HLTH-210 QUIZ #1 Flashcards

physiology

study of how living organisms and their parts normally function

human physiology

how cells, tissues, organs, and organ systems function and work together

pathophysiology

how normal physiological processes are altered in disease

normal cell function depends on what

maintaining a suitable internal environment

homeostasis

the maintenance of a relatively stable internal environment despite internal or external change

set point

the target value the body tries to maintain for a regulated variable

set point is not

always fixed, it can shift when the body’s needs change

normal range

the range of values within which a regulated variable can fluctuate while normal function is maintained

adaptive change

regulated adjustments the body makes in response to changing conditions

adaptive change may involve…..

a temporary shift in a set point or other physiological adjustments

dynamic equilibrium

a state of balance in which conditions remain stable even when continuous changes are occurring

examples of dynamic equilibrium

• blood glucose levels

• blood oxygen levels

negative feedback

moves a regulated variable back toward its set point or normal range

how many interacting components does homeostasis require and what are they

four; stimulus, sensor, control center, and effector

stimulus

change or threat of change in a reg variable

sensor

detects change and sends info to control center

control center

evaluates info and determines what response is needed

effector

carries out response

where is the control center in the brain

the hypothalamus

positive feedback

does not maintain homeostasis - response amplifies original change and continues until a specific event stops the process

example of positive feedback

• blood clotting

• childbirth

feed forward

helps maintain homeostasis by anticipating change (body responds before reg variable

changes)

example of feed forward

• seeing/smelling food and releasing saliva or stomach growls

homeostasis depends on balance between

inputs and outputs

when the body faces competing demands what might it do

it might prioritize some variables over others to preserve essential functions

what can disease do relating to homeostasis

it can disrupt sensor, control center, or effector (ex. type 1 diabetes)

some diseases can create what which makes the disturbance with homeostasis worse

positive-feedback cycles

immune system

cells tissues, and organs that protects body from infections and abnormal cells, and harmful substances

immunity

the protection or resistance produced by the immune system

innate immunity

• present at birth

• acts rapidly

• no previous exposure required

• non specific: recognizes broad patterns rather than one specific antigen

• responds similarly w/ repeated exposure

physical barriers

skin, mucus, cilia

chemical barriers

stomach acid, antimicrobial substances

biological barriers

normal microbiota

internal defenses

inflammation, phagocytes, natural killer cells, complement and other immune proteins

natural killer cells

kill infected and abnormal cells

mast cells

promote inflammation (involved in allergies)

eosinophils

important against parasites (involved in allergies)

basophils

promote inflammation (involved in allergies)

phagocytes

engulf pathogens, debris, and dead cells

neutrophils

rapid responders that engulf and kill microbes (especially bacteria and fungi) (first cells to arrive at an infection)

macrophages

engulf pathogens, dead cells, and debris; can present antigen to already activated helper T cells

dendritic cells

major antigen-presenting cells; activate naive T cells

where are dendrites most common

in tissues exposed to the external environment

antigen

molecule recognized by the adaptive immune system

carried out by lymphocytes

• b cells

• t cells

where do b cells mature in

the bone marrow

where do t cells mature in

thymus

naive b and t cells

fully developed but have not yet encountered their matching antigen

effector cells

• activated by recognizing their matching antigen

• actively carry out the immune response

memory cells

• remain after response

• respond more rapidly if same antigen is encountered again

cell-mediated immunity

• carried out by t cells

• targets infected or abnormal cells

humoral immunity

• carried out by b cells

• produces antibodies

• antibodies found in body fluids

how do we get to the humoral from cell-mediated

from the helper t cells

cytotoxic t cells (“killer T cells): adaptive immunity

kill infected or abnormal cells

helper t cells: adaptive immunity

• release cytokines that activate b cells and cytotoxic t cells

t cell receptors: adaptive immunity

• each t cell has t-cell receptors specific to a particular antigen

b cells: adaptive immunity

• when activated some become plasma cells which then secretes antibodies

• other activated b cells become memory b cells

antibodies: adaptive immunity

• binds specifically to antigens

• found in body fluids

• helps neutralize or mark pathogens for destruction

autoimmune diseases

immune system mistakenly attacks the body’s own healthy cells, tissues, or organs

