Connective Tissues Flashcards
What are the purposes of connective tissues? Where is it found?
- Bind and support (e.g. ligaments, tendons, bones)
- Protect (e.g. bones and cartilage, adipose tissue)
- Store and insulate (e.g. adipose tissue)
- Transport (e.g. blood)
Connective tissue is found to varying degrees in the different organs (e.g. lots in bones and skin, but very little in the brain)
What are connective tissues composed of? (3)
1) Specialized cells: fibroblasts, macrophages, mast cells, plasma cells, adipocytes, and white blood cells
2) Extracellular matrix: makes up the bulk of connective fibrous proteins (collagen and elastin), ground substance (proteoglycans, which are produced by fibroblasts)
3) Tissue fluid: ground substance; clear, colourless viscous fluid, and proteglycans
What is the main characteristic of connective tissue?
Characterized by an intricate extracellular matrix that has large amounts of collagen fibres (provide tensile strength), and elastin fibres (provides resiliency)
Connective tissues can be vascular (with blood vessels) or avascular (without blood vessels). Avascular tissue such as tendons and ligaments heal very poorly as opposed to vascular bone
What are the (6) general categories of connective tissue?
1) Loose connective tissue
2) Dense connective tissue
3) Cartilage
4) Bone
5) Blood
6) Lymph
Why do avascular tissues heal slower/more poorly than vascular tissue?
Without blood vessels, avascular tissues rely on the diffusion of nutrients and oxygen, which is slower
What are connective tissue proper?
Includes those connective tissues with many types of cells and extracellular fibres in a syrupy ground substance. Cells include: fibroblasts, adipocytes, macrophages, stem cells)
1) Loose (aar)
fibres create loose, open framework
-areolar tissue
-adipose tissue
-reticular tissue
2) Dense (dde)
fibres densely packed
-dense regular tissue
-dense irregular tissue
-elastic
What are fluid connective tissues?
Fluid connective tissues have distinct populations of cells suspended in a watery matrix that contains dissolves proteins
1) Blood: flows within cardiovascular system
2) Lymph: flows within lymphatic system
What are supportive connective tissues?
Support connective tissues differ from connective tissue proper in having less diverse cell populations and a matrix containing much more densely packed fibres
supporting connective tissues protect soft tissues and support the weight of part or all of the body
1) Cartilage: solid, rubbery matrix
-hyaline cartilage
-elastic cartilage
-fibrous cartilage
2) Bone: solid, crystalline matrix
What is areolar tissue?
Contains both collagen and elastin fibres and reticular, loosely arranged (e.g. between skin and muscle)
forms the basement membrane for epithelia tissue and mucous membranes
this tissue swells with the release of fluid from the blood stream, a condition called edema
fibres: reticular fibres, collagen fibres, elastic fibres
fixed cells: melanocytes, macrophages, mast cells, fibroblasts, adipocytes
wandering cells: plasm cell, free macrophages, mesenchymal cells, neutrophils, eosinophils, lymphocytes
What is adipose tissue?
Loose connective tissue that contains adipocytes
function: provides padding and cushions shock; insulates (reduces heat loss); stores energy
location: deep to the skin, especially at sides, buttocks, breasts, padding around eyes and kidneys
What is reticular tissue?
Loose connective tissue that contains reticular fibres (appears webby)
function: provides supporting framework
location: liver, kidney, spleen, lymph nodes, and bone marrow
What is dense regular connective tissue?
Contains fibroblasts and collagen fibres, one directional.
Forms tendons (muscle to bone connections) and ligaments (bone to bone connections) which are poorly vascularized, and deep fasciae around muscles which are highly vascularized
What is dense irregular connective tissue?
Contains collagen fibre bundles, fibroblasts (not usually visible)W. Located in dermis, visceral organ capsules, perichondrium, periosteum
multidirectional, looks like burger meat lol
What is elastic connective tissue?
Contains elastic fibres and fibroblasts
founds in elastic ligaments between vertebrae, walls of blood vessels
What is blood and lymph?
Fluid connective tissue; the continuous circulation of extracellular fluid, including the fluid connective tissue lymph
blood process: (idk if necessary)
1) arteries carry blood away from heart into tissues
2) capillaries exchange blood and interstitial fluid
3) at capillary networks blood pressure forces water and small solutes out of the bloodstream into surrounding interstitial fluid (filtration)
4) lymph forms as interstitial fluid enters lymphatic systems
5. lymphatic vessels form a network that returns lymph to larger veins near the heart
6) veins carry blood from capillary beds back to heart
