Connective Tissues (Classifications and Types) Flashcards
What are the two classifications of connective tissue?
Embryonic and Mature
What are the two types of embryonic connective tissues?
Mesenchyme and Mucous
What does mesenchyme connective tissue give rise to in a mature individual?
Gives rise to all other connective tissues in a mature individual
What does mesenchyme connective tissue consist of?
Mesenchymal cells in a semi-fluid ground substance containing reticular fibres
What does mucous connective tissue consist of?
Widely scattered fibroblasts embedded in a jelly-like ground substance
Where is mucous connective tissue found?
In the umbilical cord of a foetus
What are the three types of mature connective tissues?
Connective tissue proper, fluid connective tissues and supporting connective tissues
Connective tissue proper can be divided into ___ and ___ connective tissue
Loose and Dense
“Loose” connective tissue means…
More cells, less fibres
“Dense” connective tissue means…
More fibres, less cells
What are 3 types of loose connective tissue?
Areolar, Adipose and Reticular connective tissue
What is the most common connective tissue?
Areolar
What protein fibres are present in Areolar connective tissue?
Collagen, Reticular and Elastic fibres
Where can Areolar connective tissue be found?
Widely distributed around almost every structure like a packing material
What are the two types of Adipose connective tissue?
White and Brown
What is the most dominant cell in Adipose connective tissue?
Adipocytes
What are the purposes of Adipose connective tissue?
Energy storage, insulation and temperature control
White Adipose connective tissue is responsible for ___
Energy storage
Brown Adipose connective tissue is responsible for ___
Heat production (very important in infancy)
Where is adipose connective tissue found?
Places where fat accumulates (Buttocks, flanks, abdomen, orbit of the eye etc.)
What is the predominant protein fibre in Reticular connective tissue?
Reticular fibres
Where is Reticular connective tissue found?
In a supporting framework around lymphoid organs (lymph nodes, spleen and tonsils), bone marrow and liver
What are 3 types of dense connective tissue?
Regular, Irregular and Elastic
Where is Dense Regular connective tissue found?
Tendons, Aponeuroses (muscle to muscle connections)
What is Dense Regular connective tissue comprised of?
Regularly arranged collagen fibres
Is Dense Regular connective tissue slow or quick to heal?
Slow due to having only a relatively small amount of cells, which are crucial in the healing process
What colour is Dense Regular connective tissue?
Shiny white
What is the main purpose of Dense Regular connective tissue?
Attachment
What is the difference in fibre arrangement between Dense Regular and Irregular connective tissues?
Fibres are not arranged in parallel bundles in Dense Irregular connective tissue
What is the predominant cell type in Dense Irregular connective tissue?
Fibroblasts, though they are scattered sparsely across the tissue
Where is Dense Irregular connective tissue found?
In the dermis of the skin and the Lamina Propria of the gastrointestinal tract
What fibres are found in Dense Elastic connective tissue?
Elastic and Collagen fibres
What do the presence of Elastic and Collagen fibres within Dense Elastic connective tissue allow attached tissues to do?
Return to their original length after stretching
Where is Dense elastic connective tissue found?
Arterial walls and lungs
Cartilage comprises of a dense network of ___ and ___ ___
Collagen and elastic fibres
3 types of Cartilage are…
Hyaline, Elastic and Fibrocartilage
What cell type is predominant in cartilage?
Chondrocytes
Hyaline cartilage is relatively weak or strong?
Relatively Weak
What is the structure of Hyaline cartilage?
A resilient gel, in which fibres are present but not obvious
What is the purpose of Hyaline cartilage?
To provide flexibility and movement while also holding shape
Where can Hyaline cartilage be found?
Anterior ends of ribs, respiratory cartilage (Nose, trachea, bronchi, etc.)
What is the most abundant type of cartilage?
Hyaline cartilage
What does Elastic cartilage consist of?
Elastic and Collagen fibres with proteoglycans
In terms of physical properties, what does Elastic cartilage provide?
Rigid support and elasticity
Where can elastic cartilage be found?
Earlobes
Is Fibrocartilage tough or weak?
Tough
What makes Fibrocartilage tough?
Thick bundles of collagen fibres dispersed throughout the matrix
Where can Fibrocartilage be found?
Knee and Jaw joints
What are the two types of bone that can be found in a single bone?
Compact and Spongy bone
Where is Compact bone in relation to the bone itself?
The outer layer, forming the shaft of long bones
What is another name for Compact bone?
Cortical bone
What is stored in Compact bone?
Calcium and Phosphorus
What is the purpose of Compact bone?
Protection and support
What does Compact bone have that Spongy bone doesn’t have?
Osteons (Haversian systems)
What shape are Osteons?
Rod-shaped, running the long axis of a long bone
What are the 4 components present in one Osteon?
Lamellae, Lacunae, Canaliculi and the Central (Haversian) canal
What are the lamellae in an Osteon?
Small concentric rings of mineralised salts (for hardness) and collagen (for tensile strength)
What are two examples of mineralised salts that may be present in lamellae?
Calcium phosphate and Calcium hydroxide (which together form hydroxyapatite)
What are the lacunae in an Osteon
Small spaces between lamellae that contain osteocytes
What are the canaliculi in an Osteon?
Miniature canals that radiate from lacunae and provide routes for oxygen, nutrients and waste
What is in the Central (Haversian) canal of an Osteon?
Blood and Lymphatic vessels and nerves
Where is Spongy bone in relation to the bone itself?
Underneath the compact bone
What is the structure of Spongy bone?
Porous
What is another name for Spongy bone?
Cancellous bone
Are there Osteons in Spongy bone?
No
Are there Osteons in Compact bone?
Yes
What are the two types of bone marrow?
Red and Yellow
What is the purpose of yellow bone marrow?
Triglyceride (fat) storage
What is the purpose of red bone marrow?
Production of red blood cells
What are the main bone cells?
Osteogenic cells, Osteoblasts, Osteocytes and Osteoclasts
When are Osteogenic cells present?
When bone is first formed
What do Osteogenic cells do?
Start to lay down collagen before they get trapped in that collagen
What happens to Osteogenic cells trapped in collagen?
They become Osteoblasts
What do Osteoblasts do?
Lay down more collagen and start the mineralisation process, starting the laying down of new bone
What happens to Osteoblasts that become trapped within the Extracellular matrix of bone?
They become Osteocytes
What do Osteocytes do?
Maintain bone tissue, remodel new bones and exchange and transfer nutrients and wastes through the bone via gap junctions
Are Osteoclasts large or small?
Large
Are Osteoclasts single or multinucleated?
Multinucleated
How are Osteoclasts formed?
Formed from the fusion of blood monocytes
What is the purpose of Osteoclasts?
To break down bone
What is the extracellular matrix of blood?
Blood Plasma
What are the formed elements of blood?
Red Blood cells, Platelets, Eosinophil, Basophil, Neutrophil, Monocytes, Macrophages, T-lymphocytes, B-lymphocytes
What is another name for Red Blood cells?
Erythrocytes
What is the purpose of Red Blood cells?
Transport of oxygen and carbon dioxide
What is another name for Platelets?
Thrombocytes
What is the purpose of Platelets?
Clotting
What are the purposes of Eosinophils?
To counter certain parasitic worms and in acute allergic response
Are Basophils mobile or stationary?
Mobile
What is the purpose of Basophils?
To release substances that intensify inflammatory reaction
Are Neutrophils and Monocytes phagocytic?
Yes
T-lymphocytes and B-lymphocytes are involved in the ___ response
Immune response
