Cell Biology and Histology Flashcards

A collection of flashcards covering key terms and definitions from the lecture notes on cell biology and histology.

Cell Theory

All organisms are composed of one or more cells; cells are the smallest living units; cells arise only by division of previously existing cells.

Prokaryotic Cells

Cells without a defined nucleus, containing a single circular molecule of DNA.

Eukaryotic Cells

Cells with a defined nucleus bound by a nuclear envelope and double helix DNA.

Cytoplasm

Substance filling the interior of the cell, containing sugars, amino acids, proteins, and organelles.

Plasma Membrane

The phospholipid bilayer that encloses the cell, controlling the movement of substances in and out.

Diffusion

Movement of substances down their concentration gradient from high to low concentration.

Active Transport

Transport of substances across a membrane that requires energy (ATP), often with transporter proteins.

Ribosomes

RNA-protein complexes that serve as the site of protein synthesis, assembled in nucleoli.

Mitochondria

Organelles known as the 'powerhouse of the cell' that are involved in cellular metabolism.

Chloroplasts

Organelles found in photosynthetic organisms, containing thylakoids for capturing light energy.

Endoplasmic Reticulum (ER)

Network of internal membranes involved in protein and lipid synthesis.

Golgi Apparatus

Collection of membrane stacks that package and distribute molecules synthesized in the cell.

Lysosomes

Membrane-bound vesicles containing digestive enzymes for breaking down waste materials.

Cytoskeleton

Network of protein filaments that provides structural support and shape to the cell.

Epithelial Tissue

A type of tissue that covers body surfaces and forms glands; categorized as covering or glandular.

Connective Tissue

Tissue that supports, binds together, and protects other tissues; includes bone, blood, and adipose.

Muscle Tissue

Tissue specialized for contraction and movement; includes skeletal, cardiac, and smooth muscle.

Nervous Tissue

Tissue composed of neurons and glial cells; responsible for transmitting electrical impulses.

Tumors

Abnormal growth of cells; classified as benign (non-cancerous) or malignant (cancerous).

Neurons

The basic unit of nervous tissue, responsible for conducting impulses; includes sensory, interneurons, and motor neurons.

Synapse

The junction between two neurons, where neurotransmitters are released to transmit signals.

Hydrolysis

The chemical breakdown of a compound due to reaction with water, important in digestion.

Apocrine Glands

Type of exocrine gland that releases secretion in fragments of the cells.

Merocrine Glands

Type of exocrine gland that releases secretion through exocytosis without cellular damage.

Holocrine Glands

Type of exocrine gland where the entire cell disintegrates to release secretions.

Osteocytes

Mature bone cells housed in lacunae responsible for maintaining bone tissue.

Chondrocytes

Cells found in cartilage that produce and maintain the cartilaginous matrix.

Hematopoiesis

The process of blood cell formation occurring in the bone marrow.

Z disc (Z line)

The boundary between adjacent sarcomeres in muscle tissue.

Myofibrils

Long, threadlike structures within muscle fibers that contain the contractile proteins actin and myosin.

Sarcolemma

The cell membrane of a muscle cell, invaginated to form T-tubules.