Transcript Year 11 Physiological Responses to Exercise - PE

Year 11
Achievement Standard 1.2
The Respiratory System
 The lungs, mouth, throat and nose make up the respiratory
system
 One of the major functions of the respiratory system is to bring
oxygen into the body and remove carbon dioxide.
 Oxygen is inhaled down through the bronchi and into the
alveoli of the lungs. From there it is transferred into the blood.
Carbon dioxide and other wastes (metabolites) are transferred
from the blood through the lungs and out of the body.
 When exercising, breathing occurs faster and more deeply,
allowing more oxygen to be inhaled and transferred to the blood
and muscles where the oxygen is used to help fuel exercise.
Trachea
(wind pipe)
Alveoli
Bronchioles
Intercostal
muscles
Figure 1: The Respiratory System
Ribs
Bronchus
Lung
Diaphragm
The Heart
 The heart is a muscle that contains four chambers. The upper
two chambers are called atria and the bottom two are called
ventricles.
 The heart’s job is to pump blood around the body. It does this by
squeezing the blood out of the ventricles. The blood leaves the
heart through a large vessel called the aorta; from there it goes
out to the muscles and organs where they take oxygen out of the
blood. The blood then returns to the heart and lungs to be reoxygenated
 During exercise, muscles require more oxygen. This means that
during exercise the heart has to work faster by beating more
times in a minute and harder by pumping more blood out with
each beat.
Aorta
Vena cavae
Semilunar valves
Pulmonary artery
Pulmonary veins
Left atrium
Right atrium
Bicuspid valve
Tricuspid valve
Right ventricle
Septum
(dividing wall)
Figure 2: The Human Heart
Left ventricle
Cardiac muscle
The Circulatory System
 In effect there are two different circulations of blood
within the body:
 Pulmonary circulation: circulation of blood between
the heart and lungs – ensures deoxygenated blood
from the body is ‘refuelled’ with oxygen from the
lungs.
 Systemic circulation: circulation of blood between
the heart and body – ensures ‘refuelled’ blood is
distributed to the muscles of the body.
The Circulatory System – Part II
 There are three main types of blood vessel in the human body:
 Arteries – thick-walled vessels that carry blood away from the
heart at a high pressure.
 Capillaries – thin-walled vessels that oxygen and nutrients can
move into from cells.
 Veins – thin-walled vessels which carry blood towards the heart
at low pressure after the oxygen and other materials have been
taken out. This series of vessels relies on gravity and contracting
muscles to transport the blood. Valves which are located in the
vessel walls keep the blood going in one direction (preventing
the blood from moving backwards).
Figure 3: The Circulatory System
Cardiovascular Fitness
 Cardiovascular (heart, lungs and blood vessels)
 Cardiovascular fitness is a measure of the body’s ability to
utilise oxygen. In other words, it is an indicator of how
fast somebody is able to breathe in oxygen into the lungs,
transport it through the body to the muscles and use it to
provide energy for the exercise that the person is doing.
 As cardiovascular fitness improves, the heart gets larger
and stronger and is able to pump more blood and with it
more oxygen to the muscles. The muscles can also take
more oxygen from the blood and become better at using
oxygen to produce energy.
Physiological responses to exercise
 Short-term: or acute responses to exercise – what
actually happens to the body while a person is
exercising.
- e.g. Increase in heart rate, perspiration.
 Long-term: or chronic responses to exercise – what
happens to the body as a result of regular exercise.
- e.g. The heart gets stronger and larger, resting and
exercise heart rate decrease
Energy Systems
 Three pathways provide energy for physical
activity
- Two are anaerobic (without oxygen), and the other
aerobic (with oxygen).
- These three energy systems overlap and sometimes
combine to power all human movement.
- The type of energy pathway that is used is dependent on
the type of activity being performed.
Energy Systems – Part II
Aerobic system
- Energy is supplied to the body through the consumption of oxygen. This combines with
lactic acid to produce water, therefore there is no effect on performance. Activities that
use this energy system include running, swimming and cycling long distances
Anaerobic lactic system
- The anaerobic lactic system is used for shorter-duration, high-intensity activity typically
lasting between 30-90 seconds. Energy is supplied through the consumption of
carbohydrate. This causes the build up of lactic acid, which eventually causes
performance to decrease. At this point the person either lowers their intensity or allows
the aerobic system to continue fuelling the exercise, or they stop exercising completely.
Activities that use this energy system include rugby, netball or soccer, where highintensity activity is performed for short periods of time.
Anaerobic CP system
- The anaerobic CP system is used for very short duration, high-intensity activity typically
lasting up to 30 seconds. Energy is supplied to the body through the consumption of
creatine phosphate. There are no by products with this energy system and it keeps going
until all the stored energy is used up. This energy pathway replenishes after 2-3 minutes.
Activities that use this energy system include jumping, short sprints or striking actions.
Figure 4: Energy Systems