Patho exam 1

genotype

the coding

phenotype

the expression

heterozygous alleles

when two DIFFERENT alleles are inherited

Homozygous allele

When two IDENTICAL alleles are inherited

Types of Chromosome aberrations

• Euploidy

• polyploidy

• Aneyploidy

Euploidy

Cells with “NORMAL” amounts of cells

both gametes and diploid cells are present

Polyploidy

Presence of more than 2 complete sets of chromosomes

Aneuyploidy

Gain or loss of one or more individual chromosomes

Down Syndrome

• Abnormality of chromosome number 21

  • trisomy 21

• needs clinical diagnosis

• manifestations

  • low nasal bridge, epicanthal folds, protruding tongue, low set ears

  • intellectual disability (Avg. IQ 20-70)

  • Incidence rises with increasing age

Turner Syndrome

Single X Chromosome (X) → Female

Characteristics:

• short stature

• wide chest

• lymphedema

• infertility

• multiple moles

Klinefelter Syndrome

Extra X Chromosome (XXY) → male

Characteristics:

• longer legs

• broader hips

• gynecomastia

• reduced body hair

• small testes

• reduced muscle mass

• infertility

Epigenetics

the study of changes in gene functions that are heritable and that are not attributed to alterations in the DNA sequence itself

→ explores how behavior and environmental factors can switch genes on or off—adjusting how cells read genetic coding

Can be affected by:

• nutrition

• toxins, pollutants, and radiation

• lifestyle

DNA Methylation

Methyl groups attaches to DNA strand → cells are unable to read this portion of DNA

this can be a good AND bad thing

(ex. parts of the sheet music are blank)

Methylation of BRCA 1 and 2 can lead to breast, ovarian, and prostate cancer

Histone Modification

Chemical changed (Methyl groups) occur on histones, preventing unraveling

(ex. You can’t open the music book)

Innate Immunity

Defense mechanisms that are present at birth and provide the initial response to invasion and injury

first line of defense against actual or potential invaders

primary cellular components of innate immunity

• mast cells

• platelets

• neutrophils

• basophils

• monocytes/macrophages

• dendritic cells

Mast cells

Found in connective tissue and close to vessels in skin, GI, and respiratory tract linings

Release histamine

Platelets

Aggregates to help stop bleeding; degranulation releases serotonin to accelerate inflammation

Neutrophils

primary phagocyte in early inflammation which phagocytizes pathogens and removes cellular debris and dead cells from lesions

Basophils

least prevalent granulocyte

contains heparin

release histamine

particularly involved in adaptive immune response, esp. w/ asthma or allergies

monocyte/macrophage

largest WBC

migrates to inflammation and transforms into macrophage

responds to presence of chemical mediators

cleanup and repair crew

dendritic cells

consumes invaders

presents “remnants” to Helper T cells

promotes activation of adaptive immunity

immunity pathway

Symptoms of Local Inflammation

Rubor → Redness

Calor → Heat

Tumor → Swelling

Dolor → Pain

Functio Leasa → Loss of Function

Symptoms of Systemic Inflammation

Fever

Increased WBC count → Check CBC

Increased synthesis of plasma proteins → Check ESR and CPR

4 Phases of Wound Healing

1. Hemostasis

2. Inflammation

3. Proliferation and New Tissue Formation

4. Remodeling and Maturation

Hemostasis

Phase 1

Damage leads to vasoconstriction then vasodilation and clotting cascade

fibrin mesh of blood clot acts as a scaffold

*Primary goal is to keep blood in and invaders out

Inflammation

Phase 2

Begins in minutes

Involves macrophages, mast cells, neutrophils, and lymphocytes

Phagocytosis

*Primary goal is to catch and eliminate invaders present and clearing debris

Proliferation and New Tissue Formation

Phase 3

Begins 3-4 days after injury

Angiogenesis

Fibroblast activation

Granulation tissue formation

*Primary goal is to begin rebuilding what has been lost/damaged

Remodeling and Maturation

Phase 4

Begins weeks after injury

Re-epithelialization

Scar formation

Wound contraction

*Primary goal is to strengthen and reorganize the newly formed tissue

Swelling

results from increased capillary permeability and fluid movement into the tissues

histamine released → inc vasucular permeability

inc capillary hydrostatic pressure → pushes fluid into tissues

dec. oncotic pressure → proteins accumulate in tissues

Osmotic Forces

Pulling force → pulling of fluids and solutes from one side to the other

Na, K, Glucose

Oncotic Forces

Pulling force → pulling of proteins/maintaining levels in blood volume

plasma proteins

Hydrostatic forces

pushing force → pushes water out through semipermeable membrane

maintains fluid pressure (BP)

Fluid alterations

• Isotonic alteration: fluid is shifting equally/everywhere → equal sodium everywhere

• Hypotonic alteration: low sodium in bloodstream and increased water → lost osmotic pulling force

• hypertonic alteration: too much sodium in bloodstream and water is leaving cells → massive osmotic pulling force

Isotonic imbalance

• TBW loss equivalent to electrolyte loss

  • leads to hypovolemia (too little plasma volume)

