Cardiovascular and Respiratory System

1. The Cardiovascular
Respiratory System
The Cardiovascular System

2. Components
The cardiovascular system consists of:
• The Heart
• Blood Vessels
– Arteries and Arterioles
– Veins and Venules
– Capillaries
• Blood

3. Functions
• Circulate blood to all parts of
the body
• Transport water, oxygen and
nutrients to cells
• Remove wastes, including
carbon dioxide, from cells
• Maintain body temperature-
known as homeostasis.
• Helps fight disease (WBCs)

4. The Heart
• Hollow muscular structure
made from cardiac muscle.
• It is the size of a clenched
fist.
• It’s located in the centre of
the chest, behind your
sternum (slightly to the
LHS).
• It is a pump which pushes
blood around the body.

6. Heart Anatomy
• Composed of four chambers:
– Two atria (L & R): Receive blood from the body
– Two ventricles (L & R) : Pump blood back out into the
body.
• The septum divides the heart into two pumps:
1.Left side- Oxygen rich (red coloured)- From the lungs to
the body.
2.Right side- De-oxygenated(blue coloured)- From the
body to the lungs.

7. Pulmonary & Systemic Circuits
• The Pulmonary Circuit:
Deoxygenated blood circulates
into the pulmonary artery
to the lungs to pick up O2
and transport back to heart
• The Systemic Circuit:
Oxygenated blood from the heart
circulates through the arteries
around the body to the various
tissues and back to the heart

9. Heart Valves
• Blood pumped does not mix as valves located
between atria and ventricles only allow blood to
move in one direction

10. The “Pulse”
• ‘Pulse’: is a pressure wave that results from the
thrust that occurs when the ventricles of the
heart contract
• The pulse can be felt in 4 locations around the
body:
– Temporal (Temple)
– Carotid (Side of Neck)
– Radial (Base of thumb)
– Femoral (Groin)

12. Heart Rate
• Your heart beats over 100,000 times per day.
• Heart rate (HR) is measured in bpm.
• The sinoatrial node is located in the R atrium
and generates an electrical signal which causes
the heart to contract.

13. Factors Affecting HR
• Gender- female may be 5-10 bpm faster due to
smaller heart size.
• Age and Size- higher at birth compared to adulthood
• Body size
• Fitness- lower HR due to less work/resistance
• Body Position- 5-10 times less when lying down
• Food Digestion- increase during eating
• Emotion- can increase by 50bpm when stressed,
excited or nervous

14. Blood Vessels
• Blood vessels are designed to deliver blood to
the organs & tissues that require it.
• Each connecting blood vessel will be smaller
than the previous but will have a larger cross-
sectional area.
• There are three main types:
1. Arteries and Arterioles
2. Veins and Venules
3. Capillaries

15. 1. Arteries and Arterioles
• Carry oxygen-rich blood from heart to
body.
• Walls are elastic and expand with each
heart beat. Contain a muscle
component.
• Arteries further reduce in size to
become arterioles as the network of
blood vessels work their way into the
depths of the body.
• The Coronary Artery supplies the hearts
chambers with oxygen and nutrients.

16. 2. Veins and Venules
• Veins carry deoxygenated blood back to the heart.
• The deoxygenated blood has little oxygen and contains
high amounts of waste products.
• Veins have no pulse, blood flow is steady and constant.
• The walls of veins are thin and not as elastic as artery
walls.
• The return of blood to the heart depends on contraction of
skeletal muscle- which squeezes the blood as they
contract.
• One way valves working against gravity and prevent
backflow of blood to organs and muscles.

18. 3. Capillaries
• Smallest blood Vessels in body.
• Exchange of nutrients and waste between the blood and
the body cells occurs in the capillaries .
• Heat from cells is also absorbed into blood through the
capillaries.
• When you begin to exercise capillaries dilate to allow
increased blood flow.
• Wall only one cell thick.
• A long term exercise program may increase the number of
capillaries supplying blood to muscles, allowing an
increased oxygen supply to muscle and removal of wastes.

19. Importance of cooling down after
exercise
• Blood Pooling may occur after exercise if an
adequate cool down is not performed
• During exercise blood flow can increase from
5L (resting) to 30L per minute
• During the cool down the muscle pump
system gradually returns the excess blood to
the heart- reducing the blood flow
• If this does not occur then blood pools in the
legs

20. Removal of heat from body
• Blood carries heat produced by cells to the
surface of the skin
• Exercise causes blood vessels to vasodilate
close to the skin surface so the heat can
radiate outwards
• This gives the skin a red colour
• For this to work effectively the body needs
lots of water to carry the heat and allow
perspiration to occur

21. Blood
• Only body tissue that is liquid
• It is used to transport various
substances to the organs and other
tissues.
• Blood cells make up 45% of the blood
volume
• While plasma makes up the other 55%
• The three types of blood cell are:
1. Red blood cells
2. White blood cells
3. Platelets

22. Blood Cells
1. Red Blood Cells (RBC):
• Contain haemoglobin which carries oxygen molecules and gives the red colour
• Produced in bone marrow
• 120 day lifespan, 99% of all blood cells
• Concave disc shape
2. White Blood Cells (WBC):
• Part of the immune system (fight infection)
• Called leukocytes and form pus
• Produced in bone marrow and lymph tissue
• 10 day lifespan

23. Blood Cells
3. Platelets
• Clot blood to stop bleeding
• Produced in bone marrow
Plasma:
• Liquid part of the blood
• Also contains- Soluble food molecules, waste
products, hormones and antibodies.
• Transports and assists in the removal of wastes

24. Blood Pressure
• As blood is pumped out of the heart it creates
pressure within the arteries which is known as
blood pressure (BP).
• It measures the pressure exerted by the blood
against the walls of the arteries
• It is used to assess the functioning or
“healthiness” of the heart and blood vessels.

