Name: elastic tissues in skin, vessels, and ears
Uploaded: 2023-04-30T11:53:09.000Z
Duration: 1 min 12 s
Channel: JoVE

Tissues such as skin, lungs, and blood vessels must be strong as well as elastic to work properly. Tissues owe their elastic properties to the elastic fibers present in their extracellular matrix.
Each of these fibers is composed of tropoelastin aggregates assembled on the microfibrils.
Tropoelastins are the precursors of elastin molecules, made up of alternating hydrophobic and cross-linking domains.
The hydrophobic motifs, which cover more than 80 percent of the total protein, allow elastin to self-associate, stretch, and recoil when needed. The cross-linking domains allow cross-links to form between neighboring tropoelastin molecules.
Together, these structural features allow fibres to stretch more than fivefold compared to a rubber band of a similar cross-section.
As elastin fibers mature, the elastin aggregates form an amorphous core surrounded by microfibrils. These elastin structural features confer remarkable tissue elasticity.

elastin is responsible for tissue elasticity

Elastin is Responsible for Tissue Elasticity

Elastic fiber contains the protein elastin along with lesser amounts of other proteins and glycoproteins. The main property of elastin is that it will return to its original shape after being stretched or compressed. Elastic fibers are prominent in elastic tissues found in skin and the elastic ligaments of the vertebral column.
Ligaments and tendons are made of dense regular connective tissue, but in ligaments not all fibers are parallel. Dense regular elastic tissue contains elastin fibers and collagen fibers, allowing the ligament to return to its original length after stretching. The ligaments in the vocal folds and between the vertebrae in the vertebral column are elastic. Dense irregular elastic tissues give arterial walls the strength and the ability to regain original shape after stretching
While older adults are at risk for tendinitis because the elasticity of tendon tissue decreases with age, active people of all ages can develop tendinitis. Young athletes, dancers, and computer operators; anyone who performs the same movements constantly is at risk for tendinitis.
Elastic cartilage contains elastic fibers as well as collagen and proteoglycans. This tissue gives rigid support as well as elasticity. Tug gently at your ear lobes, and notice that the lobes return to their initial shape. The external ear contains elastic cartilage.
This text is adapted from<a href="https://openstax.org/books/anatomy-and-physiology-2e/pages/4-3-connective-tissue-supports-and-protects"> Openstax, Anatomy and physiology 2e, Section 4.3: Connective tissue supports and protects.</a>

Elastic fiber contains the protein elastin along with lesser amounts of other proteins and glycoproteins. The main property of elastin is that it will ...

elastin-is-responsible-for-tissue-elasticity

Education

JoVE Core

Cell Biology

Unit 1

Extracellular Matrix in Animals

KEY TERMS AND CONCEPTS

elastic tissues in skin, vessels, and ears

Elastic tissues contain elastin, a protein mixed with smaller amounts of other proteins and glycoproteins. Elastin helps tissue return to its original shape after it is stretched or compressed. This property is important in body parts that must bend, stretch, and recoil.

Elastic fibers are found in elastic tissues in the skin and in the elastic ligaments of the vertebral column. Ligaments and tendons are both made of dense regular connective tissue, but ligaments do not always have all of their fibers arranged in parallel. Dense regular elastic tissue contains elastin fibers and collagen fibers. This combination lets the ligament return to its original length after stretching.

Some ligaments are elastic, including the ligaments in the vocal folds and between the vertebrae in the vertebral column. Dense irregular elastic tissue gives arterial walls strength and the ability to regain their original shape after stretching. Tendons can also lose elasticity with age, which helps explain why older adults are at risk for tendinitis. Active people of all ages can develop tendinitis, including young athletes, dancers, and computer operators who repeat the same motions often.

Elastic cartilage contains elastic fibers, collagen, and proteoglycans. It provides rigid support and flexibility at the same time. The external ear contains elastic cartilage, which is why the ear lobe returns to its initial shape when gently pulled.

Elastic Tissues in Skin, Vessels, and Ears

the extracellular matrix

How the Extracellular Matrix Shapes Tissues

The extracellular matrix, or ECM, helps animal tissues stay organized and keeps cells in the right place. It is made of structural molecules that support tissue shape and give certain tissues their special properties. The ECM usually contains a gel-like ground substance, fibrous parts, and many molecules with different jobs. One major group is glycosaminoglycans, or GAGs, which are polysaccharides. GAGs fill much of the space outside cells and can take up a large volume compared with their...

glycosaminoglycans

GAGs in Tissue Support and Lubrication

Glycosaminoglycans, or GAGs, are long, linear polymers that help build and protect animal tissues. They are also called mucopolysaccharides. Their repeating units are made of an amino sugar, such as N-acetylglucosamine or N-acetylgalactosamine, plus a uronic acid, usually glucuronic acid or iduronic acid. GAGs are found in the extracellular matrix of vertebrates, invertebrates, and bacteria. Their polar nature lets them attract water. This makes them useful as lubricants and as shock absorbers...

