Lecture 3: CV & R Anatomy & Physiology Flashcards
arteries
carry blood away from the heart
veins
carry blood to the heart
capillaries
site of exchange of substances
blood
contains hemoglobin
Pathway
arteries to arterioles to capillaries to venules to medium veins to large veins
Electrical Conduction System of the Heart
-SA node- heart’s pacemaker, works on auto-rhythmicity, initiates impulses spread
Inernodal pathways
AV Node- continues electrical impulses at the AV bundle to the bundle branches
AV bundle-
Purkinje fibres
Right bundle branch
Left bundle branch
Slight delay between atrial and ventricle contraction comes from
AV node
SA node to
atrial contraction
AV node to
ventricular contraction
ECG
Electrocardiogram
-graphic representation of the electrical activity in the heart
Normal Heartbeat
range=60 to 100bpm
Fast Heartbeat
tachycardia
-over 100bpm
Slow Heartbeat
bradycardia
-less than 60bpm
Irregular heartbeat
Arrhythmia
-number of different causes
P-wave
activation/depolarization of the atria= contraction o the atria that pushes blood into the ventricles
QRS comples
ventricular contraction/depolarization
T-wave
Re-polarization of the ventricles
Difference between P-wave and QRS complex
- ventricular contraction is much more forceful a contraction
- QRS complex hides the re-polarization of the atria
- re-polarize atria at the same time
BP is higher..
in systemic circulation
-aorta, large arteries, small arteries arterioles
BP is lower
in systemic circulation
-capillaries, venules, small veins, large veins, venae cavae
in pulmonary circulation
-pulmonary arteries, arterioles, capillaries, venules, pulmonary veins
Respiratory System
responsible for exchange of O2 and CO2 between air and blood
COnducting portion
nose to bronchioles
Respiratory Portion
actual gas exchange between bronchioles and alveoli
Contraction and Expansion of Thoracic Cage
- high pressure to low pressure gradient
- must elevate rib cage
- contraction of intercostals and diaphragm
Accessory Muscles
Inspiration- sternocleido mastoid, serratus anterior, pec minor, scalenes (increase chest cavity size)
Expiration- transverse thoracis, obliques, rectus abdominus (compress abdominal cavity)
Acute CV response to Resistance Training
^ CO, SV, HR, O2 uptake, SBP, BF to active muscles
-largely dependent on intensity and volume of exercise, muscle involvement, rest period length
When is SBP highest?
Sticking point
accluding blood flow
-valsalva manoeuvre
When are CO, SV, & HR highest?
at the end of exercise
Reactive hyperemia
^ BF after exercise is finished
Chronic CV responses to RT
-Resting HR, no change or decrease
(sedentary more change than fit person)
-Resting BP no change or decrease slightly
(sedentary more change than fit person)
-SV increases in absolute magnitude
-Cholesterol & LDLs may not change or slightly decrease while HDL’s may increase
Chronic CV Responses to RT
not effective in improving VO2 max
- no change in capillary density
- no O2 extraction improvement
- very high blood lactate concentrations
- low intensity high volume training may increase capillarization and improve O2 extraction
What type of RT may improve O2 extraction
cross fit plyos circuit training aerobic endurance training
Chronic Ventilatory Response to RT
- unaffected or only moderately improved by anaerobic training
- tidal volume increases
- breathing frequency increase
- improved ventilation efficiency (how much O2 we get out of each breath)
Acute CV response to Aerobic Training
^CO, SV, HR, SBP, BF to active muscles, decrease DBP
Stroke Volume
regulated by teh end diastolic volume and action of catechoamines (epi, norepi, dopamine, ^BP&HR, fight or flight response)
-amount of blood available to pump @end of diastole
Frank Starling Mechanism
force of contraction is a function of the length of the fibres of the muscle wall
-more blood returning to heart=more stretching of wall=^contraction force
What muscles are suppressed during exercise?
- digestive & immune system
- blood flow to active muscles is increased by dilation of local arterioles, but decreased to other organ system via constriction of arterioles
Acute Respiratory Response to Aerobic Training
^O2 delivery to tissues, CO2 return to lungs, minute ventilation (frequency and tidal volume) and diffusion capacities
Breathing rate at rest
12-15 breaths per minute
Breathing rate during exercise
35-45 breaths/min
Chronic Responses to Aerobic Training
- ^max CO & VO2max
- slower resting and submax HR
- increased capillarization
- improved ventilation efficiency
- increased O2 extraction
- OBLA occurring at higher percentage of aerobic capacity
OBLA
Onset of blood lactate accumulation
- ^ during ^duration and intensity of aerobic metabolism
- more lactate being produced than what is being removed
Altitude Acute Physiological Changes
-hyperventilation
-increased HR
-increased CO
@ >1200m
Acclimatization effects
- rates return to normal
- ^RBC production, ^ Hb
- ^ O2 diffusing capacity
- ^capillarization
- pH balance
- acclimatization is VERY important 10-14 days
Hyperoxic Breathing
breathing O2 rich gas mixtures during rest or following exercise
- ^amount of O2 carried by blood
- likely more helpful for individuals at higher altitudes or those with respiratory illnesses/disorders
- help ^SpO2% @ sea level SpO2 is already high
Blood Doping- how to
artificially increases RBC mass
- infusion of own RBC
- infusion of someone else’s RBC
- EO erythropoetin (stimulates RBC production)
Effects of Blood doping
- Max O2 uptake increases
- improved altitude performance, thermoregulation (heat and cold stress) due to more O2 carrying capacity
Risks of Blood Doping
flu like symptoms ^BP Stroke heart attack thrombosis pulmonary embolism it is also ILLEGAL
