15 Questions
What is the main function of hyaluronic acid in the ground substance?
To trap water and make the ground substance more jelly-like
What is the role of hyaluronidase in the ground substance?
It makes the ground substance more liquid, allowing for easier movement
Which of the following is a key component of hyaluronic acid?
Glucuronic acid
What is the primary function of hyaluronic acid in the eye?
To maintain the shape of the eyeball
What is the relationship between thyroid disease and the deposition of glycosaminoglycans in the eye?
Thyroid disease causes an autoimmune reaction that leads to increased glycosaminoglycan deposition in the eye, causing exophthalmos
Which of the following glycosaminoglycans is found in bone and cartilage?
Chondroitin sulfate
What is the composition of hyaluronic acid?
Polysaccharides
Which of the following is true about hyaluronic acid?
It binds directly to protein backbones.
What makes hyaluronic acid unusual compared to other glycosaminoglycans?
It does not bind directly to protein backbones.
Which of the following is NOT a function of hyaluronic acid in the body?
Transporting oxygen in the blood
In which of the following tissues is hyaluronic acid most abundant?
Cartilage
What is the primary mechanism by which hyaluronic acid promotes wound healing?
Creating a hydrated environment for cell migration
Which of the following statements about hyaluronic acid is TRUE?
It is synthesized primarily by fibroblasts and chondrocytes
What is the primary mechanism by which hyaluronic acid contributes to joint lubrication?
Increasing the viscosity of synovial fluid
Which of the following statements about hyaluronic acid is FALSE?
It is synthesized by bacteria in the gut microbiome
Study Notes
Ground Substance
- Composed of a mixture of water, proteins (e.g., gelatin), and polysaccharides (sugars)
- Glycosaminoglycans (GAGS) join with core proteins to form proteoglycans
- GAGS are long, unbranched polysaccharides with repeating disaccharide units
- Amino sugar examples: N-acetylglucosamine, Uronic sugar examples: glucuronic acid
Hyaluronic Acid
- A glycosaminoglycan (GAG) that is not sulfated or covalently bound to a core protein
- Forms a viscous, slippery substance that binds cells together, lubricates joints, and maintains the shape of the eyeball
- Hyaluronidase breaks down hyaluronic acid, making the ground substance more liquid
Applications of GAGS
- Hyaluronic acid: lubricates joints, maintains eyeball shape, and binds cells together
- Chondroitin sulfate: provides support and adhesive features in cartilage, bone, skin, and blood vessels
- Keratan sulfate: found in bone, cartilage, and cornea of the eye
- Dermatan sulfate: found in skin, tendons, blood vessels, and heart valves
Abnormal ECM and Thyroid Disease
- Exophthalmos (bulging eyes) is associated with abnormal ECM deposition and thyroid disease (goiter)
- Autoimmune over-activation of thyroid gland and autoimmune action on fibroblasts in ECM of the eye
Connective Tissue and Extracellular Matrix
- CT = ECM + Cells
- ECM = GS + Fibers
- ECM is composed of ground substance and fibers
- Ground substance is composed of water, proteins, and polysaccharides (GAGS)
Bone Structure
- Osteon structure consists of lamellae, lacunae, canaliculi, and central (Haversian) canal
- Lamellae: concentric rings of mineral salts and collagen for hardness and tensile strength
- Lacunae: small spaces between lamellae that contain mature bone cells (osteocytes)
- Canaliculi: minute canals that radiate from lacunae and provide routes for oxygen, nutrients, and waste
- Central (Haversian) canal: contains blood, lymph, and nerves
Mature Connective Tissues
- Blood: liquid connective tissue composed of plasma (ECM) and formed elements (red cells, white cells, and platelets)
- Erythrocytes transport oxygen and carbon dioxide, while leukocytes combat disease through phagocytosis
Test your knowledge about glycosaminoglycans (GAGs) and hyaluronic acid, including their functions and properties in the body. Explore the role of hyaluronic acid in lubricating joints, binding cells together, and maintaining the shape of the eyeball.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
