Bio Option A Flashcards
Neural tube
Innate behaviour
Behaviour encoded in genes and inherited from parents
Reflex
Rapid involuntary response to a stimulus
Reflex arc
Receptor-sensory neuron-relay neuron- motor neuron- effector
Learned behaviour
Behaviour not develops os a result of experience
Reflex conditioning
Pavlov’s dog
Imprinting
Occurs at a particular stage of life and is independent of the consequences of learning
Operant conditioning
Learning by trial and error
Memory
Process of encoding, storing and accessing information
Excitatory neurotransmitters
Cause depolerization in the postsynaptic cell
Inhibitory neurotransmitters
Cause hyperpolarization in the postsynaptic cell
Summation
The adding together of all inhibitory and excitatory neurotransmitters signals from the presynaptic neurons
Slow neurotransmitters
Modulate fast neurotransmission
change metabolism inside postsyn. cell by
triggering 2nd messenger, may diffuse + affect
many cells, long-term effect
Psychoactive drugs
Affect the brain by either increasing or decreasing synaptic transmission
Nicotine
An excitatory drug found in cigarettes
Cocaine
An excitatory drug which blocks dopamine reuptake proteins
THC (tetrehydrocannabinol)
Inhibitory drug that binds to cannabinoid receptors on the postsynaptic neuron
Ethology
Study of animal behaviour in natural conditions
Neurulation
Formation of nervous system (neural tube) in Chordata
Dorsal nerve cord develops from…
Ectoderm (outer tissue layer)
spine bifida
birth defect, incomplete closure/formation of neural tube
cell division in
neural tube produces…
large numbers of cells, which gradually differentiate into neurons
some immature neurons…
migrate, and axons grow from them
neural pruning
loss of unused neurons
peripheral nervous system
nerves and sensory receptors
central nervous
system
brain and spinal cord
medulla oblongata function
vital/primitive functions (breathing, heart-rate, etc)
cerebellum function
balance, coordination
hypothalamus function
Controls pituitary gland and hunger/thirst
pituitary gland function
controls many functions through hormone release
cerebral hemispheres functions
complex thought: problem solving, memory, learning, etc
visual cortex (cerebral hemisphere)
function
vision
Broca’s area (cerebral hemisphere function
speech production
nucleus accumbens (cerebral hemisphere function
pleasure
animal experiments
ethical issues, sir David Fernier - monkeys + dogs,
electrical shocking/removal of motor cortex
autopsy
dissection after death, Jean-Martin Charcod - ALS,
MS
lesions
damaged brain regions, Broca’s area
FMRI (magnetic resonance imaging)
shows activity (blood glucose levels) and structure in brain areas, Pierce - neurotypical vS autistic brain activity levels
stroke
disruption of blood supply to the brain
Photoreceptors
light (rod and cone cells in eye)
thermoreceptors
temperature (skin nerve cells)
mechanoreceptors
movement (hair cells in ear cochlea)
chemoreceptors
chemicals (tongue)
rod cells
more sensitive to light and allow vision in dim light 4 (greyscale), found throughout retina
cone cells
work best in bright light and enable you to see colors, three types (RGB) and found in fovea of retina
ganglion cells
connected to bipolar cells and sends visual info to brain through optic nerve
bipolar cells
receive input from rod/cone cells and send action potentials to ganglion cells
Opsin
photosensitive pigments in the photoreceptors
optic chiasma
point at which optic nerve fibers cross in the brain
cochlear implant
sound picked up by microphone, radio signal sent from transmitter to receiver, converts it to electric signal
info from left visual
field…
detected by right-half of retina, processed by right hemisphere
info from right visual field…
detected by left-half of retina, processed by left hemisphere
development of birdsong
both innate (length, number of notes) and learned
(frequency range, complexity)
taxis (innate behavior)
movement in response to environmental stimulUs: negative phototaxis - fly larvae move away from light
positive phototaxis - eugena move toward light
kinesis (innate behavior)
change in the rate of activity in response to an environmental stimulUs
woodlice in low humidit - increased movement woodlice in high humidity - decreased movement
examples of ethology
- migration in blackcap birds
- foraging in shore crabs
- courtship in birds of paradise
- breeding strategies in salmon
- feeding on cream by blue tits
- synchronized estrus in lionesses
presynaptic neuron is depolarized,
postsynaptic neuron is excited to fire
presynaptic neuron
is hyperpolarized,
action potential inhibited in postsynaptic neuron
CNS makes decisions by…
taking sum of inhibitory and excitatory signals
fast acting
neurotransmitters
directly change electrical potential of postsyn.
