Physiology Flashcards
name the main component of CSF
water
where is CSF produced?
secretory epithelium of the choroid plexus
where does the CSF circulate?
subarachnoid space
where is CSF absorbed?
venous circulation
name the 3 major functions of CSF
mechanical protection
homeostatic function
circulation
clinical CSF analysis is obtained via what?
lumbar puncture
where in the brain is the choroid plexus found?
3rd, 4th and lateral ventricles
name the 4 ventricles
2 lateral ventricles
third ventricle
fourth ventricle
what connects the lateral and third ventricle?
foramen of Monroe
what connects the third and fourth ventricle?
cerebral aqueduct
the foramen of Magendie is found on the ______ aperture connecting the fourth ventricle to the subarachnoid space whereas the foramina of _______ is found on the lateral apertures connecting the fourth ventricle to the subarachnoid space.
the foramen of Magendie is found on the MEDIAN aperture (single) connecting the fourth ventricle to the subarachnoid space whereas the foramina of LUSCHKA is found on the lateral apertures (pair) connecting the fourth ventricle to the subarachnoid space.
the subarachnoid space is found between the ___ and ____ _____
the subarachnoid space is found between the PIA and DURA MATER
name the following tumour pathology of the ventricles, choroid plexus and CSF:
(a) found at interventicular foramen
(b) arising from the ependymal cells lining the ventricles
(a) colloid cyst
(b) ependymomas
also choroid plexus tumours
name the following definitions:
(a) accummulation of blood in the ventricles
(b) arterial bleed between skull and dura
(c) venous bleed between dura and arachnoid
(a) ventricular haemorrhage
(b) epidural hematoma
(c) subdural hematoma
the following definitions describe what pathology:
accumulation of CSF in the ventricular system or around the brain (either due to obstruction or overproduction)
subsequent enlargement of one or more ventricles and increase in CSF pressure
hydrocephalus
name the enigmatic condition causing headache and visual disturbances but no imaging features of hydrocephalus despite increased CSF
idiopathic intracranial hypertension
define papilloedema
optic disc swelling due to increased intracranial pressure transmitted to the subarachnoid space surrounding the optic nerve
list the visual symptoms of a patient with papilloedema
enlarged blind spot
blurring of vision
visual obscurations
vision loss
what does aqueous humour contain?
bicarbonate
where is aqueous humour made? what chamber is this in?
epithelial layer of the ciliary body in posterior chamber of the eye
where does aqueous humour drain once in the anterior chamber of the eye?
scleral venous sinus through a trabecular meshwork and the angle of Schlemm
what drug reduces production of aqueous humour and is used to reduced ocular pressure in glaucoma?
carbonic anhydrase inhibitors -
dorzolamide (eye drops) avoiding systemic effects
acetazolomide (oral) also targets kidneys leading to acidosis
name the 3 cells in the direct vertical pathway for signal transmission
photoreceptors to bipolar cells to ganglion cells
what cells receive input from photoreceptors and project to other photoreceptors and bipolar cells?
horizontal cells
what cells receive input from bipolar cells and project to ganglion cells, bipolar cells, and other amacrine cells?
amacrine cells
photoreceptors convert ________________ radiation to ______ signals
photoreceptors convert ELECTROMAGNETIC radiation to NEURAL signals
name the 2 types of photoreceptors
rods and cones
name the 4 main regions of photoreceptors
outer segment
inner segment
cell body
synaptic terminal
with light exposure, Vm ________________!
with light exposure, Vm HYPERPOLARIZES!
name the visual pigment molecules in rods
rhodopsin and opsin
what converts 11-cis-retinal to all-trans-retinal?
light
lowered Na entry results in __________________
lowered Na entry results in HYPERPOLARIZATION
there is more _________ in the dark and less of it in the light
there is more GLUTAMATE in the dark and less of it in the light
define visual acuity
ability to distinguish 2 nearby points
what is visual acuity determined by?
photoreceptor spacing and refractive power
rods/cones are for seeing in dim light and rods/cones are for seeing in normal daylight
rods = dim cones = normal
there is more convergence in ___ system, increasing sensitivity while decreasing ______
there is more convergence in ROD system, increasing sensitivity while decreasing ACUITY
name the colour for the following cones:
(a) short WL -
(b) middle WL -
(c) long WL -
(a) short WL - BLUE
(b) middle WL - GREEN
(c) long WL - RED
what is the following explaining:
achromatic peripheral retina high convergence high light sensitivity low visual acuity
rods
what is the following explaining:
chromatic central retina (fovea) low convergence low light sensitivity high visual acuity
cones
