Nervous System Flashcards
A number of different proteins are involved in nerve function. Which does not require a membrane potential?
Diffusion of the neurotransmitter across the synapse
Between which structures do sensory neurons carry nerve impulses
From receptors to the CNS
What are the changes in the membrane potential during an action potential ?
- ) Na+ ions diffuse in; inside becomes more positive
2. ) K+ ions diffuse out; inside becomes more negative
What causes the formation of a nerve impulse on the post-synaptic membrane?
Neurotransmitter binding with receptor sites
Functions of the medulla oblongata
Controls automatic and homeostatic activities (swallowing, digestion, vomiting, breathing and heart rate)
Functions of the hypothalamus
Maintains homeostasis via coordination of the nervous and endocrine systems, produces hormones secreted by posterior pituitary
Outline how endorphins act as painkillers
- Endorphins are produced by the pituitary gland that functions as the body’s natural painkiller
- Endorphins are typically released by the body during periods of stress, injury or physical exercise
- Pain is perceived in body tissues when impulses are sent from pain receptors to sensory areas of the brain
- Endorphins bind to opiate receptors on pre-synaptic neurons to block the transmission of pain signals
Describe different aspects of the processing of visual stimuli
Photoreceptors (rod and cone cells) in the retina convert light into nerve impulses
- The impulses pass to bipolar cells, which relay the signal to the optic nerve (via ganglion cells)
Edge Enhancement sends signals from rods and cones, follow both vertical and lateral pathways
- Photoreceptors stimulate opposing bipolar cells but inhibit adjacent bipolar cells (lateral inhibition)
- This makes light spots lighter and dark spots darker, with the contrast greatest at the edges (edge enhancement)
Contralateral processing is when stimuli is processed on the opposite side of where it was detected
- Information from the left half of the visual field is detected by the right half of the retina in both eyes and is processed by the right hemisphere
- Information from the right half of the visual field is detected by the left half of the retina in both eyes and is processed by the left hemisphere
- At the optic chiasma, information from both eyes may swap so that the left or right visual field is processed together
- The optic nerves that swap sides are transmitting signals contralaterally, while the optic nerves that do not swap are transmitting signals ipsilaterally
- Impulses continue to the thalamus where the optical information is processed before an image forms in the visual cortex
List two types of human sensory receptors
Mechanoreceptors: respond to mechanical forces and movement found in the eyes
Chemoreceptors: responds to chemical substances found in the nose/tongue
What is the role of the hypothalamus in homeostasis?
Monitoring body temperature
Between which structures do sensory neurons carry nerve impulses
From receptors to the CNS
Which part of the brain has a role in the control of the heartbeat and how are message passed from this part of the brain to the heart?
part of the brain: medulla
type of message: nerve
What causes the formation of a nerve impulse on the post-synaptic membrane?
Neurotransmitters binding with receptor sites
Which event directly leads to an action potential?
Membrane potential reaches the threshold potential
What is the effect of a neonicotinoid pesticide on the transmission of a nerve impulse between neurons in an insect?
It irreversibly binds with ACh receptors on the postsynaptic membrane
How does potassium move across the membrane of a neuron during repolarization?
Facilitated diffusion
Neurons transmit electrical impulses. Which statement describes part of this process?
Ion channels let Na+ diffuse into the cell to depolarize the membrane
What is essential for conduction of nerve impulses to be saltatory?
Wrapping of myelin around the axon
If schizophrenia is caused by an overabundance of the neurotransmitters dopamine and serotonin in the synapses of some area of the brain, which drug action could work in treating he symptoms?
Increased re-uptake of dopamine and serotonin by presynaptic neurons
Distinguish using examples between innate and learned behaviors
Innate behavior is inherited from parents and so developing independently of the environment. Example: palmar grasp reflex: if an object touches the skin in the palm of a baby’s hand, the baby grips the object by closing its fingers around it
Learned behavior is acquired information from past experiences to adapt to new situations.
Example: human offspring inherit the capacity to learn a language, most of the time its a different language. The ability to make sense of vocal patterns and language spoken
Using two examples, discuss how the process of learning can improve survival
The process of learning can improve survival as animals learn to stay away from predators and stay close to their group.
Imprinting: is learning occurring at a particular life stage and is independent of the consequences of behavior
- Imprinting occurs during a short critical period in which the organism adopts behavioural characteristics from a stimulus
- Filial imprinting - bonding to the parent - gooses learn to identify their mothers and learn to stay together
Operant Conditioning: is a form of learning which consists of trial and error experiences
- Lambs learn not to touch electric fencing, they explore their environment, and if electric fencing is used to enclose their flock, lambs sooner or later touch it, with their nose. They receive a painful electric shock, through operant conditioning they avoid touching the fence in the future
Type of receptor cell that detect sound as well as an example
mechanoreceptors: hair cells in the cochlea
Outline the role of inheritance and learning in the development of birdsong in young birds
The development of birdsong in young birds involves both innate and learned behaviors
Most birds are born with a crude template song that is genetically inherited (innate behaviour)
- The possession of an innate template prevents birds from adopting the songs of a different species of bird
- Whilst young, fledglings learn to expand and refine their song by listening to, and mimicking, the adult version (motor learning)
- Birds raised in isolation will lack the necessary song complexity that develops through social interaction
- The time taken to develop a birdsong differs between species and songs, but once established, the final song is rarely altered
Outline Pavlov’s experiments into conditioning in dogs
Pavlov’s experiment is a form of classical conditioning where he experimented on dogs.
- Dogs normally salivate (unconditioned response) in anticipation of being fed (unconditioned stimulus)
- Pavlov sounded a bell (neutral stimulus) prior to feeding a dog
- After many repetitions, the dog came to associate the bell with food and began to salivate to the bell (conditioned response)
- Pavlov described this as a conditioned reflex – the stimulus that prompted the response had been changed
