Test Bank for Pathophysiology 9th Edition

Metabolic absorption

In metabolic absorption, all cells take in and use nutrients and other substances from their surroundings.

Nucleus

The nucleus contains the nucleolus, a small dense structure composed largely of RNA, most of the cellular DNA, and the DNA-binding proteins, such as the histones, which regulate its activity.

Peroxisomes

Peroxisomes are so named because they usually contain enzymes that use oxygen to remove hydrogen atoms from specific substrates in an oxidative reaction that produces H2O2, which is a powerful oxidant and potentially destructive if it accumulates or escapes from peroxisomes.

Lysosomes

The lysosomal membrane acts as a protective shield between the powerful digestive enzymes within the lysosome and the cytoplasm, preventing their leakage into the cytoplasmic matrix.

Digestive enzyme development sequence

The enzyme is transcribed from DNA by RNA in the nucleus, proceeds to the ribosome for synthesis, and is transported in a secretory vesicle to the cell membrane.

Enzyme transcription process

The enzyme is transcribed from DNA by RNA in the nucleus, proceeds to the ribosome for synthesis, and is transported in a secretory vesicle to the cell membrane.

Cell cycle phases

The four designated phases of the cell cycle are: (1) the G1 phase (G = gap), which is the period between the M phase (M = mitosis) and the start of DNA synthesis; (2) the S phase (S = synthesis), during which DNA is synthesized in the cell nucleus; (3) the G2 phase, during which RNA and protein synthesis occurs; and (4) the M phase, which includes nuclear and cytoplasmic division.

Organic compound for transportation

Proteins act as (1) recognition and binding units (receptors) for substances moving in and out of the cell; (2) pores or transport channels for various electrically charged particles called ions or electrolytes and specific carriers for amino acids and monosaccharides; and (3) specific enzymes that drive active pumps that promote the concentration of certain ions, particularly potassium (K+), within the cell while keeping concentrations of other ions, for example, sodium (Na+), below the concentrations found in the extracellular environment.

Diseases related to proteolytic cascades

Understanding the various steps involved in proteolytic cascades is crucial for designing drug interventions for autoimmune and malignant disorders.

Structure preventing water-soluble molecules

The lipid bilayer prevents water-soluble molecules from entering cells across the plasma membrane because it is impermeable to most water-soluble molecules.

Fluid mosaic model

The fluid mosaic model accounts for the flexibility of cellular membranes, their self-sealing properties, and their impermeability to many substances.

Cell communication methods

Protein channel (gap junction) is used to communicate within the cell itself and with other cells in direct physical contact.

Plasma membrane-bound signaling molecules

Molecules involving receptors that affect the cell itself and other cells in direct physical contact.

Hormone secretion

The release of signaling molecules such as neurotransmitters.

Extracellular chemical messengers

Chemical signals such as ligands that communicate between cells.

Chemical signaling categories

Three categories: (1) local-chemical mediator, (2) hormone, and (3) neurotransmitter.

Paracrine signaling

A mode of chemical signaling where local chemical mediators are quickly taken up, destroyed, or immobilized.

Neurotransmitters

Chemical signals secreted by neurons to stimulate an adjoining cell.

Acetylcholine

A neurotransmitter that stimulates the movement of a muscle cell.

Hormonal signaling

A mode of chemical signaling that uses blood to transport communication to cells some distance away.

Local-chemical mediator

A secreted chemical that acts on the cells in the immediate environment.

Guanosine triphosphate (GTP)

A molecule that can act as a second messenger in signaling pathways.

Adenosine triphosphate (ATP)

A molecule that provides energy for cellular processes.

Adenosine monophosphate (AMP)

A second messenger involved in signaling pathways.

Guanosine diphosphate (GDP)

A molecule that can act in signaling pathways but is not a second messenger.

Chemical messengers

Ligands that bind to specific membrane receptors to facilitate communication.

Second messenger pathways

Two major pathways are cyclic AMP (cAMP) and calcium (Ca++).

Glycolysis

A process that provides energy for the cell under anaerobic conditions, producing a net of two ATP per glucose molecule.

Oxidative phosphorylation

The mechanism by which energy from carbohydrates, fats, and proteins is transferred to ATP.

Oxidative cellular metabolism

A process that involves the use of oxygen to produce ATP from nutrients.

Tricarboxylic acid phosphorylation

A less common mechanism for ATP production not primarily associated with oxidative phosphorylation.

Passive transport

Transport driven by osmosis, hydrostatic pressure, and diffusion.

Receptors

Proteins that can bind with substances being transported.

Signal molecules

Hundreds of kinds of molecules used by cells to communicate, such as insulin.

Postsynaptic membrane

The membrane of a neuron or muscle cell that receives signals from neurotransmitters.

Ligands

Chemical messengers that bind to receptors on target cells.

Cellular communication

The process by which cells receive signals from their environment.

Extracellular fluid

The fluid surrounding cells that contains signaling molecules.

Direct physical contact

A method of communication between cells that involves physical interaction.

Chemical signaling

The process by which cells communicate through the release and reception of chemical signals.

Passive transport

A process where water and small electrically uncharged molecules move easily through pores in the plasma membrane's lipid bilayer, driven by osmosis, hydrostatic pressure, and diffusion.

Active transport

A mechanism that requires energy and receptors capable of recognizing and binding with substances to move them into the cell.

Diffusion

The movement of a solute molecule from an area of greater solute concentration to an area of lesser solute concentration.

Hydrostatic pressure

The mechanical force of water pushing against cellular membranes, such as the blood pressure generated in vessels by the contraction of the heart.

Osmosis

The movement of water down a concentration gradient across a semipermeable membrane from a region of higher water concentration to a region of lower water concentration.

