ANSWER THE ESSAYS AND THE QUESTIONS
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APLECTURE2A.pptBody Tissues
Lecture 4 August 7th 2013
Tissues
Groups of cells similar in structure and function
4 Primary Tissue Types
- Epithelium
- Connective tissue
- Nervous tissue
- Muscle
Tissue Functions
- Epithelium
- Covering
- Connective
- Support
- Muscle
- Movement
- Nervous
- Control
Location of Tissues
- Depends on organ
- Most organs contain several tissue types
- Arrangement tissues determines
- Organ structure & function
Histology
- Study of tissues
Epithelial Tissue
- Lining, covering, glandular tissue
- Forms various glands
- Covers all free body surfaces
- Line body cavities
- Forms boundaries
Epithelial Tissue Function & Location
- Protection
- Absorption
- Filtration
- Secretion
- Epithelium of skin
- Lining of respiratory tract
- Lining of stomach and small intestine
- Kidneys
- Glands
Function
Location
Characteristics of Epithelium
- Cells
- Close together
- Form continuous sheets
- Cell junctions
- Membranes
- Apical Surface
- Basement Membrane
- Avascular
- Regenerate easily
Classification of Epithelium
- Simple epithelium
- One layer of cells
- Stratified epithelium
- More than one cell layer
- Cells at free surface
- Squamous
- Flat cells
- Cuboidal
- Cube-shaped
- Columnar
- Column-shaped
Number of Cell Layers
Shape of Cells
Simple Epithelia Functions
- Absorption
- Secretion
- Filtration
Types of Simple Epithelia
- Simple Squamous
- Simple Cuboidal
- Simple Columnar
- Pseudostratified Columnar
Simple Squamous Epithelium
- Single layer squamous cells
- Forms membranes
- Filtration
- Exchange substances
- Alveoli, walls capillaries, serous membranes
Simple Cuboidal Epithelium
- One layer cuboidal cells
- Glands, ducts, walls kidney tubules, surface ovaries
Simple Columnar Epithelium
- Single layer tall cells
- Goblet cells
- Lines digestive tract
Pseudostratified Columnar Epithelium
- Single layer of cells differing in height
- Appears stratified
- Absorption & secretion
- Pseudostratified ciliated columnar epithelium
- Respiratory tract
Stratified Epithelium Functions
- More durable
- Protection
Types of Stratified Epithelium
- Stratified squamous
- Stratified cuboidal
- Stratified columnar
- Transitional
Stratified Squamous Epithelium
- Most common stratified type in body
- Free edge – squamous
- Basement membrane – cuboidal or columnar
- Found in sites that receive abuse or friction
- Esophagus, mouth, outer skin
Stratified Cuboidal Epithelium
- Surface – cuboidal
- Rare in body
- Ducts of large glands
Stratified Columnar Epithelium
- Surface – columnar
- Rare in body
- Ducts of large glands
Transitional Epithelium
- Modified stratified squamous
- Lining bladder, ureters, urethra
Glandular Epithelium
- Gland
- One or more cells
- Secrete product
- Secretions
- Protein molecules
- Aqueous fluid
Types of Glands
- Ductless
- Secrete into blood
- Hormones
- Thyroid, adrenals, pituitary
- Ducts
- Secrete into duct
- Sweat and oil glands, liver, pancreas
Endocrine Gland
Exocrine Gland
Connective Tissue Function & Location
- Connects body parts
- Protecting
- Supporting
- Binding together other tissue
- Found everywhere in body
- Most abundant tissue
Function
Location
Characteristics of Connective Tissue
- Blood supply varies
- Most are vascularized
- Tendons, ligaments poor supply
- Cartilage avascular
- Cell types vary
- Amount extracellular matrix varies
- Nonliving substance
- Outside cells
Extracellular Matrix
- Why connective tissue differs
- Produced by connective tissue cells
- Secreted to exterior
- 2 elements
- Ground substance
- Fibers
Ground Substance
- Mostly water
- Adhesion proteins
- Glue
- Cells attach to matrix fibers
Fibers
- Collagen
- White
- Elastic
- Yellow
- Reticular
- Fine collagen
Functions provided by Extracellular Matrix
- Soft packing tissue around organs
- Bears weight
- Withstand stretching
- Withstand abrasion
- Adipose Tissue
- Mostly cells
- Soft matrix
- Bone/Cartilage
- Few cells
- Hard matrix
Connective Tissues Classification
- Bone
- Cartilage
- Dense Connective Tissue
- Loose Connective Tissue
- Areolar
- Adipose
- Reticular
- Blood
Bone
- Osseous tissue
- Bone cells in cavities
- Lacunae
- Hard matrix
- Calcium salts
- Collagen fibers
- Protects and supports other body organs
Cartilage
- More flexible than bone
- Found in few places in body
- Hyaline
- Fibrocartilage
- Elastic
Hyaline Cartilage
- Most widespread
- Abundant collagen fibers
- Rubbery matrix
- Glassy appearance
- Forms supporting structures
- larynx
- Attaches ribs to sternum
- Covers ends of bones at joints
- Fetal skeleton
Fibrocartilage
- Compressible
- Forms disks between vertebrae
Elastic Cartilage
- Provides elasticity Supports external ear
Dense Connective Tissue
- Collagen fibers
- Fibroblasts
- Fiber forming cells
- Tendons
- Attach muscles to bones
- Ligaments
- Connect bone to bone
- More elastic fibers
- Dermis
Loose Connective Tissue
- Softer
- More cells
- Fewer fibers
- Areolar
- Adipose
- Reticular
Areolar Tissue
- Most widely distributed connective tissue
- Cobwebby
- Cushions and protects body organs
- Packing tissue
- Holds internal organs in position
- Loose network of fibers
- Reservoir water and salts
- Cells obtain nutrients and release wastes in matrix
Adipose Tissue
- Fat
- Drop stored oil makes up volume fat cell
- Nucleus displaced to side
- Subcutaneous tissue beneath skin
- Insulates body
- Protects from extreme temp
- Protects organs
- Kidneys, eyeballs
Reticular Tissue
- Interwoven reticular fibers
- Reticular cells
- Lymphoid organs
- Lymph nodes, spleen, bone marrow
Blood
- Vascular tissue
- Blood cells
- Matrix
- Plasma
- Fibers only visible during clotting
Muscle Tissue Function & Location
- Specialized to contract (shorten) to produce movement
- Muscle fibers
- Elongated cells
- Skeletal muscles
- Cardiac muscle
- Hollow organs
Function
Location
Muscle Tissue Classification
- Skeletal Muscle
- Cardiac Muscle
- Smooth Muscle
Skeletal Muscle
- Attached to skeleton
- Voluntary control
- Muscular system
- Contraction pulls bones or skin
- Long, cylindrical, multinucleate cells
- Striations
Cardiac Muscle
- Heart
- Striations
- Uninucleate, branching cells
- Intercalated disks
- Cell junctions
- Involuntary control
Smooth Muscle
- No striations
- Single nucleus, spindle-shaped cells
- Walls hollow organs
- Stomach, bladder, uterus, blood vessels
- Slower contractions
- Involuntary control
Nervous Tissue
- Cells
- Neurons
- Supporting cells
- Neurons
- Irritability and conductivity
- Supporting Cells
- Insulate, support, protect neurons
