Tissues Derived From Eukaryotic Cells (2A) - Bio & Biochem
- What is the primary function of muscle tissue?
- Contraction to produce movement and force. Muscle tissue contains contractile proteins that enable voluntary and involuntary movements throughout the body.
- What does 'stratified epithelium' mean?
- Multiple layers of epithelial cells. Multiple layers provide enhanced protection in areas subject to mechanical stress, like the skin or esophagus.
- What does 'simple epithelium' mean?
- A single layer of epithelial cells. A single layer maximizes efficiency in processes like diffusion and secretion in organs such as lungs and intestines.
- What is the defining feature of epithelial tissue regarding cell spacing and extracellular matrix?
- Tightly packed cells with minimal extracellular matrix. This arrangement allows epithelial tissue to form continuous sheets that serve as barriers or interfaces for exchange.
- What is the primary function of connective tissue in the body?
- Support, binding, and structural framework. Connective tissues provide structural integrity and connect other tissues, facilitating organ support and repair.
- What is the basal surface of an epithelial cell?
- The surface attached to the basement membrane. The basal surface connects to underlying connective tissue, providing anchorage and nutrient access.
- What is the defining feature of connective tissue regarding cells and extracellular matrix?
- Sparse cells embedded in abundant extracellular matrix. The matrix provides mechanical support and enables functions like binding tissues and storing energy.
- Which epithelial tissue typically lines the trachea and uses cilia to move mucus?
- Pseudostratified ciliated columnar epithelium. Appearing multilayered but single-layered, its cilia propel mucus to trap and remove debris from airways.
- What is the apical surface of an epithelial cell?
- The surface facing the lumen or external environment. The apical surface often has specializations like microvilli or cilia for interaction with the environment.
- Which epithelial tissue is best adapted to resist abrasion (for example, skin surface)?
- Stratified squamous epithelium. Multiple layers of flattened cells keratinize to form a durable barrier against friction and pathogens.
- What is the key functional advantage of simple squamous epithelium?
- Rapid diffusion and filtration. Its thin, flat cells facilitate efficient gas exchange in alveoli and filtration in kidney glomeruli.
- What are the two criteria used to classify epithelial tissue?
- Number of layers and cell shape. Classification by layers (simple or stratified) and shapes (squamous, cuboidal, columnar) correlates with specific functions.
- What is the function of cilia on epithelial cells?
- Move fluid or mucus across the cell surface. Cilia beat rhythmically to propel substances, aiding in clearance of airways or movement in fallopian tubes.
- What does it mean that epithelium is avascular?
- It has no blood vessels; it is nourished by diffusion. Avascularity ensures epithelium relies on nearby capillaries in connective tissue for oxygen and nutrients.
- What is the primary function of nervous tissue?
- Rapid signaling and information processing. Nervous tissue consists of neurons and glia that transmit electrical impulses for coordination and response.
- What are gap junctions primarily responsible for between adjacent animal cells?
- Direct intercellular communication via ion and small molecule flow. Gap junctions form channels allowing rapid sharing of signals and metabolites for coordinated activity.
- What is the basement membrane in epithelial tissue?
- Specialized extracellular matrix anchoring epithelium. Composed of basal lamina and reticular lamina, it separates epithelium from connective tissue and supports regeneration.
- What are the four primary tissue types found in animals?
- Epithelial, connective, muscle, nervous. These tissues originate from eukaryotic cells and form the structural and functional basis of animal organs.
- What is the defining feature of transitional epithelium in the urinary system?
- Cells change shape to allow stretching. In the bladder, this allows expansion without tearing, accommodating volume changes during urine storage.
- What is the primary function of epithelial tissue in the body?
- Barrier and exchange (protection, absorption, secretion). Epithelial tissues line surfaces and cavities, regulating interactions between the body and its environment.
- Which epithelium type is specialized for absorption and secretion and commonly has microvilli?
- Simple columnar epithelium. Found in the digestive tract, its tall cells with microvilli enhance nutrient uptake and mucus production.
- What is the function of microvilli on epithelial cells?
- Increase surface area for absorption. Microvilli are finger-like projections that amplify membrane area for efficient nutrient and ion transport.
- What are tight junctions in epithelial tissue primarily responsible for?
- Prevent paracellular leakage; maintain apical-basal polarity. Tight junctions form seals between cells, creating selective barriers and separating membrane domains.
- What are desmosomes primarily responsible for in epithelial tissue?
- Strong cell-cell adhesion to resist mechanical stress. Desmosomes link intermediate filaments between cells, providing tensile strength in tissues under stress.