PSYCHOBIOLOGY: the CNS & brain Flashcards
what is sensory adaptation?
getting used to a specific stimulus - we only sense when things are changed
how do we respond to changes in the environment?
specialised receptor cells connected to sensory neuron’s respond to changes in touch, smell, sight etc
describe the process of signal transmission into the CNS from the body not including the head
sensory signals enter the CNS through the spinal cord via the dorsal root of spinal nerves
describe the process of signal transmission into the CNS from the head
sensory signals send axons directly into the brain via cranial nerves
describe the transmission of precisely localised information in the CNS
neurone which transmit precisely localised information eg fine touch send axons to the top of the spinal cord
describe the transmission of poorly localised information in the CNS
neurons which transmit poorly localised information eg temp synapse immediately with other neurons upon entering the spinal cord
describe the process of transmission in the visual system
- photoreceptors are hit by a photon
- a cascade of chemical changes in the photoreceptor triggers the bipolar neuron which triggers the ganglion cells
- axons of ganglion cells form a pathway into the thalamus
- neurons connect to thalamic neurons & axons are sent to the visual cortex in a process called optic radiation
what is signal passing dependent on?
whether the pattern of input to a neutron is strong enough
- signal dies if input is too weak
what is the hindbrain made up of?
medulla, pons & cerebellum
structure & function of medulla and pons
structure = where spinal cord enters brain
function = contains several nuclei of the autonomic NS
structure & function of cerebellum
structure = not part of brain stem
function = balance & motor
function of the midbrain
combines information from different senses & directs attention
name of hindbrain
rhombencephalon
name of midbrain
mesencephalon
name of forebrain
diencephalon (thalamus and hypothalamus) & telencephalon (cerebral hemisphere, basal ganglia, limbic system and cortex)
structure & function of thalamus
structure = top of midbrain, deep in centre of brain
function = main relay station for sensory signals, receives input coming from higher areas
structure & function of hypothalamus
structure = in front of & below thalamus, directly connected to pituitary gland
function = gateway to endocrine system
structure of cerebral hemispheres
- 2 highly similar
- each covered in cerebral cortex
grey matter = cortex & subcortical nuclei
white matter = myelinated axons of neurons
what is cerebral cortex?
stacked layers of neurons covering each hemisphere
functions of cerebral hemispheres
- incoming signals from diencephalon go up the cerebrum
- each hemisphere mainly receives input from and sends output to the contralateral side of the body
structure of the basal ganglia
subcortical nuclei surrounding the thalamus
- consists of globes pallidus, putamen & caudate (corpus striatum)
function of the basal ganglia
motor control processes
structure of the limbic system
subcortical = almost complete circle formed by fornix & hippocampus, ending in mammillary body & amygdala
cortical = cingulate cortex directly above corpus callosum, connected to hypothalamus & olfactory system
function of the limbic system
memory & emotion