immunodeficiency

one or more components of immune system are absent or do not function properly

who are the main players in the humoral response

b-cells

active immunity

a person’s own immune cells produce antibodies and memory cells (ex. infection, vaccine)

passive immunity

transfer of preformed antibodies to an individual (no memory cells) (ex.in utero, breast milk, injection of immunoglobulin)

natural immunity

person acquires immunity from natural, biological, means (ex. infection, placental transfer, breastfeeding)

artificial immunity

person acquires immunity thru medical intervention (ex. vaccine, injection of immunoglobulin)

immunization

a process of developing an immune response that protects against or helps fight disease (achieved thru vaccination)

immunization relies on

specificity and memory of adaptive immune system

edward jenner

observed how ppl with cowpox did not develop small pox

louis pasteur

studied chicken cholera where he found that old, weakened culture could protect chickens from later infection

louis pasteur also helped establish…

priniciple of attenuation (alive, but weakened)

vaccination exposes the immune system to what

to an antigen without actually causing the disease

vaccination triggers what kind of response

adaptive immune response

success of a vaccination depends on what

specificity

memory

what are the types of vaccines

• whole pathogen vaccines

• subunit vaccines

• toxoid

• nucleic acid vaccines

live attenuated

• made w living microbe

• attenuated = weakened

• replicates but has ability to cause disease

• weakened form of target pathogen

ex. influenza, smallpox, MMR

pros and cons: live attenuated

pro:

• strong immune system response

• mimics natural infection

cons:

• not recommended to ppl w severely weakened IS

inactivated

• made w an inactivated pathogen (sometimes referred to as “killed)

• genome is damaged

• cannot replicate

ex. hepatitus A, influenza, polio

pros and cons: inactivated

pros:

• good immune system response but weaker than live attenuated

• safe for ppl w/ weakened immune system

cons:

• immunity less durable than w live attenuated

• req multiple doses or boosters

subunit

• contains only part of the pathogen rather than whole one

• subunit vaccines cannot replicate or cause infection

ex. novavax COVID-19, influenza

pros and cons: subunit

pros:

• well tolerated

• more stable than live attenuated

• safe for immunocompromised ppl

cons:

• produces weaker IS response than whole-pathogen vaccines

• requires multiple doses/boosters

toxoid

• bacteria causes diseases because they produce toxins

• toxoids target the toxin not the bacteria itself

• vaccine uses inactivated toxin so it doesn’t cause harm

ex. tetanus

pros and cons: toxoid

pros:

• relatively stable and safe

cons:

• may require multiple doses/boosters

nucleic acid vaccines

• deliver nucleic acids into the body and cells take it up and create proteins

• provides instructions for cells to make an antigen

types of nucleic acid vaccines

• viral vectors

• mRNA

• DNA

efficacy

how well vaccines work in a control clinical trial (compares how often the disease occurs in the vaccinated group w/how often it occurs in the placebo group)

effectiveness

a measure of how well vaccines work in the real world

herd immunity

indirect protection that occurs when enough ppl in a pop are immune when transmission is reduced

where can immunity come from

• vaccination

• current or prior infection

vaccine hesitancy

delay in acceptance or refusal of vaccines despite availability of vaccination services

(due because of safety concerns or misinformation, lack of trust, cultural or religious reasons, etc)

what is the only human disease to be eradicated

smallpox

what is a non-human disease that was also eradicated

rinderpest (a cattle disease)

infectious diseases

illness caused by pathogen, such as virus, bacterium, fungus, parasite, etc

communicable disease

an infectious disease that can be transmitted from an infected person, animal or reservoir to a susceptible host

direct

person to person transmission

indirect

transmission thru vehicle, environmental

elimination

absence of a sustained endemic transmission in a defined geographic area

control

reduction of disease to an acceptable level

exposure stage of communicable disease

may or may not result in infection

incubation stage of communicable disease

• infection is present but symptoms have not yet appeared

prodromal stage of communicable disease

• early, nonspecific symptoms may appear

• immune response are under way