anatomy and physiology- tissue

What is histology?

The study of tissues and how they are arranged into organs.

What are the four basic tissue types?

Epithelial, connective, muscle, and nervous tissue.

What is the primary function of epithelial tissue?

Covers surfaces, lines cavities, and forms glands.

What is the primary function of connective tissue?

Supports, binds, protects, stores, and transports.

What is the primary function of muscle tissue?

Produces movement through contraction.

What is the primary function of nervous tissue?

Communication through electrical signals.

What are the three primary germ layers?

Ectoderm, mesoderm, and endoderm.

What develops from ectoderm?

Epidermis and nervous system.

What develops from endoderm?

Digestive and respiratory tract linings and digestive glands.

What develops from mesoderm?

Connective tissues including cartilage, bone, and blood.

What embryonic tissue develops from mesoderm?

Mesenchyme.

What are cell junctions?

Specialized connections between cells that provide adhesion, communication, and support.

What is the function of a tight junction?

Seals neighboring cells together and prevents substances from passing between them.

Where are tight junctions commonly found?

Stomach and intestinal epithelium.

What is the function of an adherens junction?

Provides mechanical stability by linking neighboring cells.

What is the function of a desmosome?

Prevents cells from pulling apart under stress.

Where are desmosomes common?

Epidermis and other epithelia.

What is the function of a hemidesmosome?

Anchors epithelial cells to the basement membrane.

What is the function of a gap junction?

Allows communication between adjacent cells.

Where are gap junctions commonly found?

Cardiac muscle and smooth muscle.

What are the major functions of epithelial tissue?

Protection, secretion, excretion, absorption, filtration, and sensation.

Is epithelial tissue vascular or avascular?

Avascular.

How does epithelial tissue receive nutrients?

From underlying connective tissue.

What is the basement membrane?

A layer that anchors epithelium to connective tissue.

What is the apical surface?

Surface facing a body cavity, lumen, or exterior.

What is the basal surface?

Surface attached to the basement membrane.

What is the lateral surface?

Surface between neighboring cells.

What is covering and lining epithelium?

Epithelium that covers body surfaces and lines internal spaces.

What is glandular epithelium?

Epithelium specialized for secretion.

What is simple epithelium?

One layer of cells.

What is stratified epithelium?

Multiple layers of cells.

What is pseudostratified epithelium?

Appears multilayered, but all cells contact the basement membrane.

What does squamous mean?

Flat, thin cells.

What does cuboidal mean?

Cube-shaped cells.

What does columnar mean?

Tall, narrow cells.

What does transitional mean?

Cells that change shape when stretched.

What is the function of simple squamous epithelium?

Rapid diffusion and filtration.

Where is simple squamous epithelium found?

Alveoli, glomeruli, endothelium, and serosa.

What is the function of simple cuboidal epithelium?

Absorption and secretion.

Where is simple cuboidal epithelium found?

Kidney tubules, glands, bronchioles.

What is the function of simple columnar epithelium?

Absorption and secretion.

Where is simple columnar epithelium found?

Digestive tract, uterus, kidney, uterine tubes.

What is the function of pseudostratified ciliated columnar epithelium?

Secretes and propels mucus.

Where is pseudostratified columnar epithelium found?

Respiratory tract.

What is the function of stratified squamous epithelium?

Protection from abrasion.

Where is keratinized stratified squamous found?

Epidermis.

Where is nonkeratinized stratified squamous found?

Mouth, esophagus, tongue, vagina.

What is the function of transitional epithelium?

Allows stretching.

Where is transitional epithelium found?

Urinary bladder and ureters.

What is endothelium?

Simple squamous epithelium lining blood vessels.

What is mesothelium?

Simple squamous epithelium lining serous membranes.

What is the function of goblet cells?

Secrete mucus.

In which epithelial tissues are goblet cells commonly found?

Simple columnar and pseudostratified columnar epithelia.

What is a gland?

A cell or organ that secretes substances.

What is an endocrine gland?

Ductless gland that secretes hormones into the blood.

What is an exocrine gland?

Gland that secretes through ducts.

How do merocrine glands secrete?

Exocytosis.

Examples of merocrine glands?

Sweat glands, pancreas, gastric glands.

How do apocrine glands secrete?

Part of the cell buds off.

Example of apocrine secretion?

Mammary glands.

How do holocrine glands secrete?

Entire cell ruptures and becomes part of the secretion.

Example of holocrine glands?

Sebaceous (oil) glands.

What is the major characteristic of connective tissue?

Cells occupy less space than the extracellular matrix.

Is connective tissue generally vascular?

Yes, although cartilage is avascular.

What are the major functions of connective tissue?

Binding, support, protection, immune defense, movement, storage, heat production, and transport.

What is the function of a fibroblast?

Produces fibers and ground substance.

What is the function of an adipocyte?

Stores fat.

What is the function of hyaluronic acid?

Helps regulate water balance and tissue lubrication.

What is the function of chondroitin sulfate?

Provides support and resilience.

What is the function of collagen fibers?

Strength and resistance to stretching.

What is the function of elastic fibers?

Stretch and recoil.

What is the function of reticular fibers?

Form supportive frameworks.

Function of areolar tissue?

Supports epithelia and wraps organs.

Location of areolar tissue?

Under epithelia and between muscles.

Function of adipose tissue?

Energy storage, insulation, cushioning.

Function of reticular tissue?

Forms supportive stroma.

Where is reticular tissue found?

Lymph nodes, spleen, thymus, bone marrow.

Function of dense regular connective tissue?

Withstands pulling forces in one direction.

Location of dense regular connective tissue?

Tendons and ligaments.

Function of dense irregular connective tissue?

Withstands stress from multiple directions.

Location of dense irregular connective tissue?

Dermis and organ capsules.

Function of elastic connective tissue?

Stretch and recoil.

What is a chondrocyte?

Mature cartilage cell.

What is a lacuna?

Space occupied by a chondrocyte.

What is the perichondrium?

Connective tissue covering around cartilage.

Function of hyaline cartilage?

Support and smooth joint movement.

Locations of hyaline cartilage?

Trachea, larynx, costal cartilage, fetal skeleton, articular cartilage.

Locations of elastic cartilage?

External ear and epiglottis.

Function of fibrocartilage?

Shock absorption and resistance to compression.

Locations of fibrocartilage?

Intervertebral discs, menisci, pubic symphysis.

What is a membrane?

A tissue sheet that covers a surface, lines a cavity, or divides a space.

What structures make up a mucous membrane?

Epithelium and lamina propria.

What is the lamina propria?

Areolar connective tissue beneath the epithelium.

Where are mucous membranes found?

Digestive, respiratory, urinary, and reproductive tracts.

What is the function of serous membranes?

Produce serous fluid that reduces friction.

What membrane surrounds the lungs?

Pleura.

What membrane surrounds the heart?

Pericardium.

What membrane surrounds abdominal organs?

Peritoneum.

What is the visceral layer?

Layer directly covering the organ.

What is the parietal layer?

Layer lining the cavity wall.