Bio-1150 Patho review resource Part 1
Path- (Bio-1150) Comprehensive Review
ATP Production in Respiration
Aerobic Respiration
Total ATP produced: approximately 30–32 ATP per one glucose molecule.
Key Point: Occurs in the presence of oxygen.
Anaerobic Respiration
Total ATP produced: 2 ATP per one glucose molecule (plus lactic acid).
Key Point: Occurs without oxygen.
Simplified Explanation:
With oxygen = about 30 ATP.
Without oxygen = only 2 ATP.
Sodium-Potassium Pump
Functionality:
Uses 1 ATP to move 3 Na⁺ ions out of the cell and 2 K⁺ ions into the cell.
Maintains a more negative charge inside the cell and proper ion balance.
Simplified Explanation: Little pump in the membrane that trades 3 sodium for 2 potassium using energy.
Organelle Identification and Functions
Mitochondria:
Function: Produce ATP - referred to as the "powerhouse of the cell".
Simplified: Cell’s power plants.
Ribosomes:
Function: Protein synthesis - read mRNA to build proteins.
Simplified: Protein factories.
Endoplasmic Reticulum (ER):
Rough ER: Has ribosomes; synthesizes proteins for export and membranes.
Smooth ER: Synthesizes lipids and detoxifies drugs.
Simplified: ER functions as the cell’s assembly line: rough = protein; smooth = fats & detox.
Cilia:
Function: Move mucus and fluids across surfaces.
Simplified: Tiny "brooms" that sweep stuff along (e.g., in airways).
Microtubules:
Function: Support shape of the cell and facilitate transport and chromosome movement.
Simplified: Internal tracks and skeleton of cells.
Nucleus:
Function: Contains DNA and controls cell activities.
Simplified: The control center or brain of the cell.
Nucleolus:
Function: Synthesizes rRNA and assembles ribosome subunits.
Simplified: Factory inside the nucleus for building ribosomes.
Golgi Complex:
Function: Modifies, sorts, and ships proteins and lipids.
Simplified: Post office/packaging center of the cell.
Lysosomes:
Function: Digest waste, old organelles, and bacteria due to the presence of enzymes.
Simplified: Garbage disposal and recycling center of the cell.
Muscle Contraction Mechanism
Process:
Nerve Signal: Trigger signals the release of Ca²⁺ ions.
Myosin Interaction: Myosin heads attach to actin filaments and pull them, causing muscle contraction.
Collective Action: Multiple fibers contract together, leading to overall muscle shortening.
Simplified Explanation: Calcium enters → myosin pulls actin like rowers → muscle shortens.
Protein Synthesis Overview
Organelles Involved: Ribosomes (free in the cytoplasm or attached to rough ER).
Function of mRNA:
Definition: Messenger RNA, which carries genetic information from DNA.
Formation: Synthesized in the nucleus through transcription from DNA.
Role: Carries instructions to ribosomes for protein synthesis.
Simplified Explanation: mRNA is a photocopy of a gene that tells ribosomes how to build a protein.
Function of tRNA:
Definition: Transfer RNA, carrying specific amino acids.
Formation: Transcribed from DNA in the nucleus, functioning in the cytoplasm.
Role: Matches its anticodon to the mRNA codon to add the correct amino acid.
Simplified Explanation: tRNA is the delivery truck that brings amino acids to ribosomes.
Triplet Codon and Codon Definition
Codon: A sequence of three bases on mRNA, which codes for a specific amino acid or functions as a start/stop signal.
Simplified Explanation: A codon is three letters on mRNA that specify which amino acid to add.
DNA and RNA Comparison
Similarities:
Both are nucleic acids made from nucleotides and carry genetic information.
Differences:
Sugars: DNA has deoxyribose; RNA has ribose.
Nitrogenous Bases: DNA uses thymine (T), while RNA uses uracil (U).
Strands: DNA is double-stranded; RNA is usually single-stranded.
Location: DNA is confined mostly to the nucleus, while RNA functions in both the nucleus and cytoplasm.
Simplified Explanation: DNA = double structure, with T, for long-term storage. RNA = single structure, with U, for temporary messaging.
Lysosomal Storage Diseases
Tay–Sachs Disease:
Characteristic: Inability to break down specific lipids in neurons.
Symptoms: Initially normal, followed by a loss of development milestones, seizures, and a cherry-red spot in the eye.
Gaucher Disease:
Characteristic: Lipid accumulation occurs in macrophages.
Symptoms: Includes enlarged liver and spleen, bone pain, and anemia.
Niemann–Pick Disease:
Characteristic: Inability to break down sphingomyelin.
Symptoms: Associated with massive spleen and liver, neuro decline, and sometimes a cherry-red spot.
Simplified Explanation: All involve waste buildup in lysosomes; Tay-Sachs affects the brain, Gaucher affects marrow & spleen, Niemann-Pick impacts the liver/spleen/brain.
Steps in Protein Production
Transcription (In Nucleus): DNA is copied to form mRNA.
Translation (In Cytoplasm at the Ribosome):
Ribosome reads mRNA codons.
tRNAs bring appropriate amino acids based on codon sequence.
Amino acids are linked to form proteins.
Simplified Explanation: DNA → mRNA in the nucleus (transcription); mRNA → protein at ribosome (translation).
Tetracycline Mechanism in Bacteria
Mechanism: Binds to bacterial 30S ribosomal subunit and blocks tRNA attachment, preventing protein synthesis.
Simplified Explanation: Tetracycline sits on bacterial ribosome so it can’t read the recipe to make proteins.
DNA Location in Cells
DNA exists primarily in the nucleus, with some found in mitochondria.
When actively being transcribed or replicated, DNA is loosely arranged as chromatin (not tightly coiled).
