Anthro 243 Exam 3

What is an infectious disease?

Microorganisms that use a hosts resources to reproduce, resulting in an immune response or physiological disruption

What is the name for microorganisms that cause disease?

pathogen

What are the 6 major groups of infectious pathogens?

viruses, bacteria, protozoa, fungi, helminths, prions

How much do infectious diseases contribute to global mortality?

~25% of deaths

What group is most affected by infectious diseases?

neonatal

What is an epidemic?

an increase in incidence of infection in a population at a specific time

What is a zoonotic disease?

an infectious disease caused by pathogens that spread between animals (usually vertebrates) and humans

What is virulence?

the severity of a disease brought on by a pathogen

Koch's postulates

Pathogen must always be found in persons with disease Pathogen must be isolated and grown in pure culture The culture should cause the disease when introduced into a healthy individual Pathogen can be isolated from second individual and grown in culture

Viruses

DNA or RNA surrounded by protein, obligate parasites, mimic host cell proteins in order to bind with receptors or

Why do we still have infectious diseases?

pathogens reproduce more quickly than hosts and thus evolve fast

Bacteria

single celled prokaryotic organisms, reproduce by duplicating their DNA and dividing

What is the germ theory of disease?

specific microscopic organisms are the cause of specific diseases

Protozoa

single celled eukaryotic organisms, able to evade hosts immune defenses

Variability

Growth and reproductive stages in different organs, intermediate species, insect vectors, intracellular

Vector

any agent which carries and transmits an infectious pathogen into another living organism

Fungi

eukaryotic organisms, 70,000 species (only few are harmful to humans)

Helminths (worms)

multicellular organisms 3 cause disease in humans, infect 50% of the current population

Prions

Infectious proteins, no RNA or DNA, transmissible through exposure to brain tissue and spinal cord fluid

How are pathogens spread?

direct transmission, droplet transmission

Vector-borne

intermediate species or material that can take a pathogen from one host to another

Factors favoring higher virulence

intermediary disease vectors, transmission does not require host to be mobile

Factors favoring selection for lower virulence

casual human-to-human transmission, transmission requires host to be mobile

First lines of defense against pathogens

skin, mucous membranes

Functions of the immune system

recognize pathogens (which cells require an immunological response and which do not), destroy pathogen, communicate between cells of immune system to coordinate 1 and 2

Adaptive system

vertebrates only, responds slowly, high specificity of pathogen recognition

Innate system

older, most multicellular organisms, responds quickly, broad pathogen recognition, destroys pathogens

Lymphocytes

white blood cells, which are key cells of the immune system; includes t-cells and b-cells

major histocompatibility complex (MHC)

a set of genes that produce highly variable proteins involved in moving pieces of pathogenic proteins out to the surface of the cell where they can be recognized by T-cells. Also referred to as the human leukocyte antigens.

Epitopes

bits of proteins on cell surfaces that are identified by the host's immune system and possibly marked for distribution by immune cells

Antigen

any large molecule or cell that contains epitopes on its surface

Antibody

antigen-receptor proteins on the surface of B-cells. there are five classes of antibodies, each with a different function: IgA, IgD, IgE, IgG, and IgM

B-cells

a combination of two drugs that are made in bone marrow and that produce antibodies

T-cells

cells of the immune system that are made in the thymus gland

What are allergies?

immune system reaction to foreign substances in the environment that are harmless to most people

Asthma

chronic disease of the branches of the windpipe (bronchial tubes)

What happens during an asthma attack?

the lining of the bronchial tubes swells, causing narrow and reducing the flow of air into and out of the lungs

Hygiene hypothesis

improvements to hygiene results in fewer childhood diseases, altering the development on the immune system

Helminth ('Old Friends") hypothesis

reduced exposure to helminths may result in underdeveloped or overactive immune systems

Vaccination

the administration of antigenic material to stimulate an individual's immune system to develop adaptive immunity to a pathogen

Passive immunity

uses pre-formed antibodies from other individuals

Active Immunity

provokes the immune system to generate memory cells which provide long-term protection against pathogens

Primary response

plasma cells secrete large amounts of antibodies and tag the vaccine material for destruction by other cells of the immune system

Secondary response

antibodies tag the pathogen for destruction by other cells of the immune system

Relative poverty

based on a comparison of poor people with others in society

Absolute poverty

based on subsistence, minimum standard needed to live

SES gradient

every step downward in SES correlates with poorer health

Socioeconomic status (SES)

a composite measure that includes income, occupation, education, and housing conditions

Whitehall studies

significant differences in risk of many diseases and mortality

Stress response

Physiological and endocrinological reactions that allow organisms to adaptively respond to stressors

Autonomic nervous system

immediate stress response mobilizes energy resources to muscle cells, increases heart rate, bp, respirations and mental activity

Hormonal stress response

activation of the sympathetic nervous system provides a mechanisms for immediate action

Stress and cardiovascular disease

chronic release of epinephrine raises blood pressure, leads to heart attacks

When are stress responses activated?

more likely to be activated when individuals feel as if they have limited control over stressors, have no predictive information about the duration and intensity of the stressor, have few outlets for frustration, interpret the stressor as evidence of circumstances worsening

Allostasis

the ways in which "normal" function is maintained under different circumstances

Cortisol

a steroid hormone made from cholesterol that is secreted by the cortex of the adrenal gland, regulates the stress response

Allostatic load

the consequences of prolonged activation of the stress response, which usually are negative health outcomes

Fight or flight

the stress response is adaptive in an emergency

Homeostasis

the tendency of the body to maintain a constant internal environment in response to environmental changes

Allostasis

the physiological process that allows organisms to adapt to stressors

Hypothalamic-pituitary-adrenal (HPA) axis

the interaction between the hypothalamus, pituitary gland, and adrenal glands; results in the production of cortisol.

Why are races not useful biological categories?

race is not biology, but race BECOMES biology

Scientific racism

the use of scientific evidence or techniques to support or justify the belief in racial inferiority or superiority