biological essential reading Flashcards
what is golgi staining?
silver staining that stains neurites with great detail, revealing the morphological heterogeneity of the neuron
role of sensory neurons
receive information from the external world and convey this information to the brain via the spinal cord
have specialied endgins on their dendrites for light, sound, touch, taste and smell
role of motor neurons
carry signals from the spinal cord to the muscles to produce movement
what are interneurons?
connect sensory neurons, motor neurons and other motor neurons
what are purkinje cells?
type of interneuron that carry information from the cerebellum to the rest of the brain and spinal cord
what are pyramidal cells?
found in cerebral cortex and serve as a main excitatory neuron
what are bipolar cells?
found in the retinas of the eyes and have a single axon and a few dendrites
what is the refractory period?
the time following an action potential during which a new action potential cannot be initiated
how do neurotransmitters leave the synapse?
- reuptake occurs when neurotransmitters are reabsorbed by the terminal buttons of the presynaptic neuron’s axon
- neurotransmitters can be destroyed by enzymes in the synapse in a process called enzyme deactivation, where specific enzymes break down specific neurotransmitter
- neurotransmitters can bind to the receptor sites called autoreceptors on the presynaptic neurons. Autoreceptors detect how much of a neurotransmitter has been released into a synapse and signal the neuron to stop releasing the neurotransmitter when an excess is present
role of acetylcholine
neurotransmitter involved in voluntary motor control by activating muscles
also contribute to regulation of attention, learning, sleeping, dreaming and memory
what neurotransmitter is implicated in alzheimers?
acetylcholine- deterioration of Ach producing neurons
role of dopamine
neurotransmitter that regulates motor behaviour, motivation, pleasure and emotional arousal
what neurotransmitter is implicated in schizophrenia and parkinsons?
high dopamine levels=schizophrenia
low levels=parkinsons
role of glutamate
major excitatory neurotransmitter involved in information throughout the brain
enhances transmission of info
too much=overstimulate the brain, causing seizures
role of GABA
primary inhibitory neurotransmitter which stops the firing of neurons
too little GABA can cause neurons to become overactive
role of noradrenaline
neurotransmitter that influences mood and arousal which is particularly involved in states of vigilance
role of serotonin
involved in the regulation of sleep and wakefulness, eating and aggressive behaviour
which neurotransmitters are implicated in mood and arousal?
low levels of noradrenaline and serotonin
role of endorphins
chemicals that act within pain pathways and emotion centres in the brain
lack of endorphins could lower pain threshold or reduce the ability to self-soothe
what are agonists?
drugs that increase the action of a neurotransmitter
what are antagonists?
drugs that block the function of a neurotransmitter
L-DOPA
dopamine agonist to help treat parkinsons
used to treat MPTP (destroy dopamine neurons) causing paralysis
what are spinal reflexes?
simple pathways in the NS that rapidly generate muscle contractions
levels of the spinal cord
cervical, thoracic, lumbar, sacral and coccygeal
higher level of damage=worse the prognosis (e.g quadriplegia)
what makes up the hindbrain?
cerebellum, medulla and pons
role of the hindbrain
respiration, alertness and motor skills
what does the medulla contain?
the reticular formation which regulates sleep, and arousal
what makes up the midbrain?
tectum (orientation) and the cerebral peduncles (movement)
what makes up the forebrain?
cerebral cortex and subcortical structures
what are mirror neurons?
cells that are active when performing an action oneself or when observing the same action performed by another (motor cortex)
role of the thalamus
relays and filters info from the senses and transmits the info to the cerebral cortex
role of the hypothalamus
regulates body temperature, hungerm thirst and sexual behaviour
what is located below the hypothalamus?
the pituitary gland
what is the limbic system?
a group of forebrain structures which also include the amygdala and huppocampus which are involved in motivation, emotion, learning and memory
what are the basal nuclei?
subcortical structures that direct intentional movements
what are association areas?
composed of neurons that help provide sense adn meaning to info registered in the cortex
what is a prototypical executive function task?
stroop task
what is a hot executive function?
impulses and urges that are biological imperatives or emotionally charged drives that threaten to take over control of our thoughts and actions
what is a cool executive function?
logical choices one has to make when presented with a problem to solve that requires rationality
fundemental discoveries of EEG
sleep and wakefulness
hubel and wiesel (1962)
inserted electrodes into the occipital lobes of cats and observed patterns of individual neurons
discovered neurons in the PVC are activated whenever a contrast between light and dark occurs in the visual field
what are feature detectors?
neuronsin the visual cortex that selectively respons to certain aspects of a visual image
what is computerised axial tomography?
technique that recombines multiple X-ray photograph into a single image
this shows different densities of tissue in the brain
skull is most dense so is white and least dense like ventricles and fissures are dark
used to locate lesions or tumours which appear dark as they are less dense than cortex
