1.2 Levels of organisation Flashcards
(30 cards)
Define a tissue.
A group of cells working together with a common function, structure and origin in the embryo.
What is it called when cells become specialised for different functions?
Cell differentiation.
What does epithelial tissue form?
A continuous layer, covering or lining the internal and external surfaces of the body.
Where do the cells of epithelial tissue sit?
On a basement membrane made of collagen and protein.
Do epithelial tissue have blood vessels?
No, only nerve endings.
What are the functions of epithelial tissue?
Often have a protective or secretory functions.
What are the simplest forms of epithelial tissues?
Cuboidal epithelium-cube shaped cells, usually just one cell thick.
Where would epithelial tissue be found?
Proximal convoluted tubule of a kidney nephron and ducts of salivary glands.
Columnar epithelium has what?
Elongated cells.
Where would columnar epithelium be found?
Lining tubes that substances move through, such as the oviduct and the trachea, have cilia.
Squamous epithelium consists of what?
Flattened cells on a basement membrane.
Where would squamous epithelium be found?
The walls of the alveoli and they line the Bowman’s capsule of the kidney nephron.
What are the three main types of muscle tissue?
Skeleton, smooth and cardiac.
Where is skeleton muscle found?
Attached to bones.
What does skeleton muscle generate?
Locomotion in mammals.
Skeleton muscle has bands of what?
Long cells or fibres.
The bands of long cells in skeleton muscle means?
Gives powerful contraction, but the muscle tires easily.
Why are skeleton muscles called voluntary muscles?
You can choose whether or not to contract them.
In smooth muscle, what shape are the cells?
Individual spindle-shaped cells.
Smooth muscle can contract __, but contract less __ than skeletal muscle.
Rhythmically, powerfully.
Where does smooth muscle occur?
In the skin, in the walls of blood vessels
and in the digestive and respiratory tracts.
Why are smooth muscles called involuntary muscles.
You cannot control them.
Where is cardiac muscle found?
Only in the heart.
What are the structures and properties of the cells in cardiac muscle?
The cells have stripes but lack the long fibres of skeletal muscle.
