connective tissue Flashcards
connective tissue is the most _____ tissue type
abundant
connective tissue is made up of what
of small cells far apart from each other
primarily fibrous tissue which vary only in density and cellularity
connective tissue has a large amount of what
extracellular material (matrix)
explain blood supply in terms of connective tissue
Often has a good blood supply (but not all types do)
can be Found between other tissues
how can connective tissue be classified
using their matrix characteristics
name the connective tissue cell types
fibroblasts
microphages
plasma cells
mast cells
adipocytes
describe fibroblasts
(Principe active cell of tissue) - present in several tissues
Secretory function and lays critical role in wound healing
describe macrophages
(type of white blood cell so belong to immune system)- from monocytes
Engulf bacteria & cell debris by phagocytosis
describe plasma cells
develop from B lymphocytes so also called plasma B cells
Make antibodies
describe mast cells
(migrant cell type)- near blood vessels
part of reaction to injury – release histamine/ inflammatory substances
describe adipocytes
- fat cells or adipose cells
Store triglycerides (fat)
explain the extracellular matrix
3D network of extracellular molecules
Important to structure and biochemical support to surrounding cells
Fluid, gel or solid plus protein fibres are contained within the substance
Ground substance - between cells and fibres
name and describe the 3 fibre types
Collagen fibers:
very strong & flexible
Elastic fibers:
smaller stretch and return to original length
Reticular (form a mesh) fibers:
provide support & strength by sitting along side other cell types and support and nourish them
- found in basement membranes to provide organ support
where are Loose Connective Tissue found
most common type of connective tissue in all vertebrates
name and explain the 3 loose connective tissues
Areolar:
cells embedded in a matrix of glycoproteins and elastin and collagen fibers
Adipose:
cells filled with fat droplets
Reticular:
mesh of reticulin fibers
what do loose connective tissues do
Holds organs together and needed for attachment of epithelial tissues to other underlying tissues
describe subcutaneous areolar connective tissue structure
subcutaneous = the base layer of skin deep under
No real organised structure to them, its very loose and open
Cells are quite far apart
This would be found in the skin layers
describe adipose tissue structure
Large gaps between the cells where the fat is stored
Very small sit of cytoplasm which is around outside of cell with appearance of a flattened non centre nuclei. So very distinctive characteristic of adipose tissue
Mas of cell is devoted to its function of storing adipose
describe structure of reticular connective tissue
Reticular fibres form a soft skeleton or a stroma that has supporting role. Often found in lymph node, stromal cells, bone marrow, and spleen , and around the kidney
Adipose tissue is also held together by reticular fibre
Tissue type that never exists alone
The fibres are made up of collagen and glycoproteins
Has thin and branching appearance
explain dense connective tissue
type of connective tissue that has fibers as primary matrix element. Mainly composed of type one collagen. They form strong rope like structures, so tissues like tendons and ligaments contain high amounts of dense connective tissue
Dense connective tissues also make up lower parts of the skin (dermal layer)
Dense connective tissue is arranged with high levels of organisation where sheets of tissue are laid down for strength .
Or arrangement may be more irregular in its appearance
what do tendons attach
skeletal muscle to tissue
what do ligaments connect
bones to bones at the joints.
