copyright © 2010 pearson education, inc. connective tissue

52
pyright © 2010 Pearson Education, Inc. Connective Tissue

Upload: carmella-walton

Post on 16-Jan-2016

228 views

Category:

Documents


3 download

TRANSCRIPT

Page 1: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Connective Tissue

Page 2: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Connective Tissue

• Most abundant and widely distributed tissue type

• Four classes

• Connective tissue proper

• Cartilage

• Bone tissue

• Blood

Page 3: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Table 4.1

Page 4: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Functions of Connective Tissue

• Binding structures - connects tissues to one another – Tendons & ligaments

• Provide support and movement – bones

• Protection – bones, cells of the immune system.

• Serve as framework

• Transportation -blood

• Storage - fat

• Insulation - fat

Page 5: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Characteristics of Connective Tissue

• Connective tissues:

• Most abundant tissue type

• Varying degrees of vascularity

• Cells separated by nonliving extracellular matrix [ECM] (ground substance and fibers)

• Cells are not as abundant nor as tightly packed together as in epithelium

Page 6: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Structural Elements of Connective Tissue

• The major components of CT:

• Matrix

• Cells

Page 7: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Structural Elements of Connective TissueMatrixMatrix

• Connective Tissues do not form cellular membranes like epithelial tissues.

• Instead, scattered cells are dispersed in a substance called ECM (extracellular matrix).

• The matrix constitutes the nonliving extracellular material.

• The characteristics of the matrix are responsible for the nature of the specific CT.

• Two materials compose the matrix:

• Ground substance

• Fibers

Page 8: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Structural Elements of Connective TissueGround substance

• Homogeneous material consisting largely of a complex mixture of proteins produced by CT cells.

• Medium through which solutes (nutrients) diffuse between blood capillaries and cells

• It occupies the area around the cells and fibers

• Components:

• Interstitial fluid

• Adhesion proteins (“glue”)

• Proteoglycans

• Protein core + large polysaccharides (chrondroitin sulfate and hyaluronic acid)

• Trap water in varying amounts, affecting the viscosity of the ground substance

Page 9: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Structural Elements of Connective TissueFibers – three types

• Collagenous – “white fibers”

• Composed of collagen (white fibers)

• Strongest and most abundant type (dense CT)

• Provides high tensile strength

• Holds structures together

• Tendons, ligaments

• Elastic – “yellow fibers”

• Networks of long, thin, elastin fibers that allow for stretch & recoil

• Vocal Cords and air passages

• Reticular

• Short, fine, highly branched collagenous fibers

• Form supportive networks & provides strength

Page 10: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Structural Elements of Connective TissueCellsCells

• Cells – varies according to tissue

• The structural cell for the tissue is commonly named according to the tissue type (prefix) and its activity (suffix)

• Mitotically active and/or building cell/secretory cells = “blasts”

• Mature nondividing maintenance cell = “cytes”

• Fibroblasts in connective tissue proper

• Chondroblasts and chondrocytes in cartilage

• Osteoblasts and osteocytes in bone

• Hematopoietic stem cells in bone marrow

• Fat cells, white blood cells, mast cells, and macrophages

Page 11: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Structural Elements of Connective Tissue

Major Cell Types Present

• Fibroblasts

• Fixed cell

• Most common cell

• large, star-shaped

• Produce fibers

• Macrophages

• Wandering Cell

• Phagocytic

• Important in injury or infection

• Mast Cells

• Fixed cell

• Release heparin

• Release histamine

Page 12: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.7

Macrophage

Fibroblast

Lymphocyte

Fat cell

Mast cell

Neutrophil

Capillary

Cell types Extracellularmatrix

Fibers• Collagen fiber• Elastic fiber• Reticular fiber

Ground substance

Page 13: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Classification of Connective Tissues

• CT classification is based upon these three structural characteristics of the matrix:

• Types of fibers

• Type of ground substance, and

• The structural arrangement

Page 14: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Classification of Connective Tissues

Page 15: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Classification of Connective Tissues

Page 16: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Overview of Connective Tissues

• For each of the following examples of connective tissue, note:

• Description

• Function

• Location

Page 17: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Connective Tissue Proper

• Types:

• Loose connective tissue – has a loose arrangement of fibers

• Areolar

• Adipose

• Reticular

• Dense connective tissue – has a dense arrangement of fibers

• Dense regular

• Dense irregular

• Elastic

Matrix: Flexible, viscous ground substance & have abundant fibersCells: Structural cells called fibroblasts

Page 18: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

(a) Connective tissue proper: loose connective tissue, areolar

Description: Gel-like matrix with allthree fiber types; cells: fibroblasts,macrophages, mast cells, and somewhite blood cells.

