L12- Connective And Adipose Tissue Flashcards
What are the 6 types of connective tissue? (Alpha order)
Adipose Bone Blood Cartilage Dense CT Loose CT
What are the 3 main groups of connective tissue and their functions?
- Loose Connective tissue: holds organs in place and attaches epithelial tissue to underlying tissue
- Dense Connective tissue: helps attach muscle to bone and links bones together at joints
- Specialised connective tissue; Number of diff tissue and unique ground substances —> adipose, cartilage, bone, blood lymph
What is the structure of connective tissue?
- Cells- mainly mature fibroblasts, fixed adipocytes and reticular cells
- Fibres: Collagen, elastin and reticulin fibres
- Ground substance: proteoglycans (glucosaminoglycans e.g. hyaluronic acid)
What makes up the extracellular matrix?
Ground substance and fibres
Functions of connective tissue?
- Binding and supporting e.g. holding skin, gut lungs together
- Protecting e.g. bones protect organs
- Insulating e.g. fat
- Storing reserve fuel and cells (bone marrow and fat tissue)
- Transporting substances within body (Blood and interstitium)
- Separation of tissues (fascia and tendons/cartilage)
Cell types found in connective tissue?
- undifferentiated mesenchymal cells
- fibroblasts
- storage cells
- adipocytes
- macrophages
- mast cells
What are fibroblasts and their functions?
- most common cells in ct
- synthesise and secrete collagen and other fibres that lie within ground substance (EC matrix)
- scars are formed by fibroblast activity during tissue repair (collagen)
What is a myofibroblast?
Modified fibroblasts
- contain actin and myosin
- responsible for wound contraction when tissue loss has occurred
Function of macrophages in CT?
- derived from blood monocytes, move into loose connective tissue especially during inflammation
- phagocytic and can degrade foreign organism and cell debris
- also antigen presenting cells
- contain numerous lysosomes which break down ingested material
Function of mast cells in CT?
- release chemical signals that diffuse through ground substance and trigger inflammation
- Cytoplasm of mast cells packaged with secretory vesicles which contain: histamine (increase blood wall permeability), heparin (anticoagulant) and cytokines (attract eosinophils and neutrophils)
- coated with Ige molecules which bind allergens
a) What are the two types of adipocytes?
B) compare them
A) White adipocytes and brown adipocytes
B) White: - Yellow - Unilocular (single enormous lipid droplet) - peripheral nucleus - normal amt of mitochondria - lots in adults, none in neonates - function: padding, shock absorber, insulin and energy reserve
Brown:
- Brown
- multilocular: multiple small lipid droplets
- central nucleus
- lots of mitochondria (colour)
- only adipocytes in neonates, some in adults
- function: insulation and energy reserve.
What are the types of fibres in CT?
- Collagen
- Elastin
- Reticulin
A) What are the types of collagen?
A) there are 4 types:
- type 1: found in tendons, organs and skin dermis (forms fibres)
- type 2: doesn’t form fibres- found in hyaline and elastic cartilage
- type 3: forms fibres around muscle and nerve cells and within lymphatic tissue and lymphatic organs CALLED RETICULIN
- type 4: form basement membrane
Function of:
A) collagen
B) reticulin
C) elastin
A) flexible with high tensile strength
B) provides a supporting framework/sponge
C) allows tissues to recoil after stretch or dissension
a) Which fibre is not present in areolar tissue?
B)Where is this fibre found?
A) Reticulin
B) lymphatic tissue