Post on 24-Feb-2016
description
transcript
TissuesA. Tissue – a grouping of cells that are
similar in structure and perform a common or related function
B. Histology – the study of tissues; requires a microscope
C. 4 basic types1. Epithelial tissue (epithelium)2. Connective tissue3. Nervous tissue4. Muscle tissue
TissuesD. Epithelium
1. FunctionsA) ProtectionB) AbsorptionC) FiltrationD) ExcretionE) Secretion
Tissues2. General Categories
A) Lining & covering epitheliumB) Glandular epithelium
3. Characteristics of epitheliumA) Cellularity – almost entirely cellsB) Polarity
1) Apical border
Tissues2) Basement membrane
C) Connective tissue supportD) Innervated but avascularE) Highly reproductive
4. Classification – many types named according to the number of cell layers and the cell’s shape
TissuesA) Number of cell layers
1) Simple2) Stratified
B) Cell’s shape1) Squamous2) Cuboidal3) Columnar
TissuesC) Types of epithelium
1) Simple squamousa) Lines the
systemic capillaries, glomeruli in the kidneys & alveoli in the lungs
b) Filtration, absorption & secretion
Tissues2) Stratified
squamousa) Nonkeratinized
i) Lines the mouth, esophagus & vagina
ii) Protection
Tissuesb) Keratinized
i) Makes up the epidermis of skin
ii) Protection3) Simple cuboidal
a) Found in the kidney tubules & secretory ducts of small glands
Tissuesb) Secretion &
absorption4) Simple columnar
– may be ciliated & contain goblet cellsa) Lines the
majority of the digestive tract
Tissuesb) Absorption,
secretion of mucus & enzymes, propulsion
5) Transitionala) Lines the ureters,
bladder & parts of urethra
b) Can be compressed without damage providing protection
Tissues6) Pseudostratified
columnar – may be ciliated & have goblet cellsa) Found in portions
of respiratory tract (trachea & bronchi)
b) Secretion & propulsion of mucus
TissuesE. Connective Tissue
1. CharacteristicsA) Common origin
1) MesenchymeB) Varying vascularityC) Extracellular matrix
Tissues2. Structural components
A) Ground substance – fills space between cells and contains the protein fibers
B) Protein fibers – provide support & flexibility1) Collagen fibers2) Elastic fibers3) Reticular fibers
TissuesC) Cells
1) Fibroblasts – connective tissue proper
2) Chondrocytes – cartilage3) Osteocytes – bone or osseous tissue
4) Hemocytes – blood5) Adipocytes – adipose
3. Types of Connective Tissue
TissuesA) Areolar (loose)
connective tissue1) All 3 fiber types2) Most widely
distributed CT in body
3) Serves to hold organs together while allowing movement
TissuesB) Dense regular connective tissue1) Collagen fibers
dominate – very strong
2) Run in a parallel arrangement
3) Strength dependent on direction of force
4) Forms tendons and ligaments
TissuesC) Dense irregular
connective tissue1) Collagen fibers
dominate but in an irregular arrangement
2) Strength in multiple directions
3) Dermis of skin, joint capsules
TissuesD) Adipose (fat)
tissue1) Scanty matrix2) Highly vascular3) Serves
protective function (cushioning organs), prevents heat escape, energy storage
4) Under skin, around kidneys, in breasts
TissuesE) Cartilage – 3 types
1) Hyaline cartilagea) Large number
of collagen fibersb) Chondrocytes
within lacunaec) End of long
bones, nose, trachea & larynx
Tissues2) Elastic cartilage
a) Almost identical to hyaline but with increased elastic fibers
b) Support with great flexibility
c) Outer ear & epiglottis
Tissues3) Fibrocartilage
a) Alternating rows of chondrocytes and collagen fibers
b) Has great compression abilities and resist tension
c) Intervertebral discs & menisci of the knee
TissuesF) Bone (osseous
tissue)1) Similar to
cartilage in structure but more collagen fibers and the presence of calcium salts (make bone hard)
2) Osteoblasts & osteocytes in lacunae
TissuesG) Blood
1) Matrix = plasma2) Fibers are
soluble and seen only during clotting
3) Functions in transport and protection
TissuesF. Nervous Tissue
1. Neurons – generate & conduct impulses
2. Neuroglial cells (neuroglia) – non-conducting cellsA) provide
support for neurons
TissuesG. Muscle Tissue
1. Composed of muscle fibers (cells) containing myofilamentsA) protein fibers that function in contraction
2. Functions primarily for movement3. Three types
TissuesA) Skeletal
1) Striated (striped) appearance
2) Multinucleated3) Voluntary4) Makes up all
skeletal muscles
TissuesB) Smooth
1) Non-striated appearance
2) Mononucleated3) Involuntary4) Found around
the hollow organs and structures of the body (except heart)
TissuesC) Cardiac
1) Striated appearance with prominent intercalated discs
2) Mononucleated3) Branching4) Involuntary5) Found only in
the heart