Physiology + Homeostasis Flashcards
Normal Pulse (heart rate)
Adult normal resting HR 60-100 beats/min
Blood pressure - not really considered a vital sign
The force of the blood pushing against the artery walls during contraction and relaxation of the heart
mmHg
HIGHER NUMBER = SYSTOLIC
- when heart contracts
LOWER NUMBER = DIASTOLIC
- artery pressure when heart in diastole, when ventricles are relaxing and refilling
USE SPHYGMOMANOMETER at the brachial artery of the arm
NORMAL RANGE - 120/80
HYPERTENSION
- fear, stress, excitement, kidney disease e.g. stenosis(narrowing) of renal artery
- diseases arising: atherosclerosis, heart failure, cerebral haemorrhae, kidney failure
- DRUGS: thiazide diuretics / calcium-channel blockers / ACE inhibitors / beta blockers
HYPOTENSION
- lowest during sleep
- pregnancy, endocrine problems
- nutritional deficiency
ELEVATED - 120-129/ less than 80
STAGE 1: 130-139/ 80-89
STAGE 2: 140 and hugher / 90 and higher
https://www.gla.ac.uk/media/Media_678204_smxx.pdf
Respiratory Rate - rate of breathing
adult normal resting RR 12-20 breaths/min
- count how many times the chest rises
increases with fever + illness + asthma + anxiety + pneumonia + congestive heart failure
Dyspnoea – difficult, laboured breathing
* Tachypnoea – rapid breathing
* Apnoea – temporary absence of breathing
* Kussmaul’s – increased rate and depth, with long
grunting expirations – lobar pneumonia/DKA
* Stridor – a harsh, high-pitched noise on inspiration –
obstruction
Oxygen Saturation
normal >96%
nail polish removed – absorbs light and gives false reading
oximeters use light absorptice charactersitics of haemoglobin and the pulsating nature of blood flow in the arteries to measure the level of oxygen in the body
Consciousness
ACVPU (alert, confusion, verbal, pain, unresponsive)
Capillary refill time
normal <2 seconds
phrenic nerve innervates
diaphragm + intercostal muscles
respiratory centre of the brain
pons + medulla oblongata
Systolic arterial Blood pressure
Oressure exerted by the blood on the walls of the aorta when the heart contracts
Blood pressure
outwards (hydrostatic) pressure exerted by the blood on blood vessel walls —– in clinical practice we often measure the systemic arterial blood pressure and express it as SYSTOLIC + DIASTOLIC blood pressures
systemic systolic arterial blood pressure + NORMAL RANGE
the pressure exerted by the blood on the walls of the aorta and systemic arteries WHEN THE HEART CONTRACTS
90-120 mmHg
systemic Diastolic arterial blood pressure + NORMAL RANGE
the pressure exerted by the blood on the walls of the aorta and systemic arteries WHEN THE HEART RELAXES
60-80 mmHg
Hypertension + RANGE
clinical blood pressure of 140/90 mmHg or higher ++ daytime average of 135/85 mmHg or higher
Pulse pressure + NORAML RANGE
difference btween systolic + diastolic blood pressures
30-50 mmHg
Mean arterial blood pressure (MAP) + FORMULA + range
the average arterial blood pressure during a single cardiac cycle, which involves contraction and relaxation of the heart
MAP = ((2 x diastolic) + systolic) / 3
or
MAP= DBP + 1/3 pulse pressure
70-105 mmHg
at least 60mmHg needed to perfuse vital organ e.g. brain, heart, kidneys
Temperature
taken either
- axillary ( tend to be lower than thsoe temp taken by mouth)
- by ear (ear drum temp, reflects body’s core temp - internal organs)
- skin on forehead
pulse rate = measure of heart rate
indicates
1. heart rhythm
2. strength of pulse
NORAMAL RANGE = 60-100 bpm
-> Females ages 12 and older, in general, tend to have faster heart rates than do males.
