Lab # 5: Cardiorespiratory Physiology Flashcards
9 points for taking pulse
- Carotid
- Apical
- Brachial
- Radial
- Temporal
- Politeal
- Femoral
- Posterior Tibial
- Pedal
Where is the carotid pulse taken?
Either side of neck: the carotid artery
Where is temporal pulse taken?
Where is brachial pulse taken?
At the elbow joint: brachial artery runs down upper portion of arm
(splits into two at the elbow)
Where is the radial pulse taken?
On the inside of the wrist (thumb side)
–> Radial artery is branched off from the brachial artery (its “sister” is the ulnar artery)
Where is the femoral pulse taken?
On the inside of the upper leg (femoral artery)
Where is the popliteal pulse taken?
Back of the knee (popliteal artery)
Where is the posterior tibial pulse taken?
On the outer side of the ankle (posterior tibial artery)
Where is the pedal pulse taken?
Top of the foot –> The plantar arch are a group of vessels that the pulse is measured from
–> Plantar arch branches off from the popliteal artery
What is the order of blood flow?
(starting from blood entering heart from circulation)
- Vena cavae
- Right atrium
- Right ventricle
- Pulmonary arteries
- Lungs
- Pulmonary veins
- Left atrium
- Left ventricle
- Aorta
- Aortic system
- Arterioles
- Capillaries
- Venules
- Veins
What is the blood pressure gradient through the circulatory system?
Blood pressure continuously drops from the point it is pumped out of the left ventricle
Left ventricle = Highest pressure
Right atrium = Lowest pressure
Arteries > arterioles > capillaries > venules > veins
Do all veins carry deoxygenated blood and do all arteries carry oxygenated blood?
NO: Generally yes but the pulmonary arteries/veins are an exception!
Pulmonary Arteries = Pump deoxygenated blood to the lungs
Pulmonary Veins = Pump oxygenated blood to the heart
What is an anastomoses?
Why is it important in circulation?
A connection or opening between two things that are normally diverging or branching
Vascular anastomosis = Connection between 2 blood vessels
–> Creates a backup pathway for blood flow if something blocks a blood vessel
Allows blood to reach tissues even if a primary blood vessel becomes blocked or damaged –> prevents tissue ischemia and maintains proper circulation throughout the body
What is/creates pulse?
The contraction of the left ventricle generates a pressure wave in the aorta that then propagates through the arteries (through the elastic expansion/recoil)
–> this pressure wave generates the pulse that we can feel where arteries are closer to the surface
What information can palpating a pulse provide?
Detects:
1) Frequency of the pressure wave (heart rate and rhythm)
2) Amplitude of the pressure wave (strength/quality of heart contraction)
What follows behind the pressure wave generated by the left ventricle contracting?
The blood!
–> Blood follows the pressure wave!
What is an example of a vascular anastomosis?
The radial and ulnar arteries both supply blood to the palmar arches
–> If one artery fails, the other is backup which allows blood flow to be maintained
What is the unit of measurement of wave frequency?
Hertz (Hz)
What is a transducer?
A machine that converts a biological/mechanical signal into an electrical signal
What was the input for the PowerLab Hardware?
The transducer OUTPUT (electrical signal)
What 3 processes did the PowerLab hardware do with the electrical signal input?
What was the final output?
- Amplification
- Filtering
- Sampling
–> = an electrical digital signal output!
What is amplification (in Power Lab)?
The process of increasing the amplitude of the wave being recorded
–> Allows for us to detect small functions and then increase its magnitude proportionally so that it is large enough for analysis
What is filtering ( in Power Lab)?
Suppresses unwanted components or features from a signal.
Usually means removing some frequencies to suppress interfering signals and to reduce background noise.
What is sampling of an analog signal?
The process of converting a continuous analog signal into a digital signal by taking measurements of its value at regular intervals in time
Essentially capturing “snapshots” of the signal at specific points to create a discrete representation of the original continuous data
What can be an issue with sampling of an analog signal?
