Chapter 3 Part II: Histology Flashcards
What are the four primary types of tissues?
epithelial, connective, nervous, and muscle tissues
What is the epithelium?
The covering of a body surface or the lining of a body cavity.
What is the function of the epithelium? (7)
-Protection from dehydration
-Protection from chemical and mechanical damage
-Absorption
-secretion
-ion transport
-Filtration
-Forms slippery surfaces
What are the special characteristics of epithelial cells? (6)
• Cellularity
• Specialized contacts/junctions
• Polarity
• Support by connective tissue
• Avascular but innervated
• Regeneration
What does ‘epi’ mean?
surface
What does innervated mean?
contains nerve endings
What does cellularity mean?
composed almost entirely of sheets of cells, separated by minimal amount of extra-cellular material
What does polarity mean in epithelial cells?
they have an upper (apical) and lower (basal) surface
What are the main types of Epithelia?
Surface and Glandular Epithelia
What is the surface epithelia?
consists of tightly packed cells that form a continuous layer covering the body surface (skin) or lining body cavities
What are the glandular epithelia?
secretory epithelial cells that form Exocrine and Endocrine glands
How are epithelia given their name?
First name indicated number of cells, last name describes the shape of the cells
What are the three types of number classifications given for epithelial cells?
simple, stratified, pseudostratified
What are the three types of tissue shapes?
Squamous
Cuboidal
Columnar
What is the basic description of simple squamous epithelium
single layer flat-cells with disc-shaped nuclei
What are the special types of simple squamous epithelium?
Endothelium
Mesothelium
What is the endothelium?
Thin and flattened lining of hollow organs
What is the function of mesothelium?
Lines serous or ventral body cavities and covers visceral organs of those cavities
What are the functions of simple squamous epithelium? (2)
- Passage of materials by passive diffusion and filtration
- Secretes lubricating substances in serosae
Where can simple squamous epithelium be found? (6)
- Alveoli of lungs
- Lining of heart
- blood
- lymphatic vessels
- Lining of ventral body cavity
- covering organs (serosae)
What are simple cuboidal epithelium cells?
single layer of cube-like cells with large, spherical central nuclei
What is the function of simple cuboidal epithelium?
secretion and absorption
Where is the location of simple cuboidal epithelium cells? (3)
- Kidney tubules,
- Secretory portions of small glands, salivary glands and pancreas
- Ovary surface
What is the description of Simple Columnar Epithelium?
single layer of column-shaped (rectangular) cells with oval nuclei
• Some bear cilia at their apical surface
• May contain goblet cells