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Watch this video that describes the procedure known as the lumbar puncture, a medical procedure used to sample the CSF. Because of the anatomy of the CNS, it is a relative safe location to insert a needle. Why is the lumbar puncture performed in the lower lumbar area of the vertebral column?

The ventricular system

Cerebrospinal fluid (CSF) circulates throughout and around the CNS. In other tissues, water and small molecules are filtered through capillaries as the major contributor to the interstitial fluid. In the brain, CSF is produced in special structures to perfuse through the nervous tissue of the CNS and is continuous with the interstitial fluid. Specifically, CSF circulates to remove metabolic wastes from the interstitial fluids of nervous tissues and return them to the blood stream. The ventricles    are the open spaces within the brain where CSF circulates. In some of these spaces, CSF is produced by filtering of the blood that is performed by a specialized membrane known as a choroid plexus. The CSF circulates through all of the ventricles to eventually emerge into the subarachnoid space where it will be reabsorbed into the blood.

The ventricles

There are four ventricles within the brain, all of which developed from the original hollow space within the neural tube, the central canal    . The first two are named the lateral ventricles    and are deep within the cerebrum. These ventricles are connected to the third ventricle    by two openings called the interventricular foramina    . The third ventricle is the space between the left and right sides of the diencephalon, which opens into the cerebral aqueduct    that passes through the midbrain. The aqueduct opens into the fourth ventricle    , which is the space between the cerebellum and the pons and upper medulla ( [link] ).

Cerebrospinal fluid circulation

This diagram shows the cross section of the brain and the major parts are labeled. Arrows on the figure show the direction of circulation of the cerebro-spinal fluid.
The choroid plexus in the four ventricles produce CSF, which is circulated through the ventricular system and then enters the subarachnoid space through the median and lateral apertures. The CSF is then reabsorbed into the blood at the arachnoid granulations, where the arachnoid membrane emerges into the dural sinuses.

As the telencephalon enlarges and grows into the cranial cavity, it is limited by the space within the skull. The telencephalon is the most anterior region of what was the neural tube, but cannot grow past the limit of the frontal bone of the skull. Because the cerebrum fits into this space, it takes on a C-shaped formation, through the frontal, parietal, occipital, and finally temporal regions. The space within the telencephalon is stretched into this same C-shape. The two ventricles are in the left and right sides, and were at one time referred to as the first and second ventricles. The interventricular foramina connect the frontal region of the lateral ventricles with the third ventricle.

The third ventricle is the space bounded by the medial walls of the hypothalamus and thalamus. The two thalami touch in the center in most brains as the massa intermedia, which is surrounded by the third ventricle. The cerebral aqueduct opens just inferior to the epithalamus and passes through the midbrain. The tectum and tegmentum of the midbrain are the roof and floor of the cerebral aqueduct, respectively. The aqueduct opens up into the fourth ventricle. The floor of the fourth ventricle is the dorsal surface of the pons and upper medulla (that gray matter making a continuation of the tegmentum of the midbrain). The fourth ventricle then narrows into the central canal of the spinal cord.

Questions & Answers

why the heart is protected with that sac
Joshua Reply
To prevent collision with the lungs, lubricates the heart, protects the heart from infection in the event a peripheral organ is effected, and stabilizes the heart within the mediastinum.
This app should be updated too much as there is very little information for some topics.I hope you will consider my information....
aman Reply
adenohypophysis is made up of what type of cells and what is the name of those cells?
Mannu Reply
armstrong Reply
motor root of the trigeminal nerve
what is the nervous system about
what passes through foramen ovale?
Farah Reply
what are the organelles of a cell
Amina Reply
muscular system
nucleus ribosome Golgi body call membrane cytoplasm
these are the cellular components that functions to provide energy,remove waste and cell division
Organelles of the cell are: Mitochondria,Ribosome,golgi apparatus, nucleus, secretory granules, nuclear e t c
what are local hormones
Local hormones are hormones that effect the cell that released them or cells near the releasing cell and they do not circulate within the blood stream.
the trachea bifurcated into how many branches on the right lung
three lobes
Explain the normal flow of blood.
how can we maintain the internal living things
Choolwe Reply
how many seconds does a human will stop if you sneeze
Kharl Reply
1 sec not specific
physiology of vision
Sudipta Reply
Can pure water become gel like?
ovie Reply
what is Homeostasis
Laura Reply
It is the ability of an organism to co ordinate it's internal environment so as to achieve balance in all areas
what is anatomy
Sandra Reply
what is physiology
The study of how the body works
the branch of biology dealing with the functions and activities of leaving organisms and their parts including all physical and chemical processes
the study of human body . phicically and chemically it's called anotomy physiology
the branch of biology dealing with the functions and activities of living organisms
which vein do we inject to give infusions
it is the scientific study of the body structure
What Choolwe Muselitata said is the definition of anatomy
Physiology can also be described as the way in which a living organism or bodily part functions
Anotomy is the science which we humen body of structure and function know as the anotomy
study of the body funtion and structure
functional study of the body
it is the study about the functions of body organs
what are the vital sign procedure
jeniffer Reply
You start the TPR then BP after explaining the procedure to the patient and your requirements ready.
which type of vein to you inject to give infusions?
how long do u take radial pulse
Flavian Reply
1 minute
You can take it for 15 seconds , the number you got you multiply wth 2
but in the aspect of the multiplying that isn't right
radial pulse kya hai?
for more accurate values you must do the 1 minute
1 minute.
60 seconds
1 minute
yes @sabina
What is homeostasis
Winter Reply
Homeostasis is the state of relative stability of the body's environment
what are fluids
fluid is a substance that has no fixed shape and yield easily to external pressure
Difference between hemostasis and homeostasis
Hemostasis is blocking or stopping blood flow from a damaged blood vessel by coagulation of that vessel or obstructing it.
Homeostasis is a balanced state. An equilibrium. The body does this by regulating itself by using hormones and neurotransmitters to keep chemicals balanced within the body.
Examples of site of homeostasis
For example, to much calcium in the blood would stimulate the release of calcitonin from the thyroid gland. Calcitonin will decrease calcium levels by depositing it into the skeleton. This is known as bone deposition, a homeostatic mechanism. Parathyroid hormone is the opposite to calcitonin.
There are a lot of homeostatic mechanisms in the body. Insulin and glucagon is another one. These two regulate glucose (sugar) levels in the blood. High glucose levels would cause insulin from the pancreas beta cells. Insulin lowers blood sugar. Glucagon increases blood sugar

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Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
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