Connective Tissue Flashcards
Which embryonic germ layer is Connective Tissue derived from
Mesoderm
Functions of connective tissue (5)
-structural framework
-protection
-energy stores
-transport of nutrients
-defense from pathogens
Connective tissue consists of (2)
-cells
-matrix (protein fibres and fluid ground substance)
The matrix is (3)
-everything but the cells
-majority of volume
-fibres and ground substance
Three categories of connective tissue
-connective tissue proper (loose and dense)
-supportive connective tissue (cartilage and bone)
-fluid connective tissue (blood and lymph)
Tendons connect
Muscle to bone
Ligaments connect
Bone to bone
Connective Tissue Proper is composed of (3)
-cells (fixed or migratory)
-fibres (collagen, reticular, elastic)
-ground substance
Fixed cells include (4) and their main purpose is (3)
-Fibroblasts
-Adipocytes
-Mesenchymal Stromal Cells (stem cells)
-Macrophages
—>local maintenance, repair, and energy storage
Migratory cells include (6) and their purpose is to ____
-mast cells
-lymphocytes
-monocytes
-eosinophils
-neutrophils
-plasma cells
—>aggregate to defend against invading pathogens and repair damaged tissue
Three main types of fibre
-collagen
-reticular
-elastic
Collagen Fibres (4)
-long, straight, flexible, strong
-stain pink with eosin
-most common fibre in connective tissue proper
-tendons and ligaments
Reticular Fibres (4)
-same protein as collagen but thinnner
-need a special silver stain to see
-tough, flexible, branching/interwoven network (called Stroma)
-found in parenchyma of spleen, liver, lymph nodes, glands, and bone marrow
Elastic Fibres (6)
-composed of the protein Elastin
-branch and wavy
-stretch and recoil in a relaxed state
-organized into discontinuous sheets
-can only see with specialized stain
-found in internal and external elastic laminate of arteries and arterioles (helps maintain blood pressure)
Ground Substance (3)
-surrounds the cells and fibres of connective tissue proper
-clear and viscous (slows passage of pathogens and facilitates phagocytosis)
-contains proteoglycans and glycoproteins
Fibroblasts (6)
-most abundant type of fixed cell
-ONLY cells that are ALWAYS present
-involved in wound healing
-nucleus is oval shaped and centrally placed
-elongated, process lie along fibres
-secrete protein subunits that form the various fibres
Mesenchymal Stem/Stromal Cells (MSCs) (5)
-smaller and less differentiated than fibroblasts
-stellate (star) or fusiform (spindle) shape
-oval nucleus with a prominent nucleolus
-along capillaries
-multipotent
Which is the precursor cell from which other connective tissue tissue cells develop?
Mesenchymal Stem/Stromal Cells (MSCs)
Adipocytes (Adipose Cells) (6)
-involved in lipid storage
-fixed cell of connective tissue proper
-main cell type in adipose tissue
-present in loose connective tissue
-contain one or more lipid droplets
-nucleus is displaced peripherally, cytoplasm is very narrow
Macrophages (Histiocytes) (6)
-lie along fibres
-stellate (star) or fusiform (spindle) shape
-large, irregularly shaped nucleus
-can be difficult to distinguish from fibroblasts
-function is to phagocytose dead tissue and foreign material + activate immune system
-store antigenic material which is presented to antibody producing cells
With the exception of ____, migratory cells of connective tissue proper are immigrants from the blood
Mast cells
Define Amoeboid and provide 4 examples
Cells that can pass between endothelial cells of vessels to enter tissue (lymphocytes, monocytes, eosinophils, neutrophils)
Plasma cells differentiate from ____
Lymphocytes
Mast Cells (4)
-large cells, shape varies between species
-small, round nucleus
-basophilic granules contain Heparin and Histamine (released in response to injury and infection)
-can form tumours / produce overactive allergic reactions
Plasma Cells (4)
-ovoid, basophilic cytoplasm
-“cartwheel” pattern nucleus
-high numbers present in lymph nodes and connective tissue of digestive tract
-produce antibodies
Loose (Areolar) Connective Tissue (8)
-the least specialized connective tissue
-binds cells/structures but allows movement
-mostly composed of ground substance (shock absorption and inhibition of microorganisms from entering)
-loosely arrange fibres
-cells resist infection and assist wound healing
-fixed and migratory cells
-highly vascular
-form packing around organs and supports epithelial
Dense Connective tissue can be
Regular or Irregular
Dense Connective Tissue (3)
-high strength, few nerves and blood vessels
-collagen fibres abundantly present
-can be regular or irregular based on collagen fibre arrangement
If collagen fibres run parallel, the tissue is
Regular Dense Connective Tissue
Examples of Regular Dense Connective Tissue (3)
-tendons
-ligaments
-joint capsules
If collagen fibres are randomly arranged, the tissue is called
Irregular Dense Connective Tissue
Two examples of Irregular Dense Connective Tissue are
-dermis
-organ capsules
Elastic Connective Tissue (4)
-mainly made of elastic fibres
-can be irregularly or regularly arranged
-high elasticity, moderate strength
-airways of respiratory tree, arteries, ligaments of abdominal cavities, and vertebral column
Reticular Connective Tissue (2)
-forms the fibrous framework/support of soft tissues
-spleen, liver, lymph nodes, and bone marrow
Adipose Tissue can be
-white
-brown
Adipose Tissue (4)
-mostly Adipocytes (fat cells)
-storage of energy and water
-provides padding, packaging, and insulation
-can be white or brown
Which type of adipose tissue would be found in young animal and hibernators?
Brown Adipose Tissue
White Adipose Tissue (3)
-makes up the bulk of body fat
-cells are large and unilocular
-peripheral nuclei with a rim of cytoplasm
Brown Adipose Tissue (5)
-small, multilocular cells
-nuclei is round and centrally placed
-involved in heat production (especially in young animals and hibernators)
-contains mainly capillaries and nerves
-colour due to cytochrome respiratory pigment (mitochondria)
Lipoma (7)
-a benign neoplasm composed of Adipocytes
-very common in dogs
-common in budgies and gallahs
-rare in cats
-can feel soft or moderate firm
-can grow to a significant size
-removed surgically
