tissues: the living fabric ch 4 b connective tissue
TRANSCRIPT
Tissues: Tissues: The living The living
fabricfabricCh 4 b
Connective Tissue
First
Let’s review Epithelial tissue
What type is this?
Simple cuboidal epithelium
What type is this?
Simple cuboidal epithelium
What type is this?
Transitional epithelium
What type is this?
Transitional epithelium
What type is this?
Pseudostratified epithelium
Pseudostratified epithelium
What is this called?
Pseudostratified epithelium
What is this called? Cilia!
What type is this?
Stratified squamous epithelium
What tissue is
this?
What type is this?
Simple columnar epithelial tissue
Connective Tissue
Connective Tissue
•Found throughout the body•Most abundant and most widely distributed
Connective Tissue
•Four Main classes–Connective tissue proper
•Includes fat and fibrous tissue of ligaments
–Cartilage–Bone–Blood
Functions of Connective Tissue
•Binding and support•Protection•Insulation•Transportation
–blood
Characteristics of Connective Tissue
• Connective tissues have:–Common origin
•Arise from Mesenchyme (an embryonic tissue)
–Varying degrees of vascularity•From avascular to rich in blood vessels
Characteristics of Connective Tissue
•Has large amounts of nonliving extracellular matrix, consisting of ground substance and fibers
Structural Elements of Connective Tissue
• Has 3 main elements:• 1. Ground substance –
unstructured material that fills the space between cells
• 2. Fibers – collagen, elastic, or reticular
Structural Elements of Connective Tissue
• Has 3 main elements:
• 3. Cells – fibroblasts, chondroblasts, osteoblasts, and hematopoietic stem cells
Structural Elements of Connective Tissue
• Ground substance and fibers make up the matrix
Ground Substance• Functions as a molecular sieve
through which nutrients diffuse between blood capillaries and cells
Proteoglycan Structure
Ground Substance
• Composed of:– Interstitial (tissue) fluid–Adhesion proteins– serves as the glue
–Proteoglycans – (protein core with glycosaminoglycans (GAGs) attached•Traps water
Fibers – 3 types •Collagen –
–Strongest, most abundant; –tough and provides high tensile strength
–(stronger than steel fibers the same size)
–Glistening white appearance – called white fibers
Fibers•Elastic –
–long, thin fibers –form branching network–allows for stretch–Contains rubber-like protein called elastin
–Appear yellow so sometimes called yellow fibers
Fibers•Reticular –
–branched collagenous fibers – form delicate networks–Abundant where connective tissue abuts other tissue types•Basement membrane of epithelial
•Form nets around capillaries
CellsImmature and Mature forms
• Actively mitotic immature cells that secrete ground substance and fibers in their particular matrix
CellsImmature and Mature forms
• Fibroblasts – connective tissue proper
• Chondroblasts – cartilage • Osteoblasts – bone• Hematopoietic stem cells – blood
Cells• Once matrix is synthesized, the
blast cells mature into less active cells (indicated by the suffix –cyte)
• Hematopoietic stem cells are always actively mitotic
• Other cell types in connective tissue include White blood cells, plasma cells, macrophages, and mast cells
Types of Types of Connective TissueConnective Tissue
Connective Tissue: Embryonic
•Mesenchyme – embryonic connective tissue–Gel-like ground substance with fibers and star-shaped mesenchymal cells
–Gives rise to all other connective tissues
–Found in the embryo
Connective Tissue: Embryonic
Figure 4.8a
Connective Tissue Proper
•2 subclasses
•Loose connective tissue–Areolar, adipose, and reticular
•Dense connective tissue–Dense regular, dense irregular, and elastic
Connective Tissue Proper: Loose
•Areolar connective tissue–Gel-like matrix with all three connective tissue fibers
–Fibroblasts, macrophages, mast cells, and some white blood cells
–Wraps and cushions organs–Widely distributed throughout the body
Areolar Connective Tissue
Figure 4.8b
Connective Tissue Proper: Loose
•Adipose connective tissue–Matrix similar to areolar connective tissue with closely packed adipocytes (fat cells)
