Advanced Patho Exam 1 Study Guide

Prokaryotes vs. Eukaryotes

• Prokaryotes lack a nucleus and membrane-bound organelles, possessing instead a single circular chromosome located in a nucleoid.
• Examples of prokaryotes include cyanobacteria, bacteria, and rickettsiae.
• Eukaryotes have complex cellular organization with membrane-bound organelles and a well-defined nucleus, including higher animals, plants, fungi, and protozoa.

Eukaryotic Cell Structure

• The nucleus is the largest membrane-bound organelle, facilitating the movement of molecules between the nucleus and cytosol via the nuclear envelope.
• Nucleolus consists of RNA, DNA, and histone proteins; it plays a key role in ribosome synthesis and cell division.
• Cytoplasm comprises the cytoplasmic matrix and cytosol, which is crucial for protein synthesis, hormone transport, and cellular maintenance.

Eukaryotic Organelles

• Ribosomes are sites for protein synthesis.
• Endoplasmic reticulum (ER) exists in two forms: rough (with ribosomes) and smooth (without ribosomes), both involved in protein synthesis.
• The Golgi complex processes, packages proteins for delivery, forming secretory vesicles.
• Lysosomes digest toxins, organelles, and foreign materials; they originate from the Golgi and contain hydrolases.
• Peroxisomes detoxify harmful substances, containing oxidative enzymes.
• Mitochondria are the powerhouses of the cell, generating ATP through oxidative phosphorylation.
• The cytoskeleton maintains cellular shape, enabling motility and organelle transport.

Cellular Metabolism

• Anabolism is energy-consuming, while catabolism releases energy.
• Digestion and glycolysis (splitting of glycogen) occur in the cytoplasm, with anaerobic processes taking place without oxygen.

Cellular Adaptations

• Atrophy refers to a decrease in cell size due to various physiological or pathological conditions.
• Hypertrophy involves increased cell size, often resulting from hormonal stimulation or chronic overload.
• Hyperplasia is an increase in cell number, occurring in compensatory or hormonal contexts.
• Dysplasia indicates abnormal cell growth, while metaplasia is the reversible replacement of one cell type with another.

Cellular Death Mechanisms

• Necrosis is the process of cellular autodigestion following local cell death, marked by various types: coagulative, liquefactive, caseous, fat, and gangrenous necrosis.
• Apoptosis is programmed cell death, contrasting necrosis by avoiding inflammation and rapid engulfment of cellular debris.

Somatic Death

• Postmortem changes include algor mortis (body cooling), livor mortis (blood settling), rigor mortis (muscle stiffening), and autolysis (enzyme release).

Transport Mechanisms

• Diffusion involves solute movement from high to low concentration, while osmosis is the movement of water across a semipermeable membrane.
• The sodium-potassium pump actively transports sodium out and potassium into the cell, crucial for action potentials.

Inflammation Types

• Acute inflammation lasts 8-10 days, marked by vascular responses; chronic inflammation persists for longer and is often due to failed acute responses.
• Characteristics of chronic inflammation include dense lymphocyte infiltration and granuloma formation.

RNA Synthesis

• RNA is synthesized from DNA via RNA polymerase during transcription, followed by translation into proteins by ribosomes.

Electrolyte Imbalances

• Hypokalemia (low potassium) can cause neuromuscular irritability and muscle weakness.
• Hyponatremia (low sodium) leads to symptoms like confusion, intracellular dehydration, and hypotension.

Inflammatory Response Goals

• The inflammatory response aims to control damaging processes, prevent infection, control bleeding, and prepare for healing.

Chemical Mediators of Inflammation

• Mast cells play a central role by releasing histamine and other mediators, activated by physical or chemical stimuli.

Systemic Manifestations of Acute Inflammation

• Fever is triggered by pyrogens affecting the hypothalamus.
• Leukocytosis is increased leukocyte levels; acute-phase reactants rise due to liver activity.

