Lecture 11 - Connective & Adipose Tissue (Part 2) Flashcards
what are the 4 main kinds of dense connective tissue? n
Dense irregular - fibres not in parallel bundles
Dense regular - fibres arranged in parallel bundles (tendons and ligaments)
Fascia - separates muscle from other tissue
Aponeurosis - connects muscle to muscle
Give the main example of dense irregular connective tissue
The superficial layer of the dermis in the skin.
What are the two main examples of dense regular connective tissue?
1) Tendons
2) Ligaments
How strong are tendons?
What is the role of tendons?
What is the reasoning for their strength?
What do tendons consist of?
- Very Strong (stronger than muscle, as strong as bone)
- Tendons connect muscles to bones
- Skeletal muscle fibres interdigitate with tendon collagen bundles at myotendinous junctions providing strength
- 68% water, 2% elastin, 30% collagen (70% type 1, 30% type 3)
What is the role of ligaments?
How are their collagen fibres arranged?
What are they wrapped in?
- Ligaments connect bone to bone
- Collagen fibres arranged in parallel arrangement but ungulate.
- Wrapped in and separated by fascicles
What are the 3 types of fascia?
Why is fascia flexible and able to resist great unidirectional tension forces?
- Superficial, deep, visceral/parietal
- They contain closely packed bundles of collagen oriented in a wavy pattern (parallel)
What is aponeuroses?
Pearly white fibrous tissue that attached flat muscle to muscle, tendon to tendon and tendon to ligament.
Give an overview summary of irregular and regular dense tissue and examples of each.
- Both contain fibroblasts
- Collagen 1 fibres in all direction in irregular, parallel in loose
- Resist stress in all direction in irregular, 1 direction in loose
- Deep layer of the dermis, submucosa of intestine for irregular. Tendons, ligaments and aponeuroses for regular
What is vitamin C required for in connective tissue?
Vit C required for production of procollagen, and hydroxylation of proline and lysine. Fibroblasts secrete this procollagen which is converted into collagen. These form collagen fibrils via aggregation which provides strength to tissue.
What condition is caused by Vit C deficiency and what problems does it cause?
Why do these problems arise?
- Scurvy
- Poor wound healing & impaired bone formation
- The hydroxylation of proline and lysine step via Vit C can no longer happen in collagen synthesis, therefore they have collagen deficiencies
What are the key symptoms of scurvy?
- Gum disease
- Bruising of skin
- Bleeding
- Poor wound healing
What kind of genetic disorder is Marfan’s syndrome and what does it affect?
What are the main symptoms?
- Autosomal dominant which affects expression of fibrillin 1, therefore elastic tissue is abnormal
- Abnormal heigh, arachnodactyly, joint dislocation and risk of aortic rupture (as there is alot of elastin around the aorta)
What is elastin and which tissues have lots of it?
- Elastin is the primary component of elastic fibres and is surrounded by fibrillin.
- Dermis, Artery Walls, Lungs
Which layer of an elastic artery is elastin usually found in?
- Tunica intima (inside)
- Tunica media (middle)
- Tunica adventitia (outer)
- Tunia media (elastin lamellae)
What is osteogenesis imperfecta?
What are the symptoms?
- Brittle bone disease (mostly autosomal dominant but polygenomic), due to mutated collagen. Fibres do not “knit together” or insufficient amount are produced.
- Weakened bones, short stature, a blue sclera, hearing loss, hyper-mobility, flat/arched feet, poor teeth development
