Connective Tissue (CT)
Characteristics
1. CT is most varied tissue in make-up, location, and function
2. Lots of intracellular space= (matrix)
3. Matrix contains fibers and ground substance
4. Usually vascular
5. Made from mesenchyme- embryonic CT
CT Classification
CT
proper fluid supporting
dense loose
Areolar
adipose
reticular
I
rregular
regular
blood
lymph
cartilage bone
fiborous
elastic
hylaine
spongy
compact
elastic
Functions of CT
1. Establishes structural framework
2. Transport substances
3. Protection of organs
4. Supporting, surrounding, and interconnecting other tissue types
5. Storing energy reserves
6. Defending body from invading microbes
Types of CT
1. CT proper- ex. fat, tendons - divided into 2 types based on proportions of cells, fibers, ground substance
a. Loose
b. Dense
2. Fluid CT- ex. blood, lymph
3. Supporting CT- ex. Cartilage, osseous
Cells of CT
ALWAYS ( in CT proper)1. Fibroblasts- make ground substanceMAYBE• Macrophages- large amoeboid, engulf pathogens• Chondrocytes- cartilage cells• Adipocytes- fat cells• Erythrocytes- RBC• Mesenchymal- stem cells, respond to local injury by
making more cells• Mast cells-stimulate local inflammation after injuryMany others
Fibers of CT
1. Collagen- strongest, long, straight, unbranched, like rope, make up ligaments and tendons
2. Reticular- same fibers as collagen, web-like, support
3. 3. Elastic- branched, wavy, stretch and return to original length, connect vertebrae
CT proper1. Loose CT- “packing material”,
a. Areolar –separates skin from deeper tissues
CT proper1. Loose CT- “packing material”,
b. Adipose – store energy, insulate, protect (padding)
CT proper1. Loose CT- “packing material”,
c. Reticular- interlacing fibers create stroma(3-D network), inside organs of liver and spleen
CT proper2. Dense CT-”fibrous tissue”
a. Regular- collagen fibers run parallel
ex. Tendons
CT proper2. Dense CT-”fibrous tissue”
b. Irregular- collagen fibers interwoven in no pattern
ex. Nerve and muscle sheaths
CT proper
2. Dense CT-”fibrous tissue”
c. Elastic- a type of dense, regular, w/ more elastic fibers
ex- walls of bl.v
Fluid CT
1. Blooda. Formed elements- RBC, WBC, plateletsb. Plasma- watery matrix
2. Lymph
Supporting CT
1. Cartilage
a. avascular
b. Surrounded by perochondrium (for attachment)
c. Cells called chondrocytes, located in lacunae or nests
d. Matrix is gel-like
2. Types of Cartilage
A. Hyaline
-most common in body
-few, closely packed collagen fibers
-tough, and flexible
-makes up fetal skeleton
- adult –trachea rings, nose, costal area of ribs
2. Types of Cartilage
B. Elastic
-elastic fibers
-outer ear
2. Types of Cartilage
C. Fibrocartilage
-many collagen fibers, little matrix
-between vertebrae, cushions, absorbs shock
3. Osseous Tissue/Bone
A. Matrix is solid, made of
1. collagen fibers
2. calcium salts
B. Cells are osteocytes, located in nests called “lacunae”
C. Covered with periosteum- has fibrous layer for attachment, and cellular layer for repair
Spongy Bone
• Made of trabeculae• Contain lacunae and osteocytes
CT Classification
CT
properfluid supporting
dense loose
Areolar
adipose
reticular
I
rregular
regular
blood
lymph
cartilage bone
fiborous
elastic
hylaine
spongy
compact
elastic