Simplified Explanation: DNA is found mainly in the nucleus, usually in a loose form (chromatin) to allow for reading and copying.
Definitions of Terms
Ischemia: Low blood flow to tissue.
Hypoxia: Low oxygen in tissue.
Hypoxemia: Low oxygen in blood.
Necrosis: Unplanned cell death with inflammation (messy death).
Apoptosis: Programmed cell death (cell suicide).
Gangrene: Large area of dead tissue, often in limbs.
Differentiation: How specialized a cell is.
Metaplasia: Mature cell type replaced by another.
Dysplasia: Abnormal cell growth/appearance; pre-cancer condition.
Hypertrophy: Cells increase in size.
Hyperplasia: Increase in cell number.
Atherosclerosis: Fatty plaques in arteries.
Kwashiorkor: Severe protein deficiency in children, manifested by edema.
Infarction: Tissue death due to prolonged ischemia (e.g., heart attack).
Simplified Explanation:
Ischemia = low blood; hypoxia = low O₂; necrosis = messy death; apoptosis = programmed death; hypertrophy = larger cells; hyperplasia = more cells; atherosclerosis = clogged arteries; infarction = dead tissue from lack of blood.
Clinical Definitions
Hypertension: High blood pressure.
Hypotension: Low blood pressure.
Hypothyroidism: Low thyroid function causing tiredness, weight gain, cold intolerance, and slowed heart rate.
Hyperthyroidism: High thyroid function causing anxiety, weight loss, heat intolerance, and increased heart rate.
Diabetes Mellitus: Elevated blood glucose levels due to insulin dysfunction.
Berry Aneurysm: Small bulged arteries in the brain that can rupture.
Barrett’s Esophagus: Abnormal cell changes in the lower esophagus, increasing cancer risk.
Stem Cell Restoration: Utilization of stem cells to repair damage.
Therapeutic Cloning: Cloning cells/tissue for therapy.
Reproductive Cloning: Cloning to create entire organisms.
Transplantation: Transferring organs/tissue from donor to recipient.
Keloid: Overgrown, thickened scar beyond the original wound.
Oxidative Stress: Damage caused by excessive free radicals.
Simplified Explanation: Most are issues of being too high/too low; keloids are overgrown scars; oxidative stress is "rusting" of cells due to free radicals.
Fat Soluble Vitamins
List: Vitamin A, D, E, K.
Simplified Explanation: ADEK = fat-soluble vitamins.
Free Radicals vs Antioxidants
Free Radicals: Unstable molecules with unpaired electrons that cause damage to DNA, proteins, and membranes.
Antioxidants: Molecules that neutralize free radicals (e.g., vitamins C and E).
Simplified Explanation: Free radicals damage cells; antioxidants neutralize them.
Pulse Oximeter Function
Function: Measures oxygen saturation (SpO₂) of hemoglobin in blood through light absorption.
Simplified Explanation: It shows the percentage of blood that is carrying oxygen.
Prenatal Testing Purposes and Types
Types of Prenatal Tests:
Ultrasound: Assesses fetal anatomy, growth, placenta, and amniotic fluid.
Maternal Blood Tests: e.g., NIPT, quad screen to screen for Down syndrome, neural tube defects.
Chorionic Villus Sampling (CVS): Early genetic testing from placenta (10–13 weeks).
Amniocentesis: Genetic testing from amniotic fluid (15–20 weeks).
Purpose: To detect birth defects, chromosomal problems, and structural issues early in pregnancy.
Simplified Explanation: Prenatal tests monitor baby’s growth and genetic health to find problems early.
Marfan Syndrome Characteristics
Description: Genetic connective tissue disorder affecting fibrillin.
Physical Features: Tall, thin build, long limbs, chest deformities; risk of aortic aneurysm/dissection.
Simplified Explanation: Think of a tall, lanky person with long fingers at risk of heart issues.
Ehlers-Danlos Syndrome Characteristics
Description: Genetic disorder affecting collagen, resulting in hyper-elastic skin, hypermobile joints, easy bruising, and poor wound healing.
Similarities and Differences to Marfan:
Similar: Both are connective tissue disorders.
Different: EDS shows stretchy skin/joints; Marfan is tall with aortic risks.
Simplified Explanation: EDS = "rubber skin and joints"; Marfan = tall with a risk of serious vascular issues.
Karyotype Definition
Definition: A photographic representation of an individual's chromosomes arranged in pairs for diagnosis of genetic abnormalities.
Simplified Explanation: A chart that shows all of someone’s chromosomes, helpful for identifying genetic issues.
Polymerase Chain Reaction (PCR)
Definition: A lab technique that amplifies DNA to create many copies.
Use: Detects small amounts of viral or bacterial DNA and specific genes.
Simplified Explanation: PCR is a DNA photocopier used for tests.
Wilson’s Disease Characteristics
Description: Genetic defect affecting copper excretion (ATP7B gene).
Effects: Copper accumulation in liver, brain, and eyes.
Presentation: Liver disease, neurological/psychiatric symptoms, Kayser–Fleischer rings (brown rings in eyes).
Simplified Explanation: Wilson’s causes copper overload, leading to damage to organs and behavioral changes.
Familial Hypercholesterolemia Characteristics
Description: Genetic defect affecting LDL receptors.
Effects: Significantly high LDL cholesterol from young age.
Symptoms: Development of xanthomas (cholesterol deposits) and early heart attacks.
Simplified Explanation: An inherited condition with very high LDL cholesterol leading to early cardiovascular events.
Fertilization Process Overview
Mechanism: Sperm (23 chromosomes) fertilizes an egg (23 chromosomes), resulting in a zygote (46 chromosomes).
Simplified Explanation: Mom's egg gives 23; Dad's sperm gives 23 → baby has 46 total chromosomes.