–Reserves food stores, insulates against heat loss, and supports and protects
Connective Tissue Proper: Loose
•Adipose connective tissue–Found under skin, around kidneys, within abdomen, and in breasts
–Local fat deposits serve nutrient needs of highly active organs
Connective Tissue Proper: Loose
•Adipose connective tissue–Abundant – –average person 18% of body weight is adipose
–Chubby person body can be 50% adipose tissue
Adipose
Figure 4.8c
Connective Tissue Proper: Loose
•Reticular connective tissue–Loose ground substance with reticular fibers
–Reticular cells that lie in a fiber network–Forms a soft internal skeleton, or stroma, that supports other cell types
Connective Tissue Proper: Loose
•Reticular connective tissue–Found in lymph nodes, bone marrow, and the spleen
Reticular Connective Tissue
Figure 4.8d
Connective Tissue Proper: Dense Regular
•Parallel collagen fibers with a few elastic fibers
•Major cell type is fibroblasts
•Attaches muscles to bone or to other muscles, and bone to bone
•Found in tendons, ligaments, and aponeuroses
Dense Regular Connective tissue
Figure 4.8e
Connective Tissue Proper: Dense Irregular
•Irregularly arranged collagen fibers with some elastic fibers
•Major cell type is fibroblasts•Withstands tension in many
directions providing structural strength
Connective Tissue Proper: Dense Irregular
•Found in the dermis, submucosa of the digestive tract, and fibrous organ capsules
Dense Irregular
Figure 4.8f
Cartilage• Stands up to tension and
compression• Tough but flexible• Lacks nerve fibers• Avascular• Cartilage matrix is up to 80%
water• Heals very slowly
Cartilage
•3 types – –hyaline–elastic–fibrocartilage
Connective Tissue: Hyaline Cartilage
• Most abundant• Glassy blue white appearance• Supports, reinforces, cushions, and
resists compression• Forms the costal cartilage • Found in embryonic skeleton, the
end of long bones, nose, trachea, and larynx
Connective Tissue: Hyaline Cartilage
Figure 4.8g
Connective Tissue: Elastic Cartilage
• Similar to hyaline cartilage but with more elastic fibers
• Maintains shape and structure while allowing flexibility
• Supports external ear (pinna) and the epiglottis
Connective Tissue: Elastic Cartilage
Figure 4.8h
• Similar to hyaline cartilage but with more elastic fibers
• Maintains shape and structure while allowing flexibility
• Supports external ear (pinna) and the epiglottis
Connective Tissue: Fibrocartilage Cartilage
• Matrix similar to hyaline cartilage but less firm with thick collagen fibers
• Provides tensile strength and absorbs compression shock
• Found in intervertebral discs, the pubic symphysis, and in discs of the knee joint
Fibrocartilage Cartilage
Figure 4.8i
• Matrix similar to hyaline cartilage but less firm with thick collagen fibers
• Provides tensile strength and absorbs compression shock
• Found in intervertebral discs, the pubic symphysis, and in discs of the knee joint
Connective Tissue: Bone (Osseous Tissue)
• Hard, calcified matrix with collagen fibers found in bone
• Osteocytes are found in lacunae and are well vascularized
• Supports, protects, and provides levers for muscular action
Connective Tissue: Bone (Osseous Tissue)
• Stores calcium, minerals, and fat• Marrow inside bones is the site of
hematopoiesis (blood formation)
Bone (Osseous Tissue)
Figure 4.8j
Connective Tissue: Blood
•Red and white cells in a fluid matrix (plasma)
•Contained within blood vessels
•Functions in the transport of respiratory gases, nutrients, and wastes
Connective Tissue: Blood
Figure 4.8k
What kind is this?
Reticular connective tissue
Hyaline Cartilage
What kind is this?
Adipose (fat)
What kind is this?
Adipose (fat)
What kind is this?
Adipose (fat)
What kind is this?
Blood
What kind is this?
Blood
What kind is this?
Blood
What kind is this?
Dense Regular connective
What kind is this?
Dense Regular connective
What kind is this?
Dense Irregular connective
Quiz – Next time!
I will be checking study guides pages 8-
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