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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

what is partial pressure?
Tariq Reply
it is the pressure exerted by mixture of gases...
Fatukasi
What is the Important of studying anatomy and philosophy
Michael Reply
because to know the mechanisms of our body
Tariq
how many region do we have in human body
nsofor Reply
head thorax abdomen and many kind of...
Shan
what is principal ponatine nucleas
Tariq
Human body can be divided into different regions on the basis of: 1. Systems: e.g. digestive system, respiratory system, excretory system etc.. 2. Parts: e.g. head, thorax, neck, upper limbs, lower limbs etc..
AMEL
we have 9 region in d human body
ZAINAB
what is systematic anatomy?
nsofor Reply
it is the anatomy or study of a certain body system for example the digestive system. or respiratory system.
Summer
It is a group of structure that work together to perform a unique function..
RAPHERA
describe the division of anatomy and physiology
Vissa Reply
the what and the how
Josh
anatomy is the structure. physiology is the function.
Gavin
what is homeostasis?
nsofor
the balance if everything in your body
Kare
is the tendency of the body to maintain the internal environment
Flora
It is the ability of systems and living organisms to adjust its internal environment
RAPHERA
how does a saggital plane look like and a frontal plane
susan Reply
saggital plane divides left and right.. frontal plane divides front and back.. I'm trying to upload a picture but idk how.
Pipiena
tnx sis
Angella
The sagittal plane is a vertical plane that divides the body into left and right anteriorly whilst the frontal plane divides the body into the posterior(back) and anterior(front) parts. They're all perpendicular to the transverse plane.
Sirius
what is a neurones?
Angella Reply
how many systems are there in human
Angella
It is a cell that specialized to conduct nerve impulse
RAPHERA
What is ovulation
Joy Reply
Ovulation is release of mature ovum from ovary
AMEL
what is physiology
Firdaus Reply
The study of how e body systems or structures function and interrelate with each other
Prettygal
what is the composition of the ground substance?
Nana Reply
large carbohydrates and proteins which is known as acid mucopolysacchrides
adam
thanks👍
Nana
you guy welcome
adam
Hi guys am new here
Nji
how does the negative feedback helps in maintaining body temperature at its normal range
dzreke
I need good sites that I can test myself on chapters 1,3,4,5. I have an exam tomorrow
Ana
please can you kindly share your questions here after the exams please
dzreke
What causes the banding pattern seen in the muscle fibril under the electron microscope
Nji
what organelles controls protein synthesis?
Katie Reply
Ribosome
AMEL
hmm...the ribosomes?
Fatukasi
ribosome
adam
Ribosome
Opara
Ribosome
Saifkhan
ribosome
DR
ribosome
ELIZABETH
are ribisomes made in the rRNA?
Lola
nop they are produced by cells of Nucleolus
adam
Is there anything about nerve and muscle physiology?
AMEL Reply
how many types of epithelial tissues do we have
Benedicta Reply
Epithelial tissues are grouped in two ways.. ●Based on the number of layers.(Simple and stratified ) ●Based of their shapes(Squamous,Cuboidal and columnar) Also we can have a combination of the two,say,simple Squamous
Prince
awww thanks dearie😊😊😊💖
Benedicta
describe the function and structure of blood
Belindah Reply
It has four main components: plasma, red blood cells, white blood cells, and platelets. Blood has many different functions, including: transporting oxygen and nutrients to the lungs and tissues.
Arlena
well answered arlena.. #thumbs up#
Fatukasi
have u some prepared MCQs on CNS and Special senses physiology?
dr
Anyone got the human heart labelled diagram
Sawmtei
you can download from Google... I don't think it's possible to share docs or files here
Fatukasi
ok thanks
Sawmtei
you're welcome..
Fatukasi
thanks
dr
Thank you
Drs
what's an easy way of knowing the different structures of tissues what they do and where their found
Lola
are you know function of the blood?
Drs
to carry nutrients to parts of the body
Lola
well Lola the easiest way is to attributes the tissues based on their funcs(especially those with similar funcs)..you can create your own mnemonics that will help you rmba em..and the a random reading.. it helps you retain em better
Fatukasi
and try random reading*
Fatukasi
ok thanks
Lola
funtction of WBCs
DR
bone tissue
Waqar
Blood is a fluid connective tissue made up of blood cells suspended in plasma, which is the fluid part of blood. The cell include erthrocytes, leukocytes and thrombocytes. Blood is responsible for transportation of substances around e body eg hormones oxygen and substances
Prettygal
Blood is responsible for defence... As it acts as a defense mechanism against microbes through action of leukocytes which destroy any foreign substances
Prettygal
identy the vein and arteries of coronary circulation
abdifatah Reply

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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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