Punnett Square Explanation
Definition: A grid that illustrates all possible allele combinations from parental genotypes.
Use: Alleles from one parent are placed on top, and the other on the side; boxes filled to show potential offspring traits.
Simplified Explanation: A little chart to see the odds of kids inheriting certain traits.
Dominant and Recessive Traits
Definitions:
Dominant Trait: Only one copy of the allele is needed for expression (e.g., Aa or AA).
Recessive Trait: Two copies of the allele are needed for expression (e.g., aa).
X-linked Traits: Genes located on the X chromosome, often presenting symptoms in males more frequently.
Simplified Explanation: Dominant = one copy needed; recessive = two copies needed; X-linked = defect on X chromosome, often affecting males.
Cystic Fibrosis Overview
Definition: An autosomal recessive disorder caused by a mutation in the CFTR gene.
Characteristics: Causes thick, sticky mucus affecting the lungs and pancreas.
Symptoms: Frequent lung infections, poor weight gain, greasy stools.
Simplified Explanation: Cystic fibrosis leads to thick mucus that clogs the lungs and pancreas, resulting in infections and malnutrition.
Huntington’s Chorea Description
Definition: An autosomal dominant neurodegenerative disease.
Onset: Typically appears in middle age.
Symptoms: Characterized by chorea (involuntary movements), mood swings, and dementia.
Simplified Explanation: Huntington’s causes brain degeneration, leading to movement issues and behavioral changes in mid-life.
Platelet Attraction in Injury Response
Mechanism: Platelets are drawn to injury sites by:
Exposure of collagen beneath the damaged endothelium.
Presence of von Willebrand factor (vWF) aiding adhesion.
Release of local chemical signals (e.g., ADP, thromboxane A₂, and thrombin).
Simplified Explanation: Platelets stick to the injury site due to exposed collagen and help clotting through chemical signals.
White Blood Cell (WBC) Responses to Infections
Bacteria: Primarily attacked by neutrophils (acute response) and also by monocytes/macrophages.
Viruses: Primarily fought off by lymphocytes (T cells, B cells, NK cells).
Parasites: Especially worms are primarily targeted by eosinophils.
Simplified Explanation: Neutrophils attack bacteria, lymphocytes target viruses, and eosinophils respond to parasites.
WBC Secretion of Histamine in Allergic Reactions
Histamine Secretion: Basophils in blood and mast cells in tissues are responsible for histamine release.
Increases in Allergic Reactions: Eosinophils, alongside basophils and IgE-related cells, rise in allergic responses.
Simplified Explanation: Basophils and mast cells release histamine; eosinophils increase during allergies and parasite infections.
WBC Response Timeline in Injury
First Responders: Neutrophils arrive first in acute inflammatory responses.
Simplified Explanation: Neutrophils are the first white blood cells to reach sites of injury or infection.
Overview of CRP and ESR Tests
C-Reactive Protein (CRP):
Definition: A protein by the liver that indicates inflammation.
Indicators: High levels correlate with increased inflammation.
Erythrocyte Sedimentation Rate (ESR):
Definition: Measurement of how quickly red blood cells settle in a tube within one hour.
Indicators: Increased speed points to chronic inflammation.
Simplified Explanation: Both CRP and ESR tests indicate inflammation; CRP is a protein marker while ESR measures sedimentation rates of red blood cells.
Hyperbaric Oxygen Therapy Indications
Mechanism: Patient is placed in a chamber with 100% oxygen at high pressure.
Common Uses:
Carbon monoxide poisoning.
Decompression sickness ("the bends" in divers).
Non-healing diabetic or ischemic wounds.
Certain serious infections (like gas gangrene).
Simplified Explanation: Use hyperbaric oxygen for carbon monoxide poisoning, divers affected by pressure changes, and stubborn wounds.
Classic Signs of Inflammation
Signs of Inflammation:
Redness (rubor) due to increased blood flow.
Heat (calor) due to increased blood flow/metabolism.
Swelling (tumor) due to fluid leaking into tissues.
Pain (dolor) due to chemical mediators and swelling.
Loss of function due to swelling/pain and tissue damage.
Simplified Explanation: Inflammation presents as redness, warmth, swelling, pain, and reduced functionality in affected areas.
Left Shift in Blood Work
Definition: An increase in immature neutrophils ("bands") in the blood, indicative of acute infection or stress.
Simplified Explanation: Left shift means there are lots of new baby neutrophils in the blood, often because of a significant infection.
Fever Definition and Pathophysiology
Definition: Fever is defined as an elevated body temperature, usually > 38°C (100.4°F).
Pathophysiology:
Immune cells release pyrogens (e.g., IL-1, IL-6, TNF-α) that increase PGE₂.
These act on the hypothalamus to raise the body’s temperature set point.
Body responds by shivering and vasoconstriction to achieve the new temperature.
Simplified Explanation: Fever occurs when immune chemicals tell the brain's thermostat to raise the body temperature.
Pressure Ulcers (Decubitus Ulcers)
Definition: Localized injuries to the skin and tissue resulting from prolonged pressure, typically over bony areas.
Risk Factors: High risk in immobile patients who are not frequently repositioned.
Treatment Strategies:
Pressure relief (changing position, specialized mattresses).
Skin cleanliness and dryness maintenance.
Use of appropriate wound dressings.
Debridement of necrotic tissue if necessary.
Provide adequate nutrition and control infection.
Simplified Explanation: Pressure ulcers develop from lying still too long; treated by relieving pressure and taking care of the wound.
Nutrition for Wound Healing
Essential Nutrients:
Protein: Required for tissue repair and collagen synthesis.
Vitamin C: Critical for collagen formation.
Zinc: Vital for enzymatic functions during healing.
