-
Mitral valve prolapse
when one valve doesn't close all the way
-
pathway of blood through the heart
vena cava- right atrium- tricuspid valve- right ventricle- pulmonary semilunar valve- pulmonary arteries- lungs- pulmonary veins- left atrium- bicuspid (mitral valve)- left ventricle- aorta
-
microscopic structure of the heart
striated and interconnected disks.
-
What is the inherent rythym of the SA node compared to the bottom of the heart?
60 bpm vs 30 bpm
-
What is the typical electrical pathway of the heart?
SA node- AV node- bundle of HIS- purkinje fibers
-
What arteries supply blood to the heart?
- Left coronary:
- -circumflex: LA/ lateral wall of left ventricle
- -anterior descending: ventricular septum/ anterior surface of LV
- Right coronary: RA/inferior wall of RV
-
CAD
coronary artery disease
-
ectopic beat
when beat doesn't originate from SA node
-
Systole (what it is and how long)
- time during contraction
- 1st sound heard, 1/3 time
-
diastole (what it is and how long)
- time between contractions, 2/3 time
- more consistent
-
ECG
- electrocardiogram
- records QRS waves as a function of time
-
-
-
on an ECG, how many large boxes make up one second?
5
-
how many large boxes on an ECG make up 1 mV?
2
-
P wave
atrial depolarization
-
PR interval
- beginning of P to beginning of QRS
- time for stimulus to go SA throug AV junction
-
QRS
ventricular depolarization and atrial repolarization
-
T wave
ventricular repolarization
-
U wave
- rarely seen
- final component of ventricular repolarization
-
RR interval
time for one HR cycle
-
How many leads are in a typical ECG?
- 12
- type I: frontal, horizontal, bipolar, positive =>
- type II: frontal, diagonal neg slope, bipolar, positive at bottom
- type III: frontal, diagonal pos slope, bipolar, positive at bottom
- AVr: frontal, opposite to type II, unipolar, positive at top
- AVl: frontal, opposite to type III, unipolar, positive at top
- AVf: frontal, perpindicular to type I, positive at bottom
- V1: transverse, right of sternum
- V2: left of sternum
- V3: between V2 and V4
- V4: mid clavicular
- V5: left of v4
- V6: left of V5
-
cardiac output (Q)
amount of blood ejected by the heart/min
-
Q at rest
5-6 L/min for both trained and untrained
-
Max Q
- >30 L/min trained
- 20-25 L/min untrained
- 5-6 fold from rest
-
do males or females have higher max Q?
males, but they also have lower submaximal VO2
-
what equation is used to determine Q
Q (L/min) = SV (ml/beat) * HR (b/min)
-
What is stroke volume?
- ml of blood ejected per beat.
- increased from rest to moderate exercise in non-athletes, and then plateaus
- changes with posture
-
Is your stroke volume higher lying down or sitting?
- lying down
- Q is higher as well lying down, HR is lower lying down
-
Which of the three increases in a linear fashion with increased intensity?
Q, HR, SV
Q and HR
-
what is the RHR in a trained and untrained individual?
- trained: 40
- untrained: 70-90
-
Since HR lowers with training, what typically happens with SV?
increases
-
What happens to the Q, HR, and SV as you exercise past 30 min?
- Q is maintained
- SV gradually falls
- HR gradually rises
-
what are the three ways venous blood returns to the heart?
- muscle pump
- respiratory pump
- venoconstriction
-
at rest and exercise, how much blood goes to the muscles?
- rest: 20%
- max exercise: 80%
-
Why does the skin decrease in % Q distribution between light and moderate exercise?
Because the body starts to sweat
-
As exercise increases, what happens to the amount of blood to the brain?
nothing, the percent distribution is lowered, but the same amount is supplied there.
-
Blood flow distribution is a result of what?
- autoregulation: local
- -O2 demand
- -reflex vasodilation to working muscles
- Extrinsic Neural Control: not local
- -sympathetic vasoconstriction
- -sympathectic stimulation in heart causes vasodilation
-
Why does blood flow increase in the heart during exercise?
to increase oxygen consumption
-
What is the equation to determine VO2?
- VO2 = SV * HR * a-vO2 diff
- VO2 = delivery * extraction
-
in a person with hypertension (HBP), what drop can someone expect during exercise in mmHg?
- 8-10 mmHg
- moderate exercise is more effective than vigorous exercise
-
what 3 functions concerning blood are important to exercise physiology?
- transportation
- temperature regulation
- acid-base (pH) balance
-
psuedo anemia
seems when there's anemia, but just more plasma
-
composition of blood
- 55-60% plasma
- 40-45% formed elements
-
how can you increase blood viscosity and what is the benefit?
increase hematocrit and it increases O2 transportation
-
What is plasma made of?
- 90% H2O
- 7% plasma proteins
- 3% other
-
What are formed elements composed of?
- >99% red blood cells
- <1% white blood cells and platelets
-
How do you measure blood O2 content and what are the values at rest and exercise?
- a-vO2 diff = arteriol - venous
- rest: 6 mL
- exercise: 16-18 mL
-
What happens to Plasma Volume (PV) with exercise?
- decreases because of pressure pushing it out of capillaries, and sweating and breathing causes loss of fluid.
- can lose up to 10-20%
- decrease impairs performance
-
hemoconcentration:
when PV decreases, O2 carrying capacity increases
|
|