25. Blood Pressure
• Systolic BP: is the pressure created when the
blood is pumped out of the left ventricle and is
the top figure in BP measurement.
• Diastolic BP: is the pressure created as the
heart relaxes and refills and is the bottom
figure in BP measurement.
• Normal is 120/80; High 180/100; Low 80/60.

26. Factors Affecting BP
• Gender- women prior to menopause generally
have a lower BP than men.
• Time- it is lower during sleep and higher after
meals.
• Stress- being stress, nervous or scared will
increase BP. Long term stress can cause
hypertension (chronic high BP).

27. Stroke Volume (SV) &
Cardiac Output (Q)
SV:
– The amount of blood pumped into the systemic circuit
with one heart beat.
Avg. Adult female = 60ml
Avg. Adult Male = 80ml
– In an endurance trained male under maximal
conditions it could reach 160ml!
Q:
– The amount of blood the body pumps in one minute.
Around 5 litres at rest, up to 30 litres under maximum
effort.
– Q= SV x HR

28. Arteriovenous oxygen difference (AVO2)
• Is the amount of oxygen
taken up by the tissues of
a muscle.
• It is the difference
between the oxygen in
the arteries compared to
the veins.
• Rest: Muscles use 6mL per
100mL of oxygen

29. The Cardiovascular System & Physical
Activity
• Acute Responses:
– Increased HR
– Increased SV
– Increased Q
– Increased BP
– Increased blood flow and blood vessel diameter
– Increased body termperature
– Increased AVO2
– Increased coronary circulation

30. The Cardiovascular
Respiratory System
The Respiratory System

31. Why do we need to breath?
• Movement, growth and reproduction all
require energy.
• Energy must be taken from the food we eat
and this energy transfer is called tissue
respiration.
• This involves the use of oxygen and produces
carbon dioxide.

32. Role of Respiratory System
• Brings air from the atmosphere into the lungs
• Transfers oxygen into the blood
• Removes carbon dioxide from the blood
• Expels heat and water vapour in the air breathed
out
• Allows the vocal cords to create speech as air is
breathed out
• Ventilation- is the movement of air into and out of
the respiratory system.

34. Components
• The Pleura:
– A membrane which covers each lung
– The gap between the membrane and lung contains
fluid which allows the lungs to expand/contract
with minimal friction
• The Diaphragm:
– Moves up and down to assist breathing
– Smooth involuntary muscle

36. Inspiration
• Breathing in
• Diaphragm contracts
(involuntary), it moves
downwards, enlarging the chest
cavity.
• This creates an area of low
pressure so that the air rushes
inside.
• Air moves from high to low
pressure.

37. Expiration
• Breathing out
• Occurs when the diaphragm relaxes and the
chest cavity returns to its ‘at rest’ state.
• The air pressure inside the chest cavity becomes
higher.
• Air is forced out of the lungs.

38. • Inspiration: ribs lift up and out, volume of lungs increase, diaphragm contracts, air
pressure drops, air forced in.
• Expiration: volume of lungs decreases, diaphragm relaxes, ribs lower, air pressure
increases, air forced out.

39. Gas Exchange in the lungs
• The alveolar capillaries have very thin walls
which aid diffusion.
• This allows oxygen to diffuse from high
pressure in the alveoli to low pressure in the
capillaries.
• Carbon dioxide is also able to move from high
pressure in the capillaries to low pressure in
the alveoli.

41. Respiratory Volumes & Capacities
• Respiratory Rate: Amount of times you breathe per minute
– Avg resting adult = 12-18times per min
• Tidal Volume: The amount of air breathed in or out during normal
respiration.
– Avg adult = 0.5litres
• Vital Capacity: The largest volume of air that can be expired after a
maximal inspiration.
• Residual Volume: The amount of air left in the lungs after a
maximal expiration.
• Ventilation: Amount of air inspired per minute.
– Ventilation= tidal volume X respiratory rate.
– For an average adult
• Ventilation = 0.5L x 12 breaths/min = 6L/min

42. Measuring Lung Volume

45. Maximal Oxygen Uptake (VO2 Max)
• The VO2 Maximum is the maximal amount of
oxygen that can be taken into the body and
transported to and used up by the muscles
during exercise.
• It is the best indicator of how aerobically fit you
are.
• It is the largest amount of oxygen that you can
use per minute.

46. Maximal Oxygen Uptake (VO2 Max)
• It is determined by your max HR,
stroke volume and AVO2
difference.
• Tests such as the 20m shuttle run,
12 minute walk/run and the Repco
7 min ergometer cycle test all
predict VO2.
• An accurate test must be
completed in a lab.

48. The Respiratory System & Physical Activity
• Acute Responses:
– Increased RR
– Increased tidal volume
– Increased ventilation
– Vital capacity remains the same
– Increased O2 uptake
– Increased effort intercostal muscles and diaphragm