Cells, Tissues, Organs and Systems Flashcards
(34 cards)
What is the level of organisation in an organism
Atom Molecule Macromolecule Organelle Cell Tissue Organ Organ system Organism
In multi-cellular organisms; cells may grouped together to form…..
Tissues
Formed from the functional grouping of multiple tissues that interact to make organ systems
Organs
Organ systems collectively carry out the life functions of the
Complete Organism
What is the basic unit of life
Cells
Function of Cells
Carry out particular tasks
e.g RBC
Have distinct shapes and different types of chemical recepetors
Function of Tissues
Group of cells with similiar function and structure
e.g muscle tissue is made up of many allinged muscle cells
Function of Organs
Group of tissues grouped together to make a structure with a special function
e.g Stomach is an organ which has an epithelial lining, gland tissue, muscle layer, blood vessels and nerves.
Function of a system
Usually a group of organs whose function is closely related.
Digestive system – oesophagus, stomach, liver, pancreas, intestines.
What do all cells of an organism have in common
They share an identical genome (set of instructions)
What is differentation?
Newly formed cells become more specialised and distinct as they nature.
When does differentation occur
When a specific gene (instruction) is ‘switched on’
- Activation of genes is the result of chemical signals.
- Cells can change structure and shape.
- Specialised cells carry out specific functions
What does epithelial tissue cover
Covers many surfaces and linings of body cavities
What does epithelial tissue line?
Internal cavities
Function of Epithelial tissue
Acts as a protective layer and as a barrier against infection by microbes or water loss.
Examples of Epithelial Tissue
Outer part of the skin Linings of the digestive tract Lungs Blood vessels Body cavity Various ducts
What does connective tissue involve (parts in our body)
Bone Cartilage Blood Tendons Ligaments
Function of connective tissue
Supports, connects and separates tissue and organs.
What does connective tissue consist of
Fibres (elastin and collagen), ground substances and cells.
What is the intercellular matrix?
A large portion of connective tissue – a network of protein fibres. Can be liquid, semisolid or solid.
Examples of intercellular matrix
Blood and lymph (they are non-fibrous forms of CT)
What does connective tissue contain?
- Collagenous fibres which are non-elastic and do not tear easily when pulled lengthwise.
- Elastic fibres that can stretch and return to their original length, and reticular fibres which are thin and branched – forming a network.
Muscle Tissue
Specialised to convert chemical energy (ATP) into mechanical energy for movement.
Description of Smooth muscle
Walls of many internal cavities, e.g intestines
