Week 1 Flashcards
What bones make up the Neurocranium?
Frontal
Parietal x2
Occipital
Sphenoid
Temporal x2
Ethmoid
What bones make up the Viscerocranium?
Nasal x2
Palatine x2
Vomer
Maxilla x2
Mandible
Zygomatic x2
Lacrimal x2
Ethmoid
Name structures 1-5
1 - Pterion
2 - Zygomatic Arch
3 - Mastoid Process
4 - External Acoustic Meatus
5 - Mandibular Angle
Name the 3 suture lines
Coronal
Sagittal
Lambdoid
Name the 3 Structures
Groove for sup. sagittal sinus
Granular Foveolae (Arachnoid Granulations)
Grooves for middle meningeal arteries
What are Fontanelles and what is their purpose?
ant. and post. fontanelles are soft areas between the skulls bones after birth that allow the head to be easier pushed out during birth and for the skull to grow
What is the Pterion?
The H shaped suture point where the temporal, frontal, parietal and greater wings of sphenoid join
What would be a possible issue caused by trauma to the Pterion?
Haematoma
What nerves pass through the Sup. Orbital fissure?
Sup. + Inf. Oculomotor CN III (branches)
Trochlear CN IV
Abducens CN VI
Lacrimal n.
Frontal n.
Nasociliary n.
Sup. + Inf. ophthalmic vein
what structures pass through Inf. Orbital fissure?
Zygomatic branch of maxillary n.
Infra orbital n.
Inf. ophthalmic vein
What do the superior aspects of the temporalis muscle and its fascia attach to on the skull?
Temporalis - Inf. temporal line
Fascia - Sup. temporal line
Within what structure does the Facial CN VII branch?
Parotid Gland
What is the purpose of the Cribriform foramina?
Allow the Olfactory CN I bulbs to receive nerve fibres from Nasal cavity
What is the main symptom of a fractured cribriform plate?
CSF Rhinorrhoea
What is the function of the Sup. and Inf. articular cavities in the Temporomandibular joint (TMJ)?
Sup. allows sliding for initial opening
Inf. allows rotation for biting motion
Lateral ligament in the Temporomandibular joint (TMJ) prevents what?
Post. dislocation
What are the two major systems of descending pathways from cortex to motor centres?
Lateral Pathways & Ventromedial (Medial) Pathways
What’s the function of the lateral pathways?
Control voluntary movement
Control distal muscles
Mainly controlled by cerebral cortex
What is Apraxia?
Inability to perform complex sequence of movements (ie. brushing teeth, drawing sketch)
What is a potential cause of Apraxia?
Damage to premotor area of brain
What percentage of Corticospinal tract (CST) nerves are in the Lateral & Anterior CST respectively?
85% & 15%
Lateral tract nerves will decussate in the medulla where as the anterior will stay ipsilateral until they innervate bilaterally at level of their ventral root
What is the most common causes of lesions of corticospinal neurons?
Infarcts related to cerebrovascular incidents (particularly middle cerebral a.)
Trauma
Tumours
Demyelinating diseases
What is the difference between +ve and -ve signs of corticospinal neuron lesions?
+ve is the appearance of an abnormal response
-ve is the loss of function (weakness or paralysis)
Corticospinal lesions may give rise to what?
Upper motor neurone syndrome
What are the symptoms of Upper motor neurone syndrome?
Pyramidal muscle weakness (hemiparesis)
No muscle atrophy
No fasciculations
Increased muscle tone
Increased stretch reflexes
Abnormal reflexes
What are the symptoms of Lower motor neurone lesions?
Muscle weakness (lesion dependant)
Muscle atrophy
Fasciculations
Reduced muscle tone
Reduced stretch reflexes
What is the main function of the Ventromedial pathways?
Posture
What are the principal compensatory reflexes for Vestibular, Collicula, Reticular, and Tectal?
Body
Head / Body
Body
Head / Trunk
What are the functions of the Corpora Quadrigemina?
Controls position of head and eyes in response to visual, auditory and somatic stimuli
Also transmits auditory signals to auditory centre in brain
What are the pros and cons of a CT scan?
Fast & widely available however, produces ionising radiation
CT scans are taken in what plane?
Supraorbitomeatal plane
What 3 ways can an MRI be weighted?
T1, T2, or PD (proton density)
What is the benefit of a T1 weighted MRI?
Good for anatomy and contrast
How do substances appear on a T1 weighted MRI?
Water (CSF) is dark
Grey matter is dark grey
White matter is off-white
Fat is white
What is the benefit of a T2 weighted MRI?
Good for identifying pathology - inflammation, oedema
How do substances appear on a T2 weighted MRI?
Water is white
White matter is darker than grey mater
What benefit is there to Diffusion Weighted Imaging (DWI)?
Very good for detection of ischemia, infarct, and stroke
What may be done complimentary to a Diffusion Weighted Image?
Apparent Diffusion Coefficient (ADC)
Examples of MRI contraindication
Implanted metal devices
Foreign bodies (shrapnel)
Claustrophobia
What benefit is there to SPECT & PET?
Useful for identifying cancer, infection, coronary artery disease, brain disorders
What does the ABC’S system for interpreting Brain scans stand for?
Adequacy, Alignment, Artefact
Bones, Blood & Brain
CSF-filled spaces
Subcutaneous & surfaces, symmetry
What structure carries sensory info from the lower trunk and lower limbs in the spinal cord (below C6)?
Fasciculus Gracilis
What structure carries sensory info from the upper trunk and upper limbs in the spinal cord (above C6)?
Fasciculus Cuneatus
Where in the spinal cord are Fasciculi Gracilis and Cuneatus found?
Dorsal Column (medial & lateral respectively)
At what spinal & vertebral levels are the cervical and lumbar enlargements of the spinal cord?
Cervical
Spinal: C4 - T1
Vertebral: C4 - C7
Lumbar
Spinal: L2 - S3
Vertebral: T11 - T12
What is the function of the Clarke n. and at what levels is it present?
Relay for proprioceptive info traveling to the cerebellum, C8 - L3