BrainOrgan central to the nervous systemThe brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrateanimals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for special senses such as vision, hearing, and olfaction.
AstrocyteAstrocytes (from Ancient Greek, ástron, "star" and , kútos, "cavity", "cell"), also known collectively as astroglia, are characteristic star-shaped glial cells in the brain and spinal cord.
CapillaryA capillary is a small blood vessel, from 5 to 10 micrometres in diameter, and is part of the microcirculation system. Capillaries are microvessels and the smallest blood vessels in the body. They are composed of only the tunica intima (the innermost layer of an artery or vein), consisting of a thin wall of simple squamous endothelial cells.
Passive transportPassive transport is a type of membrane transport that does not require energy to move substances across cell membranes. Instead of using cellular energy, like active transport, passive transport relies on the second law of thermodynamics to drive the movement of substances across cell membranes.
Semipermeable membraneSemipermeable membrane is a type of synthetic or biologic, polymeric membrane that allows certain molecules or ions to pass through it by osmosis. The rate of passage depends on the pressure, concentration, and temperature of the molecules or solutes on either side, as well as the permeability of the membrane to each solute. Depending on the membrane and the solute, permeability may depend on solute size, solubility, properties, or chemistry.
Circulatory systemOrgan system for circulating blood in animalsIn vertebrates, the circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the body. It includes the cardiovascular system, or vascular system, that consists of the heart and blood vessels (from Greek kardia meaning heart, and Latin vascula meaning vessels).
Central nervous systemThe central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, and the spinal cord. The retina is also technically part of the CNS. The CNS is named so because the brain integrates the received information and coordinates and influences the activity of all parts of the bodies of bilaterally symmetric and triploblastic animals—that is, all multicellular animals except sponges and diploblasts.
BloodBlood is a specialized form of connective tissue and body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells of the body, and transports metabolic waste products away from those same cells. Blood is composed of blood cells suspended in plasma. Plasma, which constitutes 55% of blood fluid, is mostly water (92% by volume), and contains proteins, glucose, mineral ions, and hormones.
Basement membraneThe basement membrane, also known as the basal lamina, is a specialized form of extracellular matrix (ECM) common to all multicellular animals. It is a very thin, flexible, and strong sheet-like type of ECM that provides a supporting base for all types of epithelial tissue, separates it from another cell layer such as endothelium, and anchors it to the underlying connective tissue (stroma).Active transportIn cellular biology, active transport is the movement of molecules or ions across a cell membrane from a region of lower concentration to a region of higher concentration—against the concentration gradient. Active transport requires cellular energy to achieve this movement. There are two types of active transport: primary active transport that uses adenosine triphosphate (ATP), and secondary active transport that uses an electrochemical gradient.
EndotheliumThe endothelium (pl.: endothelia) is a single layer of squamousendothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel wall. Endothelial cells in direct contact with blood are called vascular endothelial cells whereas those in direct contact with lymph are known as lymphatic endothelial cells.
PericytePericytes (formerly called Rouget cells) are multi-functional mural cells that adhere to the external surface of the endothelial cells that form the endothelium of capillaries and other microvessels. Pericytes are embedded in the basement membrane of blood capillaries, where they communicate with endothelial cells by means of both direct physical contact and paracrine signaling.*As an Amazon Associate I earn from qualifying purchases.