Wound Healing

• Healing involves resolution (regeneration) or repair (scar formation).
• Dysfunctional wound healing can occur due to various factors such as infection, excessive scarring, and suboptimal nutrient conditions.

Genetic Disorders

• Down syndrome (Trisomy 21) is the most common aneuploidy, with characteristic physical features and risks.
• Autosomal recessive disorders express equally in genders, while autosomal dominant disorders show no generational skipping.
• X-linked disorders primarily affect males; females can be carriers.
• Genetic concepts include homozygous (identical alleles), heterozygous (different alleles), genotypes, and phenotypes.

Risk and Recurrence

• The recurrence risk for genetic conditions varies by trait dominance; autosomal recessive traits require both parents to be carriers.
• X-linked recessive disorders show generational skipping and primarily affect males.

Fragile X Syndrome

• Often leads to intellectual disability, prevalent especially in males due to single X chromosome presence.### Metafemale Syndrome
• Characterized by a variable range of symptoms including sterility, menstrual irregularities, and mental retardation.
• Symptoms worsen with each additional X chromosome present.

Turner Syndrome

• Identified by a 45, X karyotype, representing females with a single X chromosome.
• Key features include absence of ovaries leading to sterility, short stature (~4'7"), and webbing of the neck.
• Common indicators are edema of feet in newborns, sparse body hair, underdeveloped breasts with wide nipples, and a high incidence of aborted fetuses.
• Typically, X chromosome is inherited from the mother; cases often result from the loss of the paternally transmitted X chromosome.
• Treatment involves estrogen to promote the development of secondary sexual characteristics.

Klinefelter Syndrome

• Identified by an individual having at least two X chromosomes and one Y chromosome, with the common karyotype being 47, XXY.
• Characterized by male appearance accompanied by female-like breast development (gynecomastia) and small testes.
• Sparse body hair and long limbs are also noted characteristics.
• More severe abnormalities may occur in individuals with additional X chromosomes (e.g., XXXY or XXXXY).

Recurrence Risks

• Recurrence risks for multifactorial diseases fluctuate due to varying gene frequencies and lifestyle factors across populations.
• Higher recurrence risk is observed if multiple family members are affected.
• Severity of expression in the proband correlates with increased recurrence risk.
• The risk rises if the proband belongs to the less commonly affected sex.
• Recurrence risk generally diminishes rapidly with distantly related relatives.

Immunoglobulin G (IgG)

• IgG is the most abundant immunoglobulin, comprising 80-85% of total antibodies in the body.
• It offers significant protection against infections and is capable of crossing the placenta, providing fetal and neonatal immunity.
• IgG consists of four subclasses: IgG1, IgG2, IgG3, and IgG4.

Cellular Injury Mechanisms

• Chemical Injury:
  • Lead is a toxic metal found in old paint and represents a common industrial overexposure, significantly hazardous for children.
  • It disrupts intracellular calcium levels and alters zinc and magnesium, leading to impaired neurotransmitter function and decreased cellular energy. Affects nervous, immune, and reproductive systems with developmental repercussions.
  • Carbon monoxide, the most prevalent chemical asphyxiant, reduces blood’s oxygen-carrying capacity, leading to symptoms such as headache, confusion, weakness, and potential loss of consciousness.

Active vs. Passive Immunity

• Active Immunity: Involves the production of antibodies or T cells following natural exposure to an antigen or immunization.
• Passive Immunity: Involves the transfer of preformed antibodies or T lymphocytes from a donor to a recipient.

Prokaryotes vs. Eukaryotes

• Prokaryotes lack a nucleus and membrane-bound organelles, possessing instead a single circular chromosome located in a nucleoid.
• Examples of prokaryotes include cyanobacteria, bacteria, and rickettsiae.
• Eukaryotes have complex cellular organization with membrane-bound organelles and a well-defined nucleus, including higher animals, plants, fungi, and protozoa.