ALIASING = sampling a signal at a frequency that produces a signal that does not represent the analog signal
What is this an example of?
Aliasing!–> The blue curve represents the sampled signal from the (green) analog signal
–> It is NOT similar to the analog signal = not an accurate representation of the actual signal
What is the Nyquist rate?
The minimum sampling rate needed to accurately represent a signal
–> Samples per unit of time = 2x the frequency of the analog signal!
What were the two major processes carried out by the PowerLab machinery?
- Signal conditioning (filtering and amplifying the analog input)
- analog to digital conversion (carried out by sampling!)
What is the dicrotic notch?
A little notch (slight dip) in the pressure wave that represents the closure of the aortic valve
What does the dicrotic notch signal?
The end of contraction (systole) and the beginning of relaxation (diastole)
What does the highest peak denote?
The MAX systolic pressure!
–> Max pressure reached during contraction
What does 1 pulse wave denote?
One heart beat!
Amplitude of pulse wave =
Force of contraction
Calculation of heart rate from pulse wave graph
(# of pulse waves / period of seconds) = Beats per second
–> BPS * 60s/min = BPM
What are the valves of the heart and where do they lie?
1)** Right AV Valve (Tricuspid valve)**= between R atrium and R ventricle
2) Pulmonary semilunar valve = between R ventricle and pulmonary artery
3)Left AV Valve (biscupid / mitral valve) = Between L atrium and L ventricle
4) Aortic semilunar valve = between L ventricle and aorta
Systole vs Diastole
Systole = Ventricle contractile Phase (release blood)
Diastole = Ventricle relaxation Phase (fill with blood)
Arteries act as…
Pressure reservoirs
Arterioles are major sites of…
RESTRICTION AND CONTROL
–> Smooth muscle walls are Innervated by sympathetic nervous system and can constrict/dilate accordingly = adjustments to blood flow
What controls the amount of blood that flows into capillaries?
Why must blood flow be restricted before getting to the capillaries?
- Pre-capillary sphincters
- Arterioles
–> Flow must be somewhat restricted to make sure the blood to moves slow enough through the capillaries to allow sufficient time for diffusion
What components allow for movement through veins?
AND What prevents backflow in veins?
- Muscle contractions (our physical movements)
- Valves
–> These two are needed as veins are very low pressure so there is less of a driving force for blood flow
Valves prevent backflow!
Blood Pressure Calculation
Diastolic Pressure / (1/3 Systolic Pressure)
–> We take 1/3 of SP because in a given heart cycle, more time is spent in diastole than systole
Pulse Pressure Calculation
= Systolic Pressure - Diastolic Pressure
–> Essentially showing how much your arteries expand and contract with each heartbeat
What are the alveoli?
Tiny, thin layered sacs wheres gas exchange occurs! (highly vascularized)
How does gas exchange occur at the alveoli?
CO2 and O2 diffuse down their partial pressure gradients (PCO2 and PO2)
What muscles contribute to quiet breathing? And HOW?
-
Diaphragm
–> Contracts (goes flat) during inspiration (expands chest cavity)
–> Relaxes (pushes back up) during exhalation (decreases chest cavity volume) -
Intercostal muscles
–> Contract during inspiration to push out ribs (expand chest cavity)
–> Relax during exhalation allowing ribs to come back in
What additional muscles contribute to forceful breathing? And HOW?
-
Sternocleidomastoid Muscles
–> Raise the sternum to expand chest cavity -
Abdominal Muscles
–> Contraction = increased pressure in abdomen = pushes diaphragm further up during exhalation (more forceful exhale)
How is breathing rate controlled?
- Voluntarily –> Muscles for breathing are innervated by CNS neurons that we control
- Involuntarily –> Respiratory center (MEDULLA)
What is the major respiratory center?
How does it determine whether to increase/decrease breathing rate?
Medulla of the brain
–> Has chemoreceptors sensitive to CSF pH (and therefore blood pH) which is an indicator of CO2 content
–> Because CO2 = carbonic acid in circulation which lowers the pH
