3 Histology Flashcards
What are the Four tissue types?
Epithelial (cover), muscle (contract), connective (connect), nervous (conduct)
What are the special characteristics of epithelial tissue?
Highly cellular, polar, attached, avascular, innervated, high regeneration capacity
General characteristics of connective tissue:
Diverse: all contain cells, protein fibers, and ground substance
General characteristics of muscle tissue:
Contractile. Contractile response is stimulated by nervous and/or endocrine system
General characteristics of nervous tissue?
Two types: neurons and glial cells
Neurons are excitable, high metabolic rate, non-mitotic, have extreme longevity
Glial cells are not excitable and mitotic.
General functions of epithelial tissue?
Covers surfaces: lines body cavities and organs.
General functions of connective tissue?
Protection, connection, and support
General functions of muscle tissue?
Movement. Of skeleton or organ walls.
General fn nervous tissue?
Neurons: control activities and transfer information
Glial cells: support, protect, and provide energy for neurons
Germ layer of epithelium?
All. Ectoderm, mesoderm, and endoderm.
Germ of connective tissue?
Mesoderm
Germ layer of muscle tissue?
Mesoderm
Germ layer of nervous tissue?
Ectoderm
What are the functions epithelial tissue?
Physical protection, selective permeability, secretion, sensation.
What kinds of junctions hold together epithelial cells?
Tight junctions
Adhering junctions
Desmesomes
Gap junctions
What is the purpose of tight junctions and where do they appear?
They appear near apical surface sealing the circumference of epithelial cells and forcing transport of fluids and other molecules through their cellular membranes,
Purpose and location of adhering junctions?
Deep to the tight junctions. Sealed for a length. Designed for strength.
Desmesomes
Peptide connections that occur at single stress points to reinforce cell wall.
Gap junctions
Provide molecule/ion transport
What are cilia and where do they appear?
On apical surface of certain epithelial tissues. Motile. Move stuff along them. e.g. Smokers cough/mucous ladder in lungs.
What are microvilli and where do they appear?
They appear also on apical surface. Designed to increase surface area. e.g. Kidney tubules and small intestine.
What is the function of simple squamous epithelium and where is it found?
Fns: diffusion, filtration
Locations: alveoli, lining of blood vessels/capillaries, serous membranes
What are the functions of simple cuboidal and where can it be found?
Fns: absorption and secretion
Locations: thyroid gland, kidney tubules, ovary, and most endocrine and exocrine glands.
What are the functions of simple columnar and where is it found?
Fns: absorption, secretion, and movement ( often have cilia associated)
Locations: non-ciliated in stomach, bladder, and uterine tubes. With microvilli in small intestine.