  • Manifestations

    • dec. U/O

    • dec. BP, elevated HR

    • dry mucous membranes and skin

    • SEVERE loss = shock

    • elevated hematocrit

• Isotonic fluid gains/excess (plasma volume increase)

  • Causes:

    • too much IV fluids

    • aldosterone hypersecretion

    • drug effect

  • Manifestations

    • hypertension

    • edema → hydrostatic forces altered

    • dyspnea (pulmonary edema)

hypertonic imbalance

Water loss or solute gain

osmolality is high

• causes

  • isovolemic hypernatremia (only water lost)

    • severe diarrhea

    • inadaquate water intake

    • respiratory tract infections

  • Hypovolemic (lots of water lost, some sodium lost)

    • loop diuretics, mannitol

    • renal failure

  • Hypervolemic hypernatremia (lots of sodium and water lost)

    • rare → endocrine disfunction

    • inc. Na intake along with kidney disease

• Cells shrink

hypotonic imbalances

water gain or solute loss

osmolality is low (diluted)

• causes

  • isovolemic hyponatremia (only Na lost)

    • SIADH

    • hypothyroidism

  • hypovolemic hyponatremia (lots of Na lost, some water lost)

    • severe diarrhea

    • prolonged vomiting

  • hypervolemic hyponatermia (inc. Na leads to water retention)

    • CHF

    • cirrhosis of liver

    • significant edema

• cells swell

Hypernatremia

Too much sodium (Na > 145 mEq/L )

• Manifestations:

  • Flushed skin

  • Restless

  • Inc. BP and HR

  • Edema

  • Dec. U/O

  • Seizures

  • Anxious

  • Low-grade fever

  • Thirst

  • (FRIED SALT)

Hyponatremia

too little sodium (Na < 135 mEq/L)

• Manifestations:

  • Stupor/coma

  • Anorexia

  • Lethargy

  • Tendon reflex dec.

  • Limp muscles

  • Orthostatic hypotension

  • Seizures

  • Stomach cramping

  • (SALT LOSS)

Hypokalemia

Too little potassium (K < 3.5 mEq/L)

• Manifestations:

  • Lethargy

  • Leg cramps

  • Limp muscles

  • Low, shallow breaths

  • Lethal cardiac arrythmias

  • Lots of urine

  • (6 L’s)

Hyperkalemia

Too much potassium (K > 5.0 mEq/L)

• Manifestations:

  • Muscle weakness

  • Urine abnormalities

  • Restless nerves

  • Diarrhea

  • EKG changes

  • Reflexes

  • (MURDER)

Hypocalcemia

Too little calcium (Ca < 5.5 mg/dL)

• Manifestations

  • Chvostek’s sign

  • Arrhythmias

  • Trousseau’s sign

  • Spasms

  • (CATS)

Hypercalcemia

Too much calcium (Ca > 10.5 mg/dL)

• Manifestations

  • Stones → kidney stones

  • Bones → bone pain, osteoporosis, fractures

  • Groans → abdominal pain, N/V, constipation

  • Psych Moans → depression, anxiety, confusion

Hypomagnesemia

Too little magnesium ( Mg < 1.8 Mg/dL)

• Manifestations

  • Chvostek’s signs

  • Refractory hypokalemia

  • Arrhythmias

  • Muscle spasms

  • Paresthesias

  • Seizures

  • (CRAMPS)

Hypermagnesemia

too much magnesium (Mg > 2.8 mg/dL)

• Manifestations

  • Sedation

  • Loss of reflexes

  • Unresponsiveness

  • General weakness

  • Gait problems

  • Impaired breathing

  • Slow heart rate

  • Hypotension

  • (SLUGGISH)

ABG

Arterial blood gases

Normal pH: Acidic ← 7.35-7.45 → Basic

—> typically 7.4

Normal CO2: Basic ← 35-45 → Acidic

Normal HCO3: Acidic ← 22-26 → Basic

Compensation

Is the pH in a normal range → compensated

Are either CO2 of HCO3 in normal range → uncompensated

Is the value that doesn’t match the pH in the opposite range → partially compensated

Control of serum pH

Resp system alters CO2 levels → fast

Kidneys alter HCO3 levels → slow

respiratory acidosis

lungs fail to get rid of CO2 → CO2 climbs → carbonic acid climbs → acidosis

• Causes:

  • pneumonia, airway obstruction, chest injury

  • drugs that depress the respiratory center

  • COPD → chronic resp. acidosis

  • severe impairment or lack of compensation → decomp. resp. acidosis

Metabolic acidosis

• causes

  • diarrhea → excessive HCO3 loss

  • inc use of serum bicarb

  • renal disease or failure → dec. excretion and produciton

  • decomp. metabolic acidosis

Respiratory alkalosis

drop in CO2

• Causes

  • hyperventilation

    • anxiety, high fever, overdose

    • head injury

    • brainstem tumors

Metabolic alkalosis

increase in serum bicarb

• Causes

  • loss of hydrochloric acid

  • hypokalemia

  • excessive ingestion of antacids