NURS 301 Lecture Notes - Lecture 1: Transitional Epithelium, Free Surface, Histology
Tissues
Mass of similar cells and their products with a particular
function
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Organs are made up of tissues
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Histology: study of cells and tissues using a microscope
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Different types of tissues are classified by what their cells do
and the surrounding extracellular material = matrix
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4 Classes of Tissues
Epithelial
Epi=above surface
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Classified by shape and arrangement of cells
Flat and short = squamous
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Cube shape = cuboidal
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Rectangular = columnar
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Layers
Simple
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Columnar
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Stratified
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Pseudo = not stratified
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Transitional epithelium
Changes shape e.g. when bladder fills
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Covers free surfaces of the body
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Cells are tightly packed in a sheet
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Lines body cavities and ducts
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Forms glands
Secretions
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Avascular (no blood vessels in tissue)
Nutrients from tissues with blood vessels and glucose
diffuse to epithelium
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High rate of division
E.g. skin cells always getting replaced
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Can have abnormal growth or abnormal cells
Can lead to tumors and cancer
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Cell polarity, a free surface (apical) and the attachment
surface (basal)
Basal - where the cells are attached to underlining
tissue
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Connective
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Muscle
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Nervous
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Glands
Consist of one or more cells that secrete particular substances
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Endocrine glands: secrete directly into interstitial fluids;
secretion of hormones
Secretes hormone into blood
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Exocrine glands: secrete into ducts that open on to surfaces
(e.g. on to skin or into lumen of a hallow organ); secretions
include mucus, sweat, oil, wax, and digestive enzymes
Uses duct to secrete to body surface or cavity
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Classified by cells secrete their substances, type of
secretion, and structure of gland cells and duct
Types of secretions: serous (watery) fluid, mucous,
mixture
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Structure: unicellular (goblet cells) or multicellular
Multicellular structure classification based on
duct branching, shape or secreting cells, and
arrangement of gland cells around ducts
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Simple glands
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Compound glands
Branching pattern with ducts connected to other ducts
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Three Ways of Exocrine Secretion
Merocrine
Produces little "bags" released at surface e.g. sweat glands
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1.
Apocrine
Part of cell is lost e.g. breast milk
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2.
Holocrine
Whole cell burst open, cell dies in order to secrete e.g. oil
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3.
Connective Tissue
Most abundant and widely distributed tissue in body
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Cells secrete matrix (extracellular material)
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Variety of cell types may be found
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Vascularize (blood vessels present)
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Composed of cells in an extracellular matrix
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Matrix is fluid, gel, or solid
Ground substance with polysaccharides and proteins;
hyaluronic acid - slippery binding substance
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Fivers: collage (providing flexible strength), elastic
(stretch and recoil), and reticular (stabilizing)
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Connective Tissues divide into:
Connective tissue proper
Loose
Fibers, create loose, open framework
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Fat, fibers densely packed
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Dense
Tough, strong
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Fluid connective tissues
Blood, contained in circulatory system
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Lymph
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Supporting connective tissue, less diverse cell types
Cartilage, solid rubbery matrix
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Bone, solid, crystal line matric, protection
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Online Lecture - Week 1
Sunday, March 25, 2018
11:31 PM
Document Summary
Mass of similar cells and their products with a particular function. Histology: study of cells and tissues using a microscope. Different types of tissues are classified by what their cells do and the surrounding extracellular material = matrix. Nutrients from tissues with blood vessels and glucose diffuse to epithelium. Cell polarity, a free surface (apical) and the attachment surface (basal) Basal - where the cells are attached to underlining tissue. Consist of one or more cells that secrete particular substances. Endocrine glands: secrete directly into interstitial fluids; secretion of hormones. Exocrine glands: secrete into ducts that open on to surfaces (e. g. on to skin or into lumen of a hallow organ); secretions include mucus, sweat, oil, wax, and digestive enzymes. Uses duct to secrete to body surface or cavity. Classified by cells secrete their substances, type of secretion, and structure of gland cells and duct. Types of secretions: serous (watery) fluid, mucous, mixture.
