Lesson 1 Cellular Physiology, Cell Injury

Slides & Transcript

What is the primary function of the cell nucleus?

To house the cell’s DNA and genetic material

What is the role of ribosomes?

Protein synthesis within the cell.

What is the function of the cell membrane?

Maintains cellular integrity and homeostasis; regulates transport and signaling.

What is the role of the cytoplasm?

Site of chemical reactions and housing of organelles (cytosol).

Which organelle is the powerhouse of the cell and hosts energy production?

Mitochondria, the site of aerobic respiration and ATP production.

What is aerobic respiration?

Energy production that requires oxygen.

What is anaerobic respiration?

Energy production without oxygen, producing lactic acid.

Define diffusion.

Movement of solutes from an area of higher concentration to lower concentration down the concentration gradient.

Define osmosis.

Movement of water across a selectively permeable membrane down its water potential gradient.

What is a concentration gradient?

A difference in the concentration of a substance between two regions.

What is osmotic pressure?

The pressure exerted by solutes to attract water; related to solute concentration across a membrane.

What is facilitated diffusion?

Passive transport that requires a carrier or channel to move substances down their concentration gradient; no cellular energy.

What is passive transport?

Transport that does not require energy; moves substances along their concentration gradient.

What is active transport?

Transport that requires energy (usually ATP) and moves substances against their concentration gradient (e.g., Na+/K+ pump).

What is endocytosis?

Engulfment of extracellular material into the cell via vesicles.

What is exocytosis?

Expulsion of materials from the cell via vesicle fusion with the plasma membrane.

What is homeostasis?

Maintenance of stable internal conditions within the cell or organism.

What is the difference between positive and negative feedback?

Positive feedback amplifies a process; negative feedback stabilizes the system and counteracts disturbances.

What are the four basic tissue types?

Connective, epithelial, muscle, and nervous tissues.

What is atrophy?

A adaptive cellular change characterized by a decrease in cell size.

What is hypertrophy?

An increase in cell size due to increased demand or use.

What is hyperplasia?

An increase in the number of cells.

What is dysplasia?

Abnormal development or maturation of cells that can lead to disease.

What is metaplasia?

One mature cell type is replaced by another.

What is apoptosis?

Programmed cell death; normal, controlled turnover that allows for new cell growth.

What is ischemia?

Lack of oxygen and/or blood supply to cells or tissues.

What is necrosis?

Irreversible cell death due to lack of oxygen or blood supply.

What is the difference between necrosis and apoptosis?

Necrosis is uncontrolled cell death due to injury; apoptosis is controlled, programmed cell death.

What is etiopathogenesis (etiology and pathogenesis)?

Etiology is the cause of disease; pathogenesis is the development and progression of disease.

What is intrinsic cause?

Genetics, age, or gender; examples include sickle cell anemia, cystic fibrosis, hemophilia, Turner syndrome.

What is extrinsic cause?

External factors such as infections, lifestyle (alcohol, drugs, diet, inactivity, smoking), stressors, and environment.

What is hereditary vs genetic disease?

Hereditary diseases are carried through generations; genetic diseases arise from gene variants and may or may not be inherited.

What is pharmacogenomics?

How genetic alterations influence an individual's response to medications, affecting efficacy and safety.

What is acute vs chronic disease?

Acute: sudden onset; chronic: long-lasting or persistent.

What is a sign vs a symptom?

A sign is observable by others; a symptom is felt by the patient.

What is incidence in epidemiology?

The number of new cases arising in a population during a specified period.

What is prevalence in epidemiology?

The measure of existing disease in a population at a given time.

What is morbidity?

The incidence of disease or disability within a population.

What is mortality?

The death rate in a population.

What are mitosis and meiosis?

Mitosis: cell division for growth and repair; Meiosis: division for gamete formation, increasing genetic diversity.

What is the Krebs cycle?

A sequence in aerobic respiration in mitochondria that processes acetyl-CoA to produce energy carriers and CO2; requires oxygen.

What are modes of direct cell communication?

Gap junctions; autocrine, paracrine, endocrine, and synaptic signaling.

What are receptor sites and identifying markers?

Receptors bind signaling molecules to regulate cell function; identifying markers help identify cell type/localization.

What are channels in the cell membrane?

Transmembrane proteins that allow ions or molecules to pass through the membrane.

What are the major energy-producing pathways in the cell?

Glycolysis, the Krebs cycle, and oxidative phosphorylation (electron transport chain) in mitochondria.

What is the basic building block of the body and how do cells vary?

The cell is the basic building block; cells vary in structure and function by cell type (e.g., muscle/bone vs brain/heart); human cells are eukaryotic.

Which organelle houses the cell's genetic material and guides protein production and replication?

The nucleus contains DNA, directs production of essential proteins, guides cell replication, and influences organism function.

What is the function of ribosomes?

Ribosomes are the site of protein synthesis; they use RNA to produce proteins.

What is the role of the cell membrane?

Separates intracellular fluid from extracellular fluid; maintains cellular homeostasis; is selectively permeable and stabilized by lipoproteins.

What additional roles do membrane proteins serve besides forming channels?

They act as receptors that interact with external chemicals to trigger intracellular changes and regulate transport and metabolism.

What is the function of mitochondria?

