CARDIOVASCULAR SYSTEM

The Heart - Structure Right ventricle Septum (dividing wall) Tricuspid valve Vena cavae Aorta Right atrium Semilunar valves Pulmonary artery Pulmonary veins Left atrium Bicuspid valve Left ventricle Cardiac muscle

CARDIOVASCULAR SYSTEM Blood carries oxygen around the body to where it is needed Can you name any of the blood vessels that the blood is transported in ARTERIES ARTERIOLES – very small arteries CAPILLARIES VENULES – very small veins VEINS

Arteries Veins Capillaries Blood Vessels – complete worksheet 2B Lumen Muscle + elastic fibres Non-elastic fibres Muscle + elastic fibres Non-elastic fibres Muscle + elastic fibres Arteries carry blood away from the heart and have a thick, elastic, muscular wall. They stretch as blood is pumped in and the muscle wall contracts to force blood along. Veins have a relatively thinner and less muscular wall than arteries. The blood is under a lower pressure than in the arteries. Capillary walls are one cell thick. Exchange of nutrients and respiratory gases occurs across their surface.

CARDIOVASCULAR SYSTEM

ARTERIES The wall of the heart is supplied with blood from two small vessels called the coronary ARTERIES. These can be blocked by blood clots and when this happens blood supplied to part of the heart wall is cut off, resulting in sudden death. The structure of ARTERIES, VEINS and CAPILLARIES is different.

The ARTERIES have a relatively thick wall. Most ARTERIES and ARTERIOLES (very small arteries) carry oxygenated blood away from the heart. They are more elastic than VEINS and also have higher pressure. The PULMONARY ARTERIES are different, they carry de- oxygenated blood from the heart to the lungs. They pulsate as the heart beats.

VEINS VEINS carry de-oxygenated blood to the heart. They have much thinner walls than arteries. They contain many VALVES which keep de-oxygenated blood flowing to the heart and avoid the possibility of blood flowing backwards. VEINS rarely pulsate.

They are less elastic than arteries. They carry blood at a lower pressure. The PULMONARY VEINS, which leave the lungs on the way to the heart, are different from other veins, they carry oxygenated blood. Any vessel ENTERING the heart is called a VEIN.

CAPILLARIES CAPILLARIES are vessels that link the ARTERIES with the VEINS. At one end they carry oxygenated blood which transfers supplies of oxygen and nutrients to the muscles. At the other end CAPILLARIES pick up waste and so carry de- oxygenated blood into the VEINS.

(A) (V) Lungs Heart Body How Blood is Pumped around the Body Blood flows around the body in a ‘figure of eight’ circuit, passing through the heart twice on each circuit. Blood travels away from the heart through arteries (A). Blood returns to the heart through veins (V). There are 2 separate ‘loops’ to the circuit: The top loop – carries blood from the heart to the lungs and back. The bottom loop – carries blood from the heart to all over the body and back. (A) (V)

PULMONARY CIRCULATION – CARRIES BLOOD FROM THE HEART TO THE LUNGS AND BACK AGAIN SYSTEMIC CIRCULATION – CARRIES BLOOD FROM THE HEART TO THE REST OF THE BODY AND BACK AGAIN Worksheet 2D

1. 1.Blood leaves the right side of the heart via the pulmonary artery and goes to the lungs where it is oxygenated It then travels back to the left side of the heart via the pulmonary vein. Pulmonary artery Pulmonary vein Body Heart Lungs Blood Flow around the Body – Top Loop PULMONARY CIRCULATION

3. 3.The left side of the heart then pumps the oxygenated blood around the rest of the body for use, via the aorta Once the oxygen has been used, the blood becomes deoxygenated and returns to the right side of the heart via the vena cava. Vena Cava Aorta Blood Flow around the Body - Bottom Loop Body Heart Lungs

Respiratory System – worksheet 2E alveoli epiglottis larynx trachea bronchus mouth bronchioles diaphragm

alveoli epiglottis larynx trachea bronchus mouth bronchioles diaphragm

Functions of the elements of the Respiratory system Worksheet 2E The Pharynx: The pharynx allows food and air to enter the body.

