Organisation of the Central Nervous System Flashcards
What structure connects the right and left hemispheres?
Corpus Callosum
What lies beneath the corpus callosum?
Diencephalon
What is the role of the cerebellum?
Fine tuning motor function
What are the two parts of the diencephalon?
Thalamus - relay station for information going between the cerebral cortex and other areas of the CNS
Hypothalamus - important in coordinating homeostasis (hypothalamo-hypophysial axis)
What is the role of the basal ganglia
Regulates voluntary movement
What makes the pons recognisable?
It bulges anteriorly
How did the brain initially develop and what do the three parts of this initial brain differentiate into?
It initially developed as the forebrain, midbrain and hindbrain.
The forebrain became the cerebral cortex and diencephalon
The midbrain remained as the midbrain
The hindbrain became the pons, medulla and cerebellum
What are the two types of cortical areas?
Primary Cortical Area
Association Cortex
Describe the arrangement of the primary motor cortex and the primary somatosensory cortex.
They both have somatotopic arrangement - like a little man standing upside down
What is the function of the association cortex?
The association cortex is involved in higher functions e.g. learning, perception, thinking
What is the role of Wernicke’s Area and Broca’s Area?
What is the role of Wernicke’s Area and Broca’s Area?
Wenicke’s Area - understanding language
Broca’s Area – speech
Describe the ventricular system of the brain.
There are two large C shaped ventricles called lateral ventricles. There is one lateral ventricle for each cerebral hemisphere.
The lateral ventricles narrow and form the 3rd ventricle, which is in the diencephalon
The 3rd ventricle narrows to form the cerebral aqueduct, which passes down through the midbrain and becomes a tent-shaped structure called the 4th ventricle.
The 4th ventricle is behind the pons and medulla and in front of the cerebellum.
The 4th ventricle then narrows to form the central canal, which runs down the spinal cord.
Where is cerebrospinal fluid produced?
By the choroid plexus, which is a special type of ependymal cell found in the ventricles.
Where does CSF leave the ventricles and enter the subarachnoid space?
CSF leaves the ventricles in the 4th ventricle, which has small holes in it
How is CSF reabsorbed into the venous system?
CSF is reabsorbed into the venous system by arachnoid villi.
What separates the temporal lobe from the other lobes?
Lateral Sulcus
What is the role of CSF?
CSF has a protective role - it is like the foetus being suspended in the amniotic fluid. It also has a metabolic role in exchanging nutrients and removing waste.
What is the difference between the dorsal horns and the ventral horns?
The dorsal horns are SENSORY - the impulses come towards the CNS
The ventral horns are MOTOR - the impulses go away from the CNS
What are the hole in the vertebral column that spinal nerves pass through called?
Intervertebral Foramina
What is the significant difference between the length of the spinal cord and the vertebral column?
The spinal cord is much shorter than the vertebral column
The spinal cord ends around L1/L2
What is the name of the area inside the vertebral canal beneath the point at which the spinal cord ends?
Lumbar Cistern
What is the name of the structure found in this area?
Cauda Equina
