Pe paper 1- Cardio-respiratory system and Aerobic and anaerobic exercise

Describe the Pathway of air

1. Air is breathed in through the mouth/nose

2. Air travels down the trachea

3. Air travels to the bronchi which allows it to enter both lungs

4. Air travels to the bronchioles in the lungs

5. Air reaches alveoli located at the end of the bonchioles. This is where gaseous exchange takes place.

What is a gaseous exchange

The movement of gases from an area of high concentration to an area of low concentration

The process of gaseous exchange in the alveoli

• oxygen is the the air we breath in

• When this oxygenated air reaches alveoli, it diffuses from the alveoli to the blood

• There are lots of capillaries surrounding the alveoli

• The oxygen molecules move from an area of high concentration to an area of low concentration

Why is alveoli suited for gaseous exchange?

• large surface area

• Moist thin walls (one cell thick)

• Short distance for diffusion

• Lots of capillaries surrounding (therefore large blood supply)

• Movement of gases from a high to low concentration

Haemoglobin

The red pigment found in red blood cells which transports oxygen around the body

Oxyhaemoglobin

Formed when oxygen combines with haemoglobin

Artery definition

Carry oxygenated blood away from the heart

Artery properties

• Thick walls to withstand pressure

• Carry oxygenated blood

• Allow for vasoconstriction and vasodilation

Vein definition

Carry deoxygenated blood towards the heart

Vein properties

• Thin walls

• Carry deoxygenated blood

• Large lumen (internal diameter)

• Valves to prevent backflow

Capillaries

Very thin blood vessels that allow gas exchange to happen

Capillaries properties

• very thin walls to allow for diffusion

• Huge network linking arteries to veins

• Very narrow (one cell thick)

Vasoconstriction

Reducing the diameter of arteries to reduce blood flow tot issues

Vasodilation

Increasing the diameter of arteries to increase blood flow to tissues

For chambers in the heart

Right atrium, right ventricle, left atrium, left ventricle

Atria

Upper chambers of the heart that collect blood from veins

Ventricles

Lower chambers of the heart which pump blood out of the heart to the arteries

Cardiac cycle

Sequence of events that occur when a heart beats.

A cycle is completed when the heart fills with blood and the blood is pumped out the hear

Diastole

The heart ventricle are relaxed and the heart fills with blood

Systole

The ventricles contract and pump blood into the arteries

Pathway of blood

1. Deoxygenated blood enters the right atrium via the vena cava

2. Passes into the right ventricle

3. Pulmonary transports the deoxygenated blood to the lungs

4. Gaseous exchange occurs and blood becomes oxygenated

5. Pulmonary vein transports blood to the left atrium

6. The blood passes in the left ventricle

7. The oxygenated blood exits the heart via the aorta

Cardiac output (Q)

the amount of blood ejected from the heart in one minute. (Q=HRxSV)

Heart rate (HR)

The amount of times your heart beats per minute

Stroke volume (SV)

The volume of blood pumped out of the heart by each ventricle during one contraction

How to work out maximum heart rate

220-age

What happenes during inhalation

• Diaphragm contracts to increase chest cavity volume

• Intercostal muscles contract. This cause the ribs to rise and increase chest cavity volume

• This reduces pressure in the chest cavity therefore air is drawn to the lungs

What happens during exhalation

• Diaphragm and intercostal muscles relax. This makes the chest cavity volume decrease

• This increases the pressure of air in the lungs and cause it to be expelled

A spirometer trace

A piece of apparatus designed to measure lung volumes

Tidal volume

Volume of air breathed in (or out) during a breath at rest

Residual volume

The volume of air that remains in the lungs are maximal expiration

Inspector reserve volume

The additional air that can be forcibly inhaled after inspiration of a normal tidal volume

Expiratory reserve volume

The additional air that can be forcibly exhaled after the expiration of a normal tidal volume

Aerobic respiration equation

Glucose + oxygen → Energy + C02 + water

Anaerobic respiration equation

Glucose → energy + lactic acid