Eukaryotic Cell Structure

• The nucleus is the largest membrane-bound organelle, facilitating the movement of molecules between the nucleus and cytosol via the nuclear envelope.
• Nucleolus consists of RNA, DNA, and histone proteins; it plays a key role in ribosome synthesis and cell division.
• Cytoplasm comprises the cytoplasmic matrix and cytosol, which is crucial for protein synthesis, hormone transport, and cellular maintenance.

Eukaryotic Organelles

• Ribosomes are sites for protein synthesis.
• Endoplasmic reticulum (ER) exists in two forms: rough (with ribosomes) and smooth (without ribosomes), both involved in protein synthesis.
• The Golgi complex processes, packages proteins for delivery, forming secretory vesicles.
• Lysosomes digest toxins, organelles, and foreign materials; they originate from the Golgi and contain hydrolases.
• Peroxisomes detoxify harmful substances, containing oxidative enzymes.
• Mitochondria are the powerhouses of the cell, generating ATP through oxidative phosphorylation.
• The cytoskeleton maintains cellular shape, enabling motility and organelle transport.

Cellular Metabolism

• Anabolism is energy-consuming, while catabolism releases energy.
• Digestion and glycolysis (splitting of glycogen) occur in the cytoplasm, with anaerobic processes taking place without oxygen.

Cellular Adaptations

• Atrophy refers to a decrease in cell size due to various physiological or pathological conditions.
• Hypertrophy involves increased cell size, often resulting from hormonal stimulation or chronic overload.
• Hyperplasia is an increase in cell number, occurring in compensatory or hormonal contexts.
• Dysplasia indicates abnormal cell growth, while metaplasia is the reversible replacement of one cell type with another.

Cellular Death Mechanisms

• Necrosis is the process of cellular autodigestion following local cell death, marked by various types: coagulative, liquefactive, caseous, fat, and gangrenous necrosis.
• Apoptosis is programmed cell death, contrasting necrosis by avoiding inflammation and rapid engulfment of cellular debris.

Somatic Death

• Postmortem changes include algor mortis (body cooling), livor mortis (blood settling), rigor mortis (muscle stiffening), and autolysis (enzyme release).

Transport Mechanisms

• Diffusion involves solute movement from high to low concentration, while osmosis is the movement of water across a semipermeable membrane.
• The sodium-potassium pump actively transports sodium out and potassium into the cell, crucial for action potentials.

Inflammation Types

• Acute inflammation lasts 8-10 days, marked by vascular responses; chronic inflammation persists for longer and is often due to failed acute responses.
• Characteristics of chronic inflammation include dense lymphocyte infiltration and granuloma formation.

RNA Synthesis

• RNA is synthesized from DNA via RNA polymerase during transcription, followed by translation into proteins by ribosomes.

Electrolyte Imbalances

• Hypokalemia (low potassium) can cause neuromuscular irritability and muscle weakness.
• Hyponatremia (low sodium) leads to symptoms like confusion, intracellular dehydration, and hypotension.

Inflammatory Response Goals

• The inflammatory response aims to control damaging processes, prevent infection, control bleeding, and prepare for healing.

Chemical Mediators of Inflammation

• Mast cells play a central role by releasing histamine and other mediators, activated by physical or chemical stimuli.

Systemic Manifestations of Acute Inflammation

• Fever is triggered by pyrogens affecting the hypothalamus.
• Leukocytosis is increased leukocyte levels; acute-phase reactants rise due to liver activity.

Wound Healing

• Healing involves resolution (regeneration) or repair (scar formation).
• Dysfunctional wound healing can occur due to various factors such as infection, excessive scarring, and suboptimal nutrient conditions.

