Naive T lymphocytes leave blood stream across the specialised endotherlial wall o blood vessel called High endothelial venule(HEV).
The specialized endothelium synthesis number of molecules which are involved in lymphocyte homing in the lymph node.In particlualr homing receptor GLYCAM1 and ICAM-1 and chemokine such as MIP3 beta.
Initial binding of Naive T cells to the vascular endothelium is mediated by L-selectin binding to GLYCAM1 ,subsequently chemokine binding occurs which triggers binding of intergin LFA-1 to its ligand ICAM1.
Lymphocytes are able to migrate across endothelium and into T cell area of lymph node.
Naive T cells can inspect Dendritic Cells in the lymph node for the presence of specific antigens.If T cells didn't recognise antigen,then T cells are not activated and passed out of lymph node to return to the circulation.
T cells that don meet the speciic antigen in the lymph node are activated and begins to proliferate and mature into effector cells.
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This video shows the actions of a killer T cell that attacks a fibroblast.
Video on plant cell Division
This video demonstrates the process of division in the mitotic spindles of a fly embryo
Video on Sea Urchin Fertilization
This video deomonsrates the movement of organlles on microtubules.
Video shows the path of proteins exiting the Golgi apparatus on the way to the cell surface.
Animation on Intermediate Filaments,its structure andits function
Eutreptiella use both flagella and pronounced cell shape changes to swim.
Video on Fuluidity of Lipid Bilayer
When detergent is added to red blood cell the membrane ruptures and cytosol spills out
Animation on Animal Cell Division
This Animation shows how cell react to wound and how healing takes place
This Animation shows how HCV infection and Replication
This animation shows The cells Response To HCV
These two Animation shows TCell response to HCV
T cell response to MHC II
Proliferation of T cell by IL-10
Basal ganglia (or basal nuclei) are a group of nuclei in the brain interconnected with the cerebral cortex, thalamus and brainstem. Mammalian basal ganglia are associated with a variety of functions: motor control, cognition, emotions, and learning. In modern use the term 'ganglia' is in this instance considered a misnomer; 'ganglion' refers to concentrations of neural nuclei in the periphery only (for example those of the autonomic nervous system), and the term 'basal nuclei' is preferred.
The five individual nuclei that make up the primate basal ganglia, along with their major subdivisions, are:
rostral
the striatum, which consists of
putamen
caudate nucleus
external segment of the globus pallidus (GPe)
internal segment of the globus pallidus (GPi)
caudal
subthalamic nucleus (STN)
substantia nigra (SN)
substantia nigra pars compacta (SNc)
substantia nigra pars reticulata (SNr)
substantia nigra pars lateralis (SNl)
There are 2 sets of basal ganglia in the mammalian brain, mirrored in the left and right hemispheres.
Two coronal sections are used to show the basal ganglia; the STN and substantia nigra lie deeper back in the brain (more caudal). Images show two schematic coronal cross-sections of the human brain with nuclei of the basal ganglia labeled on the right side.
Functionally, the basal ganglia consist of a series of circuits, such as skeletomotor, limbic and occulomotor circuits. Each circuit projects to specific nuclei within the basal ganglia and its projections e.g. the skeletomotor circuit projects to the ventral lateral, lateral ventral anterior and centromedian thalamic nuclei.
The intestinal fatty acid binding protein (I-FABP) belongs to a family of 15 kDa clamshell-like proteins that are found in many different tissues. So far, nine types have been identified. Their primary structures are highly conserved between species but somewhat less so among the different types. The function of these proteins, many of which are highly expressed, is not well understood. Their ability to bind lipid ligands suggests a role in lipid metabolism, but direct evidence for this idea is still lacking.
High-density lipoproteins (HDL), often referred to as the "Good Cholesterol", circulates in the blood stream collecting fat and cholesterol from arteries and transporting them to the liver for removal. The movie shows how these lipoproteins (in blue and green) can gather the fat molecules (in white and brown) into small particles allowing them to flow through blood vessels.
Scientists in the U.S. have discovered the genetic code of the woolly mammoth, an animal that's been extinct since the Ice Age. It's led to fevered speculation that there might one day be hope of reviving it.Researchers who bought mammoth hair on the internet have decoded 70% of the creature's genome, marking the first time the nearly complete genome of an extinct animal has been sequenced
The woolly mammoth (Mammuthus primigenius), also called the tundra mammoth, is an extinct species of mammoth. This animal is known from bones and frozen carcasses from northern North America and northern Eurasia with the best preserved carcasses in Siberia.
This mammoth species was first recorded in (possibly 150,000 years old) deposits of the second last glaciation in Eurasia. They were derived from steppe mammoths (Mammuthus trogontherii).
It disappeared from most of its range at the end of the Pleistocene (10,000 years ago), with a dwarfed race still living on Wrangel Island until roughly 1700 BC.
Ghrelin is a hormone produced mainly by P/D1 cells lining the fundus of the human stomach and epsilon cells of the pancreas that stimulates hunger. Ghrelin levels increase before meals and decrease after meals. It is considered the counterpart of the hormone leptin, produced by adipose tissue, which induces satiation when present at higher levels. In some bariatric procedures, the level of ghrelin is reduced in patients, thus causing satiation before it would normally occur.
Recently Scientist found that Ghrelin chages how your brain perceives food.
Ghrelin has emerged as the first circulating hunger hormone. Ghrelin and synthetic ghrelin mimetics (the growth hormone secretagogues) increase food intake and increase fat mass by an action exerted at the level of the hypothalamus. They activate cells in the arcuate nucleus that include the orexigenic neuropeptide Y (NPY) neurons. Ghrelin-responsiveness of these neurones is both leptin- and insulin-sensitive. Ghrelin also activates the mesolimbic cholinergic-dopaminergic reward link, a circuit that communicates the hedonic and reinforcing aspects of natural rewards, such as food, as well as of addictive drugs, such as ethanol.
An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, In humans, it is called an embryo until about eight weeks after fertilization
Week 1-3 5-7 days after fertilization, the blastula attaches to the wall of the uterus (endometrium). When it comes into contact with the endometrium it performs implantation. Implantation connections between the mother and the embryo will begin to form, including the umbilical cord. The embryo's growth centers around an axis, which will become the spine and spinal cord. The brain, spinal cord, heart, and gastrointestinal tract begin to form.
Week 4-5 Chemicals produced by the embryo stop the woman's menstrual cycle. Neurogenesis is underway, showing brain activity at about the 6th week. "The heart will begin to beat around the same time. Limb buds appear where the arms and legs will grow later. Organogenesis begins. The head represents about one half of the embryo's axial length, and more than half of the embryo's mass. The brain develops into five areas. Tissue formation occurs that develops into the vertebra and some other bones. The heart starts to beat and blood starts to flow.
Week 6-8 Myogenesis and neurogenesis have progressed to where the embryo is capable of motion, and the eyes begin to form. Organogenesis and growth continue. Hair has started to form along with all essential organs. Facial features are beginning to develop. At the end of the 8th week, the embryonic stage is over, and the fetal stage begins.
Animation describing the role of G-protein coupled receptors in neurotransmission.