The Brain and Cranial Nerves Essay examples

In the article “Head Rush,” Laura Sanders explains the role blood has upon our brain. As blood travels our body, it takes in our information, thoroughly giving us details on our health ,genetics and many more. Our blood actually has a bigger job that many of us didn’t know about. Past experiments are suggesting that blood has the power to control nerve cell, instead of just taking commands from them. Science textbooks point out that astrocytes connect neurons and blood vessels, but it is still uncertain as to how neurons receives its signal to carry blood to the brain. Sanders talks about two neuroscientists Robert Hill and Jaime Grutzendler of Yale University published work. Hill claims that, “endothelial cells are perfectly poised to detect

All of the activated T-cells then release cytokines and adhesion molecules that enable the T-cells to adhere to and cross over the blood-brain barrier, which normally prohibits the flow of substances into the brain (8,9). The proteins in these T-cells bind to myelin fragments on microglial cells and undergo a secondary activation (10), after which they multiply and release more cytokines, further invading the nervous system (11) and inflaming and damaging the blood-brain barrier. The greatly weakened barrier becomes easily permeable, allowing additional immune system cells, such as B-cells and cytotoxic T-cells to cross over (12). Once through the barrier, B-cells produce antibodies which bind to the oligodendracytes (the cells of the CNS which create myelin) and the myelin itself. Associated macrophages procede to destroy the myelin and may also damage the oligodendracytes (13).

The three main tissues that support and protect the CNS are commonly known as the meninges. They protect by preventing direct circulation of blood through the cells of the brain and spinal cord. These layers have elasticity within the tissues coating the CNS. In order the layers are the dura mater, the arachnoid layer, and pia mater. The last two layers have cerebrospinal fluid within which acts as a shock absorber to the brain. The cerebrospinal fluid transports hormones, white blood cells and nutrients to the cells of the

Endothelial cells in the brain are different from endothelial cells in non-neural tissues, in that they are held together by tight junctions (TJs) and undergo transcytosis at extremely slow rates3. These features restrict the paracellular and transcellular movement of molecules and ions from the blood to the brain, thus forming a physical barrier. CNS endothelial cells express a variety of transporters, both to transport essential nutrients into the brain, and to mediate the efflux of potential toxins from the brain4,5. CNS endothelial cells also express very low levels of leukocyte adhesion molecules (LAMs) which correlates with the low levels of CNS immune surveillance. These properties allow CNS endothelial cells to tightly regulate the movement of ions, molecules and cells between the blood and the

This means that it makes it difficult to get any therapeutic drugs to the brain. The blood brain barrier blocks out about 98% of small molecules and 100% of large-molecules pharmaceutics. This meant that most of the therapy that would be used comes in at a later stage when the barrier is compromised. Not only does the blood brain barrier block out most pharmaceutics but it also prevents any imaging contrast agents from entering for early diagnosis. Though by conventional means, getting a diagnosis is not possible, the blood brain barrier does allow all the oxygen and such to enter, meaning that it has a selective transport and that means that there is a way somehow to work around getting through the blood brain barrier

A few regions of the brain are absence of close-fitting junctions between the blood brain barrier and cells of the capillary walls. For instance, the area postrema of the lower brainstem can permit toxins in the blood that trigger vomiting. Also the pineal gland is void of the barrier, which allows hormones to enter, modulating day and night cycles. In terms of drugs they best infiltrate

When it comes to the blood-brain barrier I think of it as a protective layer that only lets a small portion of substances past it because it wants to protect the brain as much as it can. The blood-brain barrier is semi permeable making it selective to what passes through. In the brain it has capillaries but they are not like the normal capillary that are pours due to spaces between the endothelial cells. The capillaries in the brain are surrounded by endothelial cells that are sealed by tight junctions and a thick basement membrane. The brain barrier then has cells called astrocytes that press firmly against the basement secreting chemicals that adjust the capillary permeability. The blood-brain barrier is there to protect the brain from pathogens

