Types of Tissue (Lab)

4 Tissue Types

1. Epithelial Tissue

2. Connective Tissue

3. Muscle Tissue

4. Nervous Tissue

Simple (Epithelium)

• One cell layer thick; all cells are tightly bound, all cells attach directly to the basement membrane

Stratified (Epithelium)

Two or more layers thick, only the deepest layer directly attaches to the basement membrane

Shapes of Epithelium Cells

1. Squamous (flattened)

2. Cuboidal (cubed)

3. Columnar (columned )

Simple Squamous Epithelium (structure)

• Single layer of thin, flat, irregularly shaped cells resembling floor tiles

• The single nucleus of each cell bulges at its center

Simple Squamous Epithelium (function)

• rapid diffusion

• Filtration

• Some secretion in serous membrane

Simple Squamous Epithelium (found in)

• Air sacs in lungs (alveoli)

• Lining of the heart chambers and lumen of blood vessels (endothelium)

• Serous membranes of body cavities (mesothelium)

Simple Cuboidal Epithelium (function)

• absorption and secretion

Simple cuboidal epithelium (found in)

• thyroid gland follicles

• Kidney tubules

• Ducts and secretory region of most glands

• Surface of ovary

Nonciliated Simple Columnar Epithelium (structure)

• single layer of tall, narrow cells resembling floor

• Oval-shaped nucleus in basal region of cell

• Nucleus oriented lengthwise in cell

• Apical region of cells have microvilli

• May contain goblet cells and secrete mucin

Where is nonciliated simple columnar epithelium tissues found?

• lining of most of digestive tract

• Lining of stomach (no goblet cells)

Ciliated Simple Columnar Epithelium (structure)

• Single layer of tall, narrow, ciliated cells

• oval-shaped nucleus oriented lengthwise in the basal region of the cell

• Goblet cells may be present

Ciliated Simple Columnar Epithelium (function)

• Secretion of mucin and movement of mucus along apical surface of epithelium by action of cells

• Oocyte movement through uterine tube

Where are Ciliated Simple Columnar Epithelium found?

• lining of uterine tubes

• Larger bronchioles of respiratory tract

Stratified Cuboidal Epithelia (structure)

• two or more layers of cells

• Cells at the apical surface are cuboidal/cube shapped

Stratified Cuboidal Epithelium (function)

• protection and secretion

Stratified Cuboidal Epithelium Found in…

• large ducts in most exocrine glands

• In some parts of the male urethra

Stratified Columnar Epithelium (structure)

• two or more layers of cells Cells

• Cells at apical surface are columned shaped

Stratified Columnar Epithelium (function)

• protection and secretion

Stratified Columnar Epithelium found in…

• large ducts of some exocrine glands

• In come regions of male urethra

• Rare

Transitional Epithelium (Structure)

• appearance may vary depending on if the tissue is stretched or relaxed

• Shape of cells at apical surface changes

• Some cells may by binucleated (2 nuclei inside a single cell)

Transitional Epithelium (function)

• distention and relaxation to accommodate urine volume changes in bladder, ureters, and urethra

Transitional Epithelium are found in…

• lining of urinary bladder

• Ureters

• Part of urethra

Pseudostratified Columnar Epithelium (structure)

• single layer of cells varying in heights making it appear multilayered

• All cells connect at basement membrane

• Not all cells reach apical surface

• Ciliated form has goblet cells, nonciliated lack goblet cells

Pseudostratified Columnar Epithelium (Function)

• protection

• Ciliated form also involved in secretion of mucin and movement of mucus across surface by ciliary action

Pseudostratified Columnar Epithelium (found in…)

Ciliated form lines of most respiratory tract

• nasal cavity, part of pharynx, larynx, trachea, bronchitis

Nonciliated is rare

• lines epididyn and part of the male urethra

Loose Connective Tissue

Relatively fewer cells and fibers than in dense, fibers are loosely arranged

3 Types of LOOSE Connective Tissue

1. Areolar Connective Tissue

2. Adipose Connective Tissue

3. Reticular Connective Tissue

Areolar Connective Tissue (Structure)

• Abundant vascularized ground substance (gel-like)

• Scattered fibroblasts

• Many blood vessels

• Lesser amounts of collagen and elastic fibers

Areolar Connective Tissue (function)

• Forms delicate, thin layers b/w muscles

• Binds skins to underlying organs

• Provides nerve and blood vessel packing

Areolar Connective Tissue Is found in…

• Subcutaneous layer under the skin

• Surrounding nerves and vessels

• Surrounds organs

Adipose Connective Tissue (structure)

• closely packed fat cells (adipocytes) / large in size like marshmellows

• Nucleus squeezed to one side

Adipose Connective Tissue (function)

• protects adds cushion

• Stores energy supply in fat vacuoles

• Insulates

Adipose Connective Tissue is found in….