Vitamin A: Important for immune function and epithelial repair.
Adequate Calories and Fluids: Necessary for overall health and recovery.
Simplified Explanation: Wounds heal best with enough protein, vitamin C, zinc, vitamin A, calories, and fluids.
Stages of Wound Healing
Hemostasis: Clotting occurs to prevent bleeding.
Inflammatory Phase: White blood cells clean up debris and bacteria.
Proliferative Phase: New tissue (granulation), collagen, and blood vessels form; the edges of the wound begin to close.
Remodeling Phase: Collagen reorganizes, the scar strengthens and may shrink.
Simplified Explanation: Healing steps include stopping the bleeding, cleaning the wound, filling it in, and strengthening the scar.
Dehiscence vs Evisceration
Dehiscence:
Definition: Partial or complete opening of a surgical wound along the incision line.
Evisceration:
Definition: An abdominal wound opening leading to the protrusion of internal organs through the incision; considered a surgical emergency.
Simplified Explanation: Dehiscence is a wound that opens; evisceration is when organs come out through the wound.
Bacteria Thriving in Ischemic and Necrotic Wounds
Type: Anaerobic bacteria thrive where oxygen levels are low.
Classic Example: Clostridium perfringens, which causes gas gangrene.
Simplified Explanation: Anaerobic bacteria like Clostridium thrive in dead, oxygen-poor tissues.
Proinflammatory Mediators Causing Fever
Pyrogens Effect:
Can Cause Fever: Include IL-1, IL-6, TNF-α, and PGE₂ acting on the hypothalamus.
Do Not Directly Cause Fever: Histamine, bradykinin, leukotrienes, and complement which cause vasodilation and pain but not resetting the thermostat.
Simplified Explanation: Cytokines like IL-1, IL-6, TNF-α cause fever; histamine causes swelling and redness but not the fever itself.
Phagocytosis vs Pinocytosis
Phagocytosis:
Definition: "Cell eating" - large particles (bacteria/dead cells) are engulfed into vesicles (phagosomes) which then fuse with lysosomes for digestion.
Cells Involved: Done by neutrophils, macrophages, monocytes, and dendritic cells.
Pinocytosis:
Definition: "Cell drinking" - cell absorbs fluid and small solutes via tiny vesicles.
Cells Involved: Many cell types perform this process routinely.
Simplified Explanation: Phagocytosis is large particles eaten by neutrophils and macrophages; pinocytosis is small sips of fluid taken by many cells.
Cirrhosis and Heart Failure Overview
Cirrhosis:
Definition: End-stage scarring of the liver due to chronic damage (e.g., alcohol, hepatitis).
Results in: Portal hypertension, ascites, varices, jaundice, and reduced clotting factor synthesis.
Heart Failure:
Definition: The heart’s inability to pump sufficient blood to meet bodily needs.
Symptoms: Shortness of breath, fatigue, swelling in legs, fluid accumulation in lungs.
Simplified Explanation: Cirrhosis results in a scarred liver; heart failure indicates a weakened heart without adequate blood flow.
Reye’s Syndrome Details
Definition: Rare life-threatening condition in children usually following a viral infection (like influenza or chickenpox) after aspirin intake.
Effects: Causes acute liver failure and brain swelling (encephalopathy).
Symptoms: Include vomiting, confusion, seizures, and coma.
Simplified Explanation: Reye’s represents severe liver and brain damage in kids who take aspirin during a viral illness.
Wound Healing Intention Types
Primary Intention:
Definition: Wound edges are brought together (sutured or stapled).
Characteristics: Little tissue loss with minimal scarring.
Example: Clean surgical incisions.
Secondary Intention:
Definition: Wound edges remain open; healing occurs from the bottom up.
Characteristics: Results in larger scars and more granulation tissue.
Example: Large open ulcers or wounds left to heal on their own.
Simplified Explanation: Primary = closed and stitched; secondary = open, healing from inside out.
Respiratory vs Blood-borne Infections
Respiratory Infection:
Mechanism: Spread via droplets or airborne routes.
Affected Areas: Primarily targets airways/lungs.
Examples: Influenza, pneumonia, tuberculosis.
Blood-borne Infection:
Mechanism: Spread through blood or body fluids (e.g., via needles, transfusions, sex).
Examples: HIV, hepatitis B, hepatitis C.
Simplified Explanation: Respiratory infections spread through breathing them in; blood-borne infections are through exposure to blood/body fluids.
Meningitis Causes and Symptoms
Causes:
Bacterial Meningitis: Caused by Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae.
Viral Meningitis: Caused by enteroviruses, HSV, and others.
Deadly in College Dorms: Neisseria meningitidis (meningococcal meningitis).
Signs:
Common signs for both: Fever, severe headache, stiff neck, photophobia, nausea/vomiting, confusion.
Bacterial: Rapid onset, severely ill, may have petechial rash.
CSF: High neutrophils, high protein, low glucose.
Viral: Milder illness.
CSF: Lymphocytes dominant, normal glucose, mildly ↑ protein.
Simplified Explanation: Meningitis presents as fever, headache, and stiff neck; bacterial is more severe than viral.
Legionnaire’s Disease vs Pontiac Fever
Both: Caused by Legionella bacteria.
Legionnaire’s Disease:
Symptoms: Severe pneumonia, fever, cough, GI symptoms, confusion.
Pontiac Fever:
Symptoms: Milder flu-like symptoms without pneumonia.
Simplified Explanation: Legionnaire’s = serious pneumonia; Pontiac fever = mild flu from the same bacteria.
Protozoan Infection Definition
Definition: Infections caused by single-celled eukaryotic organisms (protozoa).
Examples: Malaria, Giardia, Toxoplasma, Leishmania.
