Histology Flashcards
Plasmalemma / cell membrane components
Lipid bilayer (including phospholipids and cholesterol)
Membrane associated proteins
Glycocalyx
Plasma membrane functions
Acts as physical barrier to enclose cell contents
Regulates material movement in and out
Establishes and maintains electrical charge difference
Functions in cell communication
Passive processes
Movement of substances down a concentration gradient due to kinetic energy of substance
No expenditure of cellular energy is required
Continues until equilibrium is reached.
Simple diffusion
Unassisted net movement of small, nonpolar substances down concentration gradient across across selectively permeable membrane
Passive process
Facilitated diffusion
Movement of ions and small, polar molecules down concentration gradient,
Assisted across selectively permeable membrane by transport protein.
Passive process
Channel mediated diffusion
Passive facilitated diffusion
Movement of ion down its concentration gradient through protein channel
Carrier mediated diffusion
Passive facilitated diffusion
Movement of small polar molecule down concentration gradient by carrier protein
Osmosis
Diffusion of water across selectively permeable membrane
Direction is determined by relative solute concentrations
Continues until equilibrium is reached
Active processes
Movement of ions or small molecules across membrane against a concentration gradient by transmembrane protein pumps
Primary active transport
Movement. Of substance up its concentration gradient
Powered directly by ATP
Active transport
Secondary active transport
Movement of substance up its concentration gradient powered by harnessing movement of a second substance down its concentration gradient
Active transport
Symport
Movement of substance up its concentration gradient is in same direction as na+
Active transport
Antiport
Active transport
Movement of substance up its concentration gradient in the opposite direction as na+
Vesicular transport
Vesicle formed or lost as material is brought into a cell or released from cell.
Exocytosis
Vesicular transport
Bulk movement of substance out of cell by fusion of secretory vesicles with the plasma membrane
Endocytosis
Vesicular transport
Bulk movement of substances into cell by vesicles forming at the plasma membrane.
Phagocytosis
Vesicular transport
Type of endocytosis in which vesicles are formed as particulate materials external to the cell are engulfed by pseudopodia
Pinocytosis
Vesicular transport
Type of endocytosis in which vesicles are formed as interstitial fluid is taken up by cell
Receptor mediated endocytosis
Vesicular transport
Type of endocytosis is which plasma membrane receptors first bind specific substances
Receptor and bound substance then taken up by cell
Cytoplasm structures
Cytosol
Organelles
Cytoskeleton
Inclusions (insoluble granules)
Cytoplasm
Contents of cells between plasma membrane and nuclear envelope
Cytoplasm function
Provides support for organelles
Serves as viscous fluid medium through which diffusion occurs.
Organelles
Membrane ground and non membrane bound structures
Organelles function
Carry out specific metabolic activities of the cell
Rough endplasmic reticulum
Modifies, transports, and stores proteins produced by attached ribosomes
Proteins are secreted, become components of plasma membrane or serve as enzymes of lysosomes
Smooth endoplasmic reticulum
Extensive interconnected membrane lacking ribosomes
Smooth endoplasmic reticulum function
Synthesizes, transports and stores lipids (steroids),
Metabolizes carbohydrates
Detoxifies drugs, alcohol and poisons
Forms vesicles and peroxisomes
Golgi apparatus function
Modifies, packages, and sorts materials that arrive from ER in transport vesicles,
Forms secretory vesicles and lysosomes
Vesicles
Spherical shaped membrane bound sacs
Contain various types of materials to be transported through cell
Vesicle function
Transport cellular material
Lysosomes
Spherical shaped membrane bound organelles formed from Golgi apparatus
Contain digestive enzymes
Peroxisomes
Smaller spherical shaped membrane bound organelles formed from ER or through fission
Contain oxidative enzymes
Lysosome function
Digest microbes or materials (ingested by cell, worn out cellular components or entire cell)
Mitochondria function
Synthesizes most ATP during aerobic cellular respiration by digestion of fuel molecules in the presence of oxygen.
Ribosomes function
Engage in protein synthesis
Bound ribosomes produce proteins that are secreted, incorporated into plasma membrane and within lysosomes
Free ribosomes produce proteins used within the cell
Cytoskeleton
Organized network of protein filaments and hollow tubes, including microfilaments, intermediate filaments and microtubules
Cytoskeleton function
maintains intracellular support and organization of cells
Participates in cell division
Facilitates movement
Microfilaments
Actin protein monomers organized into 2 thin intertwined protein filaments (actin filaments)
Microfilaments function
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Maintain cell shape Support microvilli Separate two cells during cytokinesis Facilitate change in cell shape Participate in muscle contraction
Intermediate filaments function
Provide structural support
Stabilize junctions between cells
Microtubules
Hollow cylinders composed of tubulin
Microtubules function
Maintain cell shape and rigidity Organize and move organelles Support cilia and flagella Participate in vesicular transport Separate chromosomes during cell division
Centrosome
Amorphous region adjacent to nucleus.
Contains a pair of centrioles
Centrosome function
Organizes microtubules
Participates in mitosis spindle formation during cell division
Proteasomes function
Degrade and digest damaged or unneeded proteins
Ensure quality of exported proteins
Inclusions functions
Serve as temporary storage
Tissues
Aggregate of cells and their extracellular matrix of common embryonic origin
Organized to perform a specific function(s)
General cellular activity
Synthesize and secrete components of the extracellular matrix
Specialized cell
Fibroblasts, cells of bone and cartilage
General cellular activity
Convert physical and chemical stimuli into action potentials
Specialized cells
Neurons and sensory cells
General cellular activity
Intracellular digestion
Specialized cells
Macrophages and neutrophils
Extracellular matrix composed of
Ground substance
Protein fibers
Major tissue types
Epithelial
Muscular
Nervous
Connective
Epithelial tissue
Covers body surfaces, lines body cavities and internal tubes, and forms glands
Muscular tissue
Contractile cells responsible for movement
Nervous tissue
Receives, transmits and integrates info to modulate body activity via electrical impulses
Connective tissue
Supports other three types of tissue
Hollow organ wall
Concentric layers of 3-4 tissues Mucosa Submucosa Muscular layers Serous/ adventitia
Mucosa
Epithelium with an underlying ct
Submucosa
Supportive ct with blood vessels, lymphatic, and nerves
Solid organ organization
Parenchyma
Storma
Capsule
Parenchyma
Functional part of solid organ
Bulk of tissue making up organ
Most commonly glandular epithelium