Connective tissue Flashcards
What is the function of connective tissue?
Binds, support and strengthens other body tissues, it is the major transport system of the body (e.g. blood) and is the major site of stored energy reserves (fat/adipose tissue is CT)
Where can CT NOT be, and where will it be found?
It is NOT found on body surfaces, it is however found internally in bones, blood vessels and cartilage
Is CT vascular?
It is mostly highly vascular however cartilage is avascular and tendons have a very low blood supply (these are the two exceptions)
Does CT have neural connections?
Yes except in the cartilage
What is CT made of?
Extracellular matrix (ECM) and cells
What is ECM made of?
Ground substance (GS) and fibres
What is GS made of?
Water, proteins and sugars (FYI polysaccharides: carbohydrate with multiple sugars bonded together)
What is the kind of sugar found in the GS?
Glycosaminoglycans (GAGS)
What do GAGS join with and what do they form?
GAGS join with core proteins and form proteoglycans
What are the subtypes of GAGS? What kind of sugars are in each subtype?
Sulphated GAG: Dermatan sulphate, Heparin sulphate, Keratan sulphate, Chondroitin sulphate
Non-sulphated GAG: Hyaluronic acid
What makes Hyaluronic acid unique from the other types of sugars found in CT?
Hyaluronic acid doesn’t bind directly to protein backbone, instead to various proteoglycans, it is not sulphated or covalently bonded to a core protein
What properties and functions does hyaluronic acid have?
It is a viscous slippery substance, it binds cells together and lubricates joints and maintains the shape of the eyeball
What kind of enzyme can be produced to break down hyaluronic acid? Under what circumstance would this be produced and by what?
Hyaluronidase, used to hep move through the ECM better, produced by white blood cells and some bacteria to mov embrue easily and sperm cells to get to egg
What is the application of of Chondroitin sulphate?
supports and provides the adhesive features of cartilage, bone skin and blood vessels
What is the application of of Keratan sulphate?
Found in bone, cartilage and the cornea of the eye
What is the application of of Dermatan sulphate?
Found in skin, tendons, blood vessels and heart valves
How is the tissue quality affected by ECM? Give examples
The structure of the ECM, e.g. cartilage = firm + rubbery while bone = hard + inflexible due to mineralised ECM
What is an important function of GAGS that has to do with water? How does it achieve this?
GAGS can trap more water which helps provide some of the features (e.g. Jelly like, flexible, stiff)
It is because it is a highly polar molecule therefore attracts water
Describe the structure of a hyaluronic acid/proteoglycan complex
Glycosaminoglycan’s are bonded onto protein cores to form proteoglycan’s . These proteins are connected onto the Hyaluronic acid backbone by a glycoprotein link
What are the fibre types found in ECM? What are they made of?
Collagen and thinner reticular fibres, consists mainly of collagen
Elastic fibres, made of elastin surrounded by the glycoprotein fibrillar
What is a key property of collagen? What is it highly dependent on? How much of the body is made of collaged?
It is very strong but very flexible therefore resist pulling forces
Its properties are highly dependent on water (e.g. cartilage»_space; bones)
25% of body weight = cartilage
What are reticular fibres made of? How are they arranged and what are they made of? What are their functions?
Made of collaged but in finer bundles with a coating of glycoprotein
Provide strength and support, form part of the basement membrane and form networks in vessels throughout the tissues (by being thinner and branching through tissue)
What kind of structure do elastic fibres form inside the ECM? What is it made of and what properties does it give? Where can it be found and why here?
It forms thin fibrous networks
Made of protein elastin surrounded by the glycoprotein fibrillar giving git more strength and stability allowing it to be stretched up to 150% without breaking
It is found in the skin, blood vessels and lungs as they need elastic properties
What hereditary disease impacts elastic fibres? What does the disease do to impact elastic fibres? What is the impacts of this? What notable person MAY have had this disease and how common is it?
Marfan syndrome
Dominant mutation on chromosome 15 which codes for fibrillin (structural scaffold for elastin), no longer binds to Transforming Growth Factor beta (TGFb) therefore it is not deactivated = continued growth
Tall and long limbed, chest deforming (protruding/collapsed sternum), normal lifespan but require more medical attention to control things like blood pressure, weakened heart valve arterial wall (doesn’t absorb energy from pulse therefore can rupture)
Abraham Lincoln, 1:20,000
What are the types of cells found in CT?
Fibroblasts, Adipocytes, Marcophages, Plasma cells, Mast cells, Leucocytes
What is the function of fibroblasts and where are they found?
Secrete components of the matrix (e.g. fibres and GS), found throughout the CT
What is the function of adipocytes and where are they found?
Store fats/triglycerides, found under skin and around organs
What is the function and location of macrophages? What are the two kinds?
They are phagocytic cells that battle infection, can be fixed (e.g. in alveolar tissue, spleen, liver) or wandering (attend to sites of infection/inflammation when needed)
How are plasma cells produced? What are their functions? Where are they found?
Produced by b-lymphocyte which makes anti-bodies, found in the gut, lungs, salivary glands, lymph nodes, spleen and red bone marrow (know just 3 of them)
What are the functions of Mast cells? Where are they found?
Produce histamine which helps dilate blood vessels, resided near blood vessels
What are Leucocytes? What do they do and how do they do it?
White blood cells (e.g. neutrophils and eosinophils), fight infections within tissue by migrating out of the blood
What is embryonic connective tissue? What is its name? What is its function? What is it made of?
The first tissue to form within the embryo
It is called Mesenchyme CT
Gives rise to all other CT and is made of CT cells (mesenchymal cells) in a semi-fluid GS containing reticular fibres