Genetic Disorders

• Down syndrome (Trisomy 21) is the most common aneuploidy, with characteristic physical features and risks.
• Autosomal recessive disorders express equally in genders, while autosomal dominant disorders show no generational skipping.
• X-linked disorders primarily affect males; females can be carriers.
• Genetic concepts include homozygous (identical alleles), heterozygous (different alleles), genotypes, and phenotypes.

Risk and Recurrence

• The recurrence risk for genetic conditions varies by trait dominance; autosomal recessive traits require both parents to be carriers.
• X-linked recessive disorders show generational skipping and primarily affect males.

Fragile X Syndrome

• Often leads to intellectual disability, prevalent especially in males due to single X chromosome presence.### Metafemale Syndrome
• Characterized by a variable range of symptoms including sterility, menstrual irregularities, and mental retardation.
• Symptoms worsen with each additional X chromosome present.

Turner Syndrome

• Identified by a 45, X karyotype, representing females with a single X chromosome.
• Key features include absence of ovaries leading to sterility, short stature (~4'7"), and webbing of the neck.
• Common indicators are edema of feet in newborns, sparse body hair, underdeveloped breasts with wide nipples, and a high incidence of aborted fetuses.
• Typically, X chromosome is inherited from the mother; cases often result from the loss of the paternally transmitted X chromosome.
• Treatment involves estrogen to promote the development of secondary sexual characteristics.

Klinefelter Syndrome

• Identified by an individual having at least two X chromosomes and one Y chromosome, with the common karyotype being 47, XXY.
• Characterized by male appearance accompanied by female-like breast development (gynecomastia) and small testes.
• Sparse body hair and long limbs are also noted characteristics.
• More severe abnormalities may occur in individuals with additional X chromosomes (e.g., XXXY or XXXXY).

Recurrence Risks

• Recurrence risks for multifactorial diseases fluctuate due to varying gene frequencies and lifestyle factors across populations.
• Higher recurrence risk is observed if multiple family members are affected.
• Severity of expression in the proband correlates with increased recurrence risk.
• The risk rises if the proband belongs to the less commonly affected sex.
• Recurrence risk generally diminishes rapidly with distantly related relatives.

Immunoglobulin G (IgG)

• IgG is the most abundant immunoglobulin, comprising 80-85% of total antibodies in the body.
• It offers significant protection against infections and is capable of crossing the placenta, providing fetal and neonatal immunity.
• IgG consists of four subclasses: IgG1, IgG2, IgG3, and IgG4.

Cellular Injury Mechanisms

• Chemical Injury:
  • Lead is a toxic metal found in old paint and represents a common industrial overexposure, significantly hazardous for children.
  • It disrupts intracellular calcium levels and alters zinc and magnesium, leading to impaired neurotransmitter function and decreased cellular energy. Affects nervous, immune, and reproductive systems with developmental repercussions.
  • Carbon monoxide, the most prevalent chemical asphyxiant, reduces blood’s oxygen-carrying capacity, leading to symptoms such as headache, confusion, weakness, and potential loss of consciousness.

Active vs. Passive Immunity

• Active Immunity: Involves the production of antibodies or T cells following natural exposure to an antigen or immunization.
• Passive Immunity: Involves the transfer of preformed antibodies or T lymphocytes from a donor to a recipient.

Cellular Adaptations and Death

• Pathologic vs. Physiologic Changes: Pathologic changes include chronic hemodynamic overload, while physiologic changes are due to increased demand or stimulation by hormones and growth factors.
• Hyperplasia: Increase in the number of cells due to adaptive mechanisms (compensatory) or hormonal signals (hormonal), particularly in estrogen-dependent organs.
• Dysplasia: Abnormal cellular growth and changes indicating potential neoplastic processes.
• Metaplasia: Reversible replacement of one mature cell type with another, often due to tissue damage and repair.

