Exercise Physiology

Exercise Physiology

Circulatory SystemWhat is the Human Circulatory System ? The main organ of the circulatory system is the Human Heart. The other main parts of the circulatory system include the Arteries, Arterioles, Capillaries, Venules, Veins and Blood.

The Functions of the Circulatory System ?To transport blood around the body. The blood itself also carries numerous other substances which the body requires to function.

The Blood Contains..The main substance being Oxygen, carried by a protein called haemoglobin, found inside red blood cells. White blood cells for fighting disease and infection. Blood contains platelets essential for clotting the blood, which occurs following an injury to stop blood loss. Blood also carries waste products, such as Carbon Dioxide away from muscles and organs in order to be dispelled by the lungs.

Circulatory SystemHow the Circulatory System Works There are three circulatory processes occurring simultaneously within the body.

1. Systemic Circulation carries blood around the body2. Pulmonary Circulation carries blood to the lungs 3. Coronary Circulation provides the heart with its own supply of blood.

Systemic Circulation

The heart pumps oxygenated blood out of the left ventricle, through the Aorta (the largest artery in the body). Here the Oxygen (and other nutrients) passes through the capillaries, into the tissues where it can be used to produce the energy muscles require to contract.The blood is then transported around the body to the muscles and organs. This Carbon dioxide passes back across the walls of the capillaries, into the blood stream. The blood continues back towards the heart, through the veins, into the right atrium. Once the nutrients are used during energy production (metabolism) a waste product called Carbon Dioxide is formed.Circulatory SystemPulmonary Circulation

Once blood returns to the heart it is then pumped from the right ventricle through the Pulmonary arteries to the lungs, where the waste carbon dioxide can be expelled and more Oxygen collected. The Pulmonary vein carries oxygenated blood back to the left atrium of the heart, where the cycle starts again.

Circulatory System

Circulatory System3. Human blood is colourless, it is the hemoglobin that makes it red.

4. Red blood cells live for upto 4 months and make approximately 250,000 round trips around the body before returning to the bone marrow, where they were born, to die. Between 2.5 and 3 million red blood cells (erythrocytes) are lost and replaced every second.

Circulatory SystemDid you know!!??

1. It takes 20 seconds for blood to circulate the entire body. Oxygenated blood leaves the aorta about about 1 mile an hour.

2. The power output of the heart ranges from 1-5 watts per minute. Which is the equivalent to the usage of a 60 watt bulb. It has been said that enough energy is produced a day to drive a truck 20 miles.

Circulatory System5. Due to the heart having its own electrical impulse, it will continue to beat even when removed from the body as long as it has an adequate supply of oxygen.

6. On average, the human body has about 5 liters (almost 9 pints) of blood continually traveling through it by way of the circulatory system. A kitchen tap would need to be turned on all the way for at least 45 years to equal the amount of blood pumped by the heart in an average lifetime.Circulatory SystemTerminologyHeart rate is simply the number of heart beats per minute. Stroke volume is the volume of blood, in milliliters (mL), pumped out of the heart with each beat. Cardiac output: is the volume of blood pumped by the heart per minute (mL blood/min). Cardiac output is a function of heart rate and stroke volume. Cardiac Output in mL/min = heart rate (beats/min) X stroke volume (mL/beat)

Circulatory SystemAn average person has a resting heart rate of 70 beats/minute and a resting stroke volume of 70 mL/beat. The cardiac output for this person at rest is:

Cardiac Output = 70 (beats/min) X 70 (mL/beat) = 4900 mL/minute.

The total volume of blood in the circulatory system of an average person is about 5 liters (5000 mL). According to our calculations, the entire volume of blood within the circulatory sytem is pumped by the heart each minute (at rest). During vigorous exercise, the cardiac output can increase up to 7 fold (35 liters/minute)Respiratory SystemFunction of the Respiratory System

The function of the human respiratory system is to transport air into the lungs and to facilitate the diffusion of Oxygen into the blood stream. Its also receives waste Carbon Dioxide from the blood and exhales it.