Mediated transport

A method of transport that uses transmembrane proteins with receptors having a high degree of specificity for the substance being transported.

Osmolality

A measurement of osmotic activity that is preferred over osmolarity in clinical assessments due to the greater concentration of particles in plasma.

Osmolarity

A measurement of osmotic activity that is less preferred than osmolality because it does not account for the weight of solutes in plasma.

Interstitial fluid

The fluid surrounding the capillary that receives water pushed across capillary membranes due to hydrostatic pressure.

3% saline solution

A fluid replacement used intravenously to replace sodium and chloride lost in diarrhea.

Transmembrane proteins

Proteins that span the membrane and are involved in the transport of substances across the cell membrane.

Specificity in transport

The high degree of selectivity that certain transport mechanisms have for specific substances.

Capillary membranes

Thin membranes that allow for the movement of fluid into the interstitial space due to hydrostatic pressure.

Hydrophobic membrane

A type of membrane that does not allow water and small electrically uncharged molecules to pass easily.

Hydrophilic membrane

A type of membrane that allows water and small electrically uncharged molecules to pass easily.

Sodium and chloride

Electrolytes that influence the volume of plasma and are replaced during fluid therapy.

Plasma weight

The weight of plasma is influenced more by solutes such as proteins and glucose than by water.

Fluid movement process

A process such as hydrostatic pressure, osmosis, diffusion, or active transport that describes how fluids move across membranes.

Cell hydration

The state of a cell when it absorbs water and swells.

Cell shrinkage

The state of a cell when it loses water and becomes smaller.

Fluid replacement therapy

A medical treatment used to replenish fluids and electrolytes lost due to conditions such as diarrhea.

Concentration gradient

A difference in the concentration of a substance across a space, which drives diffusion.

Solute concentration

The amount of solute present in a given volume of solution, influencing osmotic activity.

Blood pressure in capillaries

The hydrostatic pressure generated in vessels by the contraction of the heart, typically 25 to 30 mm Hg.

Mechanisms of active transport

Processes that require energy to move substances against their concentration gradient.

Integral proteins

Proteins that are embedded in the membrane and play a role in transport.

Electrically uncharged molecules

Molecules that do not carry an electrical charge and can pass through membranes more easily.

Clinical assessment of osmolality

The evaluation of osmotic activity in individuals, which is preferred due to the concentration of solutes in plasma.

Fluid movement across membranes

The process by which fluids move through cellular membranes, influenced by various pressures and concentrations.

Hypertonic solution

A hypertonic solution has a concentration of greater than 285 to 294 mOsm/kg.

Example of a hypertonic solution

3% saline solution.

Effect of hypertonic solution on cells

Water can be pulled out of the cells by a hypertonic solution; therefore the cells shrink.

Facilitated diffusion

The means by which glucose is transported from the blood to the cells.

Transport of potassium and sodium

Transported across plasma membranes by adenosine triphosphatase (ATPase) enzyme.

Mechanism of Na+ and K+ transport

ATPase enzyme induces the transporter protein to undergo several conformational changes.

Exocytosis

In eukaryotic cells, secretion of macromolecules almost always occurs by exocytosis.

Potassium diffusion

The resting plasma membrane is more permeable to potassium than to sodium.

Resting membrane potential

An excess of anions are inside the cell, resulting in the resting membrane potential.

Cholesterol uptake process

The cellular uptake of nutrients, such as cholesterol, depends on receptor-mediated endocytosis.

Action potential initiation

When a resting cell is stimulated, sodium gates open, and sodium rushes into the cell.

Change in membrane potential during action potential

The membrane potential changes from negative to positive.

Role of sodium gates

Sodium gates open, allowing sodium to rush into the cell.

Effect of sodium on membrane potential

A net Na+ moves into the cell, causing the membrane potential to reduce to zero and then become positive.

Resting plasma membrane permeability

The resting plasma membrane is more permeable to K+ than to Na+.

Cellular uptake of nutrients

Nutrients are not transported via passive transport, antiport system, or receptor-mediated exocytosis.

Macromolecule secretion

Macromolecules can be secreted across eukaryotic cell membranes during exocytosis.

Potassium concentration in ICF

Potassium has a greater concentration in the intracellular fluid (ICF).

Sodium concentration in ECF

Sodium has a greater concentration in the extracellular fluid (ECF).

Effect of potassium gates

Potassium gates open, allowing potassium to rush into the cell.

Transport mechanism uncertainty

The exact mechanism for the transport of Na+ and K+ across the membrane is uncertain.

Conformational changes in transport

Conformational changes in the transporter protein cause Na+ and K+ to move short distances.

Secretion of substances

All substances are not secreted into the cellular matrix during exocytosis.

Diffusion of solute molecules

Solute molecules do not flow freely into and out of the cell.

Action of platelet-derived growth factor

Stimulates the production of certain cells.

Platelets

Different types of cells require different factors; for example, platelet-derived growth factor stimulates the production of connective tissue cells.

Cytokines

Growth factors, also called cytokines, are peptides that transmit signals within and among cells.

Cellular reproduction

During telophase, the final stage, a new nuclear membrane is formed around each group of 46 chromosomes, the spindle fibers disappear, and the chromosomes begin to uncoil.

Eukaryotic cells

Eukaryotic cells have a characteristic set of membrane-bound intracellular compartments called organelles that include a well-defined nucleus and are larger than prokaryotes.

Phagocytosis

In phagocytosis, the large molecular substances are engulfed by the plasma membrane and enter the cell so that they can be isolated and destroyed by lysosomal enzymes.

Muscle cell function

A cell has the potential to differentiate and to gain the ability to perform one of eight specialized functions. Muscle cells can generate forces that produce motion.