Microanatomy basics Flashcards
What defines a tissue?
A collection of cells specialised to perform a particular function. The cells may be of the same type or of different types
What defines an organ?
A part of the body, composed of more than 1 tissue, that forms a structural unit respondible for a particular function
What defines an organ system?
Made up from 2 or more organs, to fulfil functions eg the digestive system
What are the 4 basic tissues?
- Epithelial tissue
- Connective tissue
- Muscle tissue
- Nervous tissue
What is the function of epithelial tissue?
It is sheets of cells that cover exterior surfaces of the body, lines internal cavities and passageways and forms certain glands
Epithelial tissue is avascular and regenerative
What is the function of connective tissue?
It binds cells and the organs of the body together and functions in the protection, support and integration of all parts of the body
What is the function of muscle tissue?
It is excitable, responding to stimulation and contracting to provide movement
What are the 3 major types of muscle tissues?
- Skeletal (voluntary) muscle
- Smooth muscle
- Cardiac muscle
What is the function of the nervous tissue?
It is excitable, allowing the propagation of electrochemical signals in the form of nerve impulses that communicate between different regions of the body
What are simple squamous epithelium adapted for?
The exchange of small molecules between separated compartments
What are simple columnar epithelium adapted for?
To perform secretory or absorptive functions
How would you describe simple squamous epithelium?
Thin, flattened cells
How would you describe simple cuboidal epithelium?
A singular layer of cuboidal cells whose width is approximately equal to their height
How would you describe simple columnar epithelium?
The height of the cells is much greater than their width
How would you described ciliated epithelium?
Consists of cells of differing shapes and heights. The apical surface is ciliated
Where is pseudostratified columnar ciliated epithelium most commonly found and what is its function?
It predominates in the upper airway (trachea and bronchi). Epithelia of this type combine a mechanical and secretory function: the goblet cells secrete mucus to trap airbourne particles, while the cilitated columnar cells move the mucus film towards the mouth
What are stratified squamous epithelium adapted for?
To withstand chemical and physical stresses
What are transitional epithelium adapted for?
Ability to stretch eg found in the bladder
How would you describe transitional epithelium?
Their structure is similar to that of stratified squamous epithelium except that the superficial cells are larger and rounded
What are glandular epithelia specialised for?
Secretion
What is the function of exocrine glands?
Glands that secrete material via a specialised duct onto an epithelial surface
Could consist of a simple coiled tube or may consist of a complex set of branching ducts linking groups of cells together called acini
What is the function of an endocrine gland?
Glands that secrete materials across their basolateral surfaces, from where it passes into the blood
They lack a duct
What is the function of serous cells?
When stimulated they produce a copious watery secretion
- What connective tissue forms the skeleton
- What is its predominant extracellular matrix component?
- Bone
- ECM components:
- Glycoproteins eg osteonectin
- Osteocalcin
- Proteoglycans
- Osteoblasts and osteoclasts
- GAG
- Calcium phosphate
- What connective tissue links the components of the skeleton together?
- What is its predominant extracellular matrix component?
- Ligaments
- Collagen type 1 and elastin
- What connective tissue connects muscles to bones to allow the skeletal elements to be moved?
- What is its predominant extracellular matrix component?
- Tendons
- Collagen type 1, proteoglycans, water
