Central nervous system Flashcards
What constitutes the central nervous system?
Brain and spinal cord
Within which structures do the brain and spinal cord lie?
Skull and vertebral canal
What are meninges?
Set of 3 membranes that encase the brain and spinal cord, separating them from the walls of their bony cases (skull and vertebral canal). Cerebrospinal fluid is located between the layers.
What are the 3 meninges from superficial to deep?
Dura mater, arachnoid mater, pia mater
What are the segments of the spinal cord?
Cervical, Thoracic, Lumbar, Sacral, Coccygeal
What does white matter contain?
Myelinated axons
What does grey matter contain?
Neuronal cell bodies
What is the name of the posterior part of the grey matter in the spinal cord?
Dorsal horn
What does the dorsal horn contain?
First order afferent neuron terminals and the cell bodies of second order sensory neurons.
What is the name of the anterior part of the grey matter in the spinal cord?
Ventral horn
What does the ventral horn contain?
Cell bodies of motor / efferent neurons
How do sensory / afferent neurons enter the dorsal horn?
Via dorsal root
How do motor / efferent neurons leave the ventral horn?
Via the ventral root
What are spinal cord tracts?
Neural pathways found within the spinal cord white matter. Ascending tracts convey information from the periphery to the brain while descending tracts carry information from the brain to the periphery.
Which regions of the spinal cord have a proportionally greater amount of grey matter?
Cervical and lumbar regions
Why do cervical and lumbar regions have a greater amount of grey matter?
Due to the innervation of the upper and lower limbs (grey matter contains cell bodies of second-order somatic afferent neurons and somatic efferent neurons - innervate skeletal muscle).
Why do cervical and thoracic regions have relatively more white matter than lumbar and sacral regions?
All information to/from the entire body must travel through the cervical region while only information of the lower limbs passes through the sacral region.
Neurons in the reflex pathway
(stimulus), sensory, interneuron, motor neuron, (muscle -> response)
Where are interneurons found?
In the spinal cord and brain stem (involved in reflexes)
Organisation of grey and white matter in the spinal cord
Grey matter on the inside, white matter on the outside (stains used may stain myelin, causing opposite appearance)
Organisation of grey and white matter in the brain
Grey matter on the outside (cerebral cortex), white matter on the inside (distributes information outwards)
What are the divisions of the forebrain?
Cerebrum and diencephalon
Function of the cerebrum
language, memory, perceptions, emotions. Sensory and motor functions
What are the parts of the diencephalon?
Thalamus and hypothalamus
Function of the thalamus
sensory processing
Function of the hypothalamus
Homeostasis (e.g. thermoregulation), emotional responses (e.g. stress), motivation, hormone production and association with pituitary gland, circadian rhythm
Parts of the brainstem
midbrain and part of hindbrain (pons and medulla oblongata)
Function of midbrain
visual and auditory reflexes, pain control
Divisions of the hindbrain
pons, medulla oblongata, cerebellum
Function of the medulla oblongata
Vital centre regulating breathing, heart rate and blood vessels
Function of cerebellum
controls balance and posture
What forms the cerebral cortex?
Grey matter
What is the name of the brain structure made of white matter?
Corpus callosum
Where is pons found in the brain?
Between the medulla oblongata and the midbrain
Lobes of the brain
frontal, parietal, temporal, occipital lobe (and insular and limbic lobes)
Which lobe is subdivided into 2?
Temporal lobe
Which lobe is in the anterior part of the brain?
Frontal lobe
Which lobe is in the posterior part of the brain?
Occipital lobe
Which lobe is posterior to the frontal lobe and superior to the temporal lobe?
Parietal lobe
Which lobe is inferior to the parietal lobe?
temporal lobe
What are the cortical sensory areas in the brain?
Auditory, somatosensory, gustatory, visual
Where is the somatosensory area located?
anterior parietal lobe
Where is the visual area located?
occipital lobe
Function of somatosensory cortex
Processes all sensory information in the body
Where is the auditory cortex located?
superior temporal lobe
Where is the gustatory cortex located?
In the frontal and insular lobe
What is the subcortical part of the brain?
islets of grey matter found beneath the cerebral cortex. Made up of the diencephalon, basal ganglia, pituitary gland, limbic structures
