Four Basic Tissue Types 2.0

Epithelial tissue

• form the basis of many of the body surfaces

  → so that one side of cell is in contact w/ the extorior and the other side in contact w/ the interior

• Function: Absorption, Secretion, and protection against foreign substances

What shapes do the epithelial tissues have?

• Squamous → flat/squashed

• Cuboidal → like a cube

• Columnar → like a column

What layers do the epithelial tissues have?

• Simple → one layer

• Stratified → more than one layer

What type of epithelial tissue is this?

Simple Squamous Epithelium

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

• the single nucleus of each cell bulges at the center

What is the function of the simple squamous epithelium tissue?

• gas exchange

• rapid diffusion, filtration, and some secretion in serous membranes

Where are simple squamous epithelial tissues found?

• Alveoli → air sacs in the lungs

• Endothelium → lining of the heart chambers and lumen of blood vessels

• Mesothelium → serous membranes of body cavities

• Amnion → sac-like membrane around the embryo

What type of epithelial tissue is this?

Stratified squamous

• top layer of the skin

• tough, anti-abrasive coverings, rapid mitosis

What is the function of the stratified squamous epithelium tissue?

Protection of underlying tissue

Where are stratified squamous epithelium tissues found?

Epidermis of the skin (top layer)!!!

What type of epithelial tissue is this?

Simple Cuboidal

• single layer of cells about as tall as they are wide; spherical, usually located in the nucleus

What is the function of the simple cuboidal epithelial tissue?

Absorption and Secretion

Where are simple cuboidal epithelial tissues found?

• Kidney tubules,

• thyroid glad follicles ,

• ducts and secretory regions of most glands,

• surface of ovary

What type of epithelial tissue is this?

Transitional Epithelium

• appearance varies, depending on whether the tissue is stretched or relaxed; shape of cells at apical surface changes; some cells may be binucleated (two nucleus)!!!!

• change from cuboidal to squamous- line the urinary passage

What is the function of the transitional epithelium tissue?

Distension and relaxation of to accommodate urine volume changes in bladder, uterus, and urethra

Where are transitional epithelium tissues located?

Lining of urinary bladder, uterus, and part of urethra

What is this type of epithelial tissue?

Nonciliated Simple Columnar Epithelium

• single layer of tall, narrow cells

• oval-shaped nucleus oriented lengthwise

• may contain goblet cells

What is the function of the nonciliated simple columnar epithelium?

Absorption and secretion; secretion of mucin

Where are nonciliated simple columnar epithelial tissues found?

Lining most of digestive tract

→ lining of stomach does NOT contain goblet cells

What type of epithelial tissue is this?

Cilliated Simple Columnar Epithelium

• single layer of tall, narrow ciliated cells, oval chaped nucleus oriented lengthwise

• globet cells may be present

What is the function of the ciliated simple columnar epithelium?

• secretion + movement of mucin along apical surface of epithelium by action of cilia

• oocyte movement through uterine tube

Where are ciliated simple columnar epithelial tissues found?

Lining of uterine tubes and large bronchioles of respiratory tract

What type of epithelial tissue is this?

Pseudostratified Ciliated Columnar Epithelium

• single layer of cells with different heights that appear multilayer

• all cells connect at basement membrane

  → not all cells reach apical surface

• Ciliated: has goblet cells and cilia

  → nonciliated does not

What is the function of the pseudostratified ciliated columnar epithelium?

• Protection

• Secretion + movement of mucin across surface by ciliary action

Where are pseudostratified ciliated columnar epithelium tissues found?

• lining most of the respiratory tract

  → nasal cavity, part of pharynx, larynx, trachea, and bronchi

• Noncilited form(rare): lines epididymis and part of male urethra

Connective tissue

• living cells in a nonliving matrix

  → connective tissue proper

  → cartilage

  → bone

  → blood

• bonding tissues together

• provides support

• provides nourishment

• stores waste

• repairs damaged tissues

What type of connective tissue is this?

Loose connective tissue (Areolar)

• Relatively fewer cells and fibers than in dense connective tissue

• irregularly arranged fibroblasts and fibers

  → thin fibers = elastin

  → thick fibers = collagen

• many blood vessels

What is the function of loose (areolar) connective tissue?

• surrounding + protecting tissues and organs

• loosely binding epithelia to deeper tissues

• providing nerve + blood vessel packing

Where is the loose (areolar) connective tissue found?

• Papillary layer of dermis

• Subcutaneous layer under the skin

• Surrounding the organs

What type of connective tissue is this?

Adipose Connective Tissue

• Closely packed adipocytes

  → “fat cells”

• Nucleus is squeezed to one side by large fat droplet

What is the function of the adipose connective tissue?