Simplified Explanation: A protozoan infection is caused by single-celled parasites.
Fifth Disease Overview
Definition: Viral illness by parvovirus B19.
Symptoms: Characteristic "slapped cheek" red rash on face, lacy rash on body; usually mild in children but can be risky for pregnant women (risk of fetal anemia).
Simplified Explanation: Fifth disease equals bright red cheeks in kids due to parvovirus.
Teratogenic Effect Definition
Definition: Effects that cause birth defects if the fetus is exposed in utero.
Causes: Can result from drugs, chemicals, infections, radiation, etc.
Simplified Explanation: Teratogenic means something that harms a developing baby and leads to birth defects.
Viruses Associated with Birth Defects (TORCH Group)
Group: Includes Toxoplasma (not a virus), Syphilis, Varicella, Parvovirus B19, Rubella, Cytomegalovirus (CMV), Herpes simplex virus, and HIV.
Simplified Explanation: TORCH refers to several infections that can cause birth defects if a mother becomes infected during pregnancy.
Malaria Description
Definition: Protozoan infection caused by Plasmodium species, transmitted via Anopheles mosquitoes.
Symptoms: Cyclical fevers, chills, sweats, anemia, splenomegaly.
Simplified Explanation: Malaria results from mosquito bites, leading to recurring fevers and anemia.
Prions Overview
Definition: Misfolded proteins that cause normal proteins to misfold, leading to brain damage.
Diseases Caused: Prions cause spongiform encephalopathies, such as:
Creutzfeldt-Jakob Disease (CJD).
Variant CJD ("mad cow disease").
Simplified Explanation: Prions are infectious proteins causing severe brain diseases.
Ebola Disease Overview
Definition: Viral hemorrhagic fever caused by the Ebola virus.
Symptoms: High fever, severe weakness, vomiting, diarrhea, rash; later may cause bleeding and shock.
Mortality: High mortality rates; requires strict isolation for control.
Simplified Explanation: Ebola is a deadly viral infection leading to fever, organ failure, and bleeding.
Tapeworm Diagnosis
Method: Usually diagnosed through the identification of eggs or segments (proglottids) in stool.
Other Methods: Imaging or serologic tests can sometimes identify tissue forms.
Simplified Explanation: Tapeworm presence is detected by examining stool samples.
Vaginal Candidiasis Diagnosis and Treatment
Definition: Yeast infection usually due to Candida albicans.
Symptoms: Itching, burning, redness, thick white discharge resembling cottage cheese.
Diagnosis: Clinical exam, microscopic examination of discharge showing budding yeast and pseudohyphae.
Treatment: Antifungals, either orally (fluconazole) or in vaginal creams.
Simplified Explanation: A vaginal yeast infection involves itching and thick white discharge, treated with antifungal medications.
Immunity Types Definitions
Innate Immunity:
Definition: Non-specific immune response present from birth (skincare, mucosal barriers, phagocytes, complement system).
Natural Active Immunity:
Definition: Immunity achieved by infection → body produces antibodies/memory cells.
Example: Contracting chickenpox leads to immunity.
Artificial Active Immunity:
Definition: Immunity acquired through vaccination.
Example: Receiving an MMR vaccine leads to immunity.
Natural Passive Immunity:
Definition: Antibodies transferred from mother to child through placenta and breast milk.
Artificial Passive Immunity:
Definition: Injection of pre-formed antibodies (immunoglobulin).
Example: Rabies immune globulin administration.
Simplified Explanation: Active immunity means your body makes antibodies; passive means receiving them. Innate immunity refers to natural defenses.
Vector and Host Definitions
Vector: Organism that transmits a pathogen from one host to another (commonly insects like ticks or mosquitoes).
Host: Organism infected by the pathogen.
Simplified Explanation: A vector carries the pathogen (like a tick); a host is the infected individual (person/animal).
Osteomyelitis Definition
Definition: Bone infection, typically due to bacteria (e.g., Staphylococcus aureus).
Causes: Originates from the bloodstream, neighboring infected tissue, or open fractures.
Symptoms: Includes bone pain, fever, redness, swelling, elevated WBC, ESR, and CRP.
Simplified Explanation: Osteomyelitis indicates a painful bone infection, usually bacterial in origin.
Leishmaniasis Overview
Description: Protozoan infection caused by Leishmania species transmitted through sandfly bites.
Types:
Cutaneous Leishmaniasis: Causes skin ulcers.
Visceral Leishmaniasis (Kala-Azar): Features fever, weight loss, splenomegaly, and anemia.
Simplified Explanation: Leishmaniasis is caused by a parasite via sandfly bites, affecting skin or internal organs.
Interferon Definition
Definition: A type of cytokine protein aiding cells' defense against viral infections.
Production Sites:
Produced by virus-infected cells (especially interferon-α and β).
Generated by certain immune cells (like T cells, NK cells produce interferon-γ).
Simplified Explanation: Interferons are proteins produced by infected cells to help neighboring cells fight viruses.
Staphylococci vs Streptococci Identification
Staphylococci (Staph):
Characteristics: Gram-positive cocci appearing in clusters (like grapes).
Examples: Staphylococcus aureus - linked to skin abscesses, MRSA.
Streptococci (Strep):
Characteristics: Gram-positive cocci appearing in chains.
Examples: Streptococcus pyogenes - leads to strep throat, rheumatic fever.
Simplified Explanation: Staph = clusters; Strep = chains.
Infectious Disease Overview
Cholera: Caused by Vibrio cholerae; causes severe watery diarrhea leading to dehydration.
Lyme Disease: Caused by Borrelia burgdorferi; characterized by a bull's-eye rash and possible joint/neuro issues.
Infectious Mononucleosis: Usually Epstein-Barr virus; presents with a sore throat, enlarged tonsils, fatigue, and splenomegaly.
