The Central Nervous System Flashcards
What is a nerve?
A combination of axons/ fibres outside of the CNS
What is a tract?
A group of myelinated axons that travel together within the CNS and share a common origin, destination and function.
What is grey matter?
A number of cell bodies that are grouped together which appear grey.
Why is white matter white.
It appears white due to the presence of myelin.
What is a nucleus or nuclei?
A group of neuronal cell bodies located in the same area and sharing the same function within the CNS.
What is a ganglion or ganglia?
They are similar to nuclei, they are a group of neuronal cell bodies, but they are found outside the CNS as a discreet swelling.
What direction do afferent fibres go?
Afferent fibres carry impulses towards the CNS or higher centres.
Normally sensory signals.
What direction do efferent fibres go?
Efferent fibres carry impulses away from the CNS or higher centres.
Normally motor signals.
What are some features of the spinal cord?
Rostrally continuous with the brain stem
Extends from the foremen magnum to L1-L2 in adults
Vertebral foramen
Ends at the conus medullaris
Cauda equine
Surrounded by dura
Cervical and lumbosacral enlargements
What are the three beginning stages of brain development?
Prosencephalon
Mesencephalon
Rhombencephalon
What is the next stage in development from the prosencephalon?
Telencephalon
Diencephalon
What structure develops from the mesencephalon?
The midbrain
What the next stage of development from rhombencephalon?
Metencephalon
Myelencephalon
What structures develop from the telencephalon?
The cerebral hemispheres.
Why structures develop from the diencephalon?
Thalamus
Hypothalamus
Subthalamus
What structures develop from the metencephalon?
Pons
Cerebellum
What structure develops from the myelencephalon?
The medulla.
What are the three distinctions of brain anatomy?
Forebrain
Midbrain
Hindbrain
Which of the secondary stages of brain development are found in the forebrain?
Telencephalon
Diencephalon
Which one of the secondary stages of brain development is found in the midbrain?
Mesencephalon
Which of the secondary stages of brain development are found in the hindbrain?
Metencephalon
Myelencephalon
What is a sulcus or sulci?
They are the depressions or grooves between the ridges of the cerebral hemispheres.
What is a gyrus or gyri?
They are the folds or ridges that can be seen in the folding appearance of the cerebral hemispheres.
If a species has more sulci and gyri what might this be an indicator of?
If there is a higher frequency of gyri and sulci it can indicate higher level of intelligence.
What are the four lines of the cerebrum?
Frontal
Parietal
Occipital
Temporal
What are the landmark sulci to look out for to orientate the brain?
Central sulcus
Lateral sulcus
What is the name given to the line dividing the two hemispheres?
Longitudinal cerebral fissure