Connective and Adipose Tissues Flashcards
Define ‘connective tissue’
Cells embedded in extracellular matrix that connects, supports and binds
List 3 common cell types found in connective tissue
- Fibroblasts
- Macrophages
- Mast Cells
- Myofibroblasts
- Adipocytes
What is the function of fibroblasts in connective tissue?
- Synthesise and secrete fibres for extracellular matrix
- Important in wound healing
What are the 3 components of connective tissue?
- Cells
- Fibres
- Ground Substance
What is the function of macrophages in connective tissue?
- Respond to inflammation by phagocytosis
- Present foreign material to T-cells
What is the function of mast cells in connective tissue?
- Specifically bind antigens
- Send signals to lymphocytes
What is the extracellular matrix and what is its function in connective tissue?
- Complex extracellular structural network of ground substance and fibres
- Provides support and transportation network
What are the constituents of Ground Substance?
- Water
- Proteoglycans covalently bonded to GAGs
What is the most common type of collagen?
Type I
What are the two types of Adipocyte?
Unilocular and Multilocular
Give two differences between white and brown adipose tissue
- White has one large lipid droplet, brown has multiple small lipid droplets
- Brown adipose tissue is normally only found in babies
- Brown adipose tissue has many more mitochondria making fat breakdown quicker
What are the constituents of collagen?
Fibrils (fibres and fibre bundles)
What are reticular fibres?
Type III collagen in which fibres in dense connective tissue that provide a supportive framework/sponge
What are elastic fibres?
A fibre in connective tissue that allows tissues to recoil after stretch or distension
What elements make up Areolar Tissue?
- Multiple cells including fibroblasts
- 2 types of fibres (collagen, elastic)
- Gel-like extracellular matrix
Name 2 places where Areolar tissue is found
- Surrounds epithelial basal lamina
- Around glands and nerves
What is the function of Areolar Tissue?
- Holds vessels
- Permits cell migration
- Packaging around organs
What are the two types of Dense Tissue and how do they differ?
Irregular - Fibres run in all directions
- Resists stress in all directions
Regular - Parallel fibres
- Resists stress in one direction
What substances form dense connective tissue?
- Fibroblasts
- Collagen I Fibres
Give an example of regular and irregular dense connective tissue
Regular - Tendons, Ligaments
Irregular- Submucosa, Deep dermis layer
What is a Myotendinous Junction?
Collagen Junction between skeletal muscle fibres and tendon collages bundles
What are the components and proportions of a tendon?
68% water
30% collagen
2% elastin
What is a ligament? Give an example
- Connects bone to bone
- Cruciate ligament in knee
What are the 3 types of Fascia and what are they made of?
- Superficial
- Deep
- Visceral/Parietal
- Made of fibrous connective tissue
What is the function of a Fascia?
To flexibly separate muscle groups
What causes Scurvy and what is its effect on collagen?
- Vitamin C deficiency
- Lack of vitamin C disrupts collagen formation and fibres can thicken
Name 2 symptoms of Scurvy
- Gum disease
- Bruising
- Bleeding
- Poor wound healing
What kind of disorder is Marfan’s and what does it affect?
- Autosomal Dominant Disorder
- Affects Fibrillin 1 gene
What defect is present in Marfan’s Syndrome?
The person has abnormal elastic tissue so it cannot recoil after being stretched
What parts of the body can Marfan’s Syndrome affect?
- At risk of AAA due to the aorta being unable to recoil when under extreme pressure
- Decreased elasticity in alveoli
What are the symptoms of Marfan’s Syndrome?
- Abnormally tall
- Arachnodactyly (abnormally long fingers and toes in comparison to palm/sole
- Longer ‘wing span’ than height
- Risk of aortic rupture
How is collagen affected in Osteogenesis Imperfecta?
Collagen fibres are mutated and do not knit together
What causes Osteogenesis Imperfecta?
- Genetic Aetiologies
Name 2 symptoms of Osteogenesis Imperfecta
- Brittle bones
- Short stature
- Hearing loss
- Hypermobile joints
