The Nervous System: The Forebrain Flashcards
Explain the steps of detection and transmission of sensory signals
- specialised receptor cells respond to environmental changes (connected to sensory neuron)
- axons of sensory neuron, not in head, enter spinal cord via dorsal root of spinal nerves
- sensory from head send axons to head via cranial nerves
- retina= signals integrated with photoreceptors, ganglion cells, bipolar cells (lower processing)
When does most info processing occur?
before a signal has reached the brain
What direction do neurons transmit signals? and despite what?
one direction despite receiving signals from different sources (higher, lower and same processing areas)
-means every input already decided by brain
What structures are in the Brain stem?
Hindbrain and midbrain
What structures are in the hindbrain?
Medulla, pons + cerebellum
What are the medulla + pons function?
It is where the spinal cord enters the brain and contains several nuclei of ANS
What is the function of the cerebellum?
the little brain
responsible for balance and motor learning
What does the midbrain do?
its above pons and is responsible for the combination of info from different sense modalities and direction of attention
What is inside the forebrain beginning with D and what is inside this?
The diencephalon
The thalamus + hypothalamus
What does the thalamus do?
main relay station for SS and receives download-going input from higher areas
What does the hypothalamus do?
in front and below of thalamus
It is the gateway to the ES
What are the two hemispheres in the cerebrum covered in\/
cerebal cortex (neurons) and contains sub-cortical nucei (cluster of neurons cell bodies)
What is inside the forebrain beginning with T and what is inside this?
The telencephalon
The basal ganglia, limbic system, cortex + corpus callosum
What is the basal ganglias function?
motor control process
-structures inside referred to as corpus striatum
what function does the limbic system?
memory and emotion
What are the cortical and sub-cortical areas in the limbic system?
Cortical: cingulate cortex, above corpus callosum
Sub-cortical: almost complete circle formed by fornix and hippocampus
What functions does the cerebral cortex have?
perception, action, cognition (signal transfer between hemis)
What is the difference between cortex and corpus callosum structures?
cerebral c= thin layers of neurons covering whole hemi
corpus c= thick bundle of axons connecting hemis
What creates the folded appearence of the brain found in the cerebral cortex?
gyri- out folded areas
sulci- inward folded areas
Outline the signal transmission and interpretation in the brain (SS)
ss from diencephalon relayed to appropriate primary centre cortex (all these signs are identical- depending on location for interpretation
Outline signal transmission and interpretation in the brain (topographic maps)
inside sensory areas, signals arrive at a similar position of receptor cells (topographic representation)
Why are there different maps for signal transmission?
for sense modaility
What does the somatotopic map do?
Signal from hand arrives at somatosensory area, which is next to arm, next to shoulder
What does the retinotopic map do?
visual signals from neighbouring retinal positions arrive at neighbouring positions in visual cortex
What does a tonotopic map do?
auditory signals from adjacent areas of chochlea arrive at adjacent areas in auditory cortex
What does the supplemetary premotor and motor cortex do?
involved in planning and guidance of sensory movements
What does the primary motor cortex do?
motor neurons send axons to spinal cord