Stores energy

→ protects

→ cushions

→ insulates

Where are adipose connective tissues found?

Subcutaneous layer

→ covering and surrounding most organs

What type of connective tissue is this?

Dense Regular Connective Tissue

• parallel collagen fibers (white fibrous tissue)

• densely packed

• fibroblast nuclei squeezed between layers of fibers

What is the function of the dense regular connective tissue?

• Attaches muscles to bone + bone to bone

• Resisting stress applied in one direction

Where are dense regular connective tissues found?

Tendons, most ligaments

What type of connective tissue is this?

Dense Irregular Connective Tissue

• predominantly collagen fibers

• randomly arranged + clumped together

• more ground substance than in dense regular connective tissue

What is the function of the dense irregular connective tissue?

Withstands stresses applied in all directions; durable

Where are dense, irregular connective tissues found?

• Dermis

• periosteum covering bone

• Perichondrium covering cartilage

• Organ capsules

Connective Tissue: Cartilage

Chondrocytes in a matrix of a thick gel

What type of Cartilage Connective Tissue is this?

Hyaline Cartilage

• clear matrix

• lacunae house chondrocytes

• covered by perichondrium

What is the function of the Hyaline Cartilage (Connective Tissue)?

• smooth surfaces for movement of joints

• model for bone growth

• supporting soft tissue

Where is the Hyaline Cartilage (Connective Tissue) found?

• covering the articular ends of long bones

• most of fetal skeleton

• costal cartilage

• most of the larynx, trachea and nose

What type of Cartilage Connective Tissue is this?

Elastic Cartilage

• matrix with thin (elastic) fibers → wiggle + stretch!

What is the function of the Elastic Cartilage (connective tissue)?

• maintains structure + shape while being flexible

Where are the Elastic Cartilages (connective tissue) found?

• External ear

• Epiglottis of larynx

What type of Cartilage Connective tissue is this?

Fibrocartilage

• matrix with thick (collagen) fibers

• easy to see

• no perichondrium

What is the function of the Fibrocartilage? (connective tissue)

• resisting compression

• absorbing shock in some joints

Where is fibrocartilage found? (connective tissue)

• intervertebral discs

• Pubic symphysis

• Menisci of knee joints

Connective Tissue: Bone

• Osteocytes embedded in a solid mineral matrix

Compact Bone: calcified matrix arranged in osteons

Spongy bone: lacks the organization of a compact bone; contains macroscopic spaces ; arranged in mesh pattern

Connective Tissue: Blood

liquid matrix with formed elements

• erythrocytes (red blood cells)

• leukocytes (white blood cells)

• thrombocytes (plateles)

What is the function of Erythrocytes?

transport oxygen and some carbon dioxide

What is the function of Leukocytes?

Initiate + control immune response

What is the function of plasma?

• contains clot elements to stop blood loss

• transporting nutrients, wastes, + hormones throughout the body

Muscle Tissue

• Contractile Tissue

• Skeletal (striated+voluntary)

• Cardiac (striated+involuntary)

• Smooth (nonstriated+involuntary)

• Cylindrical cells with an evident nuclei

What type of muscular tissue is this?

Skeletal Muscle

• Fibers are long, cylindrical, striated, parallel, + unbranched

• striated cells have multiple peripheral nuclei

What is the function of the skeletal muscular tissue?

• moves the skeleton

  → voluntary body movements, locomotion, + heat production

Where are skeletal muscle tissues found?

• attaches to bones (sometimes the skin) → facial muscles

• sphincters= lips, urethra, + anus

What type of muscular tissue is this?

Cardiac Muscle Tissue

• small, striated cells with branches and intercalated discs

• one or two nuclei

What is the function of a cardiac muscle tissue?

Involuntary Contraction + relaxation pump in heart

Where is the cardiac muscular tissue found?

Heart wall (myocardium)

What type of muscular tissue is this?

Smooth Muscle tissue

• small, nonstriated cells with tapering ends

• one nucleus

What is the function of the smooth muscle tissue?

• involuntary movements + motion

• moves materials through internal organs

Where is the smooth muscle tissue found?

• walls of hollow internal organs

  → vessels, airways, stomach, bladder, uterus

Nervous Tissue

• contains neurons with rounded or stellate cell bodies + an axon and dendrites extending from the cell body

• Neuroglia (glial cells) lack extensive fibrous processes

Nervous Tissue: What is the function of the Neurons?

• responsible for control

• information processing, storage, and retrieval, internal communication

Nervous Tissue: What is the function of the Neuroglia (glial cells)

supporting and connecting neurons