Mitochondria produce energy in the form of ATP; cells with high energy demand have more mitochondria (e.g., heart cells).

What is endocytosis and exocytosis?

Endocytosis brings substances into the cell; exocytosis removes substances from the cell.

What is diffusion and what powers it?

Diffusion is the movement of a substance from high to low concentration; powered by a concentration gradient; it is a passive process requiring no cellular energy.

What is osmosis?

Osmosis is the movement of water across a semi-permeable membrane from areas of lower solute concentration to higher solute concentration.

What is facilitated diffusion?

Facilitated diffusion uses a carrier protein to move substances through the cell membrane along a concentration gradient.

How does active transport differ from passive transport?

Active transport requires energy to move substances against their concentration gradient, often via pumps like the sodium–potassium pump.

What is the sodium–potassium pump and why is it important?

An active transport mechanism that maintains higher intracellular potassium and lower sodium, helping preserve the cell’s electrical charge and function.

What are the main forms of cellular communication?

Gap junctions, autocrine, paracrine, and endocrine signaling.

What is the difference between aerobic and anaerobic respiration?

Aerobic respiration uses oxygen to produce ATP; anaerobic respiration occurs without oxygen, is less efficient, and produces lactic acid.

What is metabolism in cellular terms?

Metabolism encompasses anabolic (building up) and catabolic (breaking down) processes that support cell function.

What is growth and reproduction at the cellular level?

Growth involves mitosis; reproduction involves meiosis; groups of cells form tissues, which form organs and organ systems.

What are epithelial cells and their regenerative ability?

Epithelial cells cover the body's outer surface and line internal cavities; they are highly regenerative.

What is atrophy?

Atrophy is a decrease in cell size due to underuse, leading to reduced function.

What is hypertrophy?

Hypertrophy is an increase in cell size due to use or overuse; can initially improve function but may become dysfunctional.

What is hyperplasia?

Hyperplasia is an increase in the number of cells; can be a normal or pathological response.

What is dysplasia?

Dysplasia is abnormal cell growth that is irreversible, sometimes progressing to cancer.

What is ischemia, necrosis, and apoptosis?

Ischemia is lack of oxygen/blood flow; necrosis is irreversible cell death due to injury; apoptosis is programmed, controlled cell death.

What is pathophysiology?

The broad study of disordered physiology and the body's responses to disease or cellular injury.

What are etiology, predisposition factors, pathogenesis, and insidious onset?

Etiology: cause; predisposition (risk factors): tendency to develop disease; pathogenesis: development of disease; insidious onset: vague or gradual onset.

What is the difference between intrinsic and extrinsic disease causes?

Intrinsic causes originate within the body (genetics, age, gender); extrinsic causes originate outside the body (infections, toxins, environmental exposures).

What is acute vs chronic disease?

Acute diseases have rapid onset and resolution; chronic diseases persist for six months or longer and may be lifelong.

What are symptoms vs signs?

Symptoms are subjective experiences reported by the patient; signs are objective findings observed by clinicians (e.g., blood pressure, heart rate).

What are incidence and prevalence?

Incidence: number of new cases in a population over a period; Prevalence: total existing cases at a point in time, often used for chronic diseases.

What are edema, capillary hydrostatic pressure, and colloid osmotic pressure?

Edema is fluid shift from vasculature to interstitial space; capillary hydrostatic pressure (pressure pushing fluid out) and colloid osmotic pressure (protein-driven pull into vessels, e.g., albumin) regulate this balance.

What role does albumin play in osmotic pressure?

Albumin is a key plasma protein that helps maintain capillary osmotic pressure and retains fluid within vessels.

What is the lymphatic system’s role in edema?

The lymphatic system helps remove interstitial fluid proteins and excess fluid; impaired lymphatics can cause lymphedema.

What is third spacing?

Third spacing is the loss or trapping of extracellular fluid in transcellular spaces (e.g., pericardial, pleural, peritoneal) often with systemic inflammation or hypoalbuminemia.

What is dependent edema and its clinical relevance?

Edema that occurs in gravity-dependent areas (e.g., feet/ankles); elevating the legs can reduce it by decreasing the effect of gravity.

What is isotonic IV fluid and where does it stay?

Isotonic IV fluid has the same osmolarity as extracellular fluid and remains predominantly in the vasculature.

What is hypertonic IV fluid and its effect on cells?

Hypertonic IV fluid has higher solute concentration outside the cell; water tends to move out of cells into the extracellular space, causing cell shrinkage.

What are common clinical signs of fluid volume deficit?

Weak pulse, low blood pressure, flat neck veins, lethargy, temperature dysregulation, tachypnea, dyspnea, decreased urine output, and thirst (early sign).

What laboratory findings typically accompany fluid volume deficit?

Increased serum osmolality, hematocrit, BUN (Blood Urea Nitrogen); increased urine specific gravity due to concentration effects.

What findings are associated with fluid volume overload?

Bounding pulse, elevated blood pressure, neck vein distention, crackles in the lungs, increased respiratory rate, edema, pale/cool skin; dilutional labs with decreased serum osmolality and diluted hematocrit.

How does liver failure contribute to edema?

Decreased albumin production lowers capillary osmotic pressure; increased vascular pressure in the abdomen can also contribute to edema.