Botulism: Results from botulinum toxin, leading to flaccid paralysis and respiratory failure.
Tetanus: Caused by toxin blocking inhibitory neurons leading to muscle rigidity (lockjaw).
Coccidioidomycosis: Fungal lung infection ("Valley Fever") from inhaled spores; symptoms include flu-like illness, cough, and joint pain.
Toxoplasmosis: Caused by Toxoplasma gondii, which can be contracted from cat feces.
Simplified Explanation: Cholera leads to diarrhea; Lyme is tick-related; mono causes extreme fatigue; botulism leads to paralysis; tetanus induces stiffness; coccidioidomycosis causes lung infection; cat litter = toxoplasmosis.
HIV Definitions
HIV Positive: Indicates infection by HIV; confirmed through blood tests (e.g., ELISA, Western blot).
CD4 Count: Number of CD4 T-helper cells per microliter.
Normal Range: Approximately 500–1600 cells/µL.
AIDS (Acquired Immunodeficiency Syndrome):
Defined as an advanced stage of HIV infection with either a CD4 count < 200 cells/µL or an AIDS-defining illness such as Pneumocystis pneumonia, Kaposi sarcoma, etc.
Opportunistic Infections: Infections occurring due to significant immune system weakness.
Simplified Explanation: HIV+ = virus present; AIDS = severe infection stage; low CD4 count (<200 or certain infections) indicates greater susceptibility to illness.
Urinalysis Procedure
Dipstick Test: Analyzes urine for:
Color, clarity, specific gravity, pH, protein, glucose, ketones, blood, leukocyte esterase, bilirubin, urobilinogen.
Microscopic Exam: Examines urine for:
RBCs, WBCs, bacteria, yeast, casts, crystals.
Urine Culture: Cultivates any bacteria present to identify species and antibiotic susceptibility.
Simplified Explanation: Urinalysis uses dipsticks to evaluate several parameters and microscopy to check for infections and abnormalities.
T Cell Maturation in Thymus
Function: The thymus is essential for the maturation of T lymphocytes (T cells).
Process: Immature cells are produced in the bone marrow and then mature in the thymus to become functional T cells.
Simplified Explanation: The thymus creates and trains T cells necessary for immune response.
Hepatitis A Characteristics
Description: Virus causing acute hepatitis through fecal-oral transmission (via contaminated food/water).
Nature: Short, self-limited illness without a chronic carrier state; effective vaccination is available.
Simplified Explanation: Hepatitis A is food-and-water related, acute only, and can be prevented with a vaccine.
Antibody Types and Their Roles
IgG:
Most abundant antibody in blood; can cross the placenta for fetal protection; essential for long-term immunity.
IgA:
Found in secretions (saliva, milk, tears) protecting mucosal surfaces.
IgM:
First antibody produced during acute infections; activates the complement system.
Simplified Explanation: IgG provides long-lasting immunity; IgA protects body's secretions; IgM indicates new infections.
Hypersensitivity Reactions Types
Type I (Immediate – IgE-mediated): Involves allergic reaction symptoms and requires rapid mast cell degranulation. E.g. peanut allergy.
Type II (Antibody-mediated – cytotoxic): Antibodies bind to and destroy cells, such as in hemolytic transfusion reactions.
Type III (Immune complex): Immune complexes deposit in tissues and induce inflammation, e.g., systemic lupus erythematosus (SLE).
Type IV (Delayed – T-cell mediated): T-cell reactions leading to inflammation without the involvement of antibodies. E.g., contact dermatitis.
Simplified Explanation: Type I = allergies; Type II = antibodies attacking cells; Type III = immune complexes spark inflammation; Type IV = T-cell reactions take longer.
Vaccine Immune Status Monitoring
Antibody Titer: Blood test measuring specific antibody levels to assess immunity after vaccination.
Booster Shots: Administered if antibody levels decline below protective levels; certain vaccines have set booster intervals.
Simplified Explanation: Check antibody levels (titer); get boosters if levels fall to remain protected.
Tuberculosis Overview
Definition: Chronic infection caused by Mycobacterium tuberculosis, primarily affecting the lungs.
Screening & Diagnosis: Includes skin tests (PPD), IGRA blood tests, chest X-rays, and sputum analysis for AFB and cultures.
Simplified Explanation: TB is a lung infection screened by certain tests and confirmed through imaging and sputum analyses.
Rheumatoid Arthritis (RA) Features
Characteristics: Autoimmune, chronic inflammatory arthritis with symmetric joint pain, particularly in smaller joints, and prolonged morning stiffness.
Initial Treatment: NSAIDs for pain relief, disease-modifying antirheumatic drugs (DMARDs) like methotrexate.
Simplified Explanation: RA involves joint inflammation, especially severe in the morning, requiring tailored medications and pain relievers.
Osteoarthritis (OA) Features
Characteristics: Degenerative joint disease defined by cartilage breakdown, pain during movement, and improvement with rest.
Initial Treatment: Weight management, exercise, analgesics like acetaminophen, and topical therapies.
Simplified Explanation: OA = wear and tear arthritis worsens with movement and improves with rest.
Systemic Lupus Erythematosus (SLE) Features
Characteristics: Multisystem autoimmune condition with prominent skin, joint, and kidney involvement, often recognized by a classic butterfly rash on the face.
Initial Treatment: Includes NSAIDs, hydroxychloroquine, and corticosteroids for symptom management.
Simplified Explanation: SLE is a systemic autoimmune disease that's widely variable but often features a butterfly rash.
Psoriatic Arthritis (PsA) Features
Characteristics: Associated with psoriasis, can affect distal joints, spine, or sacroiliac joints, with symptoms like dactylitis and nail pitting.