collagens are the major structural proteins of ecm

collagens-are-the-major-structural-proteins-of-ecm

Collagen Fibers Give Tissues Strength

Collagen fibers give connective tissues strength and help them resist stretching. They are one of three main fiber types secreted by fibroblasts, along with elastic fibers and reticular fibers. Collagen fibers are made from fibrous protein subunits linked into long, straight fibers. These fibers are flexible, but they also have great tensile strength. Tensile strength is the ability to resist pulling forces. Collagen fibers help ligaments and tendons stay resilient and strong. They also hold...

fibril-associated collagen

FACIT Collagens in the Extracellular Matrix

FACIT collagens are fibril-associated collagens found in the extracellular matrix. FACIT stands for fibril-associated collagens with interrupted triple helices. These collagens help connect collagen fibrils to each other and to other extracellular matrix proteins. Type II collagen fibrils in cartilage provide a clear example. They have covalently bound type IX fibril-associated collagens at regular intervals. Other FACIT collagens include types XII, XIV, XVI, XIX, XX, XXI, and XXII. These...

Elastic tissues contain elastin, a protein mixed with smaller amounts of other proteins and glycoproteins. Elastin helps tissue return to its original shape after it is stretched or compressed. This property is important in body parts that must bend, stretch, and recoil. Elastic fibers are found in elastic tissues in the skin and in the elastic ligaments of the vertebral column. Ligaments and tendons are both made of dense regular connective tissue, but ligaments do not always have all of...

fibronectins connect cells with ecm

Fibronectin and Cell Attachment in ECM

Fibronectin is an adhesive glycoprotein in the extracellular matrix of embryogenic and adult tissue. It helps regulate cell motility and attachment. In many tissues, fibronectin gives cells a place to bind and move along. A fibronectin molecule is made of two identical polypeptide chains. These chains are joined at the C-terminal by a pair of disulfide bonds. Fibronectin also binds proteoglycans and collagen. It then links to integrin proteins, which interact with transmembrane proteins in the...

matrix proteoglycans and glycoproteins

Extracellular Matrix Support Proteins

Proteoglycans and matrix glycoproteins help build the extracellular matrix. The extracellular matrix is the material outside cells that gives tissues support and structure. Proteoglycans are heavily glycosylated proteins, and they are commonly found woven through collagen fibers. Hyaline cartilage shows how proteoglycans work. This is the most common type of cartilage in the body. It contains short, scattered collagen fibers with large amounts of proteoglycans. The proteoglycans carry long...

role of matrix metalloproteases in degradation of ecm

role-of-matrix-metalloproteases-in-degradation-of-ecm

How MMPs Remodel the Extracellular Matrix

Matrix metalloproteases (MMPs) are enzymes that break down proteins and glycoproteins in the extracellular matrix, or ECM. The ECM is the dense network around cells. By cutting ECM molecules, MMPs help cells move and grow through tissue. MMPs are important during embryonic development and morphogenesis, the process that shapes body form. A classic example comes from a tadpole’s tail during metamorphosis. The first MMP activity discovered was a collagenase, an enzyme that cuts collagen. This...

basal lamina are the specialized form of ecm

basal-lamina-are-the-specialized-form-of-ecm

Basal Lamina Structure and Cell Attachment

The basal lamina is a thin extracellular layer that sits beneath cells and separates them from other tissues. It acts as a support layer for epithelium and helps anchor it to the tissue below. Its structure includes three layers: lamina lucida, lamina densa, and lamina reticularis. The basal lamina is made of glycoproteins and collagen. Key proteins in this framework include laminins, perlecan, entactin, and type IV collagen. Cell membrane proteins such as integrins and dystroglycan bind to...

laminins are the adhesive proteins of basal lamina

laminins-are-the-adhesive-proteins-of-basal-lamina

Laminin Structure and Basal Lamina Support

Laminins are large extracellular matrix proteins that help build the basal lamina. Each laminin molecule has three chains: alpha, beta, and gamma. These chains are encoded by five alpha genes, four beta genes, and three gamma genes. In humans, the alpha chains are LAMA1, LAMA2, LAMA3, LAMA4, and LAMA5. The beta chains are LAMB1, LAMB2, LAMB3, and LAMB4. The gamma chains are LAMC1, LAMC2, and LAMC3. Laminin types are named based on which three chains they contain. Laminins join with one...

type iv collagen of basal lamina

Type IV Collagen in Basement Membranes

Type IV collagen is a network-forming collagen found in basement membranes. It acts as a barrier between epithelial and endothelial cells. It also helps form the backbone of the basement membrane with laminin, entactin, proteoglycans, and fibronectin. Beyond support, type IV collagen also helps with signaling functions linked to normal body processes and disease. A type IV collagen molecule contains six alpha chains. These chains can form at least three heterotrimeric triple-helical...

key terms and concepts

Learn how elastin and elastic fibers help skin, blood vessels, ligaments, vocal folds, and the external ear stretch and return to shape.

Elastic Tissues in Skin, Vessels, and Ears | JoVE K12

cell biology

JoVE Core Cell Biology illustrates complex cellular processes in easy-to-understand yet comprehensive animated video lessons. This collection focuses on the essential components and functions of cells, including organelles and membranes, cellular transport, and cell energetics. It is complemented by scientist-in-action videos that demonstrate the application of cell biology in real-world research experiments.

Elastic Tissues in Skin, Vessels, and Ears

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