The circulatory and respiratory systems Year 8 Health

The respiratory system Your respiratory system includes the parts of the body that result in you being able to breath. Your respiratory system is made of the nose and mouth, nasal cavity, larynx, pharynx, trachea, bronchi, lungs, bronchioles, alveoli and diaphram. The journey of air from outside of your body through to your muscles and organs where oxygen is needed begins at your mouth and nose.

The respiratory system

What is the function of the respiratory system? The respiratory system allows the body to breathe, bringing oxygen into the body and removing carbon dioxide. Brings air from 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.

The journey of air - Inhalation Nose/Mouth Nasal Passage Pharynx Larynx Trachea Bronchi Bronchioles Alveoli Rest of Body

What does each part do? Nose/Mouth: Air is inhaled into the body through either the nose or the mouth Nasal Passage: Air is moistened Pharynx: A common area at the back of the mouth where food, drink and air passes Larynx: The voicebox, air passing through here is what helps you to produce the sound needed to talk Trachea: Referred to as the windpipe. It sits behind the sternum, so it provides a protected passage for the air to move into the lungs

What does each part do cont…? Bronchi: The trachea divides into two bronchi, each one feeding air to each of the lungs. Bronchioles: Each bronchi breaks up into smaller passages. These break up smaller and smaller, like branches on a tree for the air to move through the lungs. Alveoli: These are the “leaves” on the branches. This is where the oxygen is extracted from the air and transported into the bloodstream and carbon dioxide is moved out of the body and into the lungs to be breathed out of the body.

Inspiration and expiration INSPIRATION: The diaphragm begins inspiration. When it contracts it pulls the ribcage down so that there is more room for the lungs to enlarge. Air is sucked into the lungs due to the larger amount of room and lower air pressure. EXPIRATION: This occurs when the diaphragm and intercostal muscles relax. This relaxation causes the ribs to be brought in, making a smaller area for the lungs and as such squeeze the air out of the lungs.

Circulatory system The circulatory system works with the respiratory system to help transport oxygen to the major parts of the body and take carbon dioxide out of the body.

What is the function of the circulatory system? The circulatory system has many functions including: Circulating blood to all parts of the body Transporting water, oxygen and nutrients to the cells Transporting wastes, such as carbon dioxide, away from the cells Maintaining correct body temperature and; Helping to fight disease through white blood cells and antibodies contained in the blood

The journey of blood 1. Right atrium receives blood (low in oxygen) from the body. 2. Right ventricle receives blood from right atrium and pumps this blood to lungs. 3. Blood gives up carbon dioxide and takes up oxygen while in lungs. 4. Oxygenated blood returns to left atrium. 5. Blood enters left ventricle and is pumped through aorta. Blood flows to all extremities of the body. 7. Blood enters capillaries, where oxygen and nutrients are fed to cells, and carbon dioxide, water and other wastes are removed 8. Capillaries carry blood to venules, then to the veins 9. Veins return blood to the right atrium

What makes up the circulatory system? The circulatory system is made up of: The Heart Arteries: always carry oxygen-rich blood from the heart to the body. Arteries have thick, elastic, muscular walls Veins: Veins carry blood with lower oxygen content because the muscles and cells have used it. This blood is returned to the heart and then the lungs. Veins have thinner, less elastic walls. Capillaries: Capillaries are the smallest blood vessels. The exchange of nutrients and waste between the blood and the cell occurs in the capillaries. They have very thin walls to allow oxygen, carbon dioxide and nutrients to pass into the cells. Blood: The only body tissue that is a liquid. Blood cells make up 45% and plasma makes up the other 55% of the blood volume

The heart

The heart continued… The heart is a muscular organ It is responsible for pumping blood around the body The heart is a cardiac, involuntary muscle It is usually in the middle of the chest cavity, slightly off to the left The left side of the heart pumps blood to the body and as such pumps out oxygenated (oxygen rich) blood. The right side of the blood is not as strong as it is pushes the blood to the lungs to drop off wastes. The side pumps deoxygenated (oxygen poor) blood to the lungs

The heart continued… The heart is made up of four chambers, a left and right atrium and left and right ventricle. The typical human heart is about the size of two clenched fists The heart has valves between the four chambers. These valves are used to move the blood from one chamber to another and prevent backflow into a chamber that it has already passed through.

What is in blood? Blood is made up of four different components: Red Blood Cells: These carry oxygen to, and carbon dioxide from the cells and muscles. White Blood Cells: Pass through capillary walls into body cells to fight disease Platelets: Causes blood to clot when a blood vessel is damaged (if you cut yourself, platelets help to stop the bleeding by forming a scab) Plasma: Carries the blood cells. Provides cells with proteins, salts, glucose, fats, antibodies and some oxygen, while removing wastes

The human pulse Taking your heart rate is recording the pressure of the blood being pushed around the arterial system. The two most common sites for taking your heart rate are the carotid and radial pulse. The radial pulse is near the radius of your arm (the thumb side of your wrist), it is your radial artery. The carotid pulse is in your neck, it is called your carotid artery. You should always take your pulse for 10 seconds, count how many beats there are and then multiply this by six to find the beats per minute. Never use your thumb to find your pulse because you can often feel a pulse in your thumb.