Chapter 3
Connective Tissue
Muscle Tissue
Nervous Tissue
Connective TissueConnective Tissue
Found everywhere in the body
Includes the most abundant and widely distributed tissues
Functions
Binds body tissues together
Supports the body
Provides protection
Transportation
Connective Tissue CharacteristicsConnective Tissue Characteristics
Vascularized (except tendons, ligaments and cartilage)
Extracellular matrix
Non-living material that surrounds different types of living cells
Extracellular MatrixExtracellular Matrix Ground substance
Mostly water – absorbs water Adhesion proteins – serves as glue Polysaccharide molecules – as number of molecules
goes up, tissue goes from fluid to rock hard Fibers
Three types Collagen fibers (white) Elastic fibers (yellow) Reticular fibers (fine collagen)
Collagen FibersCollagen Fibers
Collagen Fibers as seen with a scanning electron microscope
Composed of:
Interwoven strands of the protein collagen.
Thick fibers with great tensile strength – i.e., it’s tough to pull them apart.
Tendons, ligaments and the deep layers of the skin
Elastic FibersElastic Fibers
In this slide, “A” is an elastic fiber – what do you suppose “B” is?
Composed of:
A protein called elastin, whose coiled structure allows it to stretch and snap back like a rubber band.
Account for the ability of the lungs, arteries, and skin to spring back after they are stretched.
Reticular FibersReticular Fibers
Composed of:
A thinner collagen fiber coated with glycoproteins.
These fibers can branch extensively and form networks for certain organs.
Osseous Tissue (Bone)Osseous Tissue (Bone) Composed of:
Cells called osteoblasts that secrete hard matrix of calcium salts and surround themselves in it until they become trapped in little cavities known as lacunae
Once enclosed in lacunae, cells are called osteocytes.
Hard matrix of calcium salts
Large numbers of collagen fibers
Functions:
Used to protect and support the body
CartilageCartilage1
2 3
3 types (classified based on fiber differences):
Hyaline Cartilage
Elastic Cartilage
Fibrocartilage
CartilageCartilage Avascular
Without blood supply
Healing of torn cartilage is a long process
Chondrocytes produce antiangiogenesis factor that prevents the growth of blood vessels.
Why do you suppose shark cartilage could be a possible aid in the fight against cancer?
Figure 3.18a
Hyaline CartilageHyaline Cartilage Most common cartilage
Composed of:
Abundant collagen fibers
Rubbery matrix
Locations:
Entire fetal skeleton is hyaline cartilage
Attaches ribs to the sternum.
Functions:
Precursor of bone in fetal skeleton
Structural attachment
Figure 3.18b
Elastic CartilageElastic Cartilage Locations:
External ear
Epiglottis – flap of tissue that covers the trachea
Functions:
Provides flexible support
What happens when you bend and release your ear?
FibrocartilageFibrocartilage Locations:
Intervertebral discs between vertebrae
Meniscus (shock-absorbing pads of cartilage) in the knee joint.
Functions:
Resists compression and absorbs shock in some joints
Dense Connective TissueDense Connective Tissue Composed of:
Main matrix element is collagen fibers
Cells are fibroblasts (manufacture fibers)
Locations and Functions:
Tendon – attach muscle to bone
Ligaments – attach bone to bone
Figure 3.18d
Areolar Connective TissueAreolar Connective Tissue
Most widely distributed connective tissue
Soft, pliable tissue
Can soak up excess fluid; reservoir of water
Composed of:
All 3 fiber types (loose arrangement)
Highly vascularFigure 3.18e
Areolar Connective TissueAreolar Connective Tissue Locations:
Underlying epithelia
Surrounds blood vessels, nerves, and esophagus
Functions: Binds epithelia to deeper
tissues
Allows passage of nerves and blood vessels through other tissues
Provides an arena for immune defense
Can soak up excess fluid
Adipose TissueAdipose Tissue Composed of:
Matrix in which fat globules predominate
Adipocytes contain large fat deposits
Locations: Subcutaneous fat beneath skin
Breast
Functions: Insulation and protection
Serves as a fuel storage
Reticular Connective Tissue Reticular Connective Tissue Composed of:
Delicated network of interwoven reticular fibers
Numerous white blood cells
Locations and Functions: Forms stroma (internal
supporting network) of lymphoid organs
Lymph nodes
Spleen
Bone marrow
Figure 3.18g
BloodBlood
Composed of: Blood cells surrounded
by fluid matrix
Fibers are visible during clotting only
Functions: Transport vehicle for
materials
Figure 3.18h
Muscle TissueMuscle Tissue
Function is to produce movement
Three types Skeletal muscle
Cardiac muscle
Smooth muscle
Skeletal Muscle Skeletal Muscle
Can be controlled voluntarily
Cells attach to connective tissue
Cells are striated
Cells have more than one nucleus
Figure 3.19b
Cardiac Muscle Cardiac Muscle Found only in the
heart
Function is to pump blood (involuntary)
Cells attached to other cardiac muscle cells at intercalated disks
Cells are striated
One nucleus per cell (uni-nucleate)
Figure 3.19c
Smooth Muscle Smooth Muscle
Involuntary muscle
Surrounds hollow organs
Attached to other smooth muscle cells
No visible striations
One nucleus per cell
Figure 3.19a
Nervous TissueNervous Tissue
Composed of:
Neurons and nerve support cells
Function:
Irritability
Conductivity
ResponsivenessFigure 3.20
Tissue RepairTissue Repair
1. Regeneration Replacement of destroyed tissue by the
same kind of cells
2. Fibrosis Repair by dense fibrous connective tissue
(scar tissue)
Determination of method Type of tissue damaged
Severity of the injury
Events in Tissue RepairEvents in Tissue Repair
Capillaries become very permeable Introduce clotting proteins
Wall off injured area
Formation of granulation tissue
Regeneration of surface epithelium
Regeneration of TissuesRegeneration of Tissues
Tissues that regenerate easily Epithelial tissue
Fibrous connective tissue and bone
Tissues that regenerate poorly Skeletal muscle
Tissues that are replaced largely with scar tissue Cardiac muscle
Nervous tissue within the brain and spinal cord