Zusammenfassung der Ressource
Vasomotor Control
Centre (VCC)
- Located in the Medulla Oblongata in the brain
regulates the redistibution of cardiac output by
controlling the Vascular Shunt Mechanism
- Chemo and
baroreceptors
stimulate
VCC
- VCC increases or decreases stimulation via the
sympathetic nervous system to either vasodilate
(widen) or vasoconstrict (narrow) the precapillary
sphincters and arterioles supplying muscles and
organs (Vascular Shunt Mechanism)
- Vasomotor Control (VMC)
Vascular Shunt Mechanism
- Organs
- Increased Sympathetic
Stimulation
- Vasoconstriction of arterioles
and precapillary sphincters
- Decreased blood flow to capillaries
or non essential organs
- Muscles
- Decreases sympathetic
stimulation
- Vasodilation of arterioles
and precapillary sphincters
- Increased blood flow to
capillaries or working muscles
- O2 and CO2 are
transported via the blood
- O2
- 97% in haemoglobin, in
RBCs as
oxyhaemoglobin (Hb02)
- 3% within blood plasm
- CO2
- 70% combined with
water in red blood
cells as carbonic acid
- 23% in haemoblobin as
carbaminohaemoglobin
- 7% dissolved in plasm
- O2/CO2 - Transport and performance
- Efficient O2 and CO2 transport aids participation
in physical activity in that it is:
- Prolongs
duration of
anaerobic and
aerobic activity
- Delays anaerobic
threshold, which increases
the possible intensity/work
rate for the activity
- Speeds up
recovery
during and
after exercise
- Smoking Impact on O2 transportation
- Tobacco smoke contains carbon
monoxide (CO). Haemoglobin (Hb) withing
bred blood cells combines with CO in
preference to O2. This reduces HbO2
association in the lungs and thus reduces
maximal O2 uptake. Blood O2
transport/supply to the working muscles
and lactate threshold are decreased
- Net Effect
- Decreases optimal performance
especially in aerobic activities.