“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” Apical surface “covering” Function= protection, absorption, secretion, excretion Location= body surfaces Cells fit closely together No blood supply Divides quickly Basement membrane

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 TISSUE- Adipose Tissue FAT cells Stored oil pushes nuclei to side Insulation & protection

LOOSE CONNECTIVE TISSUSE- Reticular 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