Physiology Flashcards
What is homeostasis
stable internal environment, essential for normal cell and body function
what does a disruption in homeostasis do
disease or death
what is the intrinsic system (generally)
local control in cell
what is the extrinsic system (generally)
regulatory mechanisms outside organ by nervous action or endocrine glands
what is positive feedback
amplifies initial change
what is negative feedback
main homeostatic control
it opposes the initial change by using a sensor, control centre and effector
what is feedforward
response made in anticipation to change
Name the vital signs
Heart rate oxygen saturation blood pressure capillary refill rate respiratory rate consciousness temperature
What is NEWS
National Early Warning System - chart used to record vitals
True/false - values on NEWS overrides clinical concern
FALSE - clinical concern and judgement will always override the news score
What else do you do besides vitals
Ask and observe how the patent is feeling
what is the sound heard in blood pressure
Korotkoff sounds
which korotkoff sound measures BP
the first sound meaurtes systolic pressure and the last muffled sound followed by an absence of sound measures the diastolic
What is blood pressure
hydrostatic pressure exerted by blood on blood vessel walls
Define systolic and diastolic
Systolic - pressure exerted by blood on blood vessel walls when heart contracts
Diastolic - pressure exerted by blood on blood vessel walls when heart relaxes
What is pulse pressure
difference between systolic and diastolic blood pressure
What is MAP
average arterial blood pressure during 1 cardiac cycle
How is MAP measured
[(2xDiastolic) + Systolic]/3
DBP + 1/3 pulse pressure
What is the minimum map to perfuse brain heart and kidneys?
what is the average MAP
60 mmHg
70-105 mmHg
what are baroreceptors and where are they located?
stretch sensitive receptors that depending on stretch cause impulses to be sent to NTS more or less
located on carotid artery and aorta
How is MAP calculated?
HR x SV x SVR
What is systemic vascular resistance
sum of resistance across all circulatory system vasculature
what neurotransmitter increases heart rate
noradrenaline
what neurotransmitter decreases heart rate
acetylcholine
how is stroke volume increased
sympathetic nerves further stimulate ventricular myocardium which causes it to increase contraction force
hormones regulate MAP in the _____
long term
what is normal core body temp
around 37.8C
what is normothermia
normal core body temp - optimum for cell metabolism and function
what ways can temperature be measured
Rectal (36.7-37.5) - most accurate
Tympanic (35.5-37.5) - most common
Oral - unreliable
what is basal metabolic rate
minimum energy required to sustain body function - hormonally influenced
what ways can heat be produced?
oxidation of food
movement of skeletal muscles - shivering and moving
Methods of heat exchange?
Conduction
Convection
Radiation
Evaporation
what detects heat gain or loss
central and peripheral thermoceptors