Function: Wraps and cushionsorgans; its macrophages phagocytizebacteria; plays important role ininflammation; holds and conveystissue fluid.

Location: Widely distributed underepithelia of body, e.g., forms laminapropria of mucous membranes;packages organs; surroundscapillaries.

Photomicrograph: Areolar connective tissue, asoft packaging tissue of the body (300x).

Epithelium

Laminapropria

Fibroblastnuclei

Elasticfibers

Collagenfibers

Figure 4.8a

Loose CT - Areolar

Page 19: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.8b

(b) Connective tissue proper: loose connective tissue, adipose

Description: Matrix as in areolar,but very sparse; closely packedadipocytes, or fat cells, havenucleus pushed to the side by largefat droplet.

Function: Provides reserve foodfuel; insulates against heat loss;supports and protects organs.

Location: Under skin in thehypodermis; around kidneys andeyeballs; within abdomen; in breasts.

Photomicrograph: Adipose tissue from thesubcutaneous layer under the skin (350x).

Nucleus offat cell

Vacuolecontainingfat droplet

Adiposetissue

Mammaryglands

Loose CT - Adipose

Page 20: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.8c

(c) Connective tissue proper: loose connective tissue, reticular

Description: Network of reticularfibers in a typical loose groundsubstance; reticular cells lie on thenetwork.

Function: Fibers form a soft internalskeleton (stroma) that supports othercell types including white blood cells,mast cells, and macrophages.

Location: Lymphoid organs (lymphnodes, bone marrow, and spleen).

Photomicrograph: Dark-staining network of reticularconnective tissue fibers forming the internal skeletonof the spleen (350x).

Spleen

White bloodcell(lymphocyte)

Reticularfibers

Loose CT - Reticular

Page 21: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.8d

(d) Connective tissue proper: dense connective tissue, dense regular

Description: Primarily parallelcollagen fibers; a few elastic fibers;major cell type is the fibroblast.

Function: Attaches muscles tobones or to muscles; attaches bonesto bones; withstands great tensilestress when pulling force is appliedin one direction.

Location: Tendons, mostligaments, aponeuroses.

Photomicrograph: Dense regular connectivetissue from a tendon (500x).

Shoulderjoint

Ligament

Tendon

Collagenfibers

Nuclei offibroblasts

Dense CT – Dense regular

Page 22: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.8e

(e) Connective tissue proper: dense connective tissue, dense irregular

Description: Primarilyirregularly arranged collagenfibers; some elastic fibers;major cell type is the fibroblast.

Function: Able to withstandtension exerted in manydirections; provides structuralstrength.

Location: Fibrous capsules oforgans and of joints; dermis ofthe skin; submucosa ofdigestive tract.

Photomicrograph: Dense irregularconnective tissue from the dermis of theskin (400x).

Collagenfibers

Nuclei offibroblasts

Fibrousjointcapsule

Dense CT – Dense irregular

Page 23: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.8f

(f) Connective tissue proper: dense connective tissue, elastic

Description: Dense regularconnective tissue containing a highproportion of elastic fibers.

Function: Allows recoil of tissuefollowing stretching; maintainspulsatile flow of blood througharteries; aids passive recoil of lungsfollowing inspiration.

Location: Walls of large arteries;within certain ligaments associatedwith the vertebral column; within thewalls of the bronchial tubes.

Elastic fibers

Aorta

HeartPhotomicrograph: Elastic connective tissue inthe wall of the aorta (250x).

Dense CT - Elastic

Page 24: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Connective Tissue: Cartilage

• Three types of cartilage:

• Hyaline cartilage

• Elastic cartilage

• Fibrocartilage

Page 25: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.8g

(g) Cartilage: hyaline

Description: Amorphous but firmmatrix; collagen fibers form animperceptible network; chondroblastsproduce the matrix and when mature(chondrocytes) lie in lacunae.

