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
What are the three types of mature CT?
Connective tissue proper, Fluid connective tissues and Supporting connective tissue
What are the subtypes of CT proper?
Loose (areolar, adipose and reticular tissue) and dense (regular, irregular and elastic fibres)
What are the difference between the subtypes of CT proper?
Loose = fibres create loose open framework Dense = fibres densely packed
What tissue type is areolar connective tissue? What is the structure, location and function of it?
CT Proper, Loose (many cells fewer fibres)
It is made of three types of fibres, collagen, reticular and elastic fibres. It is found everywhere acting like packing material and provides strength elasticity and support
What tissue type is Adipose connective tissue? What are the two types of adipose tissue? What is the structure, location and function of them?
CT Proper, Loose
Brown and white
It is made mostly of adipocytes which are made from fibroblasts. It is found with areolar CT, white = fat storage +, brown = heat generation/insulation as an infant
What tissue type is Reticular connective tissue? What is the structure, location and function of it?
CT Proper, Loose
a Fine interlacing network of reticular fibers (thin form of collagen fiber) and reticular cells
found in the stroma (supportive tissue) of the liver, spleen, lymph nodes; red bone marrow; reticular lamina, blood vessels and muscles (know 3)
Forms stroma of organs; binds smooth muscle tissue cells; lters and removes worn-out blood cells in spleen and microbes in lymph nodes
What tissue type is Regular connective tissue? What is the structure, location and function of it?
CT Proper, dense (lots of fibres densely packed
It is collagen REGULARLY arranged in bundles with fibroblasts in rows between them
It is found in most tendons and ligaments
Provides strong attachments
What tissue type is Irregular connective tissue? What is the structure, location and function of it?
CT Proper, dense
Collagen IRREGULARLY arranged with a few fibroblasts
Often occurs in reticular (deeper) region of dermis of skin, the heart, bone, cartilage, joint and, membrane capsules, kidneys, liver, testes, lymph nodes
Provides strong tensile strength
What tissue type is Elastic connective tissue? What is the structure, location and function of it?
Proper Dense
Elastic fibres with fibroblasts in between them
Lung tissue, walls of elastic arteries, trachea, bronchial tubes, vocal cords
Allows for stretching as it can recoil to original shape
What are the subtypes of Supporting CT? What are the differences?
Cartilage = solid rubbery matrix Bone = solid crystalline matrix
What tissue type is Hyaline cartilage? What is the structure, location and function of it?
Supporting connective tissue, Cartilage
It is a gel (no structure)
Most common cartilage in the body, found at the end on bones, trachea, nose etc.
Creates a smooth surface for bones to slide over
What tissue type is Osseous cartilage? What is the structure, location and function of it?
Supporting CT, bone
Made of osteons (haversian system), consists of thin columns called trabeculae; spaces between trabeculae are filled with red bone marrow
Inside the body, Support, protects, stores; houses blood-forming tissue; serves as levers that act with muscle tissue to enable movement.
What tissue type is Elastic cartilage? What is the structure, location and function of it?
Supporting, cartilage
chondrocytes in threadlike network of elastic fibers
Lid on top of larynx (epiglottis), part of external ear (auricle), auditory (eustachian) tubes.
Provides strength and elasticity, helping maintain the shape of some structures
What tissue type is Blood? What is it made of?
Fluid connective tissue
Made of blood plasma and formed elements
What are the formed elements in blood?
Red blood cells, platelets and Leukocytes
What is special about a red blood cells organelles? Is it like this in all species?
It doesn’t have a nucleus but some other species do
What is the purpose of platelets? Where are they made?
Involved in blood clotting, made from megakaryocytic in red marrow
What are leukocytes?
White blood cells
What are the sub - types of leukocytes?
Granular and Agranular
What do leukocytes do?
Combat disease
What are erythrocytes? Watch do they do?
Red blood cells, transport O2 and CO2
What are the types of granular Leukocytes?
Eosinophils, Basophil, Neutrophils
What do eosinophils do?
Protect against parasitic worms and acute allergic responses
What do basophil do?
release substances (e.g. histamine) that intensify inflammation response
What do neutrophils do?
They are phagocytic cells that engulf bacteria
What are the types of agranual leukocytes?
Monocytes/Macrophytes and lymphocytes
What are Monocytes and macrophage? What are the difference between them?
They are phagocytic cells that engulf bacteria. Monocytes mature into macrophages
What the the two types of lymphocytes? What do they both do?
T and B lymphocytes, both involved in immune response
What do B - lymphocytes do?
mature into plasma cells which release anti-bodies
How do you tell the difference between T and B lymphocytes?
They have chemical markers that distinguish them (physically identical)
What are bones? What does this mean they are made of?
Bones are organs so they are made of several connective tissue types
What are the four types of bone cells?
Osteogenic, osteoblasts, osteocytes, osteoclasts
What are osteogenic cells? What is their function?
Mesenchymal (lovely organised embryonic) stem cells, start laying down collagen and begin the bone development process
What happens to osteogenic cells as they mature?
They turn into osteoblasts
What are osteoblasts? What is their function?
Bone forming cells
Lay down more collagen and begins mineralisation of the ECM, forms bone matrix producing material
What happens to osteoblasts as the bone matures?
Develop into osteocytes
What are osteocytes? What is an important difference between these and osteoblasts? What are their functions?
Matured osteoblasts trapped within ECM
They have a reduced metabolic activity which means they produce less new bone material
Involved in maintaining bone tissue and nutrient and waste exchange
How do osteocytes perform their nutrient and waste exchange role?
Branch out and connect to other osteocytes through little tunnels in the bone and exchange nutrients/waste via gap junctions
What are osteoclasts? How are they formed? What is their function?
Large, multinuclear cells
Formed from the fusion of blood monocytes
Breaks down old/dead/broken bone tissue to reabsorb calcium and other nutrients
When do osteoclasts breakdown/reabsorb bone material?
When calcium levels are low or when there is damage to bone material
What are the steps, involving the cell types of bone tissue, of fixing a bone? Explain the role of each cell type
1 - Osteoclasts reabsorb dead bone (e.g. debris, dead ends)
2 - Chondroblasts (cells that make cartilage FYI) lay down hyaline cartilage
3 - Osteoblasts make new bone
4 - Osteoclasts remodel new bone
Over time, what do osteoclasts do to the bone to further modify it?
Straightens it
What is an osteon? How are they arranged in the bone?
The basic unit of compact bone
They are aligned along the lines of stress (e.g. long axis of bone shaft)
What are the parts of osteon?
Lamellae, Lacunae, Canaliculi, Central (harversian) canal
What are lamellae? What is their function?
Concentric rings of mineral salts, provide hardness
What kind of mineral salts are used in lamellae for their hardness and strength?
Calcium phosphate + calcium hydroxide = hydroxyapatite (hardness), collagen (strength)
What are lacunae?
Small spaces between lamellae that contains mature bone cells, i.e. osteocytes
What are canaliculi? What is their function
Small tunnels to connect the lacunae, the lacunae contain the osteocytes therefore provides the channels for nutrient and waste exchange
What is the central (haversian) canal?
The canal that transports the blood and lymphatic vessel and nerves
