PathoPharm Basic Concepts of Pathophysiology

Physiology vs. Pathophysiology

Physiology

• study of the normal functions of the body

Pathophysiology

• structural and functional changes in cells, tissue, and organs of the body

We can’t diagnose so why do we study pathophysiology?

• clinical manifestations

• medications work

• side effects

• complications

• nursing interventions work

• how to communicate with the team

Health vs. Disease

Health

• WHO “state of physical, mental, and social well-being and not merely the absence of disease and infirmary

• varies based on

  • age, genetics, gender, environment, social factors

Disease

• no longer function normally

• varies in severity in length

• acute or chronic

Language of Disease

1. Insidious- gradual, less notable onset- easily overlooked

2. Exacerbation- acute worsening

3. Remission- signs and symptoms may lessen for period but disease is still present

4. Prognosis- Likelihood of full recovery or retaining previous function

5. Mortality rate- death rate from a particular disease

6. Morbidity- disease rates in a population OR suffering from a disease or medical condition

7. Comorbidity- Presence of one or more additional disorders cooccuring with a primary disease or disorder. Ex. Coronary Artery Disease+ Diabetes mellitus II

8. Complication- A pathological process or event occurring during a disease that is not an essential part of the disease; it may result from the disease or from independent causes. Ex. pneumonia after hip surgery

9. Idiopathic- we don’t know exactly what causes it

10. IDK- Factors: Risk Factors

11. Etiology- study of disease causation. disease can be caused by infectious agents, chemicals

12. Pathogenesis- confused with etiology. step by step of how the disease develops. ex. etiology is a bacteria causes a UTI. Pathogenesis is how bacteria effects epithelial lining of urethra and body’s subsequent inflammatory response causing s/s of a UTI

Language of Disease pt. 2

• Congenital- present at birth (deafness)

• hereditary- transmitted across generations

• genetic- caused by abnormalities in genes (down syndrome)

• Inflammatory- triggered by body defenses (lupus erythematosus)

• Degenerative- caused by deterioration (osteoarthritis)

• metabolic- problem with biochemical processes

• neoplastic- uncontrolled proliferation (cancer)

Sign

• objective, measurable

• blisters, temperature, cough

Symptom

• subjective, patient reported

• itching, sweating, sore throat, SOB

Cellular Adaptation, Injury and Death

• to try and prevent injury and death, developed mechanisms of cellular adaptation

Proliferation

• normal: hyperplasia, hypertrophy

• can be abnormal: neoplasia (abnormal growth)

• should cease when stimulus is removed

• MORE GETTING BIGGER

Differentiation

• normal process

• development of cells to their intended function

• Blood cells form from immature cells

• STEM CELL

Cellular Adaptation

• normal cells

• atrophy

• hypertrophy

• hyperplasia

• metaplasia: more cells and layering atop each other

• dysplasia: lots of cells and NOT GOOD; skin cancer

Cell Injury

• reversible to a point

• causes

  • physical, chemical, biological, deficiencies, free radicals

  • lack of oxygen, lack of blood flow

• Cant repair; cell death

Hypoxia (not enough o2 to tissues), Hypoxemia (not enough o2 in blood stream)- Major causes of cell death

• Hypoxemia absence of enough oxygen in blood to sustain bodily function

• Ischemia decreased blood supply to an organ

Cell death

Apoptosis

• normal, programmed

• shrink down, phagocytosis

Necrosis

• premature death, Abnormal, Due to Injury

• rupture release byproducts of death into interstitial spaces and trigger inflammation

• swell and burst

Genetic and Congenital Disorders

Genes

• segments of DNA found on chromosomes that carry info for p’rotein production and are responsible for inheritance of specific traits

• recipes

  • set of instructions to produce a protein, say which protein to make and how to make it.

