term 2 Flashcards
-CSF blood -cranial nerve 1/2 -spinal cord 1/2/3
what is the ventricular system?
remnant of the space (lumen) of the neural tube, and interconnected series of cavities (ventricles throught the CNS)
how many ventricles are there?
4, ,two lateral the 3rd and 4th.
what are the ventricles lined with?
ependymal cels> vascularized pia> secretory cells (choroid plexus)
what produces CSF?
choroid plexus,
whats the function of the ventricular system? (purpose)
brain protection, nutrient and waste transport, and transport of neuroendocrine factors (hormones)
where sit the choroid plexus located?
there are 2 locations (lateral/3rd ventricle, and the 4th ventricle)
what does the choroid plexus formation contain?
ependymal cells, fenestrated capillaries, pia and choroid epithelium.
how is the cerebrospinal fluid made?
- filtration of blood plasma through fenestrated capillaries, 2. activate transport of ion across the choroid epithelium, 3. osmotic balance is maintained by flow of water across specific water channels.
go into detail about the ependymal cells?
they are ciliated cells that line the ventricles of the brain and central canal of the spinal cord. responsible for CSF circulation.
what is hydrocephalus?
“water on the brain”
what are the 3 components of the blood brain barrier?
choiroid epithelium ( regulates wat gets into the CSF from the plasma) intracerebral capillary ( barrier to rest of body- tight junctions) arachnoid barrier (prevents diffusion from outside CNS into subarachnoid space)
how is the arterial blood transported to the brain?
through 2 main branches from the dorsal aorta:
1) internal carotid arteries- supply the brain
2) vertebral arteres- along with basilar artery supply the brain, brainstem and cerebellum
what is the purpose of the circle of willis?
is a circulatory anastomosis that supplies blood to the brain and surrounding structures. it also connects the anterior and posterior circulatory system.
what determines/controls the cerebral blood flow?
- viscosity of blood
- how dilated blood vessels
- cerebral perfusion pressure
how do you detect aneurysms?
using an angiogram, and you use an indicator in the blood supply to get an x-ray vision of arteries in the brain. If certain arteries looks as if they are going to burst/have burst that is evidence of aneurysms (blood build ups)
how is blood drained form the brain?
via two sets of veins
- superficial veins
- deep veins
what are superficial veins?
they lie on the surface of each cerebral hemispheres within the subarachnoid space. they drain cerebral cortex, and underlying white matter
what are the deep veins?
they are drain structures in the walls of the ventricles, and the converge on the internal cerebral veins.
what is the importance of venous drainage?
importace in relation to neruosurgical procedures
important to neurologist- in clinical sunthroms.
A VENOUS OBSTRUCTION-? THROMBOSIS
how many pairs of cranial nerves are there?
12, and they are numbered sequentially in the rostral to caudal order in which they arise form the brain.
what do the cranial nerves do on a general term.
carry sensory information from ipsilateral receptors
what are the exceptions of the cranial nerves?
trochlear nerves- all fibres originate form motor neuron cells in the contralateral 1/2 of the CNS
oculomotor- some fibres originate form contralateral motor neuron cell bodies
how are the cranial nerves attached?
attached dorsally or dorsolatterally except for the trochlear nerves- attach ventrally.
the cranial nerve function can be sensory, how?
olfactory bulb-smell
optic nerve- sight
vestibulocohlear nerve- hearing and equilibrium.
the cranial nerve function can be motor, how?
occulomotor nerve- movement, pupil, lens
abducens nerve- eye movement
accessory nerve- head and shoulder movements
hyoglossal nerve- tongue movements.
the cranial nerve function can be both motor, and sensory, how?
trigeminal nerve- facial sensation, chewing
facial nerve- expression and taste
glossopharyngeal never- swallowing, taste
vagus nerve- visceral sensory, taste, swallowing, speaking, preganglionic parasympathetic
what is the hypoglossal nerve- 12
its a motor nerve with lower motor neurons, its somatic effect fibres for muscles of the tongue, and it arises from hypoglossal nucleus.
what is the pathway for the hypoglossal nerve?
the upper motor neuron cell body is within the pre-central gyrus, the axons are called corticobulbar fibers.
basically the axons enter internal capsule with the corticospinal tract, through the cerebral peduncle then the pons, and it crosses the midline within the rostral medulla. finally it terminates in the hypoglosal nucleus.
what is the spinal accessory Nerve- 11
its a motor nerve, it arises form column of lower motor neurons i the anterior gray horn, its a somatic efferent fibres for trapezius and sternocleidomastoid.
what are the nucleus ambiguus?
its the lower ‘lines’ that merge commissural nucleus. they are special visceral efferent fibers, and the supply muscles of larynx and pharynx
what is the solitary nucleus?
it extends from the lower pons to gracile nucleus, and its full of afferent fibers.
what is the regions of the solitary nucleus?
gustatory, dorsal respiratory, baroreceptor, and visceral afferent.
what is the function of the gustatory nucleus?
primary afferent supplying taste buds
what is the function of the dorsal respiratory nucleus?
afferent that controls inspiration-> movement and timing
what is the function of the baroreceptor nucleus?
receives primary afferent supplying baroreceptors in carotid sinus and aortic arch
what is the function of the visceral afferent nucleus?
includes commissural nucleus; within brainstem; recieves primary afferent supplying alimentary and respiratory tracts.
the glossopharyngeal nerve-9
what are the motor components?
what are the parasympathetic components?
what are the sensory components?
motor- nucleus ambiguus- larynx/pharynx
para- inferiror salivatory nucleus- parotoid gland
sensory- informaiton terminates in solitaty nucleus and spinal trigeminal nucleus
what is the Vagus nerve- 10
its the “wandering nerve”
its the largest cranial nerve
12 branches
and is a mixed nerve
what are the sensory components of the vagus nerve 10?
terminates in the solitary nucleus
terminates in the sylvian parietal-temporal region
terminates in the spinal trigeminal nucleus
general sensation in the pharynx, larynx, esophagus, tympanic membrane, and external ear
what are the motor components of the vagus nerve 10?
originates in the nucleus ambiguus muscles of the larynx, pharyns
what are the parasympathetic components of the vagus nerve 10?
rest and digest
dorsal motor nucleus= collection of preganglionic parasympathetic neurons in the brainstem
widely distributed throughout the cardiovascular, respiratory, GI systems
innervates most abdominal organs
what is GSA?
general somatic afferent= sensory-> pain and temperature