2.10 Tissue Level of Organisation - Epithelial; Connective; Muscle; Nervous Tissues Flashcards
Epithilium classification: number of layers
One layer: simple
>1 layers: stratified
Epithilium classification: cell shape on apical surface
Flat: squamous
Cube-like: Cuboidal
Column-like: Columnal
Common function of simple squamous epithilium
- Lines blood vessels and air sacs of lungs
- Permits exchange of nutrients, wastes, and gases
Common function of simple cuboidal epithilium
- Lines kidney tubules and glands
- Secretes and reabsorbs water and small molecules
Common function of Simple columnar epithilium. Therefore, where would it commonly be located?
- Lines most digestive organs
- Absorbs nutrients, produces mucus (have microvilli)
Common function of stratified squamous epithilium
- Outer layer of skin, mouth, vagina
- Protects against abrasion, drying out, infection
Common function of stratified cuboidal epithilium
- Lines ducts of sweat glands
- Secretes water and ions
Common function of stratified/psuedostratified columnar epithilium
- Lines epididymus, mammary glands, larynx
- Secretes mucus
What are the two types of epithelium?
- Surface: covers and lines the inside and outside surfaces of the body
- Glandular: produces a secretion
What type of epithelium is endothelium? What is its function?
- Simple squamous
- It is found in the cardiovascular and lymphatic system, since its smooth internal structure allows flow of fluids. It’s thinness allows for easy exchange of substances.
What type of epithelium is mesothelium? What is it’s function?
-Simple squamous, with thicker layer of connective tissue than endothelium.
- It is a lubricated surface, and is located in our pleura, decreasing the friction between our lungs and rib cage.
Non-keratinized stratified squamous epithelium
- Protective layer
- Moist surface, lines mouth, oesophagus, nose, vagina etc.
Keratinized stratified squamous epithelium
Like non-keratinized stratified squamous epithelium, except with a layer of dead, anucleate cells in superficial layers. This surface is tough, and resistant to tearing.
Pseudostratified columnar ciliated epithelium with goblet cells
- Nuclei on different levels, but all attached to basement membrane (hence psuedo-)
- Goblet cells secrete mucus
- Cilia filter pathogens and other shit upwards via a muco-cilliary escalator, where it can be swallowed or coughed out.
Transitional epithelium
Can change shape
- Stretched: stratified squamous
- Relaxed: stratified cuboidal
Location: ureters and bladder (makes sense; stretching is required)
How are glands formed?
Congregation and subsequent invagination of glandular epithelial cells. Connective support tissues will then grow around it.
What are the two destinations of exocrine gland secretion?
- Into the lumen of an organ
- Directly released onto epithelial cell (e.g. sweat)
What is the function of connective tissue? What properties allow it to do this?
- Provide support and function to the body (tensile and strong)
- Binds tissues and organs (flexible)
- Facilitates communication (Forms a communication network)
What is the extracellular matrix of connective tissue made of?
- Ground substance (viscous, fluid-like)
- Fibres
What are the three types of fibres in the extracellular matrix of connective tissue?
- Collagen
- Elastic
- Reticular
What is the main defining feature of connective tissue?
Extracellular matrix
What are the three classifications of connective tissue
- Connective tissue proper
- Fluid connective tissues
- Supporting connective tissues
What different types of connective tissue structures enable it to provide mechanical support and protection?
- Skeleton (structure and support)
- Skin (support)
- Fat (insulation, cushioning)
What are three other functions of connective tissue?
- Energy storage
- Immunity (carrying immune cells in blood)
- Repair