  • Control protein-making activity by saying when to make it and how

Genetics

• study of genes and role in transmitting traits from one gen to next

• friends share genes

Genomics

• Study of collection of an individual's genes (the genome)

• The interaction of those genes with one another and with environmental factors

Single gene trait and disorders

When one gene controls the expression of a specific structure, protein, or function it is referred to as a single-gene trait

Alleles

• Variation of a gene at a specific location

• Two alleles together control how that gene is expressed.

• Alleles are paired with chromosomes

• We inherit one chromosome from each parent.

• The 'specific location' is referred to as the locus.

Genetics Terms

Dominant

• Expressed whether 2 gene alleles are identical (homozygous) or different (heterozygous).

Recessive

• Expressed only when both gene alleles for the trait are identical (homozygous)

Genotype

• The genetic constitution (specific allele makeup) of a cell, an organism, or an individual

• A list of inherited instructions that may or may not have an observable effect on the organism

Phenotype

• The physical and behavioral characteristics of an organism

• In most cases, both genes and environment contribute

More than one genotype may have the same phenotype.

Some brown eyed people are carriers of the code for blue eyes, and other brown-eyed people are not.

•geno typically, these two types of brown-eyed people are the same, but phenotypically they are different

Expressivity and Penetrance

Expressivity

• The degree of trait expression a person has when a dominant gene is present

• Expression affects phenotype and can range from mild to severe.

• Personal issue (rather than a population issue).

• Variable individual expression

• For example: Eye color (amount of melanin), lactose intolerance (amount of lactase)

Penetrance

• How many who have it show it

Represents the ability of a gene to express its function.

• How often, within a population, a gene is expressed when present.

• Calculated by examining a population of people known to have the gene mutation = % of people expressing the gene (penetrant)

• Penetrant/Gene carriers (penetrant as well as normal individuals with the gene)

Sex Linked Inheritance

• If a gene is found on the X or Y chromosome, it is said to be a sex-linked trait

• It is a trait whose presence or absence is linked to an organism's gender

• Because the gene controlling the trait is located on the sex chromosome, sex linkage is responsible for the gender of the individual

Hemophilia

• A medical condition that severely reduces the ability of blood to clot, resulting in severe bleeding even from minor injuries

• This condition is typically caused by a hereditary lack of the coagulation factor VIII

• Queen Victoria

Chromosomal & Multifactorial Inheritance

Chromosomal Disorders

• Any change in the normal structure or number of chromosomes, often resulting in physical or mental abnormalities.

• Examples?

• Any change in the normal structure or number of chromosomes, often resulting in physical or mental abnormalities

• Examples:

• Down Syndrome or Trisomy 21

• Turner Syndrome

• Klinefelter Syndrome

Multifactorial Inheritance Disorders

• Associated with effects of multiple genes in combination with lifestyle and environmental factors.

• Associated with effects of multiple genes in combination with lifestyle and environmental factors

• Examples: heart disease & diabetes

Down Syndrome

• 3 Types

• Trisomy 21 (nondisjunction) accounts for 95% of cases

• ~50% of children born have a cardiac defect (Atrial Septal

Defect is most common).

• ~15% of children have hypothyroidism.

• Translocation accounts for about 4%

• Mosaicism accounts for about 1% (NDSS, 2014).

All are associated with:

• Varying levels of intellectual disability (typically mild to moderate)

• Characteristic facies: slanting eyes, small chin, round face, flat nasal bridge, abnormal outer ears

• Hypotonia in infancy

Klinefelter syndrome

• Abnormal testicular development accompanied by the presence of one or more extra X chromosomes more than the normal male XY complement.

• Most males with Klinefelter syndrome have one extra X chromosome, resulting from nondisjunction during meiotic division in one of the parents (a cell division error).

Turner syndrome

• An absence of all or part of the X chromosome.

• Characteristically, the female is short in stature, but her body proportions are normal.

• Variations in syndrome with abnormalities

Environmental Factors

Early Environmental Influences on Children's Brain Structure and Function