Respiratory SystemWhat is the Respiratory System? The respiratory system consists of the following parts, divided into the upper and lower respiratory tracts:

Respiratory SystemParts of the Upper Respiratory Tract

Mouth, nose & nasal cavity: The function of this part of the system is to warm, filter and moisten the incoming air

Pharynx: Here the throat divides into the trachea (wind pipe) and oesophagus (food pipe). There is also a small flap of cartilage called the epiglottis which prevents food from entering the trachea

Larynx: This is also known as the voice box as it is where sound is generated. It also helps protect the trachea by producing a strong cough reflex if any solid objects pass the epiglottis.

Respiratory SystemParts of the Lower Respiratory Tract Trachea: Also known as the windpipe this is the tube which carries air from the throat into the lungs. It ranges from 20-25mm in diameter and 10-16cm in length.

Bronchi: The trachea divides into two tubes called bronchi, one entering the left and one entering the right lung. The left bronchi is narrower, longer and more horizontal than the right.

Respiratory SystemBronchioles: Tertiary bronchi continue to divide and become bronchioles, very narrow tubes, less than 1 millimeter in diameter.

Alveoli: Individual hollow cavities contained within alveolar sacs (or ducts). Alveoli have very thin walls which permit the exchange of gases Oxygen and Carbon Dioxide. They are surrounded by a network of capillaries, into which the inspired gases pass. There are approximately 3 million alveoli within an average adult lung.

Diaphragm: The diaphragm is a broad band of muscle which sits underneath the lungs, attaching to the lower ribs, sternum and lumbar spine and forming the base of the thoracic cavity.

Respiratory SystemTerminology

Respiratory Volumes: is the amount of air inhaled, exhaled and stored within the lungs at any given timeTidal Volume: the amount of air which enters the lungs during normal inhalation at rest. The average tidal volume is 500ml. The same amount leaves the lungs during exhalation.Total Lung Capacity: This is the total amount of air the lungs can hold. The average total lung capacity is 6000ml, although this varies with age, height, sex and health.

Respiratory SystemDid you know!!?? Due to the heart being located on the left- hand side of most humans the right lung is slightly larger than the left.

2. The highest speed at which expelled particles from asneezehave been measured to travel is 103.6 mph (167 km/h). Guiness book of records 2004

3. We lose half a litre of water a day through breathing.ENERGY SYSTEMSMuscle Contraction causes Movement, but requires ENERGY to do so!!!The ATP MoleculeAdenosineAdenosineEnergyAdenosine Tri-phosphate (ATP)b. The breakdown of ATP into ADP + P:PPPPPPEnergy for cellular function to contract working muscleATP Production at RestATP replenish with the use of Oxygen (Aerobic)

Uses 75% Fats (lipids) and 25% CHO (glycogen)

Wastes products are expired and breathed out

23The ATP Molecule Unfortunately there is only enough ATP in the muscles to last for 2 seconds.

The body has 3 other systems to replenish ATP to ensure we can keep exercising.24ATP Production during Exercise3 Systems used to replenish ATP

ATP-CP System

Anaerobic (Lactic Acid) Glycolysis

Aerobic Glycolysis

25The ATP-CP SystemDuration: 1-15 seconds

When: Sudden increase in intensity (whilst oxygen supply catches up), or short intense movements

This system breaks down stored Creatine Phosphate (CP) in the muscle; it requires no oxygen (anaerobic)

Limitations: by amount of CP the body can store.

What sports predominantly use this system?

ATP-CP Energy SystemReplenishes ATP rapidly by breaking down Creatine Phosphate releasing energy to reform ATP

Short duration (85% of HRmax

Results in formation of lactic acid, which causes muscle fatigue

Last for 10 seconds to 2 minutes

1 molecule- 3 ATP molecule

29Aerobic SystemDuration: Unlimited

Predominant energy supplier for low to moderate intensity exercise