• subcutaneous layer

• Surrounding kidney and other organs

Reticular Connective Tissue (structure)

• ground substance is gel-like liquid

• Scattered reticular fibers, fiberblasts, and leukocytes

Reticular Connective Tissue (Function)

• Provides supportive framework for spleen, lymph nodes, thymus, bone marroe

Reticular Connective Tissue is found in…

• Forms stroma of lymph nodes

• Spleen

• Thymus

• Bone Marrow

Dense Connective Tissue

Higher proportion of fibers to ground substance; protein fibers are densely packed together

3 types of DENSE Connective Tissue

1. Dense Regular Connective Tissue

2. Dense Irregular Connective Tissue

3. Elastic Connective Tissue

Dense Regular Connective Tissue (Structure)

• densely packed

• Parallel to direction of stress collagen fibers

• scarce ground substance

Dense Regular Connective Tissue (function)

• Provides great strength and flexibility primarily in a single direction

• attaches muscle to bone

• Attaches bone to bone

• Resists stress applied in one direction

Dense Regular Connective Tissue found in…

• tendons

• Ligaments

Dense Irregular Connective Tissue (Structure)

• predominantly collagen fibers (randomly arranged and clumped together/lightly swirled)

• Fibroblasts in spaces among fibers

• More ground substance

Dense Irregular Connective Tissue (function)

• provides tensile strength in all directions

Dense Irregular Connective Tissue (function)

• Provides tensile strength/ withstands stress in all direction

Dense Irregular Connective Tissue found in…

• walls of large arteries

• Dermis

• Periosteum covering bone

• Perichondrium covering cartilage

• Organ capsules

3 Types of Cartilage Connective Tissue

1. Hyaline cartilage

2. Fibrocartilage

3. Elastic Cartilage

Hyaline Cartilage (structure)

• glassy appearing matrix

• Lacunae house chondrocytes usually covered by perichondrium

Hyaline Cartilage (Function)

• smooth surfaces for movement at joints

• Model for bone growth

• Supports Soft Tissue

Hyaline Cartilage Found in…

• Soft part of nasal septum (nose)

• most fetal skeleton

• Covers articular ends of bones

• Costal cartilage

• Larynx, trachea (supporting rings of respiratory passages)

Fibrocartilage (structure)

• parallel collagen fibers in matrix

• Lucunae house chondrocytes (looks like a shell in water)

• No perichondrium

Fibrocartilage (function)

• resists compression

• Absorbs shock in some joints

Fibrocartilage found in…

• Intevertebral discs

• Public symphysis (connects L/R hope bone)

• Menisci of knee joints

Elastic Cartilage (Structure)

• contains abundant elastic fibers

• Fibers form weblike mesh around lacunae

• Perichondrium present

Elastic Cartilage (function)

• maintans structure and shape while permitting extensive flexibility

Elastic Cartilage found in…

• external ear

• Epiglottis of the larynx

2 Types of Bone Connective Tissue

1. Compact

2. Spongy

Bone (Connective Tissue Structure)

Compact bone

• calcified matrix arranged in osteons

• Concentric lamellae arranged around a central canal containing blood vessels (looks like tree trunk)

Spongy Bone

• Contains more spaces

• Bone arranged in meshwork pattern (looks like sponge)

Bone Connective Tissue (function)

• Supports soft structures

• Protects vital organs

• Provides levers for movement

• Stores calcium and phosphorus

• Spongy bone: site of hemopoiesis (production of blood)

Bone Connective Tissue found in…

Bones of the body

Type of Fluid Connective Tissue

Blood

Blood (Connective Tissue Structure)

• contains erythrocytes (red blood cells), leukocytes (white blood cells), and platelets

• Soluble protein fibers

• Watery ground substance form plasma

Blood (Connective Tissue Function)

• Erythrocytes transport oxygen and some carbon dioxide

• Leukocytes initiate and control immune response

• Plasma contains clotting elements to stop blood loss

• Platelets help with blood clotting

• Plasma transports nutrients, wastes and hormones throughout the body

Blood Connective Tissue Found in…

• blood vessels (arteries, veins, capillaries

• Heart

• leukocytes lymphatic organs can migrate to infected/inflamed tissues of the body

Elastic Cartilage

Forms framework in outer ear

Adipose Connective Tissue

Functions as heat insulator beneath skin

Blood Connective Tissue

Contains large amounts of fluid and lacks fibers

Bone Connective Tissue

Cells arranged around central canal

Loose (areolar) Connective Tissue

Binds skin to underlying organs

Dense (regular) connective tissue

Main tissue of tendons and ligaments

Adipose Connective Tissue

Provides stored energy supply in fat vacoules

Hyaline Cartilage

Forms the flexible soft part of the nasal septum

Fibrocartilage

Pads between vertebrae that are shock absorbers

Hyaline Cartilage

Forms supporting rings of respiratory passages

Adipose Connective Tissue

Cells greatly enlarged with nucleus pushed to the side

Loose (areolar) connective tissue

Forms delicate, thin layers between muscles

Bone Connective Tissue

Matrix contains collagen fibers and mineral salts

Areolar Connective Tissue

Adipose Connective Tissue

Recticular Connective Tissues

Dense Regular Connective Tissue

Dense Irregular Connective Tissue

Elastic Connective Tissue

Hyaline Cartilage

Fibrocartilage

Elastic Cartilage

Bone (connective tissue)

Blood (connective tissue)

Transitional Epithelium

Pseudostratified Columnar Epithelium

Stratified Columnar Epithelium

Stratified Cuboidal Epithelium

Keratinized Stratified Squamous Epithelium

Nonkeratinized Stratified Squamous Epithelium

Ciliated Simple Columnar Epithelium

Nonciliated Simple Columnar Epithelium

Simple Cuboidal Epithelium

Simple Squamous Epithelium