 separate eggs that develop in the womb at the same time
- shares approximately 50% DNA
Bouchard
reported that identical twins who were separated at birth and reared apart still had more similar IQ than fraternal twins reared together
adoption studies
- investigates whether adopted children are more like their adoptive parents or biological parents
- if the child is found to be more like their adoptive parents, then environment is considered to play an important role in the development of that characteristic
Daniels and Plomin
- found that 2 year olds with shy biological mothers were also why
- however, 2 year olds were also shy if their adoptive mothers were shy
- environment influence therefore is also important in shaping personality
hormones
chemical messengers produced by endocrine glands that travels through the bloodstream and affects other parts of the body such as brain
- when acting on the brain, they influence our interest in food and sex, our mood and affects our growth
- slower than neurotransmitters in terms of speed
common hormones
- adrenaline from adrenal glands
- thyroxin from thyroid glands
- growth hormones from pituitary glands
- oestrogen and testosterone from sex organs
adrenal gland
- triggers fight or flight response and works in conjunction with SNS to speed up bodily reactions to danger
- physiological responses: pupils dilate, increased breathing rate, increased heart rate
thyroid gland
necessary for development of brain and nervous system
pituitary gland
- considered the most important gland as it triggers the release of hormones from all other glands
- stimulates growth and development of body cells and plays huge role in puberty
ovaries and testes
- ovaries: pituitary glands stimulates girls ovaries to produce oestrogen
- once oestrogen level reaches critical level:
- breast size and uterus changes
- growth of pubic and underarm hair
- testes: pituitary glands stimulates boys testes to produce testosterone
- once testosterone level reaches critical level:
- penis and prostate grows
- change in voice
- growth of facial and body hair
- growth of muscles and broadening of back
depressants
- calms activity of nervous system and slows down body’s functions
- physiological responses: slows down body functions, slurred speech, promotes relaxation in the body
- psychological responses: disinhibition, promotes relaxation in the mind, impaired judgement
- examples: alcohol, marijuana, morphine, heroin
stimulants
- excites the nervous system and arouses body’s functions
- physiological responses: increase heart rate, increase breathing rate, increase blood pressure
- psychological responses: increased self confidence, aggression, improved attention
- example: nicotine, caffeine, amphetamine, methyl amphetamine, ecstasy
hallucinogens
- changes perception and gives sensory images without input from senses
- physiological responses: pupil dilation, rapid mood, behavior fluctuation
- psychological responses: hallucination, paranoia, psychosis
- examples: LSD, marijuana, ecstasy
heredity
where individuals receiver their genes from their parents
