Formative neuro Qs Flashcards
Where are the sinuses located?
Between the meningeal and periosteal dural layers
Where is cerebrospinal fluid re-absorbed into?
Superior sagittal sinus
How does venous blood leave the brain and return to the heart?
Internal jugular vein
Does the cavernous sinus receive blood from the orbit?
No
Where does the straight sinus receive venous blood from?
The inferior sagittal sinus and the great cerebral vein
What artery carries blood to the motor cortex of the right leg?
Left anterior cerebral artery
What are berry aneurysms?
a small saccular aneurysm of a cerebral artery, usually at the junction of vessels in the circle of Willis
The middle cerebral artery is a direct continuation of what artery?
Interbal carotid artery
What is Broca’s area also known as?
Brodmann’s area 44
What does the corticospinal tract pass between in the internal capsule?
Basal ganglia and thalamus to enter the cerebral peduncle
Does the location of a stroke in the motor cortex or internal capsule affect its impact?
A stroke affecting the motor cortex will result in a lesser neurological deficit than the same sized stroke affecting the internal capsule
Which direction do lower motor neurone leave the spinal cord?
Anteriorly (ventrally)
What do alpha and gamma motor neurones innervate?
ALpha - extrafusal muscle fibres
Gamma - intrafusal muscle fibres
Where are the cell bodies of the lower motor neurones located?
In the ventral horn of the spinal cord
Where are the axons of upper motor neurones located in the spinal cord?
Lateral white matter
Where does the lateral corticospinal tract decussate?
medullary pyramids
How are the fibres of the corticospinal tract organised?
Somatotopically
(Lower extremity fibres located Laterally.
Upper extremity and head fibres located more medially.)
Where are muscle spindles found?
In skeletal muscles - composed of extrafusal muscle
What are muscle fibres of the spindle innervated by?
gamma motor neurons
what does a muscle spindle detect and do?
Contributes to the change in muscle resistance to stretch following a stroke.
Detects muscle contraction and relaxation
What does the Golgi tendon organ do?
Detects changes in muscle tension. They measure the force developed by muscle and any resultant change in length.
Where are Golgi tendons located?
Junction of skeletal muscle and tendon
What are the properties of the plasma membrane of neurons?
- Excitable
- contains many active transport pumps
- negative resting potential inside compared to outside
How does a neurone maintain a resting membrane potential?
Through Na+/k+ pumps
- membrane is more permeable to K
- Na+ channels open causing influx of Na+ into the neurone (depolarisation)
- K+ channels open so moves out of cell (depolarisation)