Functions of the elements of the Respiratory system The Epiglottis The epiglottis prevents food from being inhaled into the lower air passage (the trachea).

Functions of the elements of the Respiratory system Larynx: This is commonly referred to as the voice box. Air passes through the larynx into the trachea. Also within the larynx are the vocal cords responsible for voice production.

Functions of the elements of the Respiratory system Trachea: This is commonly referred to as the windpipe. It comprises of a large strong and flexible tube. It is vital that this tube remains open, rings of cartilage ensure that this is so.

Functions of the elements of the Respiratory system Bronchi: The trachea branches into two at its far end. These two branches comprise the bronchi. There are two branches so the air can pass into both the left and the right lung.

Functions of the elements of the Respiratory system Bronchioles: The bronchi divide into smaller and smaller tubes known as the bronchioles.

Functions of the elements of the Respiratory system Alveoli: The alveoli are tiny air sacs found at the extreme ends of the bronchioles. There are many millions of these and they go to make up the vast majority of the lung tissue. It is here that gaseous exchange take place.

Functions of the elements of the Respiratory system Lungs: There are two lungs housed within the chest cavity. They can be inflated and deflated similar to two balloons. They have the appearance and feel of sponge because of the millions of tiny air sacs. The outer surface of the lungs is covered by the pleura. The pleura is smooth and moist which reduces the amount of friction exerted on the lungs as they expand and contract.

Functions of the elements of the Respiratory system The Diaphragm: The diaphragm is a muscle situated below the lungs, it seals the chest cavity from the abdominal cavity. It is responsible for the action of breathing. By contracting and relaxing the diaphragm changes the pressure within the chest cavity. When it is contracted air is drawn into the lungs and when it is relaxed air is forced out of the lungs.

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The mechanisms of breathing worksheet 2F Taking a breath is a result of a message from the brain being sent to the lungs. This message is sent because of the growing level of carbon dioxide in the blood stream. It is possible to voluntarily hold the breath for quite a long time. However even people who are good at doing this must eventually take another breath.

INSPIRATION

EXPIRATION

The recovery process Recovery from vigorous exercise: Worksheet 2G

Measures of the Respiratory system Vital capacity: Vital capacity refers to the largest volume of air that can be expired after the deepest possible inspiration. Tidal volume: Tidal volume is the amount of air that is breathed in and out whether at rest or during exercise.

The effects of exercise and training on the respiratory system The production of carbon dioxide, water and the release of energy

The effects of exercise and training on the respiratory system Adults take between breaths per minute when resting, however during exercise we breath more frequently in order to meet the need for increased oxygen. Humans can increase their breathing rate up to 50 breaths per minute during intense activity.

How do we measure breathing? Apart from running for the bus there are 5 tests of respiratory performance  Vital Capacity. The maximum amount of air that can be breathed out (about 4.5 litres).  Residual Volume. The amount left in the lungs (about 1.5 litres).  Respiratory Rate. How many breaths we take depending on activity.  Tidal Volume. The amount of air taken in or out depending on the size of the lung.  Minute Volume. How much air is breathed in a minute (tidal volume x respiratory rate)*

Are you fit? (healthy fit that is) Why is it that fit athletes hardly get out of breath while less fit people huff and puff?  Athletes get fitter through training.  Their bodies are able to use oxygen more efficiently.  They use the maximum amount of oxygen that can be used during exercise. This is known as V0 2 max.  Very fit athletes such as middle and long distance runners work at about 85% of their maximum.  non athletes are at 65%.*

The benefits of exercise and training on the respiratory system Exercise and training develops and affects the circulatory and respiratory systems; – stronger heart muscle, – increased stroke volume, – increased cardiac output, – lower resting heart rate, – more efficient gaseous exchange, – increased vital capacity, – increased tidal volume, – increased oxygen debt tolerance

The effects and needs of different activities on the respiratory system Different physical activities will put different demands on the respiratory system. Some activities put a LARGE DEMAND on the system (meaning heavy breathing) and some activities put a SMALL DEMAND on the system (meaning easy breathing). ACTIVITY: Can you label the following activities, as either making a LARGE DEMAND or a SMALL DEMAND on the respiratory system?