Bio Powerpoints 1-3

pathophysiology: the cellular and organ changes that occur with disease and the effects that these changes have on total body function

pathology: study of the structural and functional changes in cells, tissues, and organs of the body that cause or are caused by disease

pathology: study of the functions of the human body

health: a state of complete physical, mental, and social well-being and not merely the absence of disease and infirmity

disease: an acute or chronic illness that one acquires or is born with and that causes physiologic dysfunction in one or more body systems

etiology: causes of disease

pathogenesis: the sequence of cellular and tissue events that take place from the time of initial contact with an agent of disease until the symptoms start to show

morphology: the fundamental structure or form of cells or tissues

histology: the study of the cells and extracellular matrix of body tissues

clinical manifestations: signs and symptoms used to describe diseases

• sign: a manifestation that is noted by an observer (ex: enlarged pupils)

• symptom: subjective and noted by the patient (ex: pain)

• syndrome: a compilation of signs and symptoms that are

• characteristic of a specific disease state (ex: chronic fatigue syndrome)

complications: possible adverse extensions of a disease or outcomes from treatment

sequelae: lesions or impairments that follow or are caused by a disease

diagnosis: the designation as to the nature or cause of a health problem

• validity: extent to which a measurement tool measures what it is intended to measure

• reliability: : refers to the extent to which an observation, if repeated, gives the same result

• sensitivity: the proportion of people with a disease who are positive for that disease on a given test or observation (true-positive)

• specificity: the proportion of people without the disease who are negative on a given test or observation (true-negative)

• Positive predictive value (PPV): the proportion of true-positive results that occurs in a given population

• Negative predictive value (NPV): the true-negative observations in a population

evolution of disease

• acute: relatively severe, but self-limiting

• subacute: intermediate & is not as severe as an acute disease and not as

• prolonged as a chronic disease

• chronic: continuous, long-term process

spectrum of disease severity

• preclinical: not clinically evident but progress to clinical form (ex: Hep B)

• subclinical: not clinically apparent and is not destined to become clinically apparent (ex: tuberculosis)

• clinical: manifested by signs and symptoms

• persistent chronic infectious: disease persists for years, sometimes for life (HIV/AIDS)

carrier: a person who harbors an organism but is not yet infected (can be limited or chronic)

epidemiology: the study of disease occurrence (frequency, distributions and determinants) in human population

incidence: number of new cases arising in a population at risk during a specified time

• number of new cases/total number of people

prevalence: measure of existing disease in a population at a given point in time

• all cases over a time period/population during the time period

morbidity: the effects an illness has on a person’s life

• persistence and the long-term consequences of the disease

mortality: the causes of death in a given population and the data are expressed as death rates

• crude mortality rate: : number of deaths in a given period without accounting for age, gender, race, socioeconomic status, and other factors

risk factors: multiple conditions that predispose to development of a particular disease that may inherent to the person or external

cross-sectional studies: compares the prevalence of a disease in those with the factor (or exposure) with the prevalence of a disease in those who are unexposed to the factor

case control study: compare people known to have the outcome of interest (cases) and those known not to have the outcome of interest (controls)

• based on retrospective exposures

• both exposure and disease of interest have already occurred at the time of the study

cohort study: when a group of people initially free of disease are classified according to a given exposure, and then followed up over time

• prospective

• observing a specific health outcome

natural history of a disease: the way in which a disease evolves over time from prepathogenesis phase to its termination as recovery, disability or death, in the absence of intervention

• pre-pathogenesis: the period prior to the onset of the disease

• pathogenesis: begins with entry of agent in the susceptible human host

stages of disease:

• primordial: existence of underlying condition leading to causation (ex: smoking, environmental pollution)

• primary: specific causal factors exist (immunization of measles/polio)

• secondary: early stage of disease (early detection & treatment of tuberculosis & STDs)

• tertiary: late stage of disease (treatment & rehabilitation) (ex: leprosy)

cell: the smallest structural and functional unit of life

components of the cell

• eukaryotic cells: made up of internal membrane-bound compartments called organelles

  • 3 parts: nucleus, cytoplasm, cell membrane

• organelles: small organs within cells

• prokaryotes: do not contain membrane-bound organelles

• protoplasm: intracellular fluid composed of water(70-85%), proteins, lipids, carbohydrates, and electrolytes

nucleus: largest organelle in the cell that is the control center for the cell and contains DNA (which contains genes)

• genes: contain the instructions for cellular function and survival

• the site for the three types of RNA:

  • messenger RNA 

  • ribosomal RNA

  • transfer RNA

cytoplasm: a solution that contains water, electrolytes, proteins, fats, carbohydrates and pigments, as well as the fluids and organelles outside of the nucleus

• ribosomes, endoplasmic reticulum (ER), golgi complex, lysosomes, peroxisomes, proteasomes, mitochondria

ribosomes: sites of protein synthesis; made up of rRNA and proteins; 