Initial Treatment: Similar to RA—often NSAIDs, DMARDs, or biologics.
Simplified Explanation: PsA includes joint inflammation along with skin psoriasis.
Scleroderma Overview
Definition: Autoimmune disease associated with collagen overproduction, leading to hardened skin and other organ involvement.
Initial Treatment: Includes symptom management with vasodilators, proton-pump inhibitors, and sometimes immunosuppressants.
Simplified Explanation: Scleroderma leads to stiff skin and organs from excess collagen production.
Sjögren's Syndrome Overview
Description: Autoimmune condition resulting in destruction of salivary and lacrimal glands causing dry eyes and dry mouth. May present with parotid gland enlargement.
Initial Treatment: Supplements for tears and saliva, good dental hygiene practices, and occasionally immunosuppressive drugs.
Simplified Explanation: Sjögren's causes extreme dry eyes and mouth due to immune damage to the glands.
CREST Syndrome Definition
Components:
Calcinosis: Calcium buildup in the skin.
Raynaud’s Phenomenon: Color changes in extremities due to cold.
Esophageal dysmotility: Difficulty in swallowing and reflux.
Sclerodactyly: Thickened skin on fingers.
Telangiectasia: Visible small blood vessels on skin.
Simplified Explanation: CREST is a limited type of scleroderma with distinct symptoms affecting organ systems and skin.
Mucocutaneous Candidiasis Definition
Definition: Chronic Candida infections affecting mucous membranes and skin, commonly seen with T-cell immunodeficiency or certain endocrine disorders.
Locations: Mouth (thrush), skin folds, nails, and genital areas.
Simplified Explanation: Mucocutaneous candidiasis refers to recurrent yeast infections, typically when immunity is weak.
Steps in Diagnosing HIV Exposure
Assess Exposure Risk:
Type of exposure (needle stick, unprotected sex, etc.) and source’s HIV status if known.
Baseline Testing: Conduct an initial HIV test.
Post-Exposure Prophylaxis (PEP): Start short-term antiretroviral therapy ideally within 72 hours if exposure is significant.
Follow-Up Testing: Repeat HIV tests at significant intervals (6 weeks, 3 months, sometimes up to 6 months).
Simplified Explanation: Assess risk, test for HIV, start preventive meds quickly if needed, and retest later.
Autoimmune Diseases Definition
Definition: Conditions where the immune system mistakenly attacks the body’s cells as if they were pathogens.
Examples: RA, SLE, type 1 diabetes, multiple sclerosis, Hashimoto’s thyroiditis.
Simplified Explanation: Autoimmune diseases occur when the body’s defenses turn against its own cells.
ELISA vs Western Blot Tests
ELISA: Blood test that detects antibodies or antigens using enzyme-linked reactions; commonly used for initial screenings (e.g., HIV).
Western Blot: More specific test that separates proteins based on size and detects corresponding antibodies; typically used to confirm positive ELISA tests (like for HIV).
Simplified Explanation: ELISA is a screening test, while Western Blot confirms the findings from ELISA.
Allergic Reaction vs Anaphylaxis
Allergic Reaction: General immune response (often Type I) resulting in symptoms like rash, hives, itching, and mild to moderate swelling; typically localized.
Anaphylaxis: Severe, life-threatening systemic allergic reaction characterized by airway swelling, wheezing, low blood pressure, shock, and gastrointestinal symptoms, requiring immediate epinephrine administration.
Simplified Explanation: Allergic reaction = mild; Anaphylaxis = severe reaction threatening breathing and blood flow.
Definitions of Blood Conditions
Leukocytosis: High white blood cell count.
Leukopenia: Low white blood cell count.
Neutropenia: Low neutrophil levels → increased risk of bacterial infections.
Anemia: Low red blood cell levels or hemoglobin causing fatigue, pallor, shortness of breath.
Thrombosis: Formation of abnormal clots in blood vessels.
Lymphocytopenia: Low lymphocyte levels.
Thrombocytopenia: Low platelet count causing increased bleeding risk.
Pancytopenia: Low levels of red blood cells, white blood cells, and platelets.
Iron Deficiency Anemia: Insufficient iron leading to inadequate hemoglobin production; typically characterized by microcytic, hypochromic red cells.
Hemochromatosis: Excess iron deposits leading to organ damage.
Pernicious Anemia: Vitamin B12 deficiency due to intrinsic factor deficiency; shows neurologic symptoms and macrocytic anemia.
Hemolytic Anemia: Increased destruction of red blood cells leading to jaundice; elevated reticulocyte count.
Aplastic Anemia: Bone marrow failure causing reduced blood cell lines.
Anemia of Chronic Disease: Associated with chronic inflammation affecting iron metabolism.
Sickle Cell Anemia: Genetic condition causing red blood cells to become sickle-shaped under stress, leading to pain and organ risks.
Simplified Explanation:
“-cytosis” = high; “-penia” = low;
Anemia = low RBCs; different types have different causes (iron, B12, marrow problems, or RBC destruction).
Leukemia Definition and Types
Definition: Cancer affecting white blood cell precursors in bone marrow leading to large numbers of abnormal white blood cells crowding normal cell types.
Types:
ALL (Acute Lymphoblastic Leukemia): Common in children.
AML (Acute Myeloid Leukemia): More common in adults; has rapid onset.
CLL (Chronic Lymphocytic Leukemia): Typical in older adults; slow progression.
CML (Chronic Myeloid Leukemia): Related to the Philadelphia chromosome; can manifest as acute phase complications.
Simplified Explanation: Leukemia = blood cancer, with four primary types being ALL, AML, CLL, and CML.
Multiple Myeloma Features
Definition: Cancer of plasma cells (which produce antibodies) located in the bone marrow.