-> Athletes, such as runners, who do a lot of cardiovascular conditioning, may have heart rates near 40 beats per minute and experience no problems
SYMPTOMS for hypertension
dizziness / lightheadedness
lack of concentration
blurred vision
fatigue
symptoms for hypotension
headache
short of breath
chest pain
tachycardia
Normal resting heart rate
70 bpm
60-100 bpm
intrinsic heart rate
100 bpm
vagus nerve (parasympathetic supply to the heart) exerts a continuous influence on the SA node under resting conditions, slowing down the intrinsic heart rate from 100 to produce a normal resting heart rate of 70
Ach + HEART (parasympathetic) + vagus nerve supplying BOTH the SA node and AV node —–> increasing AV NODAL DELAY + slowing down heart rate
acts on which type of receptors?
impact on
-> pacemaker potential slope
-> what is it called
muscarinic M2 Receptors (GPCR)
-> slope of pacemaker potential decreases
-> negative chronotropic effect
AFFECTING THE RATE
Noradernaline + sympathetic nerves on the heart supplying
- yes, SA and AV nodes
- ALSO the myocardium
- affecting 1+2
- acting on receptors x
- affecting RATE + FORCE of contraction
- increases rate of firing from SA node + decreases AV nodal delay
- increases force of contraction - b1 adrenoceptors
slope of pacemaker potential increases
- positive chronotropic effect, speeding HR
2 ways of calculating MAP (actually 3)
Normal range
- (2x diastolic) + systolic /all divided by 3
- Diastolic + 1/3 difference between systolic and distolic (pulse pressure)
- CO x systemic vascular resistance (stroke volume x heart rate x systemic vascular resistance) — systemic vascular resistance = total peripheral resistance
70-105 mm Hg
Cardiac output
Volume of blood pumped by EACH VENTRICLE of the heart PER MINUTE
= SV x HR
Stroke Volume (SV)
Volume of blood pumped by EACH VENTRICLE of the heart PER HEART BEAT
Systolic volume calculation
End diastolic volume (maximum filling of the ventricles) - end systolic volume (blood remaining in ventricles after contraction)
End diastolic determines cardiac preload (diastolic length/stretch of myocardial fibers)
End diastolic volume is determined by the venous return
Afterload
Resistance into which the heart is pumping
systemic vascular resistance
sum of resistance of all vasculature in the systemic cirulation
= TOTAL PERIPHERAL RESISTANCE (TPR)
Bradychardia numbers
Resting heart rate less than 60 bpm
Tachychardia numbers
Restin heart rate more than 100 bpmo
Normal resting heart rate
60-100 bpm
total duration of 1 cardiac cycle
duration of diastole
duration of systole
0.8 sec
0.5 sec
0.3 sec
palpitations
the feeling that your heart is beating too quickly or not regularly: He ended up in hospital with heart palpitations.
atrial fibrillation
a heart condition that causes an irregular and often abnormally fast heart rate.
Giant cell arthrtitis
temporal arteritis, is an inflammatory disease affecting the large blood vessels of the scalp, neck and arms. Inflammation causes a narrowing or blockage of the blood vessels, which interrupts blood flow.
Total body fluids equation
2/3 intracellular + 1/3 extracellular fluid (ECF)
ECF equation (extracellular fluid volume) ECFV
- -> what affects ECFV?
- -> what regulates ECFV?
Plasma Volume (PV) + Interstitial Fluid Volume (IFV), liquis bathing the cells
if plasma voluem falls, compenstatory mechanisms shifts fluid from the interstitical compartment to the plasma compartment
- -> water excess/deficit
-> Na+ excess/deficit
(water and salt balance) - -> RAAS, rening angiotensin aldosterone system
NPs, natriuretic peptides
ADH, antidiuretic Hormone (arginin vasopressin)
Regularly irreguar pulse
Ireegularly irregular pulse
normal arterial blood pressure
<140 systolic
<90 diastolic
Postural (Orthostatic) Hypotension positive result
indicated by a drop within 3 minutes of standing from lying position
- systolic blood pressure of at least 20 mmHg ( with/without symptoms)
- diastolic blood pressure of at least 10 mmHg (with symptoms)
symptoms for Postural (Orthostatic) Hypotension
may include thsoe of cerebral hypoperfusion e.g.
- lightheadedness
- dizziness
- blurred vision
- faintness
- falls
risk factors for Postural (Orthostatic) Hypotension
- age
- medications
- diseases e.g. diabetes/parkinsosns
- reduced intravascular volume (not taking enough fluids)
- prolonged bed rest
Postural (Orthostatic) Hypotension
failrue of baroreceptor resposnes to gravitaional shifts in blood, when moving from horizontal to vertical position
important to moment-to-moment regualtion of arterial blood pressure inclduing prevention of postural changes