cell, affects 1, short-term effect
anesthetics
interfere with neural transmission
endorphins
bind to and block receptors, painkillers
addiction
compulsive craving and use of psychoactive
risk factors of addiction
dopamine secretion, genetic predisposition, social factors
excitatory (stimulant) drug
exambles
nicotine (acetylcholine transmissions+, dopamine+)
amphetamines (adrenaline&dopamine+), MDMA/
ecstasy (serotonin&dopamine+), cocaine
(dopamine+)
inhibitory drug examples
benzodiazepines (mimics GABA), alcohol (GABA+, glutamate-), cannabis (THC binds to cannabinoid receptors)
excitatory drugs
increase synaptic transmission, bind to receptor, mimic neurotransmitter
inhibitory drugs
decrease synaptic transmission, bind to receptor, block excitatory neurotransmitter
How does the nervous system form in a developing embryo?
The nervous system forms through the development of the neural tube, which originates from the neural plate. The neural plate invaginates and folds to form the neural tube, which gives rise to the brain and spinal cord. Neurons and glial cells differentiate from the cells within the neural tube, guided by signaling molecules and genetic factors.
Which cells are the first to become nerve cells?
The cells within the neural plate are the first to become nerve cells or neurons. These cells undergo differentiation and further development to form the various types of neurons found in the nervous system.
How do the cells organize themselves to form a nervous system?
The cells in the neural tube organize themselves through a process called neuronal migration. Neurons migrate to their specific locations within the developing brain and spinal cord, guided by chemical signals and structural cues. Once in place, they extend axons and dendrites to establish connections with other neurons, forming neural circuits and networks.
What is the role of connections between neurons in the development of the nervous system?
Connections between neurons, known as synapses, play a crucial role in the development of the nervous system. Synapses enable the transmission of electrical and chemical signals between neurons, facilitating information processing and communication. They contribute to the establishment of neural circuits and networks, allowing for the development of sensory, motor, and cognitive functions.
What happens to unused synapses?
During development, there is an overproduction of synapses, more than what is necessary for normal functioning. Unused or unnecessary synapses undergo a process called synaptic pruning. Through activity-dependent mechanisms and molecular signals, unused synapses are selectively eliminated, helping to refine and sculpt the developing nervous system
What happens to synapses that are used regularly?
Synapses that are used regularly and participate in active communication between neurons undergo a process called synaptic plasticity. This involves changes in the strength and efficiency of the synaptic connections, known as synaptic potentiation. Regular use and strengthening of synapses contribute to the development of neural circuits and the establishment of functional networks in the nervous system. These processes are fundamental for learning, memory formation, and the refinement of sensory and motor abilities.
How can a neural tube structure develop into a brain and spinal cord?
The neural tube, formed during embryonic development, undergoes complex processes of proliferation, differentiation, and migration. Specialized regions within the neural tube develop into distinct structures. At the anterior end, the neural tube expands and differentiates into various regions that form the brain. The posterior region remains relatively uniform and develops into the spinal cord.
What are the main structures found in the brain called?
The main structures found in the brain are:
Cerebrum (including the cerebral cortex): The largest part of the brain responsible for higher cognitive functions.
Cerebellum: Located at the back of the brain, involved in motor coordination and balance.
Brainstem: Connects the brain to the spinal cord and controls essential functions such as breathing, heartbeat, and consciousness.
Basal Ganglia: Involved in motor control, reward, and habit formation.
Limbic System: Associated with emotions, memory, and motivation.
What is the general function of each structure?
Cerebrum: Responsible for functions such as thinking, perception, memory, language, and voluntary movement.
Cerebellum: Coordinates and regulates voluntary movements, posture, and balance.
Brainstem: Controls basic vital functions, such as breathing, heart rate, and consciousness.
Basal Ganglia: Involved in motor control, habit formation, and reward processing.
Limbic System: Regulates emotions, memory formation, and motivation.