They’re more stretchy and contain more elastic fibres than tendons
whats the Classification groups of Dense Connective Tissue
Dense regular
Dense irregular
Elastic
describe dense regular structure
Provides connection
Ex muscle to muscle
Collagen tissues in dense connective tissue and bundled in a parallel fashion
Shows fibre composition
Fibroblasts are the fibre forming cells, responsible for production of the collagen fibres seen in dense regular connective tissue
describe dense irregular connective tissue structure
Has fibres not arranged in same way a regular dense connective tissue
It has collagen fibres but less ground substance than ,loose connective tissue
Its more flexible than regular dense connective tissue
Found in dermis tissue
Collagen fibres are sparsely scattered throughout extracellular matrix, compared to the dense regular connective tissue
describe elastic connective tissue structure
Springy material in its behaviour
Large amounts found in organs and tissues that need to stretch such as arteries and lungs helping maintain the integrity of the tissue
Also found in areas needing cushioning such as areas of tissues supporting spine
elastic fibres are bundles of this protein elastin found in extracellular matrix of tissues of these type
Fibroblasts are sparsely distributed again here
Smooth muscle cells are capable of producing elastic proteins as well
explain cartilage
Resilient, smooth and elastic tissue
Forms a rubber like material so important for padding and protecting parts of body that have to withstand stress and strain – such as ends of long bones and joints
Not as hard or ridged as bone but is stiffer and less flexible than muscle
Dense network of collagen & elastic fibres embedded in chondroitin - sulphate substance – this characterizes cartilage
Stronger than dense fibrous
Cells = associated with cartilage are chondrocytes
Occur singly or in groups
Found in spaces called lacunae
Surrounded by perichondrium
No blood vessels or nerves
what are the 3 classification groups of cartilage
hyaline
fibrocartilage
elastic
what do the classification of cartilage relate to
presence of fibres
explain hyaline cartilage
(glassy cartilage – as glassy appearance)- fibers not easily visible. Its found on surface of articular joints, so smooth nature. Appropriate in areas where theres required movement
Glassy appear as so few fibres
explain chondrocytes in cartilage
= the main cells associated with hyaline cartilage responsible for producing cartilage. They sit in these lakes known as lacuna
explain fibrocartilage
fibers visible. Strongest type of cartilage, so found in vertebral discs that cushion the vertebrate
Fibrocartilage is a truly transitional tissue characterised and some structural properties of both fibrous and cartilaginous tissue
Found in regions subject to tense and compressive to have ability to be compressible, but also strength
The cartilage provides a tough tier of intervertebral desks
Cartilages of many joints are made of fibrocartilage,
All tendons have this fibrocartilage
has Lots of collagen fibres
The bundles run linear through the tissue and are separated by cartilage matrix contained in the chondrocytes
explain elastic cartilage
chondrocytes in threadlike network of elastic
e.g. outer ear cartilage
Its physiologically very similar to hyaline cartilage as fibres present are not particularly apparent but it does have elastic fibres and looks similar to hyaline cartilage
explain bone connective tissue
Osseous (connective) Tissue
Dense matrix includes calcium & phosphorous salts (hydroxyapatite) – this provides additional strength to the tissue
Denser than other types of previous connective tissue
name and describe the 2 types of liquid connective tissue
Blood:
matrix that the cells sit in is = plasma
Lymph:
matrix like blood but with less protein
explain muscular tissue
typified by Large, elongated cells
Contractile cells – have ability to contract
name and describe the 3 types of muscular tissue
Skeletal muscle tissue:
named for location. Attached to bones and for posture
Cardiac muscle tissue:
forms wall of heart
Smooth muscle tissue:
found in walls of hollow organs, such as in airways
name and explain the 2 types of neural tissue
Nerve cells & Neuroglia (support/nurse cells)
Neurons:
convert stimuli into nerve impulses and conduct them
Neuroglia:
- do not generate nerve impulses.
- serve supportive function
how well do tissues repair
Some tissues have a high capacity for regeneration and repair and others not so much
what do new cells form
form stroma (supporting connective tissue) or parenchyma (cells from functioning part of tissue/organ) – what you get depends on origin of cell. Stroma produces replacement tissue with less functional ability, so more associated with scar tissue. Whereas parenchyma will produce something that is functional
describe tissue repair in epithelial cells
originate from stem cells in defined areas of tissue layer. – so they renew themselves
describe tissue repair in bone
regenerates readily, cartilage poorly – it doesn’t repair itself
describe tissue repair in muscular tissue
can replace cells but slowly, long process
describe tissue repair in nerve tissue
is poorest at replacement although some stem cells seem to be available.
what does Replacement from stroma cause
scar tissue & functional loss.
