Primary tissues Flashcards
Types of organisms
Tissue – a group of specialised cells with a distinct function
SIngle celled organsims - grouped into pro and eukaryotes
SImple multicellular organisms ( eg sponges and hydra )
Complex multi cellular organisms ( eg higher animals/plants )
Cells group together into tissues with distinct function
division of labour and coordinated function for tissues, larger organisms possible, support and motility - exploitation of resources not available to single cells.
How to make differentiated ( specialised ) cells of tissues?
Types of cell types in our bodies
Pancreatic acinar cell with abundant secretory granules contain enzymes released for digestion in the small intestine
Differentiation and proliferation in descendants of originator ( stem ) cells make tissues
Multiple copies of cell types
Tissues contain multiple copies of cells grouped together that cooperate in a similar specialised function
(An organ usually contains a number of tissues grouped together) There are 4 basic types of body tissues:
(1) Epithelia
(2) Connective tissues
(3) Muscle
(4) Neural tissue
things to look for in diff tissue types
cell shape
prominent intracellular organelles and cell surface structure
epithelial
Cover surfaces with sheets of cells
(Enclose a sheltered internal environment:
perhaps the greatest evolutionary advance on the way to multicellularity!)
secretion, absorption, transport , barrier/protection, barrier/selective, strength/support
burns
- loss of skin barrier function
- dangers are fluid loss and infection
Cover surfaces – but varied shape and arrangement
(flat to column shaped; single or multilayered)
Show surface modifications/adaptations
Bound to each other by specialised junctions and adhesion molecules
(these are not only found in epithelial tissues!)
Sit on a specialised layer of extracellular matrix material - basement membrane (Otherwise little extracellular matrix)
cover surfaces - can be flat, cube or column shaped or multilayered
Simple squamous - cuboida- columnar - stratified types
May express surface modifications
microvilli, absorption/sensing, cillia, movement/lateral transport/ ( sensing )
Microtubule in different cillia types
may express junctions between cells
Epithelial cells sit on an amorphous basement membrane ( BM)
made of extracellular matrix molecules
Anchor for epithelial cells
Nervous tissue
Nervous system
Collects, processes/integrates and sends information
(cells are adapted for local and distant cellular communication)
Neurons - defining characteristic is the cell process
How neurons communicate?
The neuron theory proposed neurons are seperated entities - who was right?
Key characteristic features of neurons
At the end of axon
At the end of axon
