Unit 5: Ventricles Flashcards
Lateral Ventricles (Brain Ventricles- Location)
Within the cerebral hemisphere
Frontal Anterior Horn (Brain Ventricles- Location)
Begins anterior to the intraventricular foramen of monroe and extends to the frontal lobe
Body (Brain Ventricles- Location)
Posterior to the intraventricular foramen of Monro, within the frontal and parietal lobes
Atrium/Trigone (Brain Ventricles- Location)
Area of convergence of the occipital horn, the temporal horn, and the body of the lateral ventricle
Occipital (posterior) Horn (Brain Ventricles- Location)
Extends from the atrium posteriorly into the occipital lobe
Temporal (inferior) Horn (Brain Ventricles- Location)
Extends from the atrium inferiorly into the temporal lobe
Third Ventricle (Brain Ventricles- Location)
Within the thalamus and hypothalamus
Fourth Ventricle (Brain Ventricles- Location)
Within the pons, medulla, and cerebellum
Ventricles
The neural plate comes together to form the neural tube that becomes the ventricular system
- There are 4 cavities in the brain called the ventricles and are filled with cerebrospinal fluid
- All one piece that encompass the brain and spinal cord
The 4 ventricles are:
- 2 lateral ventricles
- 1 third ventricle (surrounded by thalamus (diencephalon) 1/2 on each side)
- 1 fourth ventricle (btw brainstem and cerebellum, specifically pons and medulla)
The Ventricles (image)
Interventricular Foramen of Monro
Location where lateral ventricle switches to 3rd ventricle
Cerebral Aqueduct
Location where 3rd ventricle switches to 4th ventricle
Flow of CSF
- Lateral Ventricles
- Foramen of Monroe/Intraventricular Forament)
- Third Ventricle
- Aqueduct of Sylvius
- Fourth Ventricle
- Medial: Foramen of Magendie, Lateral: Foramen of Luschka
- Flows around the spinal cord and in and around the brain in the subarachnoid space
- Exits through arachnoid granulations which poke into the superior sagittal sinus
Pathway of CSF out of 4th Ventricle
- Foramen of Magendie (medial)
- Foramen of Lushka (lateral)
Choroid Plexus
Made up of ependymal cells which produce CSF and assist in circulating it by the movement of their cilia
-The choroid plexuses are constantly producing CSF creating a small pressure gradient
Function of CSF
- Buoyancy
- Cushioning
- Cleaning
- Ionic Balance
Choroid Plexus (image)
Cisterns
Large pockets in the subarachnoid space
-Quadrigeminal Cistern, Callosal Cistern, Interpenduncular Cistern, Cisterna Magna, Premedullary Cistern, Prepontine Cistern
Cisterna Magna (cerebellar medullary cistern)
Found between the cerebellum and medulla (between the inferior margin of the vermis and the posterior rim of the foramen magnum)
Cistern in Lumbar Area of the Spine
This cistern is useful as it provides a place to extract cerebrospinal fluid through a lumbar puncture
- A needle is placed between the lumbar vertebra and into this cistern
- At this level of the spinal cord there are only spinal nerves and the fluid will help them “float” away
CSF: things you may see in a chart
- Pressure
- VIsual exam
- Chemistry
- Immunology
Normal Adult (CSF Fluid Profiles in Normal Adult and those with infectious meningitis)
White Blood Cells (per mm^3): <5-10, lymphocytes only
Protein (mg/Dl): 15-45
Glucose (mg/Dl): 50-100
Comments: If traumatic lumbar punctire, expect 1 additional white blood cell for every ~700 red blood cells
Acute Bacterial Meningitis (CSF Fluid Profiles in Normal Adult and those with infectious meningitis)
White Blood Cells (per mm^3): 100-5000, usually polymorphonuclear leukocytes
Protein (mg/Dl): 100-1000
Glucose (mg/Dl): Reduced, <40
Comments: In patients with hyperglycemia, CSF glucose is abnormal if <50% of serum glucose