exam 2

Phospholipid Bilayer

Forms the structural foundation of the cell membrane, controls substance movement, and maintains a semi-permeable barrier.

Nucleus

Contains genetic material (DNA) and controls cellular activities such as growth and reproduction.

Mitochondria

Powerhouses of the cell, responsible for energy production (ATP) through cellular respiration.

Rough Endoplasmic Reticulum (Rough ER)

Studded with ribosomes, involved in protein synthesis.

Smooth Endoplasmic Reticulum (Smooth ER)

Synthesizes lipids, detoxifies toxins, and metabolizes carbohydrates.

Golgi Apparatus

Modifies, sorts, and packages proteins and lipids for delivery to targeted destinations.

Lysosomes

Contain enzymes to break down waste, cellular debris, and foreign materials.

Ribosomes

Synthesize proteins.

Cytoskeleton

Provides structural support and aids in cell movement.

Simple Diffusion

Movement of molecules from high to low concentration without energy expenditure.

Facilitated Diffusion

Movement of molecules across the membrane via specific transport proteins without energy expenditure.

Passive Transport

Movement of substances across the membrane without energy input.

Active Transport

Movement of substances against their concentration gradient, requiring energy (ATP).

Osmosis

The diffusion of water across a selectively permeable membrane.

Endocytosis

Process by which cells engulf substances from the external environment.

Exocytosis

Process by which cells expel substances from within to the external environment.

Osmotic Pressure

The force driving water to move across a membrane towards higher solute concentration.

Hypertonic Solution

Higher solute concentration outside the cell than inside, causing the cell to shrink.

Hypotonic Solution

Lower solute concentration outside the cell, causing the cell to swell.

Isotonic Solution

Equal solute concentration inside and outside the cell, no net movement of water.

Simple Squamous Epithelium

Thin, flat cells; found in areas of diffusion or filtration.

Simple Columnar Epithelium

Tall, rectangular cells; found in areas of absorption and secretion.

Stratified Squamous Epithelium

Multiple layers of flat cells; found in areas exposed to abrasion.

Transitional Epithelium

Cells that can stretch and change shape; found in the bladder.

Endocrine Glands

Secrete hormones directly into the bloodstream.

Exocrine Glands

Secrete substances through ducts to the outside of the body.

Fibroblasts

Produce collagen and extracellular matrix.

Adipocytes

Store fat.

Macrophages

Engulf and digest foreign substances.

Mast Cells

Release histamine and heparin in response to injury.

Chondrocytes

Produce and maintain cartilage.

Osteocytes

Maintain bone tissue.

Collagen Fibers

Provide strength and resist stretching.

Elastic Fibers

Allow tissues to stretch and return to their original shape.

Reticular Fibers

Form a supporting network within tissues.

Stratum Basale

Deepest layer where new skin cells are generated.

Stratum Spinosum

Provides strength and flexibility to the skin.

Stratum Granulosum

Cells begin to die and form a barrier.

Stratum Lucidum

Found only in thick skin, provides additional protection.

Stratum Corneum

Outermost layer of dead skin cells, providing a waterproof barrier.

Pseudostratified Epithelium

Appears layered but all cells touch the basement membrane.

Skeletal Muscle

Multinucleated, striated fibers; voluntary control.

Adipose Tissue

Fat cells that store energy and provide insulation.

Bone Tissue

Hard, calcified matrix with osteocytes in lacunae.

Cartilage

Firm but flexible matrix with chondrocytes.