CONNECTIVE TISSUE
CHARACTERISTICS:
*Most abundant tissue type; Composed of ECM (GS & Protein Fibers) + Cells
(Refer to pp.129-131 for specific characteristics of each)
*Highly equipped with VAN – assists in diffusion of nutrient and waste to and
from epithelium (**Be familiar with exceptions**)
*General FXN: p. 128
CLASSIFICATION:
I. Embryologic CT (2)
A. **Mesenchyme** CT Stem Cell
B. Mucous (Umbilical Cord)
II. Mature CT
A. Loose CT (3)
D. Bone (“Osseous/ Osteo-”) (2)
1. Areolar
1. Compact
2. Adipose
2. Spongy
3. Reticular
E. Liquid CT (2)
B. Dense CT (3)
1. Blood
1. DRCT
2. Lymph
2. DICT
3. Elastic
C. Cartilage (“Chondro-”) (3)
1. Hyaline
2. Fibrocartilage
3. Elastic
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LOOSE CT (3)
1A. AREOLAR CT : consists of all fibers, all cells, semifluid ground substance
aka: “packing material”; more GS than fibers & cells
FXN: strength, elasticity, & support
RBCs in capillaries:
**d/t epithelium is AVASCULAR**
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Collagen
Fibers
Ground
Substance
Macrophage
Cells
Fibroblast:
Flat cells w/ branching
processes
LOOSE CT
1B. AREOLAR CT : consists of all fibers, all cells, semifluid ground substance
aka: “packing material”; more GS than fibers & cells
FXN: strength, elasticity, & support
Reticular
fiber
Plasma cell
Fibroblasts
Mast cell –
releasing
histamine
Collagen
fiber
LOOSE CT
2. ADIPOSE CT : Adipocytes (derived from fibroblasts); filled w/ triglyceride droplet
w/ nucleus push to periphery; *highly vascular* (significance??); BAT (fxn?)
LOC: Sub Q to skin, around heart & kidneys, yellow bone marrow, around
joints, and posterior to eyeballs
FXN: reduce heat loss, energy reserve, support & protection
Nucleus
Triglyceride
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LOOSE CT
3. RETICULAR CT : “network” branched reticular fibers and cells
LOC: Liver, spleen, lymph nodes; RBM; reticular lamina & basement
membrane; around blood vessels & muscles
FXN: support, binds; provides framework = stroma; & filters
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DENSE CT (3)
1. DRCT : composed of mainly collagen fibers in an orderly pattern or “paralleled”
(non-living…significance???) with many fibroblasts present.
LOC: Tendons (muscle-bone), ligaments (bone-bone), aponeuroses
FXN: strong attachment; withstands tensile strength along one axis
Chains of flat
fibroblasts
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DENSE CT
2. DICT :composed of mainly collagen fibers in irregular arrangement
(non-living…significance???) with few fibroblasts
LOC: fascia, reticular layer of dermis, pericardium, periosteum,
perichondrium, joint capsule, organ capsules (find examples), heart valves
FXN: provides tensile strength in many directions
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DENSE CT
3. ELASTIC CT: composed of mainly elastic fibers with fibroblasts
LOC: lung tissue, walls of elastic arteries (ex: AORTA), bronchiole tubes,
suspensory ligaments of penis, and some ligaments between vertebrae.
FXN: stretch & recoil to original shape
Elastic fibers
Fibroblasts
Refer to the “Vascular System”, Slide #12 on the JayDoc
website. Familiarize yourself for class discussion.
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CARTILAGE CT (3)
1. HYALINE: gelatinous GS, stains vibrant pink or purple, has perichondrium (*except
articular surfaces & epiphyseal “growth” plate*…significance??); weakest
LOC: most abundant cartilage in body; ends of long bonds (synovial joints),
costal cartilage, nose, larynx, … and fetal skeleton
FXN: provides smooth surfaces for movement, flexibility, & support
STRXR: Lacuna, chondrocytes, ECM
perichondrium
ECM
Lacuna w/ chondrocyte… note darkly stained nucleus
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CARTILAGE CT (3)
2. FIBROCARTILAGE: “feather-like” appearance; NO perichondrium; strongest
LOC: IVD, meniscus, pubic symphysis
FXN: support & joining structures together; strength & regidity
Nucleus of
chondrocytes
Lacuna not as apparent
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CARTILAGE CT (3)
3. ELASTIC CARTILAGE: Thread like network of elastic fibers (stains black & grainy), has
perichondrium, “corn on the cob”
LOC: epiglottic, external ear (auricle), Eustachian tubes
FXN: strength & elasticity; able to maintain shape
STRXR: Lacuna, chondrocytes, ECM, elastic fibers
perichondrium
Lacuna w/ chondrocyte… note darkly stained nucleus
Elastic fibers
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OSSEUS “BONE” CT (2)
1. COMPACT: Thread like network of elastic fibers (stains black & grainy), has
perichondrium, “corn on the cob”
LOC: refer to chapter 6
FXN: support, protection
ID STRXR: Osteon (Haversian system), Central canal (Haversian canal),
lamella, lacuna, osteocytes, canaliculi, Volkmann’s canal, & periosteum
2. SPONGY: know difference structures,
function, and location,
specific to each type of bone (p. 138-139)
and chapter 6
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LIQUID CT (2)
1. BLOOD: Consists of blood plasma & formed elements (RBCs, WBCs, & Platelets)
LOC: within arteries & veins, chambers of the heart
FXN: RBCs- O2 & CO2 ; WBCs – immunity, phagocytosis, allergic rxn; platelets
- clotting (refer to p. 140 for other terms a& identification characteristics)
Refer to slides on JayDoc website: Blood Smear – slide #17 & 20
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