The BBB is not only a physical barrier, but also a physiological barrier separating the brain and the cerebrospinal fluid (CSF) from the blood circulating through the rest of the body (Braniste et al., 2014; Engelhardt & Sorokin, 2009). This barrier is a result of the presence of endothelial cells that line the microvascular structures in the brain as well as astrocytes, pericytes, neurons, and an extracellular matrix, all of which induce a physiology that separates the brain from blood (Braniste et al., 2014; Engelhardt & Sorokin, 2009; Persidsky, 2013). Due to the different components, the BBB

Cerebrospinal fluid is the liquid that protects the CNS. Cerebrospinal fluid plays an important role in regulation of intracranial pressure and metabolic functions. The fluid circulates in two different compartments. Ventricles are the first place that the fluid circulates. The second place is what surrounds the CNS, subarachnoid space. Cerebrospinal fluid is secreted by the choroid plexus, which are located in the ventricular system. The CSF constantly reabsorbs and does so through the subarachnoid

Murine chronic cerebral hypoperfusion (CCH) results in white matter (WM) injury and behavioral deficits. Pericytes influence blood-brain barrier (BBB) integrity and cerebral blood flow. Under hypoxic conditions, perictyes detach from perivascular locations, increasing vessel permeability and neuronal injury. This study characterizes the time course of BBB dysfunction and pericyte coverage following murine experimental CCH secondary to bilateral carotid artery stenosis (BCAS). Mice underwent BCAS or sham operation. On post-procedure days 1, 3, 7 and 30, corpus callosum BBB permeability was characterized using Evans blue (EB) extravasation and IgG staining and pericyte coverage was calculated. The BCAS cohort demonstrated increased EB extravasation on postoperative days 1 (p=.03) and 3 (p=.01) when compared to sham mice. Further, EB extravasation was significantly greater (p=.03) at day 3 than at day 30 in BCAS mice. Positive IgG staining was seen at post-procedure day 3 in the BCAS group. BCAS mice demonstrated a nadir in pericyte coverage on post-operative day 3 (p50%) was reported to be 7% in women and 9% in men3. Clinical carotid endarterectomy studies of cerebral hypoperfusion, demonstrate a nearly 25% incidence of subtle cognitive decline in the absence of overt neurologic change or radiographic evidence of stroke4. Neurodegenerative diseases such as Alzheimer’s disease and vascular dementia have become increasingly more common as the population ages5-8.

This area is normally filled with Cerebrospinal fluid, which acts as A type of cushion that protects the brain from damage

The brain has many parts such as the frontal lobe and the cerebellum, which both play major roles in the Human Brain.My first topic is the parts of the brain and all what it controls,in this topic we will cover the frontal and temporal lobes.We will be covering the cerebellum and its parts inside too.We will talk about how the brain sends nerves from the frontal lobe to your eyes to cry or how your temporal lobes send nerves to your nose to smell.

The BBB is a physiological barrier between blood and brain tissue; it plays an important role in maintaining the stability of the CNS. It is like a dynamic regulation interface between the capillariesin the brain and spinal cord and the nerve tissue. In normal physiological conditions, only gas molecules and small lipid soluble molecules (withamolecular weight less than 400-600) are allowed. In addition to passive protection, it also can selectively pump harmful or excess substances out of the brain to maintain the stability of the brain’s internal environment, so thatthe CNS can function effectively [22, 23]. These features of the BBB allow it to play an effective role in the protection of the brain, butalso createdifficulties for creating drugs that can pass through

“Rapid movement of the brain puts stress on blood vessels in the subarachnoid space, which causes them to rupture. The subarachnoid space, which is normally filled with cerebrospinal fluid, fills with blood. Compared to a subdural hematoma, bleeding in a subarachnoid hemorrhage is spread diffusely through the subarachnoid space, so it does not

The brain is permeated by a vast network of tiny blood vessels called capillaries- so tiny and thin that blood cells have to pass through in single file. In the brain alone there are enough capillaries that if you laid them all out end to end they would stretch from Tucson to Tijuana.