Function: Supports and reinforces;has resilient cushioning properties;resists compressive stress.

Location: Forms most of theembryonic skeleton; covers the endsof long bones in joint cavities; formscostal cartilages of the ribs; cartilagesof the nose, trachea, and larynx.

Photomicrograph: Hyaline cartilage from thetrachea (750x).

Costalcartilages

Chondrocytein lacuna

Matrix

Cartilage - Hyaline

Page 26: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.8h

(h) Cartilage: elastic

Description: Similar to hyalinecartilage, but more elastic fibersin matrix.

Function: Maintains the shapeof a structure while allowinggreat flexibility.

Location: Supports the externalear (pinna); epiglottis.

Photomicrograph: Elastic cartilage fromthe human ear pinna; forms the flexibleskeleton of the ear (800x).

Chondrocytein lacuna

Matrix

Cartilage - Elastic

Page 27: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.8i

(i) Cartilage: fibrocartilage

Description: Matrix similar tobut less firm than that in hyalinecartilage; thick collagen fiberspredominate.

Function: Tensile strengthwith the ability to absorbcompressive shock.

Location: Intervertebral discs;pubic symphysis; discs of kneejoint.

Photomicrograph: Fibrocartilage of anintervertebral disc (125x). Special stainingproduced the blue color seen.

Intervertebraldiscs

Chondrocytesin lacunae

Collagenfiber

Cartilage - Fibrocartilage

Page 28: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Connective Tissue: Other

• Bone

• Two structural types of bone

• Compact

• Spongy

• Blood

• Atypical CT

• Develops from mesenchyme

• Consists of cells surrounded by nonliving matrix

Page 29: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.8j

(j) Others: bone (osseous tissue)

Description: Hard, calcifiedmatrix containing many collagenfibers; osteocytes lie in lacunae.Very well vascularized.

Function: Bone supports andprotects (by enclosing);provides levers for the musclesto act on; stores calcium andother minerals and fat; marrowinside bones is the site for bloodcell formation (hematopoiesis).Location: Bones

Photomicrograph: Cross-sectional viewof bone (125x).

Lacunae

Lamella

Centralcanal

Bone Tissue

Page 30: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.8k

(k) Others: blood

Description: Red and whiteblood cells in a fluid matrix(plasma).

Function: Transport ofrespiratory gases, nutrients,wastes, and other substances.

Location: Contained withinblood vessels.

Photomicrograph: Smear of human blood (1860x); twowhite blood cells (neutrophil in upper left and lymphocytein lower right) are seen surrounded by red blood cells.

Neutrophil

Red bloodcells

Lymphocyte

Plasma

Blood Tissue

Page 31: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Nervous Tissue

• Nervous system (more detail with the Nervous System, Chapter 11)

Page 32: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.9

Photomicrograph: Neurons (350x)

Function: Transmit electricalsignals from sensory receptorsand to effectors (muscles andglands) which control their activity.

Location: Brain, spinalcord, and nerves.

Description: Neurons arebranching cells; cell processesthat may be quite long extend fromthe nucleus-containing cell body;also contributing to nervous tissueare nonirritable supporting cells(not illustrated).

Dendrites

Neuron processes Cell body

Axon

Nuclei ofsupportingcells

Cell bodyof a neuron

Neuronprocesses

Nervous tissue

Page 33: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Muscle Tissue

• Skeletal muscle (more detail with the Muscular System, Chapter 10)

Page 34: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.10a

(a) Skeletal muscle

Description: Long, cylindrical,multinucleate cells; obviousstriations.

Function: Voluntary movement;locomotion; manipulation of theenvironment; facial expression;voluntary control.

Location: In skeletal musclesattached to bones oroccasionally to skin.

Photomicrograph: Skeletal muscle (approx. 460x).Notice the obvious banding pattern and thefact that these large cells are multinucleate.

Nuclei

Striations

Part ofmuscle fiber (cell)

Page 35: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Muscle Tissue

• Cardiac muscle (more detail with the Cardiovascular System, Chapters 18 and 19)

Page 36: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.10b

(b) Cardiac muscle

Description: Branching, striated, generally uninucleate cells that interdigitate atspecialized junctions (intercalated discs).

