Connective tissue Flashcards
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Connective tissue function
- Binds, supports and strengthens other body tissues
- A major transport system of the body (blood is a CT)
- A major site of stored energy reserves
What is CT composed of
Extracellular matrix (ECM) and cells
CT = ECM + CELLS
What is the ECM composed of
- Ground substance, in association with
- Protein Fibres
ECM = GS + Fibres
What is ground substance composed of
- Water
- Proteins
- Polysaccharides (sugars) - contains GAGS).
GS = H20 + proteins + polysaccharides
Function of ground substance
Supports cells and fibres, binds them together, and proides a medium for exchanging substances between blood and cells.
What are glycosaminoglycans
Long unbranched polysaccharides made up of amino acid and uronic sugar.
What are the two types of glycosaminoglycans
There are two types; sulphated and non-sulphated.
What are proteoglycans
Formed from GAGS (long unbranched polysaccharides) and binded to proteins
What is hyaluronic acid
Type of non-sulphated GAGS therefore not bound to a core protein
Viscious slippery substance that binds cells together. lubricates joints and maintains shape of eyeball
Is hyluronic acid highly polar or non-polar and what does this mean
Highly polar therefore can attract and trap water becoming sort of slippery
What is hyaluronidase
Enzyme that breaks down hyaluronic acid
This makes ground substance more liquid so allow species to move more easily in it or makes access to the egg easier for sperm.
What is hyaluronidase produced by
Produced by white blood cells, sperm and some bacteria
What is chondroitin sulphate
Type of sulphated GAGS that support and provide the adhesive features of cartilage, bone, skin , blood vessels
What is keratan sulphate
Type of sulphated GAGS found in bone, cartilage, cornea of the eye
What is dermantan sulphate
Sulphated GAGS found in skin, tendons, blood vessels, heart valves
What are the three types of protein fibres
- Collagen fibres
- Reticular fibres
- Elastic fibres
What are collagen fibres and where are they commonly found
A protein fibre that makes up the ECM of CT.
Strong but flexible to resist pulling forces.
Common in bone, cartilages, tendons and ligaments
What is the most abundant protein in body
Collagen fibres
What are reticular fibres and what is its function
A protein fibre made from collagen and glycoproteins that makes up the ECM of CT.
Provides strength and support in blood vessel walls and form branching networks around various cells.
What are reticular fibres made up of
Made up of fine bundles of collagen fibres with coating of glycoprotein. Made by fibroblasts (like reticular lamina of basement membrane)
Where are reticular fibres found
Found in basement membrane, vessels, adipose tissue, nerve fibres, smooth muscle tissues
What are elastic fibres
A protein fibre that makes up the ECM of CT.
What are elastic fibres made from and what is its function
Made up of elastin surrounded by fibrillin giving strength and stability. Allows tissue to be stretched.
Where are elastic fibres found in the body
Found in skin, blood vessles, and lung
Symptoms of Marfan’s Syndrome
Usually tall, long-limbed, and often with a chest deformity.
May have weakened heart valves and arterial walls.
How is Marfan’s syndrome caused
A defect in the elastic fibres that usually results from a dominant mutation in a gene on chromosome 15, which codes for fibrillin.
Body produces growth factor that increases body growth because it does not bind normally to fibrilin.
What are the two most common types of cells that make up CT?
Fibroblasts and Adipocytes
What are fibroblasts
Cells of CT (large and flat) widely distributed in CT
* Secrete components of that matrix (fibres and ground substances)
* move through connective tissue and secret fibres and ground substance
What are adipocytes
Cells of CT (far cells)
Found under skin and around organs.
Stores fat
What are macrophages
Phagocytic cells that developed from monocytes and destroy bacteria and cell debris by phagocytosis.
Fixed and wandering forms in CT (sites of infection/inflammation/injury)
What are plasma cells
From B-lymphocytes (produce antibodies).
Found most commonly in gut, lung, salivary glands, lymph nodes, spleen and red bone marrow
What are mast cells and where are they found
Produce histamine that dilates small blood vessels during inflammation and kills bacteria.
They are alongside blood vessels
What are leucocytes
White blood cells
Migrate out from blood
What are the two classifications of CT
- Embryonic
- Mature
Two types of embryonic CT
- Mesenchyme
- Mucous
What is mesenchyme CT
Gives rise to all other connective tissues. Consist of connective tissue cells (mesenchyme cells) in a semi-fluid ground substance containing reticular fibres
what does it have
What is mucous CT and its function
Have widely scattered fibroblasts embedded in a jelly-like ground substance.
Supports umbilical cord of foetus
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What are the types of mature CT
- Loose
- Dense
- Blood fluid
- Lymph fluid
- Cartilage supporting
- Bone supporting
What are the three types of loose CT
- Areolar connective tissue
- Adipose connective tissue
3 Reticular connective tissue
Three types of areolar CT
Collagen, reticular, and elastic.
