Transcript physiology - Western Springs College

PHYSIOLOGY
FUNCTIONING OF THE HEART
• Blood is pumped around the body from the
heart via the aorta. The blood is pumped
out under pressure and this varies
according to the activities that are being
pursued at the time.
• The device used to measure blood
pressure is called a sphygmomanometer
BLOOD PRESSURE
•
Two readings are taken when measuring
blood pressure
1. Systolic Pressure: this is the pressure at
which the blood moves through the heart
when the heart contracts
2. Diastolic Pressure: this is the force at
which the blood travels through the heart
when it relaxes
BLOOD PRESSURE
• An average blood pressure reading is:
120/80
3 MINUTE ACTIVITY
With the person beside you, discuss what
factors you think could affect a persons
blood pressure
FACTORS AFFECTING BP
•
•
•
•
•
Sex
Age
Exercise
Diet
Smoking
HEART RATE
• This is the measure of how many times
the heart beats per minute
Now that you know Heart rate is affected
by short term events…….. What factors do
you think affect heart rate?????
FACTORS WHICH CAN AFFECT
HEART RATE ARE:
•
•
•
•
•
•
Exercise
Drugs
Illness
Temperature
Emotions
Stress
Why does HR increase with
increasing intensities of exercise?
• Heart rate increases in order to supply
working muscles with oxygen.
INTENSITY
O2 DEMAND
TO
WORKING
MUSCLES
HEART RATE
TO PUMP O2
TO MUSCLES
STROKE VOLUME
• This is the amount of blood ejected by the
heart per beat. It is measured in Litres (L).
CARDIAC OUTPUT
• This is the amount of blood ejected by the
heart during a 1 minute period.
• It is measured in litres per minute (L/min)
CO = SV x HR
E.g. Calculate the CO for an athlete with a
stroke volume of 85ml/beat and a heart
rate of 155bpm.
CO
= 85/1000 x 155
= 13.2 L/min
RESPIRATORY SYSTEM
A.
B.
C.
D.
E.
F.
G.
H.
Nasal Passage
Pharynx
Larynx
Trachea
Bronchioles
Alveoli
Diaphragm
Pleura
RESPIRATORY SYSTEM
Respiratory System - very funny
Gas Exchange
INSPIRATION
• Is the process of breathing in
• The two anatomical structures involved in
this are the ribs and the diaphragm
When we breath in, the intercostal muscles
(between the ribs) contract causing the
ribs to move upward and outward.
• The effect this has on the lung is to make
their volume larger
• The lungs are now at low pressure with
respect to the air outside
• Air always moves from areas of high
pressure to areas of low pressure
• Air moves into the lungs
EXPIRATION
• Is the process of breathing out
• The two anatomical structures involved in
this are the ribs and the diaphragm
EXPIRATION PROCESS
• When we breathe out the intercostal
muscles relax moving the ribs down and
in. This decreases the lung volume. The
diaphragm returns to its original dome
shape further decreasing the lung volume.
Lungs are at high pressure compared to
the air outside. Air moves from high to low
pressure. Air moves out of the lungs.
GAS EXCHANGE
• Gas exchange invovles
two gases – these are
– Oxygen
– Carbon Dioxide
• This occurs at the alveoli
(in the lungs)
• The alveoli are covered in a network of
capillaries
• The alveoli and capiliaries are only 1 cell
thick
• Oxygen moves from the alveoli into the
blood by diffusion.
IMMEDIATE RESPONSES TO EXERCISE
Bodies Response
Heart Contractions are stronger, heart moves more
blood into the body so SV increases
Incr Stroke Volume
Incr Heart Rate
Increases to pump more blood to working muscles
Blood sent to working muscles
and away from others
Increase Blood Pressure
Increase Breathing Rate
Red face/skin
Skeletal muscle needs more blood (i.e. o2), so
more is pumped to these areas
CO influences BP, so if CO increases so will BP
(during exercise)
Number of breaths you take per minute will
increase as you try to get more o2 to your body
Mechanism to cool the bodies temperature
Increase o2 Uptake (VO2)
Increased Sweating
Why Does This Occur?
