Human Body Organisation Flashcards
What are the stages of human body organisation?
Protein –> Cell –> Tissue –> Organ –> Organ System –> Organism
Give 5 examples of cells
- Nerve cell
- Red blood cell
- Fat cell
- Epithelial cell
- Sperm cell
Give the 4 main types of tissue
- Epithelial
- Connective
- Muscle
- Nervous
Where is epithelial tissue found and what is its purpose?
Found on internal and external surface linings to cover and protect surfaces
What is connective tissue?
Groups of tough, strong cells able to bind, providing structural support and connecting other tissues to organs and bones
What is muscle tissue?
Tissue attached to bones that contract to facilitate movement
What does nervous tissue do?
Conducts impulses and coordinates bodily activities
Describe the polarity of epithelial tissue and link this to attachment
- Epithelium has an upside (apical) and a downside (basal) surface
- The basal surface keeps the cells attached to other tissues (e.g. attaches to underlying connective tissue called the reticular layer which secretes collagen and protein fibres to resist overstretching and tearing)
Describe the vascularity of epithelial tissue
Epithelial tissue is avascular, meaning it doesn’t contain blood vessels so that it can protect the underlying tissue from harm
Describe the regeneration of epithelial tissue
Epithelial cells have a large supply of stem cells in the basal membrane so that they can continuously regenerate because they are prone to wear and tear
Give 2 specialised secretions of epithelial tissue
- The lining of the digestive system provides a physical barrier to protect from dehydration, abrasion and harmful substances
- Taste buds are modified epithelial cells providing sensations for taste
What are the 2 aspects of the epithelial cells that allows them to be classified?
Number of cell layers and cell shape
What are the 2 classifications of epithelial tissue based on cell layers?
- Simple epithelium - single layer of cells
2. Stratified epithelium - more than one layer of cells
What are the 3 classifications of epithelial tissue based on cell shape?
- Squamous - flat cells
- Cuboidal - cuboid shape
- Columnar - tall and thin
What are the different types of squamous cells?
- Stacked
- Simple - capillary lining
- Stratified - skin
How are the stratified squamous cells of the skin adapted for their function?
- They use intercellular connections to control permeability of fluid movement
- They contain desmosomes which secrete cell adhesion molecules to maintain structural integrity
What are the different types of cuboidal cells?
- Simple
2. Stratified
Give 3 characteristics of cuboidal cells
- Freely permeable for right sized molecules
- Important in secretion and absorption
- Microvilli