Connective and Adipose Tissue Flashcards
What is endocytosis?
The transport of solid matter or liquid into a bell by means of a coated vacuole or vesicle.
What is phagocytosis?
The engulfment and digestion of bacteria and other foreign particles by a cell.
What is exocytosis?
The transport of material out of a cell by means of a vesicle that first engulfs the material and then is extruded through an opening in the cell membrane.
What is connective tissue?
The tissue that supports, binds or separates more specialized tissues and organs or functions as a packing tissue of the body.
Also has a role in metabolic support.
What are the characteristics of connective tissue?
Cells are scattered throughout an extracellular matrix of fibrous proteins and glycoproteins attached to a basement membrane.
- Extracellular matrix
- fibres in a protein and polysaccharide matrix
- glycoproteins, fibrous proteins and GAGs
- secreted and organised by cells in the ECM
- main component is water
- fibres in a protein and polysaccharide matrix
What are the four basic tissue types?
- Epithelial
- Connective
- Muscular
- Nervous
How is connective tissue classified?
-
Connective tissue proper
- loose irregular connective tissue (e.g. lymph)
- dense irregular connective tissue (e.g. dermis)
-
Specialised connective tissue
- dense regular connective tissue (e.g. tendons and ligaments)
- cartilage
- adipose tissue
- haemopoietic tissue
- blood
- bone
When is the ECM the predominant feature in connective tissue?
In tissue with a mechanical function - ligament, tendon and bone.
When are cells the predominant feature in connective tissue?
When tissue is specialised for protection (WBC in haemopoiesis) or metabolic maintenance (adipose and RBC).
How are red blood cells stored?
Packed red cells can be stored at 6ºC for 42 days or frozen for 10 years.
How can cells be separated from tissues?
Collagenase breaks down collagen in tissues releasing cells.
How are cells held together in tissue?
- Attachment to each other (lateral domain)
- Attachment to the basement membrane (basal domain)
- Attachment to the ECM (integrins)
What are integrins?
Transmembrane proteins that function mechanically and biochemically.
Functions:
- cell to ECM attachment
- signal transduction from ECM to cell
- immune patrolling
- cell migration
How do cells attach to each other?
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Tight junctions
- found between epithelial cells
- forms a selective and sealed barrier
-
Desmosomes
- strengthens the bond between cells
- resistant against stretching and twisting
-
Gap junctions
- connections for channels for small ions to pass through
- communication
What is the basement membrane?
Structural site for overlying cells and underlying connective tissue. Cells attach to the basement membrane by hemidesmosomes and focal adhesions.
What are hemidesmosomes?
Attachment proteins. Found in tissues that are subject to abrasion such as skin and epithelium of oral cavity. Made of integrin and plaque.