Introduction & Basic Topography Flashcards
The CNS is made up of which 3 structures?
Cerebral hemispheres
Brainstem and cerebellum
Spinal cord
The PNS is made of up which 4 structures?
Dorsal and ventral roots
Spinal nerves
Peripheral nerves
Ganglia
True or false? Grey and white matter are used in respect to the peripheral nervous system?
False!!
Grey and white matter are only used in respect to the CENTRAL nervous system
What is grey matter composed of?
Grey matter
Dendrites
What is white matter composed of?
Axons + their supporting cells
Why is white matter white?
Due to the presence of fatty myelin
What is the PNS equivalent of grey matter?
Ganglion
What is the PNS equivalent of white matter?
Peripheral nerve
At the level of nerve roots are the functions mixed or segregated?
Segregated
At the level of the nerve roots what are the dorsal and ventral roots responsible for?
Dorsal- sensory control
Ventral- motor control
Which structures detect muscle stretch when the tendon hammer is applied to the patellar ligament?
Muscle spindle afferents
What is the generic term for the neurone that receives information from the muscle spindle afferents?
Sensory muscle afferents
What is the generic term for the neurone that sends impulses to the skeletal muscle in a reflex arc?
Motor efferent
In monosynaptic reflexes like the knee jerk, where is the synapse found?
Ventral horn
Draw a labelled diagram to show the reflex arc
What spinal levels mediate the knee jerk reflex?
L3/L4
What is the Jendrassik manoeuvre?
A technique used to distract the patient while you perform the test for knee jerk reflex
What is a T1 MRI scan and how does this differ from a T2 scan?
In a T1 MRI- CSF is dark
In a T2 MRI- CSF is bright, water is bright *T2- H20*
What are the three types of spina bifida?
- Occulta
- Meningocele
- Myelomeningocele
Which type of spina bifida has the worst prognosis? Why?
Myelomeningocele
Because neural tissue comes out of the opening- likely to effect its function
The spinal cord is composed of how many segments?
31
The spinal cord runs from where to where?
Foramen magnum
L1 vertebral level
What is a funiculus?
How do impulses travel through such?
A segment of white matter containing multiple distinct tracts.
Impulses travel in multiple directions
What is a tract?
How do impulses travel through such?
An anatomically and functionally defined pathway connecting two distinct regions of grey matter.
Impulses travel in ONE direction
What is a fasiculus?
A subdivision of a tract, supplying a distinct region of the body
White matter is organised into ______. Grey matter is organised into _______.
White matter- tracts
Grey matter- cell columns
Do subdivisions of grey matter look different histologically?
Yes
What is a nucleus in respect to the CNS? Are nuclei grey or white matter?
A distinct population of neurones in the CNS supplying a given muscle (Functionally related cell bodies)
Grey matter
Define what is meant by “cortex”
Is this grey or white matter?
A folded sheet of cell bodies found on the surface of a brain structure
Grey matter
What is a fibre? Is this grey or white matter?
An axon in association with its supporting cells (e.g.oligodendrocytes)
White matter
Association fibres connect cortical regions within ___________ hemisphere(s)
the same
Commissural fibres connect ____________ hemispheres
left and right
Projection fibres connect the cerebral hemispheres with ________ and vice versa
The cord/brainstem
The midbrain is responsible for what?
Eye movements
Reflex responses to sound and vision
The pons is responsible for what?
Feeding
Sleep
The medulla is responsible for what?
CVS and Respiratory centres
Major motor pathway - MEDULLARY PYRAMIDS
Where is the primary motor cortex found?
Precentral gyrus
Where is the primary sensory cortex found?
Postcentral gyrus
What structure separates the temporal from the frontal/parietal lobes?
Lateral (Sylvian) fissure
What structure separates the parietal from the occipital lobe?
Parieto-occipital sulcus
What structure is surrounded by the primary visual cortex?
Calcarine sulcus
Can you locate these structures on this image:
Corpus callosum
Thalamus
Cingulate gyrus
Hypothalamus
Fornix
Tectum
Cerebellar tonsil
What are the cavities within the brain known as?
Ventricles
What do the brain ventricles contain?
What is the role of this structure?
Coroid plexus
Produce CSF (600-700ml a day)
Where is CSF reabsorbed?
Arachnoid granulations + others