This is a measure of the work being done by the body so it
will increase with exercise. How much it increases depends
on the intensity of the exercise
Mechanism to cool the bodies temperature
Why do you think people go white
when they are really cold?
It is our bodies way of protecting our internal organs. The
blood supply is sent inwards to keep these vitals organs
warm!
EXERCYCLE ACTIVITY
PreExercise
HR
Breaths Per
Min
Chest
Movement
Skin Colour
Sweating
During
Exercise
PostExercise
ENERGY SYSTEMS
• What is ATP?
ATP is a chemical compound responsible for
producing energy for work.
ATP = adenosine triphosphate
ATP
ADP
ENERGY
P
Our diet provides the basic ingredients for
making ATP. These are:
- Carbohydrates
- Proteins
- Fats
In our bodies there are 3 main pathways for the
breakdown of ATP to make energy. These
systems are dependent on the type of activity
being performed.
The 3 pathways are:
- ATP-CP
- Lactic Acid
- Aerobic
Anaerobic System
ATP – CP SYSTEM
• This energy system is for immediate
activity
• This system uses ATP stored in the
muscle cells
• This is the main source of energy for
activities lasting 0-10 seconds
• This system does not require oxygen and
does not cause a build up of lactic acid
which can impair performance
• For example, sprints up to about 100m
LACTIC ACID SYSTEM
• This system is for short term
activity
• The main source of energy for this
system is carbohydrate
• This system provides energy for
short term high intensity exercise
• These efforts last from 30sec up to
3 mins e.g. 400m run or 100m
swim
• Because this system does not
require oxygen but uses
carbohydrates only, significant
amounts of lactic acid can build up
that will cause performance to
decrease.
AEROBIC SYSTEM
• This system is for long term activity
• This system provides energy for long term low
intensity exercise
• These efforts tend to last longer than 3 minutes
and intensities that vary from very easy to very
hard (but not maximal) e.g. marathon running.
• Because this system
requires oxygen to burn
carbohydrates and fat,
lactic acid does not build
up, hence there is no
effect on performance.
Summary Table
Energy
System
ATP-CP
Lactic Acid Aerobic
Type of
Pathway
Anaerobic:
immediate
Anaerobic:
short term
Aerobic:
Long term
Intensity
high
high
low
Fuel Use
ATP
Carbohydrat Carbs + fats
es
Duration of
Pathway
0-10 secs
30 sec up to 3+ minutes
3 mins
FAST FEET DRILL
• Explain in detail why it is difficult to sustain high
intensity footwork like this for more than 1
minute?
• You need to refer to:
–
–
–
–
–
Energy Systems Involved
Time
Intensity
Fuel
Waste Product
The reason it is hard to maintain high
intensity footwork for more than 2-3
minutes is the energy system being
used. There are 3 energy systems
that the body has. One is the ATP-CP
system which is used for 100%
intensity and 0-10 second activities.
The second is the lactic acid system
which is used for high intensity and 10
sec – about 3 min activities. The
aerobic system is used for moderate
intensity and long term activities.
When doing fast feet for 2-3 minutes the
body would have been using the lactic
acid system. The fuel for this system is
glycogen which is stored in the muscles.
The reason you cannot maintain the high
intensity fast feet is because when your
muscles work at a high intensity they
produce the waste product of lactic acid.
This builds up in the muscles and blood
and prevents the body from continuing to
work at a high intensity. Therefore high
intensity activity can only be maintained
for a short time. When this happens you
feel muscle burn.
ENERGY SYSTEMS GRAPH
Key
Aerobic
Energy
Contribution
Lactic Acid
(%)
ATP-CP
Time (seconds)
The Breathing Process
•
The process of breathing consists of 2
phases
a) Inspiration
b) Expiration