Function: As it contracts, it propels blood into the circulation; involuntary control.Location: The walls of the heart.

Photomicrograph: Cardiac muscle (500X);notice the striations, branching of cells, andthe intercalated discs.

Intercalateddiscs

Striations

Nucleus

Page 37: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Muscle Tissue

• Smooth muscle

Page 38: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.10c

(c) Smooth muscle

Description: Spindle-shapedcells with central nuclei; nostriations; cells arranged closely to form sheets.

Function: Propels substancesor objects (foodstuffs, urine,a baby) along internal passage-ways; involuntary control.Location: Mostly in the wallsof hollow organs.

Photomicrograph: Sheet of smooth muscle (200x).

Smoothmusclecell

Nuclei

Page 39: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Epithelial Membranes

• Cutaneous membrane (skin) (More detail with the Integumentary System, Chapter 5)

Page 40: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.11a

Cutaneousmembrane(skin)

(a) Cutaneous membrane (the skin)covers the body surface.

Page 41: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Epithelial Membranes

• Mucous membranes

• Mucosae

• Line body cavities open to the exterior (e.g., digestive and respiratory tracts)

Page 42: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.11b

Mucosa ofnasal cavity

Mucosa oflung bronchi

Mucosa ofmouth

Esophaguslining

(b) Mucous membranes line body cavitiesopen to the exterior.

Page 43: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Epithelial Membranes

• Serous Membranes

• Serosae—membranes (mesothelium + areolar tissue) in a closed ventral body cavity

• Parietal serosae line internal body walls

• Visceral serosae cover internal organs

Page 44: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.11c

Parietalpericardium

Visceralpericardium

(c) Serous membranes line body cavitiesclosed to the exterior.

Parietalperitoneum

Visceralperitoneum

ParietalpleuraVisceralpleura

Page 45: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Steps in Tissue Repair

• Inflammation

• Release of inflammatory chemicals

• Dilation of blood vessels

• Increase in vessel permeability

• Clotting occurs

Page 46: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.12, step 1

Scab

Blood clot inincised wound

Epidermis

Vein

Inflammatorychemicals

Inflammation sets the stage:• Severed blood vessels bleed and inflammatory chemicals are

released.• Local blood vessels become more permeable, allowing white

blood cells, fluid, clotting proteins and other plasma proteinsto seep into the injured area.

• Clotting occurs; surface dries and forms a scab.

Migrating whiteblood cell

Artery

1

Page 47: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Steps in Tissue Repair

• Organization and restored blood supply

• The blood clot is replaced with granulation tissue

• Epithelium begins to regenerate

• Fibroblasts produce collagen fibers to bridge the gap

• Debris is phagocytized

Page 48: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.12, step 2

Regeneratingepithelium

Area ofgranulationtissueingrowth

FibroblastMacrophage

Organization restores the blood supply:• The clot is replaced by granulation tissue, which restores

the vascular supply.• Fibroblasts produce collagen fibers that bridge the gap.• Macrophages phagocytize cell debris.• Surface epithelial cells multiply and migrate over the

granulation tissue.

2

Page 49: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Steps in Tissue Repair

• Regeneration and fibrosis

• The scab detaches

• Fibrous tissue matures; epithelium thickens and begins to resemble adjacent tissue

• Results in a fully regenerated epithelium with underlying scar tissue

Page 50: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.12, step 3

Regeneratedepithelium

Fibrosedarea

Regeneration and fibrosis effect permanent repair:• The fibrosed area matures and contracts; the epitheliumthickens.• A fully regenerated epithelium with an underlying area ofscar tissue results.

3

Page 51: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc.

Developmental Aspects

• Primary germ layers: ectoderm, mesoderm, and endoderm

• Formed early in embryonic development

• Specialize to form the four primary tissues

• Nerve tissue arises from ectoderm

• Muscle and connective tissues arise from mesoderm

• Epithelial tissues arise from all three germ layers

Page 52: Copyright © 2010 Pearson Education, Inc. Connective Tissue

Copyright © 2010 Pearson Education, Inc. Figure 4.13

MesodermEndoderm

16-day-old embryo(dorsal surface view)

Epithelium

Nervous tissue(from ectoderm)

Muscle and connectivetissue (mostly frommesoderm)

Ectoderm