Connective Tissue LC Flashcards
In this image, which cells are responsible for synthesizing and secreting collagen and elastin.
Endothelial Cells
Fibroblasts
Adipocytes
Mast Cells
Plasma Cells
Leukocytes
The correct answer is “fibroblasts”. They are the common cells in the conncective tissue. They produce and maintain most of the tissue’s extracellular components. They synthesize and secrete collagen and elastin. In this picture, two levels of fibroblast activity can be observed histologically. Cells with intense activity are morphologically distinct from the quiescent fibroblasts. The more active ones have abundant cytoplasm, and have hyperchromatic bizarre nuclei. The quiescent ones are smaller and thin.
Fibroblasts are the key cells in connective tissue proper. Fibroblasts originate locally from mesenchymal cells and are permanent residents of connective tissue. Other cells found here, such as macrophages, plasma cells, and mast cells, originate from hematopoietic stem cells in bone marrow, circulate in the blood, and then move into connective tissue where they function. These and other white blood cells (leukocytes) are transient cells of most connective tissues, where they perform various functions for a short period as needed and then die by apoptosis.
In this image, identify the cells that are specialized for cytoplasmic storage of lipid!
Adipocytes, or fat cells, are found in connective tissue of many organs. They are large mesenchymally derived cells that are specialized for cytoplasmic storage of lipid as neutral fats, or less commonly for the production of heat. The large deposits of fat in the cells of adipose connective tissue also serve as cushion and insulate the skin and other organs.
In the production of collagen, which vitamin is criticallly needed?
Vitamin A
Vitamin B
Vitamin C
Vitamin D
Vitamin E
The correct answer is vitamin C. It is important for the hydroxylation of specific prolyl and lysyl residues in the endoplasmic reticulum.
In this image, identify the connective tissue!
The lamina propria in the appendix is a loose conncective tissue.This is a type of connective tissue proper that generally supports epithelial tissue. It supports microvasculature, nerves and immune defense cells.
In this image, identify the connective tissue!
In the skin, the dermis is a dense irreguar connective tissue that little ground substance; few cells (mostly fibroblasts; much of the collagen present is in randomly arranged fibers. It protects and supports organs, and resists tearing.
This picture is from a tendon. What type of connective tissue is represented?
Loose Connective Tissue
Dense Irregular Connective Tissue
Dense Regular Connective Tissue
Embryonic Connective Tissue
Specialized Conective Tissue
The correct answer is “Dense Regular Connective Tissue”. It is almost completely filled with parallel bundles of collagen; few fibroblasts aligned with collagen. It provides strong connections within musculoskeletal system; strong resistance to force.
Which of the following most distinguishes connective tissue from other types of tissues?
Its major constituent is the extracellular matrix
It comproses mainly of spindle contractile cells
It is made of collagen without any cells
It prevents diffusion of nutrients and waste products.
Its major constituent is the extracellular matrix
Connective tissue provides a matrix that supports and physically connects other tissues and cells together to form the organs of the body. The interstitial fluid of connective tissue gives metabolic support to cells as the medium for diffusion of nutrients and waste products. Unlike the other tissue types (epithelium, muscle, and nerve), which consist mainly of cells, the major constituent of connective tissue is the extracellular matrix (ECM). Extracellular matrices consist of different combinations of protein fibers (collagen and elastic fibers) and ground substance.
Which of the following cells of the connective is responsible for removing dead cells and tissue debris?
Fibroblasts
Endothelial cells
Macrophages
Myofibroblasts
Macrophages have highly developed phagocytic ability and specialize in turnover of protein fibers and removal of dead cells, tissue debris, or other particulate material, being especially abundant at sites of inflammation. Size and shape vary considerably, corresponding to their state of functional activity. A typical macrophage measures between 10 and 30 μm in diameter and has an eccentrically located, oval or kidney-shaped nucleus. Macrophages are present in the connective tissue of most organs and are sometimes referred to by pathologists as “histiocytes.”
Filling the space between cells and fibers in connective tissue, ground substance is composed of
Collagen type III, reticular fibers, elastic fibers
Collagen types I, II, III and IV, reticular fibers
Glycoproteins, Collagen type III and Elastin
Glycosaminoglycans, proteoglycans, multiadhesive glycoproteins
Glycosaminoglycans, proteoglycans, multiadhesive glycoproteins
The ground substance of the ECM is a highly hydrated (with much bound water), transparent, complex mixture of three major kinds of macromolecules: glycosaminoglycans (GAGs), proteoglycans, and multiadhesive glycoproteins. Filling the space between cells and fibers in connective tissue, ground substance allows diffusion of small molecules and, because it is viscous, acts as both a lubricant and a barrier to the penetration of invaders. Physical properties of ground substance also profoundly influence various cellular activities.
Composition of
Loose (areolar) connective tissue
vs
Dense irregular connective tissue
vs
Dense regular connective tissue
vs
Reticular connective tissue
Loose (areolar) connective tissue - Much ground substance; many cells and little collagen, randomly distributed
Dense irregular connective tissue - Little ground substance; few cells (mostly fibroblasts); much collagen in randomly arranged fibers
Dense regular connective tissue - Almost completely filled with parallel bundles of collagen; few fibroblasts, aligned with collagen
Reticular connective tissue - Delicate network of reticulin/collagen III with attached fibroblasts (reticular cells)
Function of
Loose (areolar) connective tissue
vs
Dense irregular connective tissue
vs
Dense regular connective tissue
Loose (areolar) connective tissue - Supports microvasculature, nerves, and immune defense cells
Dense irregular connective tissue - Protects and supports organs; resists tearing
Dense regular connective tissue - Provide strong connections within musculoskeletal system; strong resistance to force
In this image, what is the type of connective tissue?
Dense irregular
Dense regular
Loose (areolar)
Reticular
Loose (areolar)
The lamina propria in the appendix is a loose conncective tissue.This is a type of connective tissue proper that generally supports epithelial tissue. It supports microvasculature, nerves and immune defense cells.
Also called areolar tissue, the loose connective tissue typically contains cells, fibers, and ground substance in roughly equal parts. The most numerous cells are fibroblasts, but the other types of connective tissue cells are also normally found, along with nerves and small blood vessels. Collagen fibers predominate, but elastic and reticular fibers are also present. With at least a moderate amount of ground substance, loose connective tissue has a delicate consistency; it is flexible and not very resistant to stress.
