lecture 2 Flashcards
sensory neurons
send signals /nerve impulses to the spinal cord
interneurons
links the sensory and motor neurons in the spinal cord
motor neurons
send signals from the CNS to the muscles/glands
specialised receptor cells
repsond to changes in the environment
we only sense things when they
are changing
sensory adaptation - getting used to a specific stimulus
sensory neurons from all over the body
send myelinated axons into the spinal cord
neurons transmitting precisely localised info
- axons reach the top of the spinal cord - medulla (entrance to the Brain)
neurons transmitting poorly localised in
axons synapse immediately with other neurons
sensory neurons from the head send axons directly into the
brain via cranial nerves (nerves emerging from the brain)
all signals are transmitted via
several relay stations
the retina contains
photoreceptors which convert light into am electrical impulse
the retina sends signals to the
thalamus
what is the retina made up of
photoreceptors , bipolar cells and ganglion cells
at each stage signals are
integrated with signals from lower processing levels , same level or higher level
integration
several photoreceptors converse onto a bipolar cell
information processing
the combined input determines if the cell becomes active
brainstem
hindbrain and midbrain (without cerebellum)
midbrain
mesencephalon- above pons
combines info from different senses and directs attention
the midbrain contains
several nuclei of the Autonomic NS- clusters of cell bodies are found in the medulla and pons
hindbrain
rhombencephalon - medulla , pons and cerebellum
what his above the brainstem
diencephalon - gateway into the forebrain
thalamus
main relay station for all incoming sensory signals
receives downward going signals from the higher areas(visual cortex)
modulates relay of sensory signals
hypothalamus
small structure in front of and below the thalamus
directly connected to the pituitary gland - master gland of the ES- gateway to ES
In the forebrain is the
telencephalon - outer part
surrounds the diencephalon
main feature is the cerebral hemispheres
from the diencephalon , incoming signals
go to the cerebrum which is divided into two highly similar hemispheres - each covered in cerebral cortex - thin layers of neurons and contains sub cortical nuclei
grey matter
neurones cell bodies
white matter
neurons myelinated axons
functional organisation of the cerebrum
each hemisphere mainly receives input from contralateral side of the body
sends output to contralateral life of the body
basal ganglia
group of nuclei surrounding the thalamus which is involved in motor control
basal ganglia - consists of what nuclei
globus pallindus
putamen
caudate
amygdala is
closely connected to the basal ganglia
functionally part of the limbic system
the limbic system is composed of structures in the brain that deals with
emotions , memory and arousal
the limbic system connects
the olfactory system
hypothalamus
sensory cortical areas
cerebral cortex
thin layers of neurons covering the whole hemisphere
corpus callosum
thick bundle of axons connecting the two hemispheres - virtually all signal transfer between hemispheres occur here
cerebral cortex is
highly folded
what are the lobes of the brain
occipital
temporal
parietal
frontal
frontal
at the front - planning and motor output
occipital
at the back - visual perception
temporal
at the side- auditory perception
parietal
at the top - somatosensory perception
signal interpretation depend on the
location in therein where it arrives
topographic representation of a somtotopic map
projection of the body surface onto a brain that is responsible for our sense of touch -somatosensory cortex
retinotopic map
visual signals from neighbouring retinal positions arrive at neighbouring positions in the primary visual Cortex
tonotopic map
auditory signals from adjacent areas of the cochlea arrive at adjacent areas in the primary auditory cortex
neutron only transmit signals
in one direction - from dendrites to terminals
motor output - supplementary and premotor cortices
planning and monitoring
primary motor cortex
final output stage - execution of movement
prefrontal cortex
covers frontal lobe - planning complex behaviour , decision making
somatosensory cortex
parietal lobe - processes static sensations - position of the body in space
posterior parietal cortex
spatial reasoning
subcortical areas
basal ganglia and cerebellum
basal ganglia
modulate movements involved in selective inhibition of movements
cerebellum
posture and balance
subcortical areas
basal ganglia and cerebellum
basal ganglia
modulate movements , particularly involved in selective inhibition of movements
