3. Connective Tissues Flashcards
Where are connective tissue cells mainly derived from?
Undifferentiated mesenchymal cells
Name examples of cells derived from undifferentiated mesenchymal cells. (3)
- Fibroblast
- Fat cells
- Most cartilage and bone cells
Name examples of cells derived from the haemoatopoetic stem cell line. (5)
- Monocytes
- Macrophages
- Lymphocytes
- Mast cells
- Blood cells and others
What are the cells of connective tissues? (2)
- Fibroblasts/cytes
- Adipose cells
Name the visible fibres of connective tissues. (3)
- Collagen
- Elastic
- Reticulin
What is contained within the ground substance of connective tissues? (3)
- Proteoglycans
- Glycosaminoglycans (GAGs)
- Laminin, fibronectin (invisible fibres)
Name the 6 different types of connective tissue.
- Loose fibrous
- Dense fibrous
- Hard cartilage
- Hard bone
- White fatty
- Brown fatty
What is tropocollagen?
A triple helix of peptides
What do fibroblasts secrete?
Tropocollagen subunits
Name an example of Type 1 collagen.
Skin
Name an example of Type 2 collagen.
Cartilage
Name an example of Type 3 collagen.
Liver, bone marrow, spleen
Name an example of Type 4 collagen.
Basement membranes
Name an example of Type 5 collagen.
Placenta
How do collagen fibres look when stained with H&E?
Pink, variable thickness and length, often run in bands, extracullar
What is loose connective tissue comprised of?
- Widely spaced thin collagen fibres
- Fibroblasts/fibrocytes
- Unstained ground substance
What is dense connective tissue comprised of?
- Closely spaced thick collagen fibres
- Fibroblasts/fibrocytes
- Unstained ground substance
- May be irregular or regular
What is reticulin?
Type III collagen
Fibrillar collagen
What is the function of reticulin?
Forms a supporting scaffold in many organs
(Bone marrow, Liver, Kidney, Lymph node, Spleen)
What does elastic tissue contain?
Fine fibres (can be branched) and sheets of elastin
Elastin is produced by…
Fibroblasts
What is white adipose tissue?
Large cells with single fat globule each that usually appear white in conventional slides
What is brown adipose tissue?
Cells with many globules of fat
Where is brown adipose tissue found?
Across and down back of newborn
What are the cartilage cells?
Chondroblasts and chondrocytes
What is in the extracellular matrix of cartilage?
Glycosaminoglycans and proteoglycans
What are some extracellular fibres of cartilage?
Collagen and elastin
Where is hyaline cartilage found?
In synovial joints
What is hyaline cartilage?
Chondrocytes in lacunae surrounded by a glassy amporphous matrix
What is pericondrium?
Fibroblasts and collagen
Where is elastic cartilage found?
In the pinna, epiglottis
Where is fibrocartilage found?
In the annulus fibrosus, pubic symphysis
Where is synovium located?
Lines the inside of the joint capsule
Describe synovium.
- 1-4 layers of synovial cells
- Variable shapes- squamous to cuboidal
- Richly vascular, highly innervated
Give an example where smooth muscle is located.
Arterial wall, wall of intestine, airways of lungs
Give an example where skeletal muscle is located.
Skeletal muscles, larynx, diaphragm
Where is cardiac muscle located?
Heart, base of great vessels
Name some other contractile cells. (3)
Pericytes, myofibroblasts, myoepithelial cells
Describe smooth muscle.
- Involuntary
- Fusiform
- Central nucleus
- No striations
- Non-branching
