Final Part 2 Flashcards
Lymphatics
importance in exercise
-minimizes fluid loss in interstitial tissue and maintain plasma volume
Blood Volume
55% Plasma
45% Erythrocytes
<1% Leukocytes
How much of Blood Volume is Plasma?
55-60%
Over 90% of Plasma is water
with dissolved proteins (7%) and nutrients, electrolytes, hormones, antibodies, and wastes (3%)
What happens to plasma volume during exercise
exercise in heat can decrease plasma volume by 10-20%
What happens to PV as a training adaptation?
Endurance training and/or heat acclimatization can increase plasma volume by ~10%
Hematocrit
% of total blood volume that consists of formed elements or RBCs (~40-45)
Half Life of Platelets
10 days
4 stages of clot formation
- Vascular spasms
- Formation of platelet plug
- Formation of Blood Clot
- Growth of fibrous tissue into blood clot to close hole and vessel and retraction of clot
and size of RBCs
- outnumber WBCs 1000:1 and much larger
- 5 million RBC/mm3 blood
Erythropoiesis
RBCs produced exclusively in bone marrow via erythropoiesis
Structure and Carrying Capacity of Hemoglobin
1 Globin molecule and 4 heme groups
- each heme group contains 1 Fe++, which can bind 1 O2 molecule
- oxyhemoglobin
- 1 RBC has ~250 million Hemoglobin. 1 RBC can carry~ 1 billion O2 molecules
- Each gram of Hemoglobin can carry 1.33 ml O2
Causes of Polythemia
training and altitude
Causes of Anemia
- hemorrhage
- low iron intake
- increase RBC destruction triggered by rigors of increased circulation
- increase body temperature-“foot strike hemolysis”
Blood viscosity-training adaptation
typically with aerobic training, RBCs increase but with a concomitant and slightly greater increase in Plasma Volume
RESULT: slightly low hematocrit with an high RBC count. Allows optimal facilitation of O2 transport because low viscosity allows freer flow and less strain on vessel walls, yet you have more RBCs for O2 transport
Resting HR
Normal: 60-100 bpm
Tachycardia: >100 bpm, commonly observed in diseased populations
Bradycardia: <60 bpm, most common in aerobically trained, but may occur as result of certain injuries/ diseases
Aerobic training decrease RHR, mostly due to increase PNS stimulation and decrease SNS stimulation to heart
Pre-Exercise
Anticipatory Response: changes in physiological parameters in response to anticipation of upcoming activity
-decrease in PNS stimulation and increase SNS stimulation and increase E/NE release to increase both HR and contractive force
don’t take pre-exercise HR as true as RHR
Exercise
increasing intensity and steady state
HRmax=220-age
Influence of Age on Exercise HR
younger highly aerobically trained persons exhibit lower HR max than age-predicted value, but older highly aerobically trained persons exhibit higher HRmax than age-predicted value
HR max. Not affected much by training. If anything, decreases with training
What factors affect SV?
deccrease TPVR (due to vasodilation), mainly during low body exercise, increase SV
What happens to SV during exercise?
SV increases from rest up to 50% VO2 Max, then plateaus
What happens to SV as an adaptation to training?
SV increases from rest up to maximal activity
Recumbent vs upright (SV)
venous return not resisted by gravity in horizontal position, so SV in recumbent position is much higher than in upright position
Cardiac Output
- Q increases in direct linear proportion to exercise intensity
- up to 40-60% VO2max, increase in Q due to increase in both HR and SV
- at higher exercise intensities, increase in Q mostly from HR, since SV has plateaued or is only slowly increasing
BP depends on
diameter of vessel
volume of blood flowing through vessel per unit time
Arm vs. Leg
Legs: Large muscles mass at work means large decrease in TPVR as vessels in legs dilate
Arms: smaller muscle mass at work, less decrease in TPVR
-Thus, for same relative workload (same Q), arm exercise results in larger increase in BP than leg exercise
RPP
HR * SBP
MAP
TPVR * Q
LVH Dimensions
Left Ventricular Hypertrophy (LVH)
- due to pathological conditions OR
- normal adaptation to training- “athletes heart”
- both endurance and resistance training cause LVH
- –expressed in terms of relative body mass. endurance athletes have greater LVH than resistance athletes
- endurance training also causes an increase in LV dimensions (size of chamber)
- —due to increase PV
Summary of CV Adaptations
- LVH
- increase LV dimensions
- increase PV (~10%)
- increase RBC count
- slightly decrease hematocrit
- decrease RHR
- decrease exercise HR for a given sub maximal intensity
- decrease HR recovery period
- decrease HRmax
- increase resting SV
- incerase exercise DV for a given sub maximal intensity
- increase SV max
- increase Q max
- decrease Q for a given sub maximal intensity
- decrease resting BP
- decrease exercise BP for a given sub maximal intensity
- detraining quickly reverses adaptations