Classic Symptoms: Hypercalcemia, renal issues, anemia, and bone lesions (lytic lesions).
Notable Features: Often produces monoclonal immunoglobulins and Bence Jones proteins, which can end up in urine.
Simplified Explanation: Multiple myeloma is cancer of plasma cells causing bone pain, kidney trouble, anemia, and high calcium levels.
Chemotherapy Effects on Patients
Mechanism: Targets rapidly dividing cells in both cancerous and some normal cellular populations.
Common Side Effects:
Bone marrow suppression leading to diminished WBCs, RBCs, and platelets.
Hair loss (alopecia).
Nausea/vomiting.
Mouth sores (mucositis).
Fatigue and potential infertility risk.
Simplified Explanation: Chemotherapy combats cancer but also affects fast-growing healthy cells, leading to symptoms like hair loss and nausea.
Normal Lab Values Overview
WBC Count: Approximately 4,000–11,000 cells/µL.
Hemoglobin:
Men: Approximately 13.5–17.5 g/dL.
Women: Approximately 12–16 g/dL.
Hematocrit:
Men: Approximately 41–53%.
Women: Approximately 36–46%.
Platelet Count: Approximately 150,000–400,000 cells/µL.
WBC Differential:
Neutrophils: 40–60%.
Lymphocytes: 20–40%.
Monocytes: 2–8%.
Eosinophils: 1–4%.
Basophils: 0.5–1%.
Simplified Explanation: Healthy lab values include WBC: ~4-11k, Hgb: ~12-17, platelets: ~150-400k, neutrophils and lymphocytes comprise the majority of WBCs.
Epistaxis Definition
Definition: Medical term for a nosebleed.
Simplified Explanation: Epistaxis is simply a nosebleed.
Lymphomas Overview
Definition: Cancers arising from lymphocytes, typically in lymph nodes/lymphoid tissues.
Major Groups:
Hodgkin Lymphoma: Characterized by Reed-Sternberg cells; manifests with painless lymph node swelling, night sweats, and weight loss.
Non-Hodgkin Lymphoma: Comprises various types; presents with lymphadenopathy and B symptoms (fever, night sweats, weight loss).
Simplified Explanation: Lymphoma refers to cancers affecting lymph nodes and lymphocytes; Hodgkin has specific cells while non-Hodgkin encompasses peripheral types.
Low Platelet Risks
Consequences: Increased risk of bleeding manifesting as:
Easy bruising.
Petechiae (small red spots).
Nosebleeds and gum bleeding.
Heavier menstrual cycles.
Increased bleeding from minor injuries.
Simplified Explanation: Low platelets mean a greater tendency to bleed and bruise easily.
Megakaryocyte-Derived Components
Source: Platelets are formed from megakaryocytes in the bone marrow.
Simplified Explanation: Platelets are tiny pieces of large cells called megakaryocytes found in the bone marrow.
Monocyte-Macrophage Connection
Process: Monocytes circulate in the blood and convert into macrophages upon entering tissues. Macrophages then function as large phagocytic cells, engulfing pathogens and debris.
Simplified Explanation: Monocytes in the blood become macrophages that clean up and deal with infections in tissues.
Reed-Sternberg Cells and Bence Jones Proteins
Detection:
Reed-Sternberg Cells: Seen during biopsy of lymph nodes in Hodgkin Lymphoma.
Bence Jones Proteins: Detected in urine of patients diagnosed with Multiple Myeloma.
Simplified Explanation: Reed-Sternberg cells indicate Hodgkin Lymphoma; Bence Jones proteins indicate Multiple Myeloma.
Myeloid Stem Cell Derivatives
From Myeloid Stem Cells:
Neutrophils.
Eosinophils.
Basophils.
Monocytes (which mature into macrophages).
From Lymphoid Stem Cells:
Lymphocytes (B cells, T cells, NK cells).
Simplified Explanation: Neutrophils, eosinophils, basophils, and monocytes derive from myeloid cells; lymphocytes come from lymphoid cells.
Esophageal Varices in Cirrhosis
Mechanism: In cirrhosis, liver scarring leads to portal hypertension, causing blood to back up and form fragile veins (esophageal varices) that can rupture and cause significant upper gastrointestinal bleeding.
Consequences: This bleeding contributes to anemia already present from cirrhosis due to nutritional deficits and bone marrow suppression.
Simplified Explanation: Cirrhosis results in fragile veins in the esophagus that can burst, leading to severe bleeding and worsening anemia.
Hemoglobin Functionality
Function: Hemoglobin is a protein in red blood cells responsible for oxygen transport.
Each hemoglobin has heme groups containing iron to bind with oxygen.
In the lungs: Hemoglobin picks up oxygen.
In tissues: Hemoglobin releases oxygen and carries some CO₂ back to the lungs.
Simplified Explanation: Hemoglobin in red blood cells picks oxygen in the lungs and delivers it to tissues.
Sickle Cell Crisis Description
Definition: In sickle cell anemia, under conditions of low oxygen, dehydration, infection, or cold, RBCs deform into a sickle shape, blocking blood vessels and leading to vaso-occlusive crises.
Effects: Results in severe pain in various parts of the body, increased risk of stroke, organ damage, and acute chest syndrome.
Simplified Explanation: A sickle cell crisis occurs when red blood cells transform into a sickle shape, obstructing valves and causing intense pain and complications.
Erythropoietin Role & Common Anemia Type
Definition: Erythropoietin (EPO) is a hormone produced primarily in the kidneys that signals the bone marrow to increase red blood cell production when oxygen levels are low.
Most Common Anemia: Iron deficiency anemia is the most common type worldwide.
Simplified Explanation: EPO from the kidneys instructs marrow to produce more red blood cells; the most prevalent anemia is iron deficiency anemia.