Transcript Recap on the cardiovascular system and its response to exercise

Recap on the cardiovascular
system and its response to
exercise
The function of the circulatory
system


The circulatory system has three major function:
Transport


Body temperature control


Moving things around the body in the blood stream such as
oxygen and nutrients like glucose.
Thermoregulation, moving blood near the skin cools down the
body. That’s why you look redder when you exercise heavily.
Protection

Moving anti-bodies around the body fighting diseases and clotting
cuts.
The structure of the heart

Oxygenated blood =
more oxygen.



Found in arteries and
arterioles
Normally red in colour
Deoxygenated blood =
no oxygen


Found in the veins and
venules
Normally blue in colour
The cardiovascular system: HEART


Structure of the Heart
Surrounded by sac known as the pericardium,
which prevents friction as the heart beats.
Heart wall is made of:
–
–
–

Epicardium (outer layer)
Myocardium (strong middle layer)
Endocardium (inner layer)
Right separated from left by the Septum
Strokes of the heart



Heart rate = how many times your heart beats
(normally in one minute, BPM)
Stroke volume = blood pumped per beat.
Cardiac output = blood pumped per minute
–
Cardiac output = Stroke volume x Heart rate
Task




Calculate a persons cardiac output when
stroke volume = 10ml
Heart rate = 78 BPM
Cardiac output = ?
Circuits of the body


There are two circuits of the body you need to
know:
Systemic


Carries blood around the body via the transport system
supplying the major organs and muscles with blood.
Pulmonary

Consists of the heart and lungs, deoxygenated from the
heart to the lungs to be oxygenated. The oxygenated blood
then goes back to the heart to be pumped around the body.
Blood Flow Through the Heart
1.
2.
3.
4.
5.
Vena Cava – Superior/Inferior
Right Atrium
Tricuspid Valve
Right ventricle
Pulmonary Artery
LUNGS
Blood Flow Through the Heart
6.
7.
8.
9.
10.
Pulmonary veins
Left Atrium
Bicuspid/Mitral/Atrioventricular valve
Left Ventricle
Aorta
MAJOR ORGANS
Control of the Heart



Initial Stimulus originates in the Sinoatrial node
(SA node)
Pacemaker determines heart rate
Wave of excitation across both atria causes
them to contract
Control of the Heart




Sinoventricular node (SV node)
Both atria and both ventricles contract at the
same time
Systole-contraction of heart
Diastole-Relaxation/filling of the heart
Blood vessels




There are three types of blood vessels you
need to know:
Arteries
Veins
Capillaries
Types of Blood Vessels
Arteriole
Artery
Capillary
Vein
Venuole
Arteries



Carry oxygenated blood
away from the heart (the
pulmonary artery brings
blood to the heart!!)
They have thick strong
elastic walls.
Small arteries are called
arterioles.
Veins




Carry deoxygenated blood
back to the heart (the
pulmonary vein carries blood
away from the heart!!).
The veins have thinner walls
as the blood pressure is
lower.
Veins have valves that keep
blood flowing in the right
direction.
Small veins are called
venules.
Capillaries



Carry digested foods
and oxygen directly to
the tissue.
Take away waste
products of the body.
Very small and vary in
size.
How it works!!







Heart
Arteries
Arterioles
Capillaries
Venules
Veins
Heart
Gas exchange
Blood flow through the heart
Warm-up questions





How many circuits are there in the circulatory
system?
What type of blood is carried back to the heart?
Which type of blood vessel carries blood away
from the heart?
Which type of blood cell carries oxygen?
Which type of blood cell fights diseases?
Changes in heart rate during
exercise



There is a anticipatory rise
due to hormonal action.
Then there is a sharp rise due
to stimuli and hormonal
response.
The heart rate steadies off
during constant maximal
exercise (heart rate max)
Changes in the respiratory



Tidal volume increases.
Residual volume
increases.
Breathing rate and the
volume of oxygen
consumed is increased
due to the onset of lactic
acid.
Adaptations to the body over long
periods of exercise.



Increase in the number
of capillaries.
Increase in the efficiency
of gaseous exchange.
Lower resting heart rate.