TISSUES BEYOND KLEENEX What is a tissue Groups
“TISSUES- BEYOND KLEENEX”
What is a tissue? ? • Groups of cells that are similar in structure and function • 4 Types: epithelium, connective, nervous, muscle
EPITHELIAL TISSUE • “covering” • Function= protection, absorption, secretion, excretion • Location= body surfaces • Cells fit closely together • No blood supply • Divides quickly Basement membrane Apical surface
Types of Epithelial Tissue • Characterized by shape & # of layers • Simple (1 layer) • Stratified (many layers)
Simple Squamous Epithelium • Single, flat, thin, fish-like • Alveoli (lungs), capillaries
Simple Cuboidal Epithelium • Single, cube-shaped • Nucleus in center • Glands, kidneys, ovaries
Simple Columnar Epithelium • • • Single, long Nuclei near basement membrane Thick Goblet cells- produce mucus Digestive tract
Pseudostratified Columnar Epithelium • Appear layered, but NOT • cilia • Respiratory tract
Stratified Squamous Epithelium • Many layers, thick & flat • Protection • Esophagus, mouth, outer skin
Stratified Cuboidal Epithelium • • Layers, cubed Protection Sweat ducts Rare
Stratified Columnar Epithelium • Layers, columns • Rare • Male urethra
Transitional Epithelium • Modified stratified squamous • Stretchable • Only in urinary system
Glandular Epithelium • Cells produce and secrete substances • Endocrine Glands- secrete into body fluids or blood (hormones) • Exocrine Glands- secrete onto surface (sweat)
QUIZ Epithelial Quiz Histology
CONNECTIVE TISSUE • support, protection, binding together • Most abundant tissue in the body • Extracellular matrix- nonliving, liquid, gel-like, or hard – Collagen fibers (white -tendons) – Elastic fibers (elastic -yellow- vocal chords) – Reticular fibers (very fine)
Bone Tissue • Rigid & hard (hard matrix) • Support & protection • Osteocytes (bone cells) in lacunae (cavities) • Blood supply good, heals fast
CARTILAGE- Hyaline Cartilage • More flexible • Chondrocytes (cells) in lacunae • Nose, larynx, bone ends, fetus skeleton (growth of bones)
CARTILAGE- Elastic Cartilage • Ear, larynx • More flexible than hyaline cartilage • Elastic fibers
CARTILAGE- Fibrocartilage • Shock absorber • Knee caps, vertebrae • Contains collagenous fibers
Dense Connective Tissue • Closely packed collagen fibers • Tendons, ligaments • Blood supply low; heals slow
Loose Connective Tissue. Areolar tissue • Delicate, thin, more matrix • Cushions organs • Binds skin to organs
LOOSE CONNECTIVE TISSUEAdipose Tissue • FAT cells • Stored oil pushes nuclei to side • Insulation & protection
LOOSE CONNECTIVE TISSUSEReticular Connective Tissue • Lymph nodes, spleen, bone marrow • Reticular fibers • Used as support
Blood • Cells & nonliving plasma; blood cell = biconclave discs • Transportation of… • WBC, RBC, platelets, plasma
Muscle tissue • Contract in response to stimuli • Muscle fibers can shorten • Three types – Skeletal – Smooth – Cardiac (heart)
Skeletal Muscle • • Specialized to contract Attached to bones Voluntary Striations, many nuclei
Cardiac Muscle • Striated, 1 nucleus, intercalated disks • Involuntary • Heart only
Smooth Muscle • • No striations 1 nucleus, cells pointed at ends Involuntary Stomach, bladder
Nervous Tissue • Cells & neurons • Found in brain, spinal column, and peripheral nerves • Senses changes in the body and surroundings • Coordinate, regulate, and integrate many body functions
Nervous Tissue • Includes neuroglial cells • Cells – support and bind the components of nervous tissue – Carry out phagocytosis – Supply nutrients
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