Histology Etc. Flashcards
Function of collagen, elastin, reticular fibers:
Collagen: resist tension.
Elastin: allow for stretching.
Reticular fibers: form supportive meshwork.
Scurvy
Vit C deficiency leading to UN-linked collagen.
Ehlers-Danlos syndrome
Abnormal collagen synthesis leading to weak collagen.
Marfan’s syndrome
Mutation in fibrillin-I, a component on elastin fibers. Targets CVS, skeletal oculars, etc.
Main players in the ECM of CT (4)
Proteoglycans
Hyaluranon
Glycoproteins
EC proenzymes
Embryonic CT
Rich in ECM and MSCs. Little collagen or reticular fibers.
Function of LACT
Support and bind tissues, hold body fluids, defends against infection.
Found beneath epithelia, BVs, muscles, nerves.
Function of Reticular CT
To hold free cells.
Found in liver, bone marrow, lymph nodes, etc.
Dense irregular CT overview
Fibroblasts main cell type.
Resists tearing.
Found in dermis, organ capsules, perichondrium/periosteum, fascia.
Dense regular CT overview
Fibroblasts main cell type.
Resists pulling.
Poorly vascularized.
Found in tendons, ligaments, aponeuroses, joint capsules.
Where is elastic CT found?
BV walls, bronchioles, special ligaments.
Fibroblasts produce:
Collagen, elastin, RFs, proteoglycans, glycoproteins.
Hyaline cartilage overview
Has a perichondrium.
Type II collagen.
Articular cartilage, larynx, trachea, embryonic development.
Elastic cartilage overview
Has a perichondrium.
Type II collagen.
External ear, epiglottis, auditory tube.
Hyaline + elastin.
Fibrocartilage
No perichondrium.
Type I collagen.
IV disks, pubic symphysis, TMj.
Hyaline + dense regular CT.
Articular cartilage is __________ and lacks a __________:
Hyaline, perichondrium.
Territorial and interterritorial matrix
TM has less collagen and more GAGs than ITM.
Perichondrium overview
Has blood supply.
Source of new cartilage.
Has 2 layers: fibrous, chondrogenic.
Fibrous layer of perichondrium
Outer layer that produces type I collagen and elastin.
Chondrogenic layer of perichondrium
Inner layer that differentiates into chondroblasts.
Secretes type II cartilage.
Appositional growth overview
Cartilage formed on existing cartilage.
Undifferentiated cells –> chondroblasts –> secrete type II collagen and ground substance.
Interstitial growth overview
Takes place within cartilage mass.
Chondrocytes divide in lacunae, forming new isogenous groups.
Increases in mass but is limited due to avascular nature.
Zones of articular cartilage (4) superficial to deep:
Superficial zone
Intermediate zone
Deep zone
Calcified zone
Layers of epidermis
Stratum corneum Stratum lucidem Stratum granulosum Stratum spinosum Stratum basale