• active ribosomes either stay within the cytoplasm or are attached to the membrane of the ER

endoplasmic reticulum (ER): paired membranes and flat vesicles that connect various parts of the inner cell: rough and smooth

• rough ER: makes digestive enzymes found in lysosomes and proteins such as the protein hormone insulin

• smooth ER: synthesizes lipids including steroid hormones; store extra glucose as glycogen and involve metabolism of some hormone drugs

golgi apparatus/golgi complex: modifies substances produced in the ER and packages them into secretory granules or vesicles

• also makes large carbohydrate molecules that combine with proteins produced in the rough ER to form glycoproteins

lysosomes: a sac-like organelle in a cell that contains enzymes that break down cellular components, including phagocytosed material

• they receive their enzymes and membranes from the golgi apparatus

• primary lysosomes become secondary lysosomes after they fuse with membrane-bound vacuoles that contain material to be digested

peroxisomes: contain a special enzyme that degrades peroxides (e.g., hydrogen peroxide) in the control of free radicals

proteasomes: recognize deformed and misfolded proteins that have been targeted for degradation or proteolysis by proteases enzymes

caspase pathway: apoptotic cell death; involved in breakdown of proteins

mitochondria: powerhouse of the cell that contain enzymes that change carbon-containing nutrients into energy 

• stores most of this energy as high-energy phosphate bonds in places like adenosine triphosphate (ATP) and uses the ATP as energy

• contain their own DNA, ribosomes, and are self-replicating

• mitochondrial DNA (mtDNA): contains the instructions to make of the proteins needed for mitochondrial function

cytoskeleton: a network of microtubules, microfilaments, intermediate filaments, and thick filaments; controls cell shape and movement

cell membrane: thin membrane that surrounds cell and has semipermeable structure & contains receptors for hormones, neurotransmitters, and transporters

• made up of lipids, carbs, and proteins

• lipid bilayer: provides the basic structure of the cell membrane, proteins carry out most of the functions

  • made up mostly of phospholipids, with glycolipids and cholesterol.

    • phospholipid molecules are either:

      • hydrophilic: water-loving heads face outward on each side of the membrane

      • hydrophobic: tails project toward the middle of the membrane

• the membrane serves as a barrier that controls which substances enter and leave the cell; filters out harmful substances

• three pathways:

  • simple diffusion: concentration gradient

  • carrier proteins: transporting only one type of molecule and may be involved in active transport

  • channel proteins: transfer water-soluble molecules and serve as the ion selectivity filter

passive transport: movement via a concentration gradient, or from high concentration to low concentration with no energy

diffusion: substances move from an area of higher to an area of lower concentration

facilitated diffusion: protein-assisted diffusion for non-lipophilic substances (ex: glucose)

osmosis: water movement down the concentration gradient i. e., movement of water from high water concentration to lower

• osmotic pressure

active transport: mechanisms involve the input and use of energy for movement of against gradient

endocytosis: brings materials in the cell

• pinocytosis: cell drinking

• phagocytosis: cell eating

exocytosis: secretion of intracellular substances into the extracellular spaces

tissues: groups of cells that work together; combined with other tissues to form the organs of the body

• epithelial tissue: tissue that lines the body's surfaces and cavities, primarily functioning to protect, absorb, secrete substances, and filter materials by forming a barrier between the body and its environment

  • shape of the cells:

    • squamous: thin and flat

    • cuboidal: cube shaped

  • number of layers

    • simple

    • stratified

    • pseudostratified

    • transitional

• connective/supportive tissue: most common tissue, connects and binds or supports the various tissues; its cells produce the extracellular matrix that supports and holds tissues together

  • connective tissue proper: includes loose (areolar), adipose, reticular, and dense connective tissue

  • specialized connective tissue: functions to support the soft tissues of the body and store fat (cartilage, bone, and blood cells)

• muscle tissue: responsible for movement of the body and contains thin and thick filaments

  • thin filaments: made of actin

  • thick filaments: made of myosin

  • three types of muscle tissues: skeletal, cardiac, and smooth

    • skeletal and cardiac muscles are striated muscles

    • smooth muscles have no striations

• nervous tissue: distributed throughout the body as a communication system; divided into two:

  • central (CNS): brain and spinal cord

  • peripheral (PNS): nervous tissue outside the CNS

  • consists of two cell types:

    • neurons: nerve cells

      • soma/cell body: the nucleus and most organelles

      • dendrites: multiple elongated extensions that receive and carry stimuli from the environment, from sensory epithelial cells, and from other neurons to the cell

      • axons: generates and conducts action potentials away from the cell body to other nerve cells, muscle cells, and glandular cells

    • glial cells: supporting cells

extracellular matrix: makes up a large volume of tissue volume, and is itself made up of proteins and polysaccharides

• two main classes that make up extracellular matrix:

  • polysaccharide chains of a class called glycosaminoglycans (protein + sugar)

  • fibrous (fiber-like) proteins (collagen, elastin, fibronectin, and laminin) that are found in the basement membrane