Week 3 Flashcards
What are the two main types of epithelial tissue?
- Covering and Lining epithelium
- Glandular epithelium
What is the function of covering and lining epithelium?
It forms the outer layer of the skin, lines body cavities, and covers the walls and organs within the body.
What are the key characteristics of epithelial tissue?
- Polarity (Apical and Basal Surfaces)
- Specialized Contacts (tight junctions, desmosomes)
- Supported by connective tissue (basement membrane)
- Avascular but innervated
- Strong regenerative ability
What is simple epithelium?
A single layer of cells, found in areas where absorption, secretion, and filtration occur (e.g., alveoli in lungs, kidney glomeruli).
What is stratified epithelium and where is it found?
Stratified epithelium consists of two or more layers of cells, found in areas exposed to mechanical stress (e.g., skin).
What is pseudostratified epithelium?
Pseudostratified epithelium appears to be stratified but is actually a single layer of cells, found in the respiratory tract.
What are the different cell shapes in epithelial tissue and their functions?
- Squamous: Flat and thin, for diffusion and filtration (e.g., blood vessels).
- Cuboidal: Cube-shaped, for secretion and absorption (e.g., kidney tubules).
- Columnar: Tall and rectangular, for secretion and absorption (e.g., digestive tract).
- Transitional: Cells change shape, for stretching (e.g., urinary bladder).
What are endocrine glands?
Endocrine glands are ductless, secrete hormones into the blood or lymph to target organs (e.g., pituitary, thyroid).
What are exocrine glands and how are they classified?
Exocrine glands secrete products onto epithelial surfaces via ducts. They are classified as:
1. Unicellular (e.g., goblet cells)
2. Multicellular (e.g., sweat glands, salivary glands
How are multicellular exocrine glands structurally classified?
- Based on duct structure:
Simple (unbranched ducts)
Compound (branched ducts) - Based on secretory units:
Tubular
Alveolar
Tubuloalveolar
What is connective tissue and its main function?
Connective tissue is the most prevalent tissue in the body and plays a critical role in supporting and connecting other tissues and organs
What are the four main classes of connective tissue?
- Connective Tissue Proper
- Cartilage
- Bone
- Blood
What are the functions of connective tissue?
- Binding and supporting
- Protecting
- Insulating
- Storing reserve fuel
- Transporting substances
What are the structural elements of connective tissue?
- Ground substance
- Fibres
- Specific cell types (e.g. -blast, -cyte)
What is the function of collagen fibres in connective tissue?
Collagen fibres provide high tensile strength and toughness
What is the function of elastic fibres in connective tissue?
Elastic fibres stretch and recoil like rubber bands, providing flexibility
What are reticular fibres and their function?
Reticular fibres are short, fine collagenous fibres that form delicate networks to support cells.
What is the difference between -blast and -cyte cells in connective tissue?
-blast cells are immature and actively proliferating, while -cyte cells are mature and maintain the health of the matrix
What is the function of white blood cells in connective tissue?
White blood cells (e.g. neutrophils, lymphocytes) are involved in immune responses.
What are the subtypes of connective tissue proper?
- Loose connective tissue
- Dense connective tissue
What is the function of areolar connective tissue?
Areolar connective tissue supports and binds tissues, defends against infection, holds body fluids, and stores nutrients.
What is the function of adipose tissue?
Adipose tissue stores energy (lipids), cushions, and insulates the body.
What is the function of dense regular connective tissue?
Dense regular connective tissue provides strength and structure, found in tendons, ligaments, and fascia.
What is the function of hyaline cartilage?
Hyaline cartilage provides strong support and shock absorption, found in joints.