Types of Cellular Death

• Necrosis: Involves local cell death followed by autolysis; lysosomes digest cell contents.
  • Coagulative Necrosis: Common in kidneys, heart, and adrenal glands; results from hypoxia or chemical injury.
  • Liquefactive Necrosis: Occurs in brain tissue involving hydrolytic enzymes, leading to a liquid mass.
  • Caseous Necrosis: Characteristic of tuberculosis, combines features of coagulative and liquefactive necrosis.
  • Fat Necrosis: Caused by lipases, affecting breast and abdominal organs.
  • Gangrenous Necrosis: Soft tissue death due to severe hypoxic injury; includes dry (coagulative) and wet (liquefactive) gangrene.
  • Gas Gangrene: Involves tissue putrefaction and gas production, typically from bacterial infection.

Apoptosis

• Programmed Cell Death: Active process characterized by cell self-destruction.
• Causes: Severe injury, misfolded proteins, infections, and duct obstructions.
• Differences from Necrosis: Apoptosis minimizes inflammation through phagocytosis, while necrosis typically triggers an inflammatory response.

Somatic Death

• Definition: Complete cessation of life processes in an individual.
• Postmortem Changes:
  • Algor Mortis: Reduction in body temperature after death.
  • Livor Mortis: Blood settling causing purple discoloration in dependent tissues.
  • Rigor Mortis: Stiffening of muscles postmortem.
  • Postmortem Autolysis: Release of enzymes leading to tissue breakdown.

Transport Mechanisms: Osmosis vs. Diffusion

• Passive Transport: Both processes do not require energy.
• Diffusion: Movement of solutes from high to low concentration areas.
• Osmosis: Specific to water movement across a semipermeable membrane from high to low water concentration.

Sodium-Potassium Pump

• Function: Transports three sodium ions out and one potassium ion in, creating an electrochemical gradient crucial for action potentials.
• Active Transport: Requires ATP to function.

Electrolyte Imbalances

• Hypokalemia: Low potassium levels (normal <5.5 mEq/L).
  • Mild Symptoms: Neuromuscular irritability, tingling, cramping.
  • Severe Symptoms: Muscle weakness and potential cardiac arrest.
• Hyponatremia: Low sodium levels.
  • Causes: Sodium gain or water loss leading to intracellular dehydration.
  • Symptoms: Confusion, convulsions, hypotension.

Inflammatory Response

• Cardinal Signs: Redness, heat, swelling, and pain indicating localized inflammation.
• Goals: Limit inflammation, prevent infection, control bleeding, engage the immune system, and prepare for healing.

Chemical Mediators of Inflammation

• Mast Cells: Central to inflammatory processes; release various mediators including histamine and cytokines upon activation.
• Activation Triggers: Physical injuries, chemical agents, and immunological stimuli.

Systemic Manifestations of Inflammation

• Fever: Induced by pyrogens acting on the hypothalamus.
• Leukocytosis: Increase in white blood cell count, often showing a left shift.
• Acute-Phase Proteins: Liver-produced reactants like C-reactive protein and fibrinogen increase during inflammation.

Resolution and Repair of Tissues

• Resolution: Regeneration of tissues returning to original function.
• Repair: Replacement of lost tissue with scar tissue composed of collagen.
• Debridement: Removal of dead tissue to allow healing.

Wound Healing Processes

• Primary Intention: Minimal tissue loss, typically sutured wounds heal quickly.
• Secondary Intention: More complex healing from bottom up, resulting in scarring.
• Phases of Healing:
  • Reconstructive Phase: Initial healing begins.
  • Maturation Phase: Remodeling of the healed area.

Dysfunctional Wound Healing

• Complications: May involve hemorrhage, infection, keloids, and impaired healing due to various factors like corticosteroids or nutritional deficiencies.
• Dehiscence: Wound edges pull apart, often due to excessive tension or obesity.

Callus Formation

• Cause: Thickened skin develops in response to repeated friction or pressure, allowing protection and adaptation.

Prokaryotes vs. Eukaryotes

• Prokaryotes lack a nucleus and membrane-bound organelles, containing a single circular chromosome in the nucleoid.
• Eukaryotes have complex cellular organization with a well-defined nucleus and membrane-bound organelles, including higher animals, plants, fungi, and protozoa.

Eukaryotic Cell Structure

• The nucleus is the largest organelle with a nuclear envelope that facilitates movement of molecules to and from the cytosol.
• The nucleolus contains RNA, DNA, and histone proteins, vital for cell division and genetic control.
• Cytoplasm consists of a cytoplasmic matrix and cytosol, where protein synthesis, hormone transport, and cellular maintenance occur.

Eukaryotic Organelles

• Ribosomes are sites for protein synthesis.
• The endoplasmic reticulum (ER) is divided into rough (with ribosomes) and smooth (without ribosomes), serving as the primary site for protein synthesis.
• The Golgi complex processes and packages proteins, forming secretory vesicles for transport.
• Lysosomes digest harmful cell components and maintain cellular homeostasis, originating from the Golgi.
• Peroxisomes detoxify compounds and fatty acids using oxidative enzymes.
• Mitochondria are the cell's powerhouse, generating ATP through oxidative phosphorylation.
• The cytoskeleton supports the cell's structure and motility, facilitating movement of organelles within the cytoplasm.

Cellular Metabolism

• Metabolism involves two processes:
  • Anabolism, which uses energy for biosynthesis.
  • Catabolism, which releases energy through breakdown processes.

Energy Production

• Glycolysis splits glycogen into energy, occurring in the cytoplasm with anaerobic (without oxygen) and aerobic (with oxygen) pathways.

Cellular Adaptations

• Atrophy refers to shrinkage in cellular size due to decreased workload, blood supply, or hormonal stimulation.
• Hypertrophy is an increase in cell size, often due to increased workload.

Inflammation Types

• Acute inflammation is a short-term response lasting 8-10 days, involving vascular response and cell activation after injury.
• Chronic inflammation persists beyond two weeks and may arise from unsuccessful acute responses. It is marked by dense lymphocyte and macrophage infiltration.

Genetic Disorders

• Down syndrome (Trisomy 21) occurs in about 1 in 800 live births and is characterized by mental retardation, distinct facial features, and associated health risks. Maternal age is a risk factor.
• Autosomal recessive disorders require individuals to be homozygous for expression, with about a 25% chance for offspring of affected carriers to express the disease.
• Autosomal dominant disorders have a recurrence risk of 50% when one parent is affected.
• X-linked disorders primarily affect males, with mothers passing the allele to daughters and a 50% chance of male offspring being affected if the mother is a carrier.

Genetics Terminology

• Homozygous: Identical alleles at a locus; e.g., O blood type (OO).
• Heterozygous: Different alleles at a locus; e.g., AB blood type (A and B).
• Genotype is the genetic makeup; phenotype is the observable trait.
• Carriers are phenotypically normal individuals with one recessive allele.

Genetic Disorder Characteristics

• Fragile X syndrome is notable for mental retardation and is associated with the X chromosome.
• Turner syndrome affects females with a 45, X karyotype, resulting in sterility and physical abnormalities.
• Klinefelter syndrome (47, XXY) leads to male characteristics with female traits like gynecomastia.

Recurrence Risks in Genetics

• Recurrence risks for multifactorial diseases increase with the number of affected family members and severity of the proband's condition.

Immunoglobulin (IgG)

• IgG is the most abundant immunoglobulin, constituting 80-85% of total antibodies and providing key protection against infections while crossing the placenta.

Cellular Injury Mechanisms

• Lead poisoning, common in industrial settings, disrupts cellular functions and is particularly hazardous for children.
• Carbon monoxide poisoning impairs blood oxygen transport, causing symptoms like confusion and weakness.

Immunity Types

• Active immunity involves the body's production of antibodies after exposure to an antigen or vaccination.
• Passive immunity involves the transfer of preformed antibodies from a donor to a recipient.