Lecture 2 - Tissues Flashcards
Define tissues
Tissues are a group of cells that are similar in structure and perform a common or related function
Define histology
The study of tissues. It is a subset of Microscopic Anatomy.
What are the types of tissues and what do they do?
- Connective tissue (supports)
- Epithelial tissues (protects)
- Muscle tissue (moves)
- Nervous (controls)
Describe the types of epithelial tissue
- Covering/lining epithelium (forms outer layer of skin and internal structures)
- Glandular epithelium (forms glands of body)
What are the functions of epithelia?
Remember PASS !
- Protection
- Absorption
- Secretion
- Sensory Reception
Describe the basic structure of epithelial tissue
- Apical Surface: free surface exposed to exterior environment or cavity of organ. Often has microvilli or cilia
- Basal Surface: anchored lower surface of epithelium
- Basal Lamina: adhesive sheet beneath Basal Surface; joins epithelial tissue to connective tissue
What are some facts about epithelial tissue?
- They fit closely together to form continuous sheets
- Sit upon and are supported by Connective Tissue
- Avascular (lacks blood vessels), but Innervated (has nerves)
- High regenerative capacity
How are epithelial tissue classified? What are the classifications of epithelial tissue based on arrangement of layers?
Epithelial tissue is classified according to its arrangement of layers and cell shape.
- Simple
- Pseudostratified
- Stratified
What are the classifications of epithelial tissue based on cell shape?
- Squamous
- Cuboidal
- Columnar
What is important about the arrangement of layers and surface of epithelial tissue?
- More layers = more protection
- Single layer means it’s easier for substances to pass through
- Cilia: often helpful in moving substances or involved in sensation
Examples: Where can simple squamous epithelia be found and name its properties?
- very thin
- located in areas where absorption/secretion is important
- i.e.; blood vessels, air sacs in lungs
Examples: Where can stratified squamous epithelia be found and name its properties?
- very thick
- found in areas where protection is important
- i.e.; skin
What are epithelial glands and what do they do?
Describe the two types of glandular epithelium.
- Glands consists of one or more cells. They make or secrete a particular substance.
There are two types of epithelial glands:
- Endocrine: substance is secreted into bloodstream (usually hormones)
- Exocrine: substance travels through a duct to destination
Describe the structure of endocrine glands of the thyroid?
- the thyroid follicle is the area encompassing the epithelial cells and the stored precursor hormone.
- hormone producing epithelial cells line the stored precursor of hormone
- blood vessels are on the outside
Describe the structure of exocrine glands?
- looks like a donut
- basement membrane lines the outside of exocrine gland
- the nucleus in the epithelial cells lines the inside of the basement membrane
- lumen of duct of sweat gland in the middle
What are the role of connective tissues in the body? What are the types of connective tissue?
Connective tissue supports body structures.
There are 4 types of connective tissue:
- Connective tissue proper
- Cartilage
- Bone
- Blood
Remember CCBB.
List the major functions of connective tissue
- Binding and supporting
- Protecting
- Insulating
- Storing reserve fuel
- Transporting substances
List major connective tissue structures
Reticular fibres: They provide support in blood vessel walls and form branching networks around various cells
Collagen fibres: are strong, flexible bundles of the protein collagen, the most abundant protein in your body
Elastic fibres: are stretchable but strong fibres made of proteins, elastin, and fibrillin. Found in skin, blood vessels, and lung tissue.
Ground substance: Material between cells and fibres. Made of water and organic molecules (hyaluronic acid, chondroitin sulfate, glucosamine). It supports cells and fibres, binds them together and provides a medium for exchanging substances between blood and cells.
What is connective tissue proper and what are some of its functions?
Connective tissue proper simply refers to connective tissue that have a dense arrangement of extracellular protein fibres that gives the tissue strength and toughness.
- Binding
- Resists tension/mechanical stress
- Fat storage
- Provides reservoir for water and salts
How many types of connective tissue proper are there and where can they be found?
- 6 different types of connective tissue proper
- Can be found in adipose(fat)
- under (supporting) epithelia
- ligaments (connect bones)
What is the function of Cartilage connective tissue?
- Resists compression (high level of water in the matrix)
2. Cushions and supports body structures
What are the types of connective tissue Cartilage?
- Hyaline
- Elastic
- Fibrocartilage
What is the function of Bone connective tissue?
- Very hard; resists compression and tension
2. Support
What are the types of Bone connective tissue?
- Compact
2. Spongy
