Tissues Flashcards
Memorise/Learn (44 cards)
Define Tissue
A group of similar cells that work together to perform a common function
What are the four basic groups of tissues?
Epithelial Tissues
Connective Tissues
Muscle Tissues
Nervouse Tissues
Outline Epithelial Tissues
A tissue consisting of closely packed cells that cover the surfaces of the body and line its cavities.
Some forms are modified to to perform specialised functions (e.g. secretion, absorption, sensory or transport.
3 characteristics of Epthelial Tissues
-Cells are closely packed with little matrix material (intercellular material).
-Rest on a basement membrane.
-No blood supply.
What is simple epithelium
a type of epithelial tissue characterised by having only one layer of cells
What is stratified epithelium
a type of epithelial tissue characterised by having multiple layers of cells
Define squamous epithelium
cells are flat and sheet-like in appearance
Define cuboidal epithelium
cells are cube-like in appearance, meaning they have equal width, height and depth
Define columnar epithelium
cells are column-like in appearance, meaning they are taller than they are wide
Outline Connective Tissues
Connective tissue provides the body’s supporting framework and binds various structures together.
Examples include bone, tendons, cartilage, ligaments, fat (adipose tissue), fascia, and blood
3 Characteristics of Connective Tissue
-The cells of connective tissue are typically seperated by intercellular material (the cells only comprise a small portion of the tissue portion)
-The intercellular material (matrix) consists of fibres and ground substance, which determine the mechanical properties of the tissue
-Generally have a good blood supply
State the two components of connective tissue
-Ground Substance
-Fibres
What is Ground Substance (connective tissue)
Is the gel-like material between cells and fibers in connective tissue. It contains complex carbohydrates that make it viscous. In bone, it is mineralised to provide strength.
What is Fibres (connective tissue)
Fibres in connective tissue form the structural framework, providing strength and support. Collagen fibres give tensile strength. Elastic and reticular fibres give the tissue flexibility.
State the 4 cells in connective tissue
Fibrocytes
Adipocytes
Mast cells
Macrophages & lymphocytes
What is the role of Fibrocytes
secrete the ground substance
What is the role of Adipocytes
store fat
What is the role of Mast Cells
secrete histamine (can cause inflammation)
What is the role of Macrophages & lymphocytes
are immune cells in connective tissue. Macrophages engulf and digest pathogens and debris (phagocytosis), while lymphocytes recognise and respond to specific infections
State two ways that connective tissue can be classified
Loose or dense (depending on the abundance of fibres)
What does loose connective tissue do?
attaches epithelium to the underlying tissue, supports many organs, surrounds blood vessels and nerves and occurs between muscle
e.g. areolar and adipose tissues
What does dense connective tissue do?
-Contains many fibres (mainly collagen)
-Classified as either regular, if the fibres are parrallel (e.g. tendons and ligaments)
-Classified as either irregular, if the fibres are random (e.g. the dermis of the skin)
What is cartilage?
a tough, white elastic tissue
How does cartilage act in embryo vs adulthood?
The embryo has a skeleton made entirely of cartilage, most of which is replaced by bone as the skeleton develops. In adults cartilage covers the ends of bones in joints - it also occurs in the rib cage, outer ear, nose, throat and intervertebral discs