What is the function of aerolar CT
Strength, elasticity, and support
alot
Where is areolar CT found
Widely distributed around almost every structure, like a packing material
What is adipose CT
Adipocytes dominant
Central triglyceride droplet
Found with areolar CT.
The two types of adipose CT and their functions
White adipose: energy storage
Brown adipose: heat production
Insulation, energy source, temperature control
What is reticular CT and where is it found
An interlacing network of reticular fibres,
Found in the storms of liver, spleen, lymph nodes, red bone marrow, reticular laminate of basement membrane, and around blood vessels and muscles
What are the three types of dense connective tissue
Dense regular
Dense irregular
Dense elastic
Where is dense regular CT located
Located in tendons, ligaments, and aponeurosis.
What is the structure and appearance of regular CT
Regularly arranged collagen
Shiny white colour
Function of dense regular CT
Slow healing and attatchment
What is dense irregular CT and where is it found
Made up of collagen fibres; usually irregularly arranged with a few fibroblasts.
Often occurs in sheets such as fascia, reticular region of skin dermis, fibrous pericardium of heart, periosteum of bone, perichondrium of cartilage, joint capsules, membrane capsules around various organs also in heart valves
What is dense elastic CT and where is it found
Elastic connective tissue containing mostly elastic fibres with fibroblasts between them. Found in lung tissue, walls of elastic arteries, trachea, bronchial tubes, vocal cords, suspensions ligaments of penis, some ligaments between vertebrae.
What are the two types of supporting connective tissue
Cartilage and bone.
What are the three types of cartilage supporting CT
Hyaline, elastic, and fibrocartilage
What is hyaline cartilage
Abundant cartilage that is relatively weak with a resilient gel in which fibres ar present but not obvious
What is the location and function of hyaline cartilage
Location: in nasal septum, and ends of long bones
Function: Flexibility and movement
What is elastic cartilage
What is fibrocartilage
What are bones
Organs composed of several connective tissue types, including bone tissue.
The two types of bone tissue
- Compact
- Spongey
What is compact bone tissue
The outer layer of bone that forms the shaft of long bones. Contains osteons
What is the function of compact bone tissue
Stores calcium and phosphates
For protection and support
and what it lacks
What is spongey bone tissue
Porous inner bone tissue that lies underneath compact bone.
Lacks osteons and stores triglycerides and produces blood cells
What are the four cell types found in bone
- Osteogenic
- Osteoblasts
- Osteocytes
- Osteoclasts
What are osteogenic blood cells
Mesenchymal stem cells that develop, sand when it starts to lay down collagen, it becomes trapped and become osteoblasts
What are osteoblast blood cells
Bone forming cells. They lay down more collagen, and mineralisation process begins
What are osteocyte blood cells
Mature bone cells derived from osteoblasts trapped within the ECM.
Maintains bone tissue, and is involved in the exchange of nutrients and waste.
Have gap junctions
What are osteoclasts
Large, multi-nucleated cells formed from the fusion of blood monocytes.
Break-down bone
What are the four components that make up the osteons (haversian systems)
- Lamellae
- Lacunae
- Canaliculi
- Central (Haversian canal)
What are lamellae
Concentric rings of mineral salts for hardness, and collagen for tensile strength.
What are lacunae
Small spaces between lamellae that contain mature bone cells (osteocytes)
What are canaliculi
“minute canals” (containing EC fluid and minute osteocytic processes) that radiate from lacunae and provide routes for oxygen, nutrients, and waste.
What are central (haversion) canal
Blood, lymph, and nerves
What happens if you fracture your bone
Osteoclasts reabsorb new bone
Chondroblasts lay down hyaline cartilage callus
Osteoblasts lay down new bone
Osteoclasts remodel new bone
What is blood connective tissue
Consists of blood plasma (a liquid ECM) and formed elements (red cells, white cells and platelets).
Blood: Erythrocytes
Transpor O2 and CO2
Leukocytes
Combat disease
Leukocytes: Neutrophils and monocytes (macrophages)
Phagocytic: engulf bacteria by migrating to sites of infection and destroy microbes by phagocytosis
Leukocytes: Basophils (mature) and mast cellss
Mature are fixed in tissues, release substances e.g histamine that intensify the inflammatory reaction
Leukocytes: Eosinophils
Effective against certain parasitic worms and migrate to sites of parasitic infection and allergic responses.
Leukocytes: lymphocytes
Involved in the immune response
Platelets
Clotting
What is the function of reticular connective tissue
Forms stroma of organs, binds smooth muscle tissues cells, filters and removed worn-out blood cells in spleen and microbes in lymph nodes
Function of dense irregular connective tissue
Provides tensile pulling strength in many directions
Function of elastic connective tissue
Allows stretching of various organs, is strong and can recoil to original shape after being stretched. Elasticity is important for normal functioning of lung tissue and elastic arteries.
