Tissue and Histology (Test 2)

Most superficial layer

Epidermis

Deepest Layer

Hypodermis

Composed of epithelial tissue

Epidermis

Produces Vitamin D precursor

Epidermis

Contains tactile corpuscles

Dermis

Contains melanocytes

Epidermis

Most important in thermoregulation

Dermis (and Hypodermis for insulation)

Known as subcutaneous tissue

Hypodermis

Most pacinian (lamellated) corpuscles are located here

Dermis and Hypodermis (Primarily deep dermis/hypodermis junction)

Considered part of the skin

Epidermis, Dermis (Hypodermis is technically subcutaneous

Contains blood vessels

Dermis, Hypodermis

Composed of connective tissue

Dermis, Hypodermis

Most Superficial layer of Epidermis

Stratum Corneum

Transparent layer of epidermis

Stratum Lucidum

Deepest layer of epidermis

Stratum basale

Thickest layer in thin skin

Stratum Spinosum

Thickest layer in thick skin

Stratum Corneum

Layer closest to a blood supply in epidermis

Stratum basale

Most common location of dendritic cells

Stratum Spinosum

Most mitotically active

Stratum basale

Location of melanocytes

Stratum basale

Forms a callus

Stratum Corneum

Named for prominent cytoplasmic granules

Stratum granulosum

Named for spiky appearance on microscope slide

Stratum spinosum

Consists of dead cells

Stratum corneum, Stratum Lucidum

Contains Keratinocytes

All Layers

Cell division occurs here

Statum Basale (and lower Stratum Spinosum)

Deepest layer of skin

Reticular Layer

Most superficial layer of skin

Stratum Corneum

Forms dermal papillae

Papillary Layer

Composed of dense irregular CT

Reticular Layer

Composed of dense irregular CT

Reticular Layer

Consists of a single layer of cells

Stratum Basale

Contains more collagen fibers than any other layer

Reticular Layer

Contains Merkel cells

Stratum Basale

Composed primarily of stem cells

Stratum Basale

Layer of the epidermis

Stratum Corneum, Stratum Lucidum, Stratum Granulosum, Stratum Spinosum, Stratum Basale

Layer of the dermis

Papillary Layer, Reticular Layer

The layers that form the thick skin

Stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale

The layers that form the thin skin

Stratum corneum, stratum granulosum, stratum spinosum, stratum basale.

Composed of loose CT

Papillary layer (Areolar CT), Hypodermis (Adipose/Areolar CT)

Produces Milk

Mammary

Produces Sebum

Sebaceous

Produces Ear Wax

Ceruminous

Product released by cell rupture

Sebaceous (Holocrine Secretion)

Found only in lactating women

Mammary (Functional State)

Secretion begins at puberty

Apocrine, Sebaceous

Causes acne

Sebaceous

Leads to body odor

Apocrine

Produces Sweat

Eccrine, Apocrine

Located in the dermis

Eccrine, Apocrine, Ceruminous, Mammary, Sebaceous

Derived from epithelial tissue

Eccrine, Apocrine, Ceruminous, Mammary, Sebaceous

Melanocytes

Produces Melanin

Merkel Cells

Sensory receptors that detect light touch

Keratinocytes

Produces Keratin

Dendritic Cells (Langerhans cells)

Phagocytes of the immune system

Keratinocytes (granulosum)

Releases a lipid-based substance that creates a water barrier (Lamellar granules)

Avascular

Epithelial

Category that includes cartilage

Connective

Supports and surrounds other types of tissues

Connective

Contains neuroglia

Nervous

Often bears cilia or microvilli

Epithelial

ECM is often the primary component

Connective

Makes up most of the tissues in your nose

Connective (Hyaline cartilage)

Makes up most of the tissue in the brain

Nervous

Always connected to a basement membrane

Epithelial

Category that includes blood

Connective

Category that includes bone

Connective

Category that includes adipose tissue

Connective

Blood vessels are lined with it

Epithelial (Simple squamous)

Excitable

Muscular, Nervous

Cells in this tissue have apical and basal surfaces

Epithelial

Lines internal organs

Epithelial

Makes up most of the tissue of the heart

Muscular (Cardiac Muscle)

Specialized for communication and coordination

Nervous

Support, Protection, Resists Compression

Between bones +Joints

Between sternum + ribs

Nose

Respiratory tract

Intervertebral Discs

Hyaline Cartilage

Support, Protection, Resists tension, involved in producing and detecting sound

Ears

Epiglottis of larynx

Bones

Fibrocartilage

Support, Protection

Provides leverage for movement

Stores Calcium

Bones

Bone

Transports nutrients, gases, wastes, immune cells

Within blood vessels and chanbers of the heart

Blood

Support, Protection

Houses blood vessels supplying epithelium

Deep to epidermis

Walls of hollow organs

Membranes lining bod cavities

Loose CT

Strength, Resistance to stress in all three planes

Deepest layer of skin

Around joints and organs

Dense CT (Irregular)

Strength, Resistance to stress in one plane

Tendons, ligaments

Dense CT (Regular Collagenous)

Allows tissue to stretch and recoil

Large blood vessels

Certain ligaments

Dense CT (Regular Elastic)

Forms internal structure of many organs

Supports smaller vessels and nerves

Basement Membrane

Around vessels and nerves

Reticular CT

Warmth, insulation

Shock absorption, protection

Major energy reserve in the body

Deep to the skin in characteristic areas

Surrounds the heart and abdominal organs

Adipose CT

Provides a barrier through which gases and fluids can be exchanged

Produces serous fluid

Single layer of flat cells

Flattened, central nuclei

Air sacs of lungs

Inner lining of ventral body cavities and blood vessels

Certain parts of kidney

Simple Squamous Epithelium

Absorption

Secretion of mucus and other substances

Single layer of cube-shaped cells

Round, central nuclei

Kidney tubules

Lower respiratory tract

Thyroid gland, mammary glands, salivary glands

Simple Cuboidal Epithelium

Absorption

Secretion of mucus and other substances

Propulsion of egg through uterine tube

Single layer of rectangular cells

Oval, basal nuclei

Small intestine

Digestive tract from stomach to anus

Uterine tube

Gallbladder

Simple Columnar Epithelium

Secretes mucus and pushes it with ciliary motion

Single layer of columnar cells of different heights, giving a stratified appearance

Nasal cavity

Trachea

Upper respiratory passages

Pseudostratified Columnar Epithelium

Multiple layers of flattened cells

Apical cells dead, flaky, and filled with keratin

Cuboidal to squamous basal layer

Protection from mechanical stresses and microorganisms

Prevents water loss through skin

Epidermis

Stratified Squamous Epithelium (Keratinized)

Apical cells living and nucleated

Layers of flattened cells, cuboidal to squamous basal cells

Protection from mechanical stresses and microorganisms

Mouth, pharynx, esophagus, anus, vagina

Stratified Squamous Epithelium (Nonkeratinized)

Two or more layers of cuboidal cells

Some absorption and secretion

Ducts of sweat glands

Stratified Cuboidal Epithelium

Two or more layers of cells

Apical layer is columnar, basal layer is cuboidal

Protection

Some absorption and secretion

Ducts of certain glands

Conjunctiva of eye

Male urethra

Stratified Columnar Epithelium

Multiple layers of cells

Apical cells dome-shaped when relaxed and flattened when stretched

Protection

Gives tissues ability to stretch

Urinary bladder

Ureter

Urethra

Transitional Epithelium