Related Concept Videos

T Cell Types and Functions01:24

T Cell Types and Functions

When T cells with CD4 markers are activated, they give rise to two types of effector cells: helper T cells and regulatory T cells. Meanwhile, T cells with CD8 markers differentiate into effector cytotoxic T cells. The differentiation of CD4 T cells into helper T cell subsets, such as Th1, Th2, and Th17 cells, is dependent on the antigen type, antigen-presenting cell, and regulatory cytokines.
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
Type IV Collagen of Basal Lamina01:05

Type IV Collagen of Basal Lamina

Type IV collagen is a 400 nm long, network-forming collagen that acts as a barrier between the epithelial and endothelial cells. Type IV collagen  forms the backbone of the basement membrane by scaffolding with laminin, entactin, proteoglycans, and fibronectin. Apart from rendering structural support to the basement membrane, it also helps entail signaling potentials necessary for both pathological and physiological functions.
A type IV collagen molecule has six alpha chains which can exist in...
Collagens are the Major Structural Proteins of ECM01:13

Collagens are the Major Structural Proteins of ECM

Three main types of fibers are secreted by fibroblasts: collagen fibers, elastic fibers, and reticular fibers. Collagen fiber is made from fibrous protein subunits linked together to form a long, straight fiber. Collagen fibers, while flexible, have great tensile strength, resist stretching, and give ligaments and tendons their characteristic resilience and strength. These fibers hold connective tissues together, even during the body's movement.
Connective tissue proper includes loose...
Inflammatory Response01:28

Inflammatory Response

An inflammatory response is a localized, nonspecific immune reaction that occurs when a tissue is injured. It is characterized by redness, swelling, heat, and pain, which are commonly called the cardinal signs and symptoms of inflammation. Inflammation can sometimes result in a loss of function.
Inflammation can be triggered by various stimuli, such as impact, abrasion, chemical irritation, infections, and extreme hot or cold temperatures. These can damage cells and connective tissue fibers,...
Chronic Inflammation: Introduction01:12

Chronic Inflammation: Introduction

Chronic inflammation is a prolonged, dysregulated immune response that persists for weeks to years when the inciting stimulus is difficult to eradicate or when self‑antigens drive ongoing reactivity. Morphologically, it is defined by mononuclear cell infiltration, progressive tissue destruction, and concurrent attempts at healing via angiogenesis and fibrosis. Compared with acute inflammation, edema is less prominent while cellular infiltration predominates; triggers include persistent...
Structural Protein Function01:56

Structural Protein Function

Structural proteins are a category of proteins responsible for functions ranging from cell shape and movement to providing support to major structures such as bones, cartilage, hair, and muscles. This group includes proteins such as collagen, actin, myosin, and keratin.
Collagen, the most abundant protein in mammals, is found throughout the body. In connective tissue, such as skin, ligaments, and tendons, it provides tensile strength and elasticity.  